Control Device

This is an improvement on the control device which is shown and described in Hasmukh R. Shah et al. application Ser. No. 906,234 for Control Device which was filed on May 15, 1978.

This invention relates to control devices for a vending machine which can be used to set prices and to store those prices in a memory and more particularly to such a control device having a price-setting mode, a price verification mode and a product vending mode.

Prior control devices which provided price-setting and price verification modes for vending machines used manually-operated switches to place those control devices in, and to hold those control devices in, those modes. In the event the control device for that vending machine was inadvertently left in the price-setting or verification mode, the vending machine would be unable to vend.

The present invention provides a control device for a vending machine which can be used to set prices and to store those prices in a memory; and it can establish a price-setting mode, a price verification mode and a product-vending mode. That control device can easily be shifted out of the price-setting or price verification modes, as by inserting a coin or by pressing the cancel sale button. It is, therefore, an object of the present invention to provide a control device for a vending machine which can establish a price-setting mode, a price verification mode or a product-vending mode, and which automatically shifts that vending machine out of the price-setting or price verification mode into the product-vending mode when a coin is inserted or the cancel sale button is pressed.

The control device of the present invention has switches that are used to select the locations in a memory where prices are stored, and has further switches that are usable to set the prices in those locations. The control device automatically responds to the actuation of any of those switches to shift from the product-vending to the price-setting mode. It is, therefore, an object of the present invention to provide a control device with switches that select locations in a memory where prices can be stored, and with further switches that can change the data in those locations, and wherein actuation of any of those switches automatically places the vending machine in the price-setting mode.

The control device provided by the present invention responds to the closing of a selection switch to send a short pulse through the vending circuit. That pulse will be of such short duration that it will be unable to cause a vend to occur, but it will cause a price to be loaded into a price register for comparison with credit in a credit register so a vend can be effected if the credit exceeds the price. It is, therefore, an object of the present invention to provide a control device which responds to the closing of a selection switch to send a short pulse through the vending circuit.

If, during any transaction, the credit exceeds the price, change will be paid out. The present invention varies the manner of paying out coins in accordance with the kinds of coins which are available to make change. For example, if thirty cents is to be paid out and the nickel coin tube is empty, the control device of the present invention will use three dimes to pay out the change. It is, therefore, an object of the present invention to provide a control device which varies the manner of paying out coins in accordance with the kinds of coins which are available to make change.

Other and further objects and advantages of the present invention should become apparent from an examination of the drawing and accompanying description.

In the drawing and accompanying description some embodiments of the present invention are shown and described, but it is to be understood that the drawing and accompanying description are for the purpose of illustration only and do not limit the invention and that the invention will be defined by the appended claims.

FIG. 1 is a part of the circuit diagram of a preferred form of control device which is provided by the present invention, and it shows line-selecting switches, price-setting switches, and inventory switches,

FIG. 2 is a further part of the circuit diagram, and it shows a display on which data can be exhibited, and it also shows the latches and drivers used therewith,

FIG. 3 is a rear view of a three-section display on which data can be exhibited, and it also shows the registers and drivers associated with that display,

FIG. 4 is another portion of the circuit diagram, and it shows selection switches, vending devices, and other parts of the vending circuit,

FIG. 5 shows a portion of the circuit diagram which supplies triggering signals,

FIG. 6 shows a portion of the circuit diagram which includes a latch that is connected to a microprocessor,

FIG. 7 is a diagrammatic view showing how the sheets bearing FIGS. 1 and 2 are interrelated and how the sheets bearing FIGS. 4-6 are interrelated,

FIG. 8 is a further portion of the circuit diagram which shows coin-sensing devices and level-sensing devices, and also shows the circuitry associated therewith,

FIG. 9 shows the part of the circuit diagram which relates to the paying out of change,

FIG. 10 and FIG. 11 are parts of the flow chart for the control device of the present invention, and they show a number of debouncing steps of that flow chart,

FIG. 12 and FIG. 13 show the portion of the flow chart which represents the standby routine,

FIG. 14 shows the portion of the flow chart which is used to initialize the microprocessor for the price-setting mode,

FIG. 15 shows the portion of the flow chart wherein the price-setting routine is executed,

FIG. 16 shows a portion of the flow chart which is executed when an inventory switch is closed,

FIG. 17 is the portion of the flow chart showing the establishment of credit when coins are inserted,

FIG. 18 is a portion of the flow chart wherein the program is guided to the routine of FIGS. 19 and 20,

FIGS. 19 and 20 show the portion of the flow chart which relates to the dispensing of coins,

FIG. 21 shows current pulses which are developed prior to the closing of a selection switch,

FIG. 22 shows a current pulse which is developed after a selection switch has been closed and which is used to initiate a vending operation,

FIGS. 23 and 24 show a circuit, for an alternate embodiment of control device for a vending machine, which can place that control device in a price verification mode, and

FIG. 25 shows a circuit which can place a control device for a vending machine in a price-setting mode.

Components of Control Device

Referring particularly to FIG. 1, the numerals 183 and 185 denote normally-open, push button switches that are connected, respectively, to pins 0 and 1 of Port 4 of a microprocessor 62. Those switches can, and preferably will, be identical to the similarly-numbered switches in Hasmukh R. Shah et al application Ser. No. 906,234 for CONTROL DEVICE which was filed on May 15, 1978. Numerals 182 and 184 denote further normally-open, push button switches that are connected, respectively, to pins 2 and 3 of that port. Those switches can, and preferably will, be identical to the similarly-numbered switches in said application. The numeral 58 denotes a normally-open, single-pole, single-throw switch that is connected to pin 4 of Port 4; and the numeral 60 denotes a further normally-open, single-pole, single-throw switch that is connected to pin 5 of that port.

The numeral 134 denotes a dual 2 to 4 decoder which has its A, B and E inputs connected, respectively, to pins 4, 5 and 1 of Port 0 of microprocessor 62 by conductors 66, 68 and 70. The Q1 output of that decoder is connected to the A and B inputs of a tri-state buffer 136; and the Q0 output of that decoder is connected to the A Output Disable pin of a tri-state register 374 in FIG. 6 by a conductor 384. All of the input channels of the tri-state buffer 136 are connected to ground, but the output channels 1, 2, 3, 4, 5, and 6 are connected, respectively, to switches 183, 185, 182, 184, 58 and 60.

The numeral 132 denotes a three and fifty-eight hundredths (3.58) megahertz crystal which is connected to the crystal pin inputs of microprocessor 62. The numeral 133 denotes a driver which has the input thereof connected to pin 6 of Port 0 of the microprocessor 62. A resistor 135 connects that input and that pin to plus five (+5) volts. A conductor 83 will connect the output of that driver to a coin return electromagnet if a mechanical-type slug rejector is used with the control device. However, if an electronic slug rejector--such as the electronic slug rejector disclosed in Hasmukh R. Shah application for Coin-Handling Device which is filed of even date and which bears U.S. Pat. No. 4,353,452 issued Oct. 12, 1982--is used with the control device, pin 6 of Port 0 of the microprocessor of said Shah et al Control Device application will be directly connected to the circuitry of that electronic slug rejector to keep that electronic slug rejector from accepting further coins during a vending operation.

The numeral 150 denotes a normally-open, single-pole, single-throw switch that is connected to pin 2 of Port 0 of microprocessor 62 by a conductor 88; and the numeral 152 denotes a normally-open single-pile, single throw switch that is connected to pin 3 of that port by a conductor 90. A slide-type actuator 608 has a normal position wherein it will permit both switches 150 and 152 to be open, has a switch-closing position wherein it will hold switch 150 closed but will permit switch 152 to be open, has a second switch-closing position wherein it will hold switch 152 closed but will permit switch 150 to be open, and has a third switch-closing position wherein it will hold both switches 150 and 152 closed.

The numeral 154 denotes a opto-coupler which is connected, by a resistor 158 and a diode 156, to LINE 6 from the vending machine with which the control device is used. That opto-coupler also is connected to LINE 2 from the vending machine, as indicated by the notation L2. The output of opto-coupler 154 is connected to pin 6 or Port 4 of microprocessor 62 by a resistor 162 and a conductor 98; and it is connected to plus five (+5 ) volts by a resistor 150.

Pin 7 of Port 1 of microprocessor 62 is grounded by a conductor 74. Pins 4 and 7 of Port 5 of that microprocessor are connected, respectively, by conductors 92 and 94 to a plug and socket 33 which can be connected to a device, not shown, which will keep running counts of the number of each product that is selected and vended, and which also can keep other running counts. Pin 1 of Port 5 is connected, by a conductor 96, to the vending machine to enable the EXACT CHANGE lamp, not shown, in the vending machine to be illuminated,

The numeral 138 denotes a HEX latch which has the inputs D0 through D5 thereof connected, respectively, to pins 0 through 5 of Port 4 of microprocessor 62, via conductors 76, 78, 80, 82, 84 and 86. Those conductors also extend, respectively, to switches 183, 185, 182, 184, 58 and 60; and conductors 76, 78, 80 and 82 additionally extend, respectively, to inputs A through D of a BCD to 7-segment decoder 166 of FIG. 2 and to inputs D0 through D3 of a HEX latch 170, and conductors 84 and 86 extend, respectively, to inputs D4 and D5 of that HEX latch. A conductor 87 extends from the Q1 output of a 2 to 4 decoder 164 of FIG. 2 to input C of HEX latch 138 of FIG. 1. The Q0 output of that decoder is connected to the C input of HEX latch 170, and the Q2 output of that decoder is connected to the LE input of decoder 166. Conductors 66 and 68 are connected, respectively, to inputs A and B of decoder 164. The strobe output of microprocessor 62 is connected to input E of decoder 164 by a conductor 64.

The Q0 through Q3 outputs of HEX latch 138 are connected, via a level shifter 140, to the clock and the C1, C2and C3 inputs of an EAROM 142. The Q5 output of that HEX latch is connected, via level shifter 140 and a resistor 141, to the D input of that EAROM. The Q4 output of that HEX latch is connected, via a resistor 146, to the base of an NPN transistor 144 which has the emitter thereof grounded. The collector of that transistor is connected (a) to a junction between resistor 141 and the D input of EAROM 142, and (b) via an inverter 148, a resistor 151, and a conductor 100 to pin 0 of Port 5 of microprocessor 62.

The Q0 through Q2 outputs of HEX latch 170 of FIG. 2 are connected, respectively, to the A, B and E inputs of a 2-to-4 decoder 176; and the Q0 and Q1 outputs of that HEX latch also are connected to the A and B inputs of a 2-to-4 decoder 178. The Q3 output of HEX latch 170 is connected to input E of decoder 178. The Q0 through Q3 outputs of decoder 176 are connected to four inputs of a driver 180 which supplies corresponding amplified outputs to an eight digit display 168. The Q0 through Q2 outputs of decoder 178 are connected to further inputs of digit driver 180, and corresponding amplified outputs are supplied to further inputs of display 168. The Q3 output of decoder 178 is connected to an input of a further digit driver 181, and the corresponding amplified output is supplied to a further input of display 168. The Q4 output of HEX latch 170 is connected to a further pin of display 168 by an inverter 172 and a resistor 174. The a through g outputs of decoder 166 are connected, respectively, to the a through g inputs of all of the eight seven-segment units of display 168.

Referring particularly to FIG. 3, the numerals 194, 196 and 198 denote dual 4-bit shift registers. The numerals 192, 200, 202, 204, 206 and 208 denote HEX level shifters which are used as buffers. The outputs of register 194 are connected to the inputs of a seven-segment display 232 by seven current-limiting resistors, the outputs of register 196 are connected to the seven inputs of a seven-segment display 234 by seven further current-limiting resistors, and the outputs of register 198 are connected to the inputs of another seven-segment display 236 by another seven current-limiting resistors. A resistor 238 extends from the eighth output of register 196 to display 236 to control the decimal point. Conductor 66, an inverter 187, resistors 186 and 190, and buffer 192 connect pin 4 of Port 0 of microprocessor 62 to input D of register 198. A resistor 188 connects the junction between resistors 186 and 190 to plus-five (+5) volts. A conductor 102, an inverter 210, resistors 212 and 214, and a Darlington amplifier 218 connect pin 0 of Port 0 of microprocessor 62 to the C inputs of registers 194, 196 and 198. A resistor 216 connects the input of that amplifier to ground; and resistors 220 and 222 connect the collectors of that amplifier to plus twelve (+12) volts. Parallel-connected resistor 224 and capacitor 231 are connected to the output of amplifier 218 by a resistor 226 and a diode 228. That parallel-connected resistor and capacitor also are connected to the R inputs of registers 194, 196 and 198. The fifth output of register 194 is connected by buffer 200 to the left-hand D input of that register; and the first output of register 196 is connected by buffer 202 to the right-hand D input of register 194. The fifth output of register 196 is connected by buffer 204 to the left-hand D input of that register; and the first output of register 198 is connected by buffer 206 in the right-hand D input of register 196. The fifth output of register 198 is connected by buffer 208 to the left-hand D input of that register.

Referring particularly to FIG. 4, the numerals 240 and 244 denote single-pole, double-throw switches which are mounted on the vending machine to enable customers to select desired products. The movable contact of switch 240 is connected to line L2 of the vending machine. The numeral 242 denotes any desired number of additional selection switches which are mounted on the vending machine to enable customers to select further desired products. Those selection switches are of standard and usual design, and they are mounted in the standard and usual locations on that vending machine.

The numeral 246 denotes a vending device--which can be a solenoid, relay or a motor--that is mounted in the vending machine to initiate the vending of the product which is desired by the customer who presses selection switch 240; and one terminal of that device is connected to the normally-open contact of that switch. The numeral 248 denotes a current transformer which has the primary winding 250 thereof connected between the output of vending device 246 and one terminal of a solid state relay 290. The other terminal of that relay is connected to line L1 of the vending machine. A resistor 292 and a capacitor 294 are connected in series between the terminals of that relay to by-pass line noise and other transients around that relay. The numeral 288 denotes a driver which has the output thereof connected to the input of solid state relay 290; and the input of that driver is connected to a NAND gate 286.

The secondary winding 252 of transformer 248 is connected to the non-inverting and inverting inputs of a comparator 340 by resistors 334 and 336, respectively. A biasing resistor 332 is connected across the terminals of that secondary winding; and the junction between that resistor and resistor 334 is connected to plus five (+5) volts. The inverting input of comparator 340 is connected to plus twelve (+12) volts by a resistor 338. The output of that comparator is connected to plus five (+5) volts by a resistor 342, is connected to input D2 of an encoder 346, and via a resistor 344 and a conductor 330 to the non-inverting input of a comparator 326 in FIG. 5. The Q0 through Q2 outputs of encoder 346 are connected, respectively, to the lower inputs of OR gates 350, 352 and 354. The E out of that encoder is connected by a diode 375 to the upper input of a OR gate 380. A resistor 376 and a capacitor 378 are connected between ground and that upper input; and they constitute part of a re-setting network.

The numeral 392 denotes a further vending device in the vending machine; and it is connected to the normally-open contact of selection switch 244. The primary winding 396 of a further current transformer 394 is connected between that vending device and the upper terminal of solid state relay 290. The secondary winding 398 of transformer 394 is connected to the non-inverting and inverting inputs of a comparator 408 via resistors 402 and 404, respectively. A biasing resistor 400 is connected across that secondary winding; and the junction between that resistor and resistor 402 is connected to plus five (+5) volts. The inverting input of comparator 408 is connected to plus twelve (+12) volts by a resistor 406. The output of comparator 408 is connected to plus five (+5) volts by a resistor 410, to the D6 input of an encoder 348, and via a resistor 412 and conductor 330 to the non-inverting input of comparator 326. The Q0 through Q2 outputs of encoder 348 are connected to the upper inputs of OR gates 350,352 and 354. The E out of that encoder is connected to the E in of encoder 346.

The outputs of OR gates 350, 352 and 354 are connected, respectively, by conductors 356, 358 and 360 to the D1, D2 and D3 inputs of the tri-state register 374 of FIG. 6--which is used as a latch. The GS output of encoder 348 of FIG. 4 is connected, via a conductor 362, to the D4 input of register 374. The output of NAND gate 380 in FIG. 4 is connected, via a conductor 382, to the C input of that register. The output of comparator 326 in FIG. 5 is connected, via a conductor 328, to the R input of that register. The B output disable input of that register is grounded. The Q0 through Q3 outputs of register 374 are connected, respectively, by conductors 76, 78, 80 and 82 to pins 0 through 3 of Port 4 of microprocessor 62.

The Q output of a flip-flop 318 of FIG. 5 is connected, by a conductor 282, to one input of NOR gate 286 in FIG. 4; and by a conductor 104 to the EXT. INT. input of microprocessor 62, and by a capacitor 386 and an inverter 390 to the D7 input of encoder 348. The input of that inverter is connected to plus five (+5) volts by a resistor 388. A conductor 106 extends from pin 3 of Port 5 of microprocessor 62 to the input of an inverter 296 in FIG. 5, and also to the D and S inputs of flip-flop 318. The numerals 364, 368, 370 and 372 in FIG. 6 denote capacitors which have the lower terminals thereof connected to plus five (+5) volts, and which have the upper terminals thereof connected to the D1 through D4 inputs of register 374. Those capacitors will minimize the effects of noise and other transients.

The dotted-line representation of selection switch 242 in FIG. 4, the dotted-line inputs to the D0 through D5 inputs of encoder 348, the dotted-line inputs to D3 through D7 inputs of encoder 346, and the dotted-line resistor 414 indicate that eleven additional selection switches, eleven additional current transformers, eleven additional vending devices, eleven additional comparators, and eleven additional resistors would be used in a vending machine which vended products at thirteen (13) specifically-different prices. Significantly, it will be noted that the lower terminals of all of the primary windings of all thirteen (13) current transformers will be connected to the upper terminal of solid state relay 290. As a result, only one such relay is needed.

A power transformer 254 in FIG. 5 has the primary winding thereof connected to lines L1 and L2 of the vending machine--which are connected to a standard and usual source of 115 volts A.C. The secondary winding of that transformer supplies 24 volts A.C. to a power supply 256 which provides regulated plus five (+5) volts, plus twelve (+12) volts and minus twenty-two (-22) volts. A resistor 264 is connected to the upper terminal of that secondary winding, and a resistor 265 is connected between ground and the lower terminal of that secondary winding. Those resistors and resistors 302 and 304 constitute a voltage divider; and the junction between resistors 264 and 302 is connected to the non-inverting input of a comparator 266. A ten (10) volt Zener diode 314, which is paralleled by a capacitor 316 is connected between ground and that non-inverting input. An NPN transistor 300 is connected in parallel with resistor 304 and has its emitter grounded. A resistor 298 connects the output of inverter 296 to the base of transistor 300. Resistors 274 and 272 are connected between plus five (+5) volts and ground to constitute a voltage divider which will apply a fixed reference voltage to the inverting input of comparator 266. A resistor 270 and a capacitor 268 are connected between the output and the non-inverting input of that comparator. That output is connected to plus five (+5) volts by a resistor 267, to the C input of flip-flop 318, and to the B input of a monostable multivibrator 276. A resistor 280 connects plus five (+5) volts to one input of that monostable multivibrator and, via a capacitor 278 to a grounded input of that monostable multivibrator. The Q output of that monostable multivibrator is connected to the other input of NAND gate 286 of FIG. 5 by conductor 284.

A comparator 320 in FIG. 5 has the non-inverting input thereof grounded, and has the inverting input thereof connected to plus five (+5) volts. A resistor 322 connects the output of that comparator to the inverting input of comparator 326; and a resistor 324 connects that input to plus five (+5) volts.

A flip-flop 258 in FIG. 5 has the Q output thereof connected to the lower input of NAND gate 380 in FIG. 4 by a conductor 259 and also is connected to the power supply 256 in FIG. 5. The Q output of that flip-flop is connected to the D input thereof; and the S and R inputs are grounded. A resistor 260 and a conductor 262 connect the C input of that flip-flop to a junction 426 that is connected to the outputs 11 of switch chips 416 and 418 in FIG. 8. Chip 416 has outputs 7, 9, 14 and 16 thereof connected, respectively, to pins 0 through 3 of Port 1 of microprocessor 62 via conductors 108, 110, 112 and 114. The numerals 149, 486, 520 and 574 denote sensing coils which are identical in purpose and function to the similarly-numbered sensing coils in Raymond A. Johnson application Ser. No. 36,335 for COIN HANDLING DEVICE which was filed on May 4, 1979. Coil 149 will be mounted adjacent a passageway for dollar coins to sense the insertion of such coins. Sensor 486 will be mounted adjacent a passageway for quarters to sense the insertion of such coins. Sensor 520 will be mounted adjacent a passageway for dimes to sense the insertion of such coins. The sensor 574 will be mounted adjacent a passageway for nickels to sense the insertion of such coins. Those passageways will be located as shown by said Johnson application. One terminal of sensor 574 is connected to input 6, one terminal of sensor 520 is connected to input 8, one terminal of sensor 486 is connected to input 15, and one terminal of sensor 149 is connected to input 1 of switch chip 416.

The numerals 306, 308 and 310 denote sensing coils which are identical in function and purpose to similarly-numbered sensing coils in said Johnson application. Coil 306 will be mounted adjacent a storage tube for quarters, sensor 310 will be mounted adjacent a storage tube for dimes, and sensor 308 will be mounted adjacent a storage tube for nickels. The upper terminal of coil 308, the upper terminal of coil 310, and the upper terminal of coil 306 are connected, respectively, to inputs 6, 15 and 1 of switch chip 418. The number 803 denotes a sensing coil which is mounted adjacent a ferrous metal vane that is movable relative to the magnetic field of that coil whenever the "cancel sale" button of the vending machine is pushed to effect the moving of that vane. The lower terminals of the coils 574, 520, 486, 149, 308, 310, 306 and 803 are connected to a voltage reference source--which consists of an NPN transistor 480, an operational amplifier 484, resistors 482, 488 and 490--by resistors 446, 450, 454, 458, 462, 466, 470 and 474, respectively. The collector of transistor 480 is connected to plus twelve (+12 ) volts. Resonating capacitors 444, 448, 452, 456, 460, 464, 468 and 472 are connected, respectively, across the outputs of the coils 574, 520, 486, 149, 308, 310, 306 and 803 to constitute parts of the tank circuits which include those coils.

The numeral 230 denotes a motor which is identical in structure, purpose and function to the similarly-numbered motor in the said Johnson application. That motor is controlled by NPN transistor 830 and PNP transistor 832 which are connected in series between plus twelve (+12) volts and ground. The junction 836 between the emitter of transistor 830 and the collector of transistor 832 is connected to one terminal of that motor; and the other terminal of that motor is grounded. A resistor 828 and an NPN transistor 826 are connected in series between plus twelve (+12) volts and ground; and the collector of that transistor is connected to the bases of transistors 830 and 832 by a junction 834 to selectively energize and de-energize the motor 230, all as described in said Johnson application. A conductor 126 connects the base of transistor 826 to pin 5 of Port 5 of microprocessor 62. The motor 230 is used to effect dispensing of coins--either in response to the pressing of the "cancel sale" button or to make change. A sensing coil 312, which is identical in structure, function and purpose to the similarly-numbered coil of said Johnson application, is mounted adjacent a gear in a gear train which is driven by the motor 230. That coil will sense each revolution of that gear, all as explained in said Johnson application. A resonating capacitor 476 is connected in parallel with the coil 312; and one terminal of that coil is connected to the voltage reference by a resistor 478. The other terminal of that sensor is connected to input 8 of switch chip 418. The 7, 14, 16, 2 and 9 outputs of that chip are connected, respectively, to pins 4-6 of Port 1, pin 7 of Port 4, and pin 7 of Port 0 of microprocessor 62. Resistor 422 connects outputs 11 of chips 416 and 418 to plus twelve (+12) volts, and resistor 424 connects inputs 13 of those chips to plus twelve (+12) volts. Plus twelve (+12) volts is applied to inputs 12 of chips 416 and 418 and to the upper terminals of grounded capacitors 420 and 438. Plus twelve (+12) volts also is applied to input 10 of chip 418 and to the upper terminal of a grounded capacitor 440 by a resistor 442. In addition, plus twelve (+12) volts is applied to inputs 4 of chips 416 and 418 via paralleled resistor 434 and thermistor 436, resistor 432, and junctions 431 and 433. Paralleled resistor 428 and capacitor 430 are connected to junction 433 to by-pass noise and other transients to ground.

A conductor 128, an inverter 822, and a driver 824--in the form of an inverter--connect pin 6 of Port 5 of microprocessor 62 to a movable relay contact 820. A conductor 130, an inverter 804, and a driver 806--in the form of an inverter--connect pin 2 of that port to one terminal of a relay coil 808. Plus 12 (+12) volts is connected to the other terminal of that coil, and also to a movable relay contact 814. Coil 808, the movable contacts 814 and 820, and stationary relay contacts 810, 812, 816 and 818 constitute a reversing delay which is identical to the similarly-numbered reversing relay in the said Johnson application. The numeral 366 denotes a selector motor which is identical to the similarly-numbered selector motor in said Johnson application. By being energized in one direction, while the motor 230 is de-energized, the selector motor 366 can cause a dollar coin to be directed to the cash box of the vending machine; whereas by being energized in the opposite direction, while the motor 230 is de-energized, the selector motor 366 can cause a dollar coin to be directed to the coin cup at the exterior of the vending machine. By being left de-energized, by being energized in one direction, or by being energized in the opposite direction when the motor 230 is running, the selector motor 366 can effect the paying out of specifically-different coins. Signals from pins 2 and 6 of Port 5 of microprocessor 62 will control the energization and de-energization of selector motor 366.

Although various microprocessors could be used, a Fairchild 3870 microprocessor is preferred. Although various devices could be used as the HEX latches 138 and 170, of FIGS. 1 and 2, Motorola MC14174B HEX latches are preferred. Although various devices could be used as the level shifter 140, five-sixths (5/6) of a Motorola MC14504 level shifter is preferred. Although various devices could be used as the EAROM 142, a General Instruments ER 1400 EAROM is preferred. Although various devices could be used as the tri-state buffer 136, a Motorola MC14503B HEX Tri-State buffer is preferred. Although various devices could be used as the decoders 134, 164, 176 and 178, a Motorola MC14556B Dual 2-to-4 Decoder could be used as the decoders 134 and 164, and a Motorola MC14555B Dual 2-to-4 Decoder could be used as the decoders 176 and 178. Although various devices could be used as the decoder 166, a Motorola MC14495B BCD to 7-segment decoder is preferred. Although various devices could be used as the drivers 180 and 181, Sprague ULN 2003A drivers are preferred--the driver 180 consisting of a full Sprague driver and the driver 181 consisting of one-seventh (1/7) of such a driver. Although different devices could be used as the display 168, a National NSA 1588A 8-digit display is preferred. The display 168 will be mounted inside of the vending machine and will not be visible to customers. However, that display can easily be seen by a route man whenever he opens the vending machine to service it.

Although different devices could be used as the registers 194, 196 and 198 of FIG. 3, Motorola MC14015B Dual 4-Bit shift registers are preferred. Although different devices could be used as the displays 232, 234 and 236, Hewlett Packard HP 5082-7653 seven-segment displays are preferred. Although various devices could be used as the buffers 192, 200, 202, 204, 206 and 208, portions of Motorola MC14504B HEX Level Shifters are preferred. The displays 232, 234 and 236 are mounted at the exterior of the vending machine so they can be seen by customers, the route man, or anyone else--even when the vending machine is closed.

Although various devices could be used as the solid state relay 290 of FIG. 4, a Theta-J Corp. 0FA1201N OPTOFILM Solid State Relay is preferred. Although various devices could be used as the driver 288, part of a Sprague ULN 2003 driver is preferred. Various devices could be used as the comparators 266, 320, 326, 340 and 408--and the other eleven comparators, not shown, in FIGS. 4 and 5--but portions of Motorola MLM339 Quad Comparators are preferred. Although various devices could be used as the encoders 346 and 348, Motorola MC14532B encoders are preferred. Although different devices could be used as the flip-flops 258 and 318 of FIG. 5, a Motorola MC14013B Dual D-Type flip-flop is preferred. Although different devices could be used as the multivibrator 276, one-half of a Motorola MC14538B monostable multivibrator is preferred. Although various devices could be used as register 374, a Motorola MC14076B Quad D-Type Tri-State Register is preferred. Although various devices could be used as the current transformers 248, 394 and the other eleven (11) current transformers, not shown, in FIG. 4, TRW EO-53061-R5 current transformers are preferred. The primary windings of those transformers have only a few turns, and hence require appreciable values of current to flow through them to develop the ampere-turns which are needed to cause the secondary windings to provide usable outputs.

Various devices could be used as the power supply 256 of FIG. 5. Flip-flop 258 receives a forty-eight kilohertz (48 KHz) clock from switch chips 416 and 418 in FIG. 8; and it acts as a divide-by-two counter to provide a twenty-four kilohertz (24 KHz) signal to power supply 256. A switching voltage regulator, of standard and usual design, within that power supply responds to that twenty-four kilohertz (24 KHz) signal to develop a minus twenty-two (-22) volts. Although it is desirable to use switch chips 416 and 418, flip-flop 258, and the switching voltage regulator in the power supply 256, any source of regulated plus twelve (+12) volts, plus five (+5) volts, and minus twenty-two (-22) volts could be used. However, if such a source was used, switch chips 416 and 418 and flip-flop 258 would still be needed to supply a clock, via conductor 259, to the lower input of NAND gate 380 in FIG. 4. As a result, the use of the switching voltage regulator within the power supply 256 is preferred.

Referring to FIG. 8, various devices could be used as the switch chips 416 and 418; but Synertek C10522 switch chips are preferred. Although the thermistor 436 of FIG. 8 is useful, a temperature-compensator resistor could be used as resistor 434; and then the thermistor could be deleted.

Referring particularly to FIG. 10, the numeral 500 denotes a label which is entitled RESET and which corresponds to line 0220 of the program that is attached hereto and made a part hereof. Whenever the control device is turned on, that program will, via label 500, address step 502--which is entitled TEST AND INITIALIZE REGISTERS and which corresponds to lines 3029 through 3057 and lines 3068 through 3094 of the program. During that step, a number of registers within the microprocessor 62 are tested (lines 3029 through 3057) and then a number of those registers are initialized (lines 3068 through 3094). Other registers in that microprocessor do not require initialization; and still further registers will be initialized during later steps of the program. Among the registers that are initialized during step 502 are register 10 (hereinafer RFLG register), register 11 (hereinafter R1FLG register) and register 0 (hereinafter R2FLG register)--the RFLG and R2FLG registers being initialized to zero (0) and the R1FLG register being initialized to HEX 50. Also during step 502, pins 0 through 5 of Port 4 of the microprocessor 62 will supply a code to the D0 through D5 inputs of latch 138 of FIG. 1 and of latch 170 of FIG. 2; and pins 0 through 3 of that port will supply a code to the A through D inputs of decoder 166. Further, pins 4 and 5 of Port 0 of that microprocessor will apply a code to inputs A and B of decoder 164 of FIG. 2, and the strobe of that microprocessor will apply a signal to input E of that decoder. The resulting signal at the Q0 output of decoder 164 will clock latch 170 to enable the Q2 and Q3 outputs of that latch to apply signals to the E inputs of decoders 176 and 178. Thereupon, those two decoders will apply signals to the drivers 180 and 181 which will blank the eight seven-segment units of the display 168.

During the next-succeeding step 504, which is entitled START 2.5 MS TIMER and which corresponds to lines 3061 through 3066 of the program, the programmable timer of the microprocessor 62 is programmed to provide time periods of two and one-half milliseconds (2.5 ms). During step 506, which is entitled SET MACHINE STATE TO STANDBY (STBY) and which corresponds to lines 2976 and 2984 of the program, the machine state is set to "standby".

The numeral 508 denotes a label which is entitled DEBNCE and which corresponds to line 3118 of the program. The numeral 510 denotes a step which is entitled DEBOUNCE INPUTS and which corresponds to lines 1628 through 1748 of the program. During that step, the microprocessor 62 will initiate a subroutine which will periodically supply a changing code to pins 4, 5 and 1 of Port 0 of that microprocessor. That code will be applied, via conductors 66, 68 and 70, to the A, B and E inputs, respectively, of decoder 134. The portion of that code which conductors 66 and 68 apply to the A and B inputs, respectively, of decoder 164 of FIG. 2 is not significant at this time because it will not cause that decoder to develop a signal at its Q0 output. The decoder 134 of FIG. 1 will respond to the code, which pins 4, 5 and 1 of Port 0 periodically supply to it, to cause the Q1 output thereof to supply a signal to pins A and B of buffer 136. Thereupon, a signal will simultaneously appear at all of outputs 1 through 6 of that buffer. If, during the application of that signal to all of those outputs, any one of the switches 182, 183, 184 and 185 was in its closed state, a corresponding signal would be applied to the corresponding one of pins 0 through 3 of Port 4 of microprocessor 62. Also during step 510 and during the succeeding step 512--which is entitled 2.5 MS TIMER TIMED OUT and which represents the conclusion of one of the two and one-half millisecond (2.5 ms) successively-developed time periods which were initiated during step 504--a delay will be provided that will enable the inputs of microprocessor 62 to assume states which correspond to the steady-state logic "0's" and "1's" at those inputs. Specifically, during step 512, a comparing function will determine whether the two and one-half milliseconds (2.5 ms) timer has timed out; and, if a NO is the response, the program will loop at steps 510 and 512 until that timer has timed out. During each such looping, a comparison will be made between the states of the ports and the states in the corresponding port status registers; and any changes will be stored in three port change registers. If any change had been stored in a port change register during any of the loopings of the program at steps 510 and 512 but had not continued to the end of the then-active two and one-half millisecond (2.5 ms) time period, that change would not be present in the port change register during step 512, and hence would not subsequently be used to change the status in the corresponding port status register. In this way, the port change registers and the port status registers provide a filtering action against electrical noise and other transients.

The numeral 514 denotes a label which is entitled INDBOP and which corresponds to line 0269 of the program; and step 516 is entitled PROCESS INPUT DATA and it corresponds to lines 0269 through 0284 of the program. When the timer of step 512 times out, step 516 will be executed; and, during that step, the status registers which reflect the status of the ports of microprocessor 62 will be updated to reflect the data currently at those ports. The numeral 518 denotes a label which is entitled DISP. and which corresponds to line 0301 of the program; and a step 520 is entitled PRICE SETTING MODE and it corresponds to lines 0301 through 0348 of the program. A comparing function during step 520 will determine whether the control device is in the price setting mode, as by determining whether a price setting flag had been set in the R2FLG register.

The numeral 524 denotes a label which is entitled ECVP and is represented by line 0356 of the program; and step 526 is entitled DETERMINE COIN RETURN STATUS and is represented by lines 0356 through 0363 of the program. If it is assumed that the comparing function of step 520 provides a NO, and also if it is assumed that the control device is being used with a mechanical slug rejector, the program will move past label 528, which is entitled CRMP and corresponds to line 0368 of the program to step 530, which is entitled UPDATE CREM and which corresponds to lines 0368 through 0451. During that step, the driver 133 of FIG. 1 will respond to a signal at pin 6 of Port 0 of microprocessor 62 to apply a signal, via conductor 83, which will energize the coin return electromagnet (CREM). As a result, the CREM will withdraw a coin-blocking finger from the path of coins introduced into the vending machine, and thus enable those coins to be sensed and accepted.

A label 532 is entitled TLID and corresponds to line 0455 of the program; and a step 534 is entitled DEBOUNCE TUBE LEVEL INPUTS and corresponds to lines 0455 through 0478 of the program. During that step, a comparison will be made between the states in the port status register and the states in the tube level input status register. If those states are different, the difference will be stored in a tube level input change register. Subsequently, any difference between the data in the tube level input status register and the tube level input change register will be used to update the data in the tube level input status register. The overall result is a debouncing of the signals which are applied to pins 4, 5 and 6 of Port 1 by sensing coils 308, 310 and 306, capacitors 460, 464 and 468, resistors 462, 466 and 470, switch chip 418, and conductors 116, 118 and 120 of FIG. 8. A label 536 is entitled INVDP and is represented by line 0482 of the program; and a step 538 is entitled DEBOUNCE INVENTORY SW. INPUTS and is represented by lines 0482 through 0500 of the program. During that step, a comparison will be made between the states in the port status register and the states in an inventory switch input status register. If any differences are noted between those states, the change will be noted and stored in the inventory switch input change register. If that change in that inventory switch input change register continues, it will subsequently be used to change the status of the data in the inventory switch input status register. All of this provides a de-bouncing of the signals which are applied to pins 2 and 3 of Port 0 of microprocessor 62 by inventory switch 150 and conductor 88 and by inventory switch 152 and conductor 90, respectively, of FIG. 1. Label 540 is entitled PSWDP and is represented by line 0504 of the program; and step 542 is entitled DEBOUNCE PRICE SETTING SW. INPUTS and is represented by lines 0504 through 0525 of the program. During that step, the states in the Port 4 status register is compared with the states in a price setting switch input status register. If any differences are noted between those states, the change will be stored in a price setting switch input change register; and if that change continues, it will subsequently be used to revise the data in the price setting switch input status register. All of this provides a de-bouncing of the signals which are applied to pins 0 through 3 of Port 4 by line-addressing switch 183 and conductor 76, line-addressing switch 185 and conductor 78, price-setting switch 182 and conductor 80, and price-setting switch 184 and conductor 82, of FIG. 1. Label 544 is entitled LN6DP and is represented by line 0530 of the program. Step 546 is entitled DEBOUNCE LINE 6 INPUT and is represented by lines 0530 through 0563 of the program. During that step, the states in the Port 4 status register will be compared with the states in a line 6 input status register. If any differences are noted between those states, the change will be stored in a line 6 input change register; and, if that change continues, it will subsequently be used to change the data in the line 6 input status register. All of this provides a de-bouncing of the signal which is applied to line 6 of Port 4 of the microprocessor 62 by LINE 6, resistor 158, octocoupler 154, resistor 162 and conductor 98 of FIG. 1.

Label 548 is entitled INVCP and is represented by line 0568 of the program. Step 550 is entitled VEND? and is represented by lines 0568 through 0617 of the program; and that step provides a comparing function to determine whether an inventory flag had been set in the R1FLG register. The initialization of that register during step 502 would have re-set the inventory flag; and hence the first comparing function of step 550 will provide a NO. Step 556 is entitled 5.cent. or 10.cent. TUBE EMPTY? and is represented by lines 0624 through 0651 of the program. During that step, the state of the signals, which are applied to pins 4 and 5 of Port 1, by sensing coils 308 and 310, capacitors 460 and 464, resistors 462 and 466, switch chip 418, and conductors 116 and 118, will be checked. If those states indicate that the sensing coils 308 and 310 are, respectively, sensing nickels and dimes in the corresponding coin tubes, the comparing function of that step will provide a NO. Label 560 is entitled CHKCN and is represented by line 0656; and step 562 is entitled HAVE COINS COME IN? and corresponds to lines 0656 through 0662 and lines 0770 through 0786. During that step the portions, of the port status register, which correspond to pins 0 through 3 of Port 1 will be checked. Any difference between the port status register and the corresponding port change register will cause an updating of the port status register.

A label 564 is entitled CONRP and it corresponds to line 0666 of the program; and step 566 is entitled IS THE COIN RETURN ACTIVE? and corresponds to lines 0666 through 0689 of the program. If the comparing function of step 562 provides a NO, step 566 will check the states of the Port 4 status register to determine whether the cancel sale sensing coil 803 has sensed a movement of the ferrous vane relative to it--as would occur during the pressing of the cancel sale button. Label 568 is entitled INVSWP and corresponds to line 0693 of the program; and step 570 is entitled INVENTORY SW's ACTIVE? and corresponds to lines 0693 through 0723 of the program. If the cancel sale button has not been actuated, the comparing function of step 566 will provide a NO; and step 570 will check the states of the inventory switch input status register. If both of the inventory switches 150 and 152 are open, the comparing function of step 570 will provide a NO. Label 572 is entitled JMSP and it corresponds to line 0728 of the program; and step 574 is entitled JUMP TO MACHINE STATE and it corresponds to line 0728 of the program. During that step, the program will jump to the "standby" machine state which was stored in the Q register during step 506.

The numeral 576 in FIG. 12 denotes a label which is entitled STANDBY and which corresponds to line 2198 of the program; and the numeral 578 denotes a step which is entitled SALES TOTALIZER ON? and which corresponds to lines 2201 through 2203 of the program. A comparing function during that step will check the inventory flag of the R1FLG register to determine whether it was set. If that comparing function provides a NO, step 580--which is entitled PRICE SETTING SW. ACTIVE? and which corresponds to lines 2204 through 2206 of the program --will provide a comparing function. During the latter comparing function, the states of the Port 4 status register will be checked; and those states will indicate whether any of the switches 182, 183, 184 and 185 had been closed. If that comparing function provides a NO, step 582--which is entitled PRICE VERIFICATION MODE? and which corresponds to lines 2207 through 2209 of the program--will provide a comparing function. During the latter comparing function, the price verification mode flag, which is in the RFLG register will be checked. If that function provides a NO, connective 584 of FIG. 12--which is entitled DEBNCE and which corresponds to line 2236 of the program--and label 508 of FIG. 10 will branch the program to step 510. Thereupon, the program will loop at steps 510 and 512 until the two and one-half millisecond (2.5 ms) timer times out; and, during that looping, all of the inputs of the microprocessor 62 will be debounced. When the time of step 512 times out, the rest of the hereinbefore-identified steps of the routine of FIGS. 10 and 11 will be executed unless some change has occurred. As step 574, the program will jump to the current machine state; and, unless some change has occurred, that state will continue to be "standby". Thereupon, via label 576 and steps 578 and 580 of FIG. 12, the program will execute step 582; and, unless some change has occurred, will then continually loop through label 508 and the succeeding steps of FIGS. 10 and 11 and label 576 and steps 578, 580 and 582 of FIG. 12.

If it is assumed that a route man opens the vending machine and closes any one of the switches 182, 183, 184 or 185 of FIG. 1, the logic state at one of the pins 0 through 3 of Port 4 will be changed during the next time buffer 136 develops signals at all of its outputs 1 through 6. Thereupon, during the next looping of the program through the routine of FIGS. 10 and 11, steps 510 and 516 will sense the change of state at the appropriate one of pins 0-3 of Port 4 and will appropriately change the states in the price-setting switch input status register and in the Port 4 status register and will store any difference in the price-setting switch change register. Subsequently, during step 542, the Port 4 status register will have the states therein changed to reflect the states in the price-setting switch change register; and the microprocessor will be inhibited from supplying a strobe--as it always is when any of switches 58, 60, 182, 183 and 185 is closed. Thereupon, the comparing function of step 580 of FIG. 12 will provide a YES; and then the program will, via connective 586--which is entitled PSTP and which corresponds to line 2206 of the program--and connective 588 of FIG. 14--which is entitled PSTP and which corresponds to line 1762 of the program--will execute step 590. The latter step is entitled SET PR. SET. MODE FLAG, and it corresponds to lines 1762 through 1764 of the program; and, during that step, the price-setting mode flag in the R2FLG register will be set. During the next-succeeding step 592, which is entitled SET PR. SET. TIMER TO SLOW TIME and which corresponds to lines 1775 through 1778 of the program, the programmable timer will be set to time out every one-half (1/2) of a second. During step 594, which is entitled CHANGE MACH. STATE TO PR. SET. MODE (PSTM) and which corresponds to lines 1782 and 1783 of the program, the machine state will be changed from "standby" to "price-setting mode". Thereafter, connective 596, which is entitled DEBNCE and which corresponds to line 2026 of the program, and label 508 of FIG. 1 will cause the program to loop at steps 510 and 512 until the timer of the latter step times out. Subsequently, the program will execute steps 516 and 520; and, during the comparing function of the latter step, a YES will be produced. Thereupon, step 522, which is entitled DISPLAY ITEM NO. & PRICE and which corresponds to lines 0304 through 0348 of the program, will cause pins 0 through 5 of Port 4 of microprocessor 62 to supply data to decoder 166 and to latches 138 and 170, via conductors 76, 78, 80, 82, 84 and 86. Also, pins 4 and 5 of Port 0 and the strobe will cause decoder 164 to supply Q0, Q1 and Q2 signals to those latches and that decoder which will cause the data, in the location in the EAROM 142 which corresponds to line 0 and which represents TOTAL CASH, to be exhibited by the display 168.

The program then will execute the remaining steps of the routine of FIGS. 10 and 11; and, during step 574, it will respond to the machine state--which was set during step 594 of FIG. 14--to jump to step 602 of FIG. 15 via connective 598 which is entitled PSTM and which corresponds to line 1805 of the program. During step 602, which is entitled TIMER TIMED OUT? and which corresponds to lines 1805 through 1813 of the program, a comparing function will check the states of the price setting timer NO. 2 register to determine whether that register has been decremented to zero (0)--as will be the case at the end of the one-half (1/2) second time period which was set during step 592 of FIG. 14. If that comparing function provides a NO, connective 604, which is entitled DEBNCE and which corresponds to line 1821 of the program, and label 508 of FIG. 10 will cause the program to loop through the rest of the routine of FIGS. 10 and 11 and step 602 of FIG. 15 until the value in the price setting timer NO. 2 register is decremented to zero (0). During each of those loopings, the line number and the corresponding data will be exhibited by the display 168. When the comparing function of step 602 provides a YES, step 606, which is entitled SET PR. SET TIMER TO FAST TIME and which corresponds to lines 1830 and 1831 of the program, will set the programmable timer to time out in one-tenth (1/10) of a second. During the succeeding step 609, which is entitled WHICH TYPE OF SWITCH IS ON? and which corresponds to lines 1862 through 1871, a comparing function will determine (a) whether any of switches 182, 183, 184 and 185 is still closed, (b) which if either, of switches 183 and 185 is closed, and (c) which, if either, of switches 182 and 184 is closed.

If it is assumed that the route man closed switch 185, and if it is further assumed that switch 185 still is closed, the program will execute step 610, which is entitled UP OR DOWN and which corresponds to lines 2030 through 2034 of the program. During that step, it will be determined that switch 185 still is closed, and hence the program will execute step 612, which is entitled INCR. LINE COUNT & DISP. and which corresponds to lines 2046 through 2089 of the program. During that step, the data in the line count register will be incremented and that incremented data will be stored in the display register. Thereafter, the program will, via connective 614, which is entitled DEBNCE and which corresponds to line 2026 of the program, and label 508 of FIG. 10, loop at steps 510 and 512 until the timer of the latter step times out. Subsequently, the program will execute steps 516 and 520; and, again, the comparing function of the latter step will provide a YES and, again, step 522 will be executed. During the latter step, the newly-incremented line number--which was established during step 612 will be exhibited by the display 168.

The connective 614 of the routine of FIG. 15 and label 508 of FIG. 10 will cause the program to loop at steps 510 and 512 until the timer of the latter step times out. Thereafter, that program will execute the rest of the steps of FIGS. 10 and 11; and, in doing so, will cause the newly-incremented line number to be exhibited by the display 168. Step 574 will again cause the program to jump to step 602 of FIG. 15; and the program will then loop via connective 604, label 508 of FIG. 10, the rest of the routine of FIGS. 10 and 11 and step 602 of FIG. 15 until the comparing function of the latter step provides a YES--to indicate that the one-tenth (1/10) of a second time period which was set by step 606 has timed out.

A further "fast time" setting of the programmable timer will be provided by step 606; and then step 609 will again determine which, if either, pair of switches 183 and 185 or 182 and 184 has one of the switches thereof closed. If step 609 determines that switch 185 is still closed, step 612 will provide a further incrementing of the data in the line number register, and will store that data in the display register. Subsequently, during step 522 of FIG. 10, the display 168 will exhibit the additionally-incremented line number. As long as the switch 185 is held closed, the program will continue to loop and to increment the data in the line count register, to store the corresponding data in the display register, and then during step 522 to display the incremented line number.

If, during one of the loopings to step 609, the switch 185 was permitted to re-open, steps 510 and 516 of the next succeeding looping would sense, and store data reflecting, the resulting change of state at pin 1 of Port 4; and step 542 of that looping would change the value in the price setting switch input status register. Subsequently, in that looping, the comparing function of step 609 would determine that none of the switches 182, 183, 184 and 185 was closed. Thereupon, the program would, during step 611--which is entitled STORE AND DISPLAY DATA and which corresponds to lines 1892 through 2026 of the program--cause the data corresponding to the currently-addressed line number, and which is stored at the corresponding location in the EAROM 142, to be exhibited by the display 168. Also, the program will branch, via connective 630, which is entitled DEBNCE and which corresponds to line 1821 of the program, and step 508 of FIG. 10 to loop at steps 510 and 512 until the timer of the latter step times out. Thereafter, as long as all of the switches 182, 183, 184 and 185 remain open, and no changes occurred which affected any of the steps of the routine of FIGS. 10 and 11, the program would loop through that routine, step 609 and connective 630.

If switch 183 is closed, steps 510 and 516 will, during the next-succeeding looping of the program sense, and store data reflecting, the resulting change of state at pin 0 of Port 4; and step 542 of that looping will change the value in the price setting switch input status register. Subsequently, in that looping, the comparing function of step 609 will determine that one of the switches 183 and 185 had been closed. Thereafter, the comparing function in step 610 will determine that switch 183 was closed; and hence step 616 will be executed. That step is entitled DECR. LINE COUNT & DISP. and it corresponds to lines 2030 to 2039 of the program; and, during that step, the data in the line count register will be decremented and the decremented data will be stored in the display register. The program will, then, via connective 618--which is entitled DEBNCE and which corresponds to line 2026 of the program--branch to step 508 of FIG. 10, where it will loop at steps 510 and 512 until the timer of the latter step times out. Thereafter, the program will loop back through the rest of the routine of FIGS. 10 and 11 and through steps 602, 606, 609 and 610 of FIG. 15 to step 616; and in doins so, will cause step 522 to effect the exhibiting of the decremented line number and corresponding data by display 168. If the route man continues to hold switch 183 closed, each looping of the program through step 616 will cause the data in the line count register to be decremented and the corresponding decremented data to be stored in the display register; and, during the next-succeeding execution of step 522, the further decremented line number will be exhibited by display 168. Subsequently, when the switch 183 is released, the program will, during step 611, execute step 611, and will thereby cause the newly-decremented price to be written into the location in EAROM 142 where the price, which was decremented had been stored. Also, that newly-decremented price will be exhibited by the display 168. At this time, the program will exit at step 630 and branch to label 508, where it again will loop at steps 510 and 512 until the timer of the latter step times out. Thereafter, that program will loop through the rest of the routine of FIGS. 10 and 11 and through the routine of FIG. 15 is connective 630.

If, during any such looping of the program, switch 182 is closed, steps 510 and 516 will, during the next-succeeding looping of the program sense, and store data reflecting, the resulting change of state at pin 2 of Port 4, and step 542 of that looping will change the value in the price setting switch input status register. Subsequently, in that looping, the comparing function of step 609 will determine that one of the switches 182 and 184 has been closed. At such time, step 620, which is entitled UP OR DOWN and which corresponds to lines 2123 through 2128 of the program, will provide a comparing function wherein it will be determined that the switch 182 has been closed. Thereupon step 626, which is entitled SUB.5.cent. FROM PR. & DISP. and which corresponds to lines 2129 through 2135 of the program, will be executed to decrement the data-- which corresponds to the then-addressed line--by five cents (5.cent.); unless that data is non-alterable data, such as the running counts of the numbers of vending operations of each product and the running count of the total of the prices of all such products. Also, the newly-decremented price will be stored in a price register and also in the display register. Subsequently, the program will, via connective 628--which is entitled DEBNCE and which correponds to line 2026 of the program--and step 508 of FIG. 10, loop at steps 510 and 512 until the timer of the latter step times out. Thereafter, as long as switch 182 is held closed, the program will loop through the rest of the routine of FIGS. 10 and 11 and steps 602, 606, 609, 620 and 626 of FIG. 15; and, in doing so, will (a) cause step 522 of FIG. 10 to effect the exhibiting, by display 168, of the currently-addressed line number and the newly-decremented price, an (b) cause step 626 of FIG. 15 to again decrement the price, corresponding to that line number, by a further five cents (5.cent.). When switch 182 is permitted to re-open, the next execution of step 542 of FIG. 10 will make an appropriate change in the state of the Port 4 status register; and then step 609 will determine that none of the switches 182, 183, 184 and 185 is closed. Thereupon, the program will execute step 611, and will thereby cause the newly-decremented price to be written into the location in EAROM 142 where the price, which was decremented, had been stored. Also, the newly-decremented price will be exhibited by the display 168. At this time, the program will branch, via connective 630 and label step 508 of FIG. 10 to steps 510 and 512 where it will loop until the timer of the latter step times out. That program will, until a further one of the switches 182, 183, 184 and 185 is closed, or some other action affects one of the steps in the routine, continue to loop through the routine of FIGS. 10 and 11, and steps 602, 606 and 609 and connective 630 of FIG. 15.

If switch 184 is closed, steps 510 and 516 will, during the next-succeeding looping of the program sense, and store data reflecting, the resulting change of state at pin 3 of Port 4; and step 542 of that looping will change the value in the price setting switch input status register. Subsequently, in that looping, the comparing function of step 609 will determine that one of the switches 182 and 184 had been closed. Thereafter, the comparing function in step 620 will determine that switch 184 was closed; and hence step 622 will be executed. That step is entitled ADD 5.cent. TO PR. & DISP. and it corresponds to lines 2136 through 2138 of the program; and, during that step, the data--which corresponds to the then-addressed line--will be incremented by five cents (5.cent.); unless that data is non-alterable data. Also, the incremented data will be stored in the display register and in the price register. The program will then, via connective 624--which is entitled DEBNCE and which corresponds to line 2026 of the program--branch to step 508, where it will loop at steps 510 and 512 until the timer of the latter step times out. Thereafter, the program will loop back through the rest of the routine of FIGS. 10 and 11 and through steps 602, 606, 609 and 620 of FIG. 15 to step 622; and, in doing so, will cause step 522 to effect the exhibiting of the currently-addressed line number and the incremented price. As long as switch 184 is held closed, the program will loop through the rest of the routine of FIGS. 10 and 11 and steps 602, 606, 609, 620 and 622 of FIG. 15; and, in doing so, will (a) cause step 522 of FIG. 10 to effect the exhibiting, by display 168, of the currently-addressed line number and the newly-incremented price, and (b) cause step 622 of FIG. 15 to again increment the price corresponding to that line number by a further five cents (5.cent.). When switch 184 is permitted to re-open, the next execution of step 542 of FIG. 10 will make an appropriate change in the state of the Port 4 status register; and then step 609 will determine that none of the switches 182, 183, 184 and 185 is closed. Thereupon, the program will execute step 611, and will thereby cause the newly-incremented price to be written into the location in EAROM 142 when the price, which was incremented had been stored. Also, the newly-incremented price will be exhibited by the display 168. At this time, the program will branch, via connective 630 and label step 508 of FIG. 10 to steps 510 and 512 where it will loop until the timer of the latter step times out. That program will, until a further one of the switches 182, 183, 184 and 185 is closed, or some other action affects one of the steps in the routine, continue to loop through the routine of FIGS. 10 and 11, and steps 602, 606 and 609 of FIG. 15.

While the control device is in the price-setting mode, the closing of switch 183 or switch 185 can cause all of the lines, which correspond to locations in EAROM 142 where data is stored, to be addressed. Thereupon, the number of that line, and the data corresponding to that line, will be exhibited on the display 168. The route man will, if he wishes to change the price corresponding to any of those lines, permit both of switches 183 and 185 to be in their normally-open state, and then will close switch 182 or switch 184. However if, as the route man uses switch 183 or 185 to cause each line number and the corresponding data to be exhibited by the display 168, he sees that the prices need not be changed, he will not close either of switches 182 and 184. As a result, the price-setting mode of the control device also constitutes a price-checking mode.

The foregoing portion of the description illustrated how the control device can be put in the price-setting mode by closing switch 185. It should be recognized that the control device can also be put into the price-setting mode by the closing of any one of the switches 182, 183 and 184. This is due to the fact that the closing of any one of those switches will cause step 542 of FIG. 10 to provide a change of state in the Port 4 status register which will cause step 580 of FIG. 12 to branch the program, via connective 586 and the routines of FIGS. 14, 10 and 11, to the routine of FIG. 15.

When the route man has finished using various of the switches 182, 183, 184 and 185 to check or change the data for one or more of the lines which correspond to the products offered by the vending machine, he may want to make absolutely certain that those prices will be charged when the control device is in the product-vending mode and the customer-operated selection switch 240, 242 and 244 of FIG. 2 are used. The present invention makes this possible by providing a price verification mode for the control device. Also, the present invention makes it very easy to place that control device in that mode.

All a route man need do, to place the control device in its price verification mode, is to momentarily close either or both of the inventory switches 150 or 152 of FIG. 1. During the next succeeding executions of steps 510 and 516, the resulting change of state at pin 2 or 3 of Port 0 will cause the states in the Port 0 status register and in the inventory switch input status register to be compared, and also will cause any difference between those states to be stored in the inventory switch input change register. During the subsequent execution of step 538, the states in the Port 0 status register will be modified to reflect the data in the inventory switch input change register. Thereafter, during the execution of step 570 of FIG. 11, a comparing function will determine that one or both of the inventory switches had been closed; and the resulting YES will cause the program to branch via connective 634--which is entitled INVP and which corresponds to line 0723 of the program--to connective 636 of FIG. 16. The latter connective also is entitled INVP, and it corresponds to line 2834 of the program. Step 638, which is entitled SET PR VER. MODE FLAG and which corresponds to lines 2834 through 2837 of the program, will set a price verification mode flat in the RFLG register.

During the next-succeeding step 640--which is entitled PAYOUT COIN and which corresponds to lines 2851 through 2865 of the program--the bit in the inventory switch input register will be sensed to energize the motor 230 of FIG. 9 to keep that motor energized long enough for it to establish a cycle-control circuit, of standard and usual design, which will make certain that at least one coin will be dispensed. If inventory switch 150 had been the switch that was pressed, step 640 would have responded to a predetermined bit in that register to permit the selector motor 366 of FIG. 9 to remain de-energized--with consequent dispensing of a nickel from the nickel tube. However, if inventory switch 152 had been the switch that was pressed, step 640 would have responded to a different predetermined bit to permit the relay coil 808 to remain de-energized but would have energized the selector motor 366 in the forward direction--with consequent dispensing of a dime from the dime tube. If both inventory switches had been closed, relay coil 808 would have been energized and the selector motor 366 would have been energized in the reverse direction--with consequent dispensing of a quarter from the quarter tube.

The next-succeeding step 642 is entitled INV. SW. ON? and it corresponds to lines 2851 through 2863 of the program. During that step, a comparing function will determine whether one or more of the inventory switches 150 and 152 still is closed. If that function provides a YES, the program will loop at steps 640 and 642; and hence it will continue to effect the dispensing of coins of the desired enomination. However, when all of the inventory switches are open, the next-succeeding comparing function of step 642 will provide a NO which will initiate the execution of step 644. That step is entitled CHANGE MACHINE STATE BACK TO STANDBY (STBY), and it corresponds to line 2869 of the program which causes a jump to line 2828 which causes a jump to lines 2717 through 2722 which causes a further jump to lines 2875 through 3020 that cause a final jump to lines 0799 through 0869 of the program. At such time, the program will branch via connective 646--which is entitled DEBNCE and which corresponds to line 0869 of the program--to label 508 of FIG. 10, where the program will again loop at steps 510 and 512 until the timer of the latter step times out. During the next execution of the rest of the routine of FIGS. 10 and 11, step 574 will cause the program to jump to step 576 of FIG. 12; and, during the ensuing execution of step 582, the price verification mode flag which was set during step 538 of FIG. 10 will cause the comparing function of step 582 to provide a YES. At this time, the control device will be in its price verification mode.

Step 648 which is entitled SELECTION ACTIVE? and which corresponds to lines 2210 through 2217 of the program, will then check the states of the Port 4 status register to determine whether one of the selection switches 240, 242 or 244 of the vending machine had been closed. As explained hereinafter in the Operation Of Selection Switches section, the closing of any of the selection switches 240, 242 and 244 of FIG. 4 will cause a change of state at one or more of the pins 0 through 3 of Port 4 of microprocessor 62. Also, steps 510 and 516 of FIG. 10 will respond to those changes in state to effect appropriate changes in the states in the Port 4 status register. If the comparing function of 648 provides a NO--thereby indicating that none of the selection switches has been closed, the program will branch via connective 650--which is entitled DEBNCE and which corresponds to line 2236 of the program--to label 508 of FIG. 10, where the program will loop at steps 510 and 512 until the timer of the latter step times out. The program will continue to loop through the routine of FIGS. 10 and 11 and through steps 578, 580, 582 and 648 of FIG. 12 until the route man presses one of the selection switches 240, 242 or 244 or takes the control device out of the price verification mode. If the route man presses one of those selection switches, steps 510 and 512 will, during the next execution thereof, appropriately change the states in the Port 4 status register. During the next-succeeding execution of step 648, a YES will be obtained; and step 652--which is entitled SELECTION CHANGED? and which corresponds to lines 2218 through 2223 of the program--will determine whether a previously-pressed selection switch still is closed or a further selection switch has been closed. If it is assumed that the selection switch which is closed is the first selection switch that is closed by the route man, a YES will be provided by step 652; and step 654-which is entitled SELECTION NO. OUT OF RANGE? and which corresponds to lines 2224 through 2227 of the program--will determine whether voltage spikes or other transients have provided states in the Port 4 status register which do not fit the states corresponding to the selections which can be made by closing any of the selection switches 240, 242 and 244. If step 654 provides a NO, step 658--which is entitled READ PRICE OF SELECTION FROM EAROM and which corresponds to line 2229 of the program--will be executed.

During the latter step, the sub-routine wll call from the EAROM the price which corresponds to the selection switch which was pressed, and it will store that price in the price register. Thereafter, during step 660--which is entitled DISP, PR. ON 3 DIGIT DISP. and which corresponds to line 2235 which causes a jump to lines 0791 through 0793 which causes a jump to lines 0811 through 0868 of the program--the three sseven-segment displays 232, 234 and 236 of FIG. 3 will display the price which corresponds to the last-pressed selection switch. Thereafter, the program will branch, via connective 662--which is entitled DEBNCE and which corresponds to line 0869 of the program--to label 508 of FIG. 10, where the program will loop at steps 510 and 512 until the timer of the latter step times out. The program will containue to loop through the routine of FIGS. 10 and 11 and the routines of FIGS. 12 and 13 until a further selection switch is pressed or the control device is taken out of the price verification mode.

The pressing of a further selection switch 240, 242 or 244 will cause steps 510 and 512, during the next executions thereof, to appropriately change the states in the Port 4 status register. During the next-succeeding execution of step 648, a YES will be obtained; and step 652 will then determine whether a previously-pressed selection switch still is closed or a further selection switch has been closed. The resulting YES from step 652 will cause the program to execute steps 654, 658 and 660 of FIG. 13 are then the routines of FIGS. 10-13, as described hereinbefore. If, during the next execution of steps 652, the previously-pressed selection switch still is closed, the comparing function of that step will provide a NO. Thereupon, the program will branch, via connective 656--which is entitled DEBNCE and which corresponds to line 2236 of the program--and label 508 of FIG. 10, where it will loop at steps 510 and 512 until the timer of the latter step times out. The program then will execute the rest of the routine of FIGS. 10 and 11, jump to the routine of FIGS. 12 and 13, and then execute steps 578, 580, 582, 648 and 652 of the latter routine. The program will continue to loop through the routine of FIGS. 10 and 11 and the routine of FIGS. 12 and 13 until a further selection switch is pressed or the control device is taken out of the price verification mode.

It will be noted that the control device was not placed in the price verification mode at the time the inventory switch 150 or 152 was closed. Instead, that control device was not placed in that mode until (a) step 638 of FIG. 16 set a price verification flag, (b) step 642 of FIG. 16 provided a NO, (c) step 570 of FIG. 11 provided a NO, and (d) step 582 of FIG. 12 provided a YES. The fact that the control device was not placed in the price verification mode until step 642 of FIG. 16 provided a NO is very desirable; because it virtually obviates the possibility of a route man failing to permit both of the switches 150 and 152 to re-open. Specifically, if the route man were, somehow, to fail to shift the actuator 608 of FIG. 1 to the position wherein both switches 150 and 152 are open, the route man would be unable to effect the displaying of any data on the seven-segment displays 232, 234 and 236 of FIG. 3 when he pressed any of the selection switches 240, 242 and 244 of FIG. 4. Immediately and unmistakably, the route man would be made aware of the fact that either or both of the switches 150 and 152 was still closed. Moreover, because the motor 230 must operate and must reciprocate a coin-dispensing slide--whenever either or both of those switches have not been permitted to re-open--the resulting noise will automatically remind the route man of the need of re-opening both of those switches. In this way, by keeping the control device out of the price verification mode until after both of the switches 150 and 152 are restored to their open positions, by making it impossible for the route man to effect the exhibiting of any price on the three seven-segment displays 232, 234 and 236 of FIG. 3 until both of those switches are restored to their open positions, and by using the noise from the operation of motor 230 and the reciprocation of a coin-dispensing slide to remind the route man that he must restore those switches to their open positions, the present invention virtually eliminates any likelihood that a route man might fail to re-open the switches 150 and 152 before he closed the vending machine.

After the route man has pressed each of the selection switches of the vending machine and has satisfied himself that the desired price for each selection switch has been established, he will--unless he has previously done so--close the vending machine. Thereafter, to take the control device out of the price verification mode and to place it in the product-vending mode, the route man can (a) insert a nickel, dime, quarter or dollar, (b) press the cancel sale button, (c) depend upon a customer to insert a nickel, dime, quarter or dollar, or (d) depend upon a customer to press the cancel sale button. For purposes of illustration, it will be assumed that the route man inserts a quarter. The passage of that quarter past the sensor 486 of FIG. 8 will effect a change of state at pin 2 of Port 1; and, during the next executions of steps 510, 516 and 562 of FIGS. 10 and 11, the Port 1 status register will have the states therein changed to reflect the insertion of that quarter. The comparing function of FIG. 562 will provide a YES; and then the program will branch, via connector 664--which is entitled CRDTP and which corresponds to line 0662 of the program--to connective 666 of FIG. 17--which is entitled CRDTP and which corresponds to line 0739 of the program. Thereafter, step 668, which is entitled SET COINS CAME IN FLAG and which corresponds to steps 0741 through 0744 of the program, will set a flag in the RFLG register. During step 670, which is entitled RESET PR. VER. MODE FLAG and which corresponds to line 0743 of the program, the price verification mode flag in the RFLG register will be re-set to zero (0). Subsequently, during step 672, which is entitled CHANGE BACK TO STANDBY (STBY) and which corresponds to line 0740 of the program, the machine state will be changed to "standby". At this time, the control device will be out of the price verification mode and will be in the product--vending mode. It will be noted that the route man did not have to close, open or otherwise actuate any switch to take the control device out of the price verification mode and to place it in the conduct vending mode. In fact, the route man did not even have to insert the quarter or any other coin. Instead, he could have walked away from the vending machine as soon as he closed it; because the first subsequent insertion of a coin--whether by the route man or by a customer--would automatically take the control device out of the price verification mode and place it in the product-vending mode.

If the quarter or other first coin had been inserted by a customer, that customer could effect the dispensing of a desired product by closing the appropriate selection switch 240, 242 or 244 of FIG. 4. Alternatively, that customer could insert one or more additional coins and then select a corresponding higher-priced product. Moreover, if desired, that customer could press the cancel sale button to effect the return of a coin or coins equalling the value of the coin or coins inserted by him. All of these features inhere in the operation of the control device in the product-vending mode; and that customer and all succeeding customers can fully utilize those features in succeeding cycles of operation of the vending machine.

Step 674 of FIG. 17 is entitled ADD COINS TO CREDIT & DISP. and it corresponds to lines 0745 through 0793 which cause a jump to lines 0811 through 0868 of the program. During that step, the value of the quarter will be transferred from the Port 1 status register to the credit register. Also, the value in the credit register wll be exhibited by the seven-segment displays 232, 234 and 236 of FIG. 3 as "0.25". The program will then branch, via connective 676--which is entitled DEBNCE and which corresponds to line 0869 of the program--to label 508 of FIG. 10, where it will resume looping at steps 510 and 512. At this time, the program will execute the rest of the routine of FIGS. 10 and 11 and steps 578, 580 and 582 of the routine of FIG. 12, and then--due to the NO which step 582 will provide because the control device is out of the price verification mode--will branch to label 508 of FIG. 10.

In the assumed situation, where the route man inserted a quarter to take the control device out of the price verification mode and to place it in the product-vending mode, he will press the CANCEL SALE button. The resulting signal from sensor 803 of FIG. 8 will change the state of pin 7 of Port 4 of the microprocessor 62. During the next execution of steps 510 and 516, that change of state will be used to change the states in the Port 4 coin return input status register and in the Port 4 coin return change register. During the succeeding execution of step 566 of FIG. 11, the comparing function thereof will provide a YES. Step 678--which is entitled CHANGE MACHINE STATE BACK TO STANDBY (STBY) and which corresponds to line 0680 of the program--will change the value in the Q register to "standby". Thereafter step 680--which is entitled RESET PRICE VERIFICATION MODE FLAG and which corresponds to lines 0681 through 0683 of the program--would, if the price verification flag in the RFLG register had not already been re-set, effect the re-setting of that flag to zero (0).

The program will then branch, via connective 682--which is entitled CRETP and which corresponds to line 0689 of the program--and connective 684 of FIG. 18--which is entitled CRETP and which corresponds to line 2465 of the program--to step 686. That step is entitled CHANGE MACH. STATE TO PAY and it corresponds to lines 2480 and 2481 of the program; and it will change the state of the Q register to the state representing "pay". The next-succeeding step 688 is entitled CLEAR CREDIT DISPLAY and it corresponds to line 2482 of th program which causes a jump to lines 0799 through 0868 of the program. During that step, the seven-segment displays 232, 234 and 236 of FIG. 3 will be "cleared" by causing them to exhibit "0.00". The program will then branch, via connective 690--which is entitled DEBNCE and which corresponds to line 0869 of the program--to label 508 of FIG. 10, with consequent looping at steps 510 and 512 until the timer of the latter step times out. During the next execution of the rest of the routine of FIGS. 10 and 11, the "pay" state of the Q register, which was set by step 686 of FIG. 18, will cause step 574 of FIG. 11 to jump the program to the routine of FIGS. 19 and 20, all as explained hereinafter in the Dispensing of Coins--During Cancel Sale Operation section. At the conclusion of that routine, the program would resume its looping through the routines of FIGS. 10-12--exiting via connective 584 of FIG. 12 and re-entering at label 508 of FIG. 10--until coinage is inserted and a selection switch is closed. At this time, the vending machine will be in its "standby" condition in the product-vending mode.

It will be noted that the control device can be taken out of the price-setting mode in either of the hereinbefore-described ways in which it was taken out of the price verification mode. Specifically, that control device can be taken out of the price-setting mode by the insertion of a coin or by the pressing of the cancel sale button. As such a coin is inserted, steps 510, 512 and 562 of FIGS. 10 and 11 will cause the program to branch--via CRDTP connectives 664 and 666, respectively, of FIGS. 11 and 17--to the routine of FIG. 17. Step 672 of that routine will change the state of the Q register from PSTM--which was set by step 594 of FIG. 14 to initiate the placing of the control device in the price-setting mode--to "standby". Thereafter, during the next execution of step 574 of FIG. 11, the program will jump to the routine of FIGS. 12 and 13 rather than to the routine of FIG. 15. In this direct and simple way, the insertion of a coin promptly and automatically takes the control device out of the price-setting mode. Similarly, when the cancel sale button is pushed, steps 510, 512 and 566 of FIGS. 10 and 11 will cause the program to branch--via steps 678 and 680, CRETP connectives 682 and 684, respectively, of FIGS. 11 and 18,--and steps 686 and 688 to label 508 of FIG. 10. The change in the state of the Q register from PSTM--which was set by step 594 of FIG. 14 to initiate the placing of the control device in the price-setting mode--to "standby", which is effected by steps 678 will cause the program--during the next execution of step 574 of FIG. 11--to jump to the routine of FIGS. 12 and 13 rather than to the routine of FIG. 15. In this direct and simple way, the pressing of the cancel sale button promptly and automatically takes the control device out of the price-setting mode. As a result, the present invention provides automatic escape from the price-setting mode, just as it provides automatic escape from the price verification mode. The automatic escape of the control device from the price-setting mode is just as important as the automatic escape from the price verification mode; because a route man might be so pressed for time that he might not place the control device in the price verification mode before he closed the vending machine. The price verification mode and the price setting mode are non-public modes, and hence are quite different from the product-vending mode.

Vending machines, wherein mode switches are used to select between product-vending and price-setting modes or between product-vending and price verification modes do not ordinarily have tell-tale lamps to indicate the modes in which those vending machines are set. Consequently, if a route man failed to shift the mode switch of such a vending machine from the price-setting mode or the price verification mode to the product-vending mode, he would have no visible indication that he had failed to do so. Further, if he closed up the vending machine without shifting the mode switch from the price-setting mode or the price verification mode to the product-vending mode, there would be nothing at the exterior of the vending machine to indicate to him that he had failed to execute the critical step of shifting the vending machine out of the price-setting mode or the price verification mode. Consequently, the automatic escape which the present invention provides--either from the price-setting mode or from the price verification mode is an aid to the route man and to his employer in avoiding the total loss of vending business which would occur between service calls in the event the mode switch was not shited to the product-vending mode.

Whenever a route man services a vending machine, he must perform a number of operations--including the replacing of the products that have been dispensed, the emptying of the cash box, the emptying and re-filling of the coin tubes, and the restoration of that vending machine to its "standby" condition in the product-vending mode. A route man often is pressed for time as he services a vending machine; and, sometimes he is repeatedly interrupted by customers who insist upon obtaining desired products while the vending machine is being serviced. As a result, route men frequently are under the pressures of time commitments and of distractions as they service vending machines. Consequently, it would be desirable to reduce to an absolute minimum the number of devices which the route man must operate, and it would also be desirable to reduce to an absolute minimum the number of operations which he must perform. Further, it would be desirable to arrange the operations which the route man should perform so the operations which he must perform would automatically enforce the performance of the former operations.

The present invention ideally reduces to an absolute minimum the number of devices which the route man must operate by enabling either of the switches 150 and 152 to perform two functions, namely, effecting the dispensing of coins and placing the control device in the price verification mode. Further, the present invention ideally reduces to an absolute minimum the number of operations which the route man must perform by enabling the same actuation of switch 150 or 152 to (a) effect the dispensing of coins and (b) initiate the placing of the control device in the price verification mode. Moreover, the present invention ideally arranges an operation which the route man should perform, namely, the closing of one of the switches 150 and 152, so it is automatically performed during an operation which the route man must perform, namely, the emptying of the coin tubes. Additionally, the present invention ideally precludes the performance of an operation which should be performed, namely, the verification of prices, until a prior operation which must be performed, namely, the re-opening of switches 150 and 152, has been completed. Moreover, the present invention obviates all of the initial cost of an extra switch, all of the cost of wiring such a switch into the circuit, and all of the problems of servicing and maintaining such a switch.

It was assumed hereinbefore that the route man inserted a quarter to cause the contact device to shift out of the price verification mode and into the product-vending mode, and it subsequently was assumed that he pressed the cancel sale button to effect the return of that quarter to him. Motor 230, selector motor 366, and relay coil 808 of FIG. 9 will be energized to effect the dispensing of that quarter, all as explained hereinafter in the Dispensing of Coins--During Cancel Sale Operation section. When that quarter has been dispensed, the control device and the vending machine will be in their "standby" conditions in the product-vending mode. At such time, the program will continually loop through the routine of FIGS. 10 and 11, connective 576 of FIG. 12, steps 578,580 and 582, and connective 584 until some further action is taken by a customer.

Whenever a one dollar coin is inserted, sensor 149 of FIG. 8 will respond to the presence of that coin to apply a signal, via chip 416, to pin 3 of Port 1 of microprocessor 62. During the next looping of the program through steps 510 and 516 of FIG. 10, the data in the Port 1 status register will be compared with the states of Port 1; and any differences between those states will be stored in the Port 1 change status register. Subsequently, during step 562 of FIG. 11, the data in the Port 1 status change register will be supplied to a dollar coin register --as indicated by lines 0770 through 0786 of the program--to establish a running count of the values of all inserted coins. Each succeeding insertion of a dollar coin will provide an incrementing of the number in the dollar coin register and also will provide an augmenting of the value in the credit register. As a result, the control device will store a running count, in the dollar coin register, of the number of dollar coins which are inserted during any given transaction and also will add to the running count, in the credit register, the values represented by those dollar coins.

Importantly, the YES from step 562 of FIG. 11 will cause the program to branch, via CRDTP connectives 664 and 666 respectively, of FIGS. 11 and 17 to the routine of FIG. 17. AS pointed out hereinbefore, in the section entitled Placing Control Device in Product-Vending Mode--Cancel Sale Operation, step 670 re-sets the price verification flag to zero (0)--thereby taking the control device out of the price verification mode and putting it in the product-vending mode. Also, as pointed out hereinbefore, the route man did not have to close, open or otherwise actuate any switch to take the control device out of the price verification mode and to place it in the product vending mode. In fact, the route man did not even have to insert a dollar or any other coin. Instead, he could have walked away from the vending machine as soon as he closed it; because the first subsequent insertion of a coin--whether by the route man or by a customer--would automatically take the control device out of the price verification mode and place it in the product-vending mode.

Whenever a quarter is inserted, sensor 486 of FIG. 8 will respond to the presence of that quarter to apply a signal, via switch chip 416, to pin 2 of Port 1 of microprocessor 62. During the next execution of steps 510 and 516 of FIG. 10, the data in the Port 1 status register will be compared with the states of Port 1; and any differences between those states will be stored in the Port 1 change status register. Subsequently, during step 562 of FIG. 11, the data in the Port 1 status change register will be supplied to a quarter register to establish a running count of the number of inserted quarters and also will be supplied to the credit register to augment the running count of the values of all inserted coins. Each succeeding insertion of a quarter will provide an incrementing of the number in the quarter register and also will provide an augmenting of the value in the credit register. As a result, the control device will store a running count, in the quarter register, of the number of quarters which are inserted during any given transaction and also will add to the running count, in the credit register, the values represented by those quarters.

Again, importantly, the YES from step 562 of FIG. 11 will cause the program to ranch, via CRDTP connectives 664 and 666, respectively, of FIGS. 11 and 17 to the routine of FIG. 17. Step 670 of that routine re-sets the price verification flag to zero (0)--thereby taking the control device out of the price verification mode and putting it in the product-vending mode.

Similarly, whenever a dime is inserted, sensor 520 will provide a change of state at pin 1 of Port 1, and steps 510, 516 and 562 of FIGS. 10 and 11 will establish a running count of the number of inserted dimes in a dime register and also will augment the running count of the values of all inserted coins which is stored in the credit register. Here again, importantly, the YES from step 562 of FIG. 11 will cause the program to branch, via CRDTP connectives 664 and 666, respectively, of FIGS. 11 and 17 to the routine of FIG. 17. Step 670 of that routine re-sets the price verification flag to zero (0)--thereby taking the control device out of the price verification mode and putting it in the product-vending mode.

Whenever a nickel is inserted, steps 510, 516 and 562 of FIGS. 10 and 11 will establish a running count of the number of inserted nickels in a nickel register and also will augment the running count of the values of all inserted coins which is stored in the credit register. Again, importantly, the YES from step 562 of FIG. 11 will cause the program to branch, via CRDTP connectives 664 and 666, respectively, of FIGS. 11 and 17 to the routine of FIG. 17. Step 670 of that routine re-sets the price verification flag to zero (0)--thereby taking the control device out of the price verification mode and putting it in the product-vending mode.

The selection switch 240 of FIG. 4 can be closed to connect L2 to the upper terminal of solid state relay 290 via vending device 246 and the primary winding 250 of current transformer 248. Similarly the selection switch 244 can be closed to connect L2 to the upper terminal of that relay via vending device 392 and the primary winding 396 of current transformer 394. Further, any of the selection switches represented by the numeral 242 can be closed to connect L2 to the upper terminal of relay 290 via a vending device and a primary winding which are similar to vending device 246 and primary winding 250.

The vending machine, with which the control device of the present invention will be used, will usually be operated by 115 A.C. power. In contrast, the microprocessor 62 and most of the other components of that control device will be operated by twelve (12) volts or less D.C. The current transformers 248 and 394 and the other eleven (11) current transformers, not shown, permit signals for the control device to be transferred from the vending machine, and, importantly also permit the control device to be operated by low voltage D.C. whereas the vending machine is operated by higher voltage A.C. The resulting electrical isolation is important, because the contacts on solid state devices frequently are too close to each other and to other components to be used in places where 115 volt A.C. is used.

Resistors 272 and 274 of FIG. 5 and plus five (+5) volts apply a positive reference voltage to the inverting input of comparator 266; and that voltage will tend to make that comparator develop a logic "0" at its output. The voltage divider, which is constituted by resistors 264, 302, 304 and 265, responds to each positive-going half-cycle of the A.C. from the secondary winding of transformer 254 to apply a positive control voltage to the non-inverting input of comparator 266. That control voltage is sinusoidal; and it will repeatedly rise above, and then fall below, a value which is equal to the value of the reference voltage at the inverting input of that comparator. When the value of the control voltage rises above the value of the reference voltage, the comparator 266 will "toggle" to provide a logic "1" at the output thereof; and that logic "1" will remain at that output as long as that control voltage is higher than that reference voltage. However, when that control voltage falls below the level of that reference voltage, the output of the comparator will toggle back to logic "0".

The transistor 300 is connected in parallel with resistor 304; and, because it normally is non-conductive, it normally constitutes a high resistance in parallel with that resistor. However, that transistor can be rendered conductive to "short out" that resistor. The positive voltage, which is developed during each positive-going half cycle, will increase progressively during the first ninety degrees (90.degree.) of that half cycle, and then will decrease progressively during the rest of that half cycle. Also, that voltage will be distributed across the resistors 264, 302, 304 and 265 in proportion to the resistances thereof. When resistor 304 is not "shorted out", a higher percentage of the voltage of each positive-going half cycle will be developed across series-connected resistors 302 and 304--and hence between ground and the non-inverting input of comparator 266--then will be developed across resistor 302 when resistor 304 is "shorted out". Moreover, and significantly, if a voltage level is set--which can and must be attained at an earlier point in the half cycle when transistor 300 is non-conductive than will be the case when that transistor is rendered conductive. Also, that voltage level will be maintained for a longer time during each half cycle when transistor 300 is non-conductive than will be the case when that transistor is rendered conductive.

Pin 3 of Port 5 of microprocessor 62 in FIG. 6 normally applies a logic "1" to the input of inverter 296, and also to the D and S inputs of flip-flop 318 in FIG. 5, via conductor 106. That flip-flop will, as soon as it received a "1" at the C input thereof, respond to the logic "1" on conductor 106 to develop a logic "1" at its Q output. Moreover, until pin 3 of Port 5 applies a logic "0" to conductor 106, that flip-flip will continue to have a "1" at that Q output, and will apply that logic "1" to the left-hand input of NAND gate 286, via conductor 282. That gate will provide a logic "0" at its output whenever logic "1" is applied to both of its inputs, but will provide a logic "1" at that output whenever either or both of its inputs is "0". The Q output of monostable multivibrator 276 of FIG. 5 normally applies a logic "1" to the right-hand input of that NAND gate; and hence that NAND gate normally applies a logic "0" to driver 288 to render that driver non-conductive. As a result, that driver normally will not supply a triggering signal to solid state relay 290.

The logic "1" on conductor 106 will cause inverter 296 to develop a logic "0" at its output. Resistor 298 will apply that logic "0" to the base of transistor 300; and hence that transistor normally will be non-conductive.

During each half-cycle of the A.C. from the secondary winding of transformer 254, a positive voltage will develop between the non-inverting input of comparator 266 and ground. The rate at which that voltage will be able to rise to a voltage equal to the reference voltage of the inverting input of that comparator will be a function of the ratio between the combined resistances of resistors 302 and 304 and the total resistance of voltage divider 264, 302, 304 and 265. Whenever resistor 304 is not "shorted out" it will make the ratio higher, and hence will enable the voltage between ground and the non-inverting input of comparator 266 to rise to the pre-set level shortly after the beginning of each half-cycle and to remain above that level until very close to the trailing edge of that half-cycle. On the other hand, when resistor 304 is "shorted out"--as when transistor 300 becomes conductive--it will take longer to attain that level. The overall result is that when transistor 300 is non-conductive, the positive voltage reaches a pre-set level within a few degrees after the beginning of each half-cycle and that positive voltage will remain above that level until close to the trailing edge of that half-cycle. In contrast, when transistor 300 is conductive and is "shorting out" resistor 304, the positive voltage will not reach the preset level until a few degrees before the midpoint of the half-cycle, and that voltage will drop below that level shortly after that midpoint.

Each time the control voltage at the non-inverting input of comparator 266 becomes higher than the reference voltage at the inverting input of that comparator, the output of that comparator will provide a logic "1". However, because the B input of multivibrator 276 responds to negative-going edges, that multivibrator will not change its output during the first ninety degrees (90.degree.) of positive-going half-cycle. The control voltage at that non-inverting input will remain higher than the reference voltage until just a few degrees before the end of the positive-going half-cycle. As the control voltage falls below the reference voltage, the output of comparator 266 will "toggle" back to "0"; and the B input of multivibrator 276 will respond to that negative-going edge to apply a "0" to the right-hand input of NAND gate 286. Thereupon, the output of that NAND gate will become a logic "1", and will cause driver 288 to apply a triggering pulse to relay 290. The comparator 266, the multivibrator 276, the NAND gate 286 and the driver 288 will apply triggering pulses to the solid state relay 290 sixty (60) times every second, and hence the closing of any of the selection switches will provide essentially-immediate firing of that relay.

If it is assumed that selection switch 240 is closed, by a route man or a customer, the next positive-going, half-cycle of the A.C. will develop a positive voltage across resistors 302 and 304--and hence the non-inverting input of comparator 266--which will quickly build up to a level which exceeds the voltage at the inverting input of that comparator; and thereupon that comparator will toggle to provide a logic "1" output. During the latter portion of that half-cycle, that positive voltage will fall below the voltage at the inverting input of comparator 266; and, thereupon, the output of that comparator will change back to logic "0". Multivibrator 276 will respond to the change from "1" to "0" at its input B to apply a short-duration logic "0" to the right-hand input of NAND gate 286 via conductor 284; and the resulting logic "1" at the output of that NAND gate will enable driver 288 to render solid state relay 290 conductive. Thereupon, current will flow from L2 via switch 240, vending device 246, primary winding 250, and relay 290 to L1.

The toggling of the output of comparator 266 back to logic "0" will occur prior to the end of the positive-going half-cycle, and the logic "0" from multivibrator 276 is of such short duration that it will disappear before the end of that half-cycle. As a result, the negative-going zero crossing of the current flowing through relay 290 will promptly render that relay non-conductive; and hence, at the instant the selection switch 240 is closed, only a very narrow, short-duration current pulse will be applied to the vending device 246. That pulse will be unable to actuate that vending device; and hance that vending device will not respond to that pulse. Similarly, when selection switch 244, or any of the other selection switches represented by the switch 242, is initially closed, only a very narrow, short-duration current pulse will be applied to the corresponding vend-device. Again, the relay 290 will be rendered conductive for such a short length of time that the vending device, whose selective switch was closed, can not be actuated.

Although the narrow, short-duration current pulses--which are provided by relay 290 when transistor 300 is non-conductive--are too short to actuate vending device 246 or 392 or any of the other eleven vending devices, not shown, those pulses are long enough to cause the secondary winding 252 or secondary winding 398 or any of the other eleven secondary windings, not shown, to provide a usable output pulse. In the assumed situation where selection switch 20 was closed, resistors 334 and 336 will apply that output pulse to the non-inverting and inverting inputs of comparator 340. Those resistors, resistors 332 and 338, the plus five (+5) volts, and the plus twelve (+12) volts provide a bias for comparator 340 which enables that comparator to ignore each pulse from secondary winding 252, unless that pulse is developed by the flow of more than one hundred and twenty milliamperes (120 MA) through primary winding 250. This is very desirable; because it will keep any leakage currents in the primary circuit of transformer 248 from developing a pulse in the secondary circuit of that transformer which could toggle comparator 340. Leakage currents can sometimes develop across the "open" selection switches of vending machines where those vending machines are used in damp or moist locations, or in locations where the air has unduly-high amounts of metallic or graphitic dust therein. Some control devices, which have used prior selection switch circuits rather the sub-circuit of FIG. 5, have experienced problems because of leakage in the selection circuits.

Each output pulse, which will be developed by the secondary winding 252 in response to a flow of one hundred and twenty or more (120+) milliamperes through the primary winding 250, will provide a voltage differential between the inverting and non-inverting inputs of comparator 340 that will "toggle" that comparator. Thereupon, a changed-state output will be applied to the D2 input of encoder 346 and also, via resistor 344 and conductor 330, to the non-inverting input of comparator 326 of FIG. 5. The inverting input of comparator 326 responds to comparator 320 and to plus five (+5) volts to keep a "low" logic state on conductor 328--and hence at the R input of the tri-state register 374 which is used as a latch--as long as the non-inverting input of comparator 326 receives a signal from only one of resistors 344, 412 and the other eleven resistors represented by the numeral 414. As a result, that R input will not normally receive an output from comparator 326 via conductor 328.

Because the selection switches 240, 244 and the eleven other selection switches which are represented by numeral 242 are connected in series relation, and because the closing of any of those switches will disconnect L2 from all selection switches which are disposed to the right of that closed switch, the closing of two selection switches in rapid succession should not provide a simultaneous "toggling" of the outputs of the comparators corresponding to those selection switches. However, in the event the comparator which corresponds to the first-closed selection switch is slower-than-usual in "toggling" back to its normal state, and in the event the comparator which corresponds to the second-closed selection switch is faster-than-usual in "toggling" to its actuated state, the outputs of both comparators could be in their actuated states at the same instant. Without comparator 326 and resistors 344, 412 and 414, the outputs of those simultaneously-actuated comparators might effect the dispensing of the second-selected product, and might even effect the dispensing of both the first-selected and second-selected products. However, by providing that comparator and those resistors, and by keeping that comparator from "toggling " its output until it receives current through at least two of the resistors 344, 412 and 414, the present invention keeps the closing of two selection switches from effecting the dispensing of the second-selected product--much less the dispensing of products corresponding to both selection switches.

Specifically, in the event two comparators were tricked into being in their actuated states at the same time, the resistors 344, 412 and 414, which correspond to those comparators, will supply sufficient current to the non-inverting input of comparator 326 to "toggle" that comparator. The resulting signal on conductor 328 would constitute a re-set signal at the R input of tri-state register 374; and, thereupon, that tri-state register would be rendered incapable of developing any usable data at its Q0 through Q3 outputs. Consequently, no product would be dispensed.

If it is assumed that a customer closed selection switch 240 and made no effect to close another selection switch, only the comparator 340 would be "toggled", and comparator 326 would not apply a re-set signal to the R input of tri-state register 374. The application of the "toggled" output of comparator 340 to input D2 of encoder 346 would cause that encoder to apply a three-bit code to inputs D1 through D3 of tristate register 374 via the lower inputs of OR gases 350, 352 and 354. Because comparator 408 is not supplying a signal to encoder 348, the GS output of that encoder will be supplying a "0" to input D4 of the tri-state register. This means that tri-state register 374 will have a four-bit code applied to its D1 though D4 inputs.

If selection switch 244, rather than selection switch 240, had been actuated, comparator 408 would have applied a signal to the D6 input of encoder 348, and comparator 340 would not have applied a signal to encoder 346. The QO through Q2 outputs of encoder 348 would have supplied a three-bit code to the D1 through D3 inputs of tri-state 374 via the upper inputs of OR gates 350, 352 and 354. Also, the GS output of that encoder will have applied a logic "1" to the D4 input of that tri-state register, and hence would have enabled that encoder to supply a four-bit code to inputs D1 through D4 of that register.

The four-bit Code at the D1 through D4 inputs of tri-state register 374 will not appear at the outputs QO through Q3 of that register until a clock signal is applied to the C input of that register. Consequently, until that clock signal is developed, conductors 76, 78, 80 And 82 will be unable to apply signals to the 0 through 3 pins of Port 4 of microprocessor 62. Whenever an input signal is applied to any of the D1 through D6 inputs of encoder 348 of FIG. 4, the Eout of that encoder will apply a signal to the Ein of encoder 346; and, when the latter encoder receives such a signal, it provides an Eout in the form of a logic "0". However, diode 375 will prevent that logic "0" from appearing at the upper input of OR gate 380, but after a short delay the capacitor 378 will discharge through the resistor 376 to supply a logic "0" at that input of OR gate 380. As long as the upper input of OR gate 380 is at logic " 1", a logic "1" will continue to appear at its output and thus at the C input of tri-state register 374. That logic "1" will not be effective to clock the data into the tri-state register 374, because the C input of that register responds only to a positive going signal. The flip-flop 258 of FIG. 5 continuously receives a forty-eight kilohertz (48 KHz) signal at its C input--from either or both of the switch chips 416 and 418 of FIG. 8, via junction 426, conductor 262, and resistor 260 in FIG. 5. That flip-flop will serve as a divide-by-two counter; and hence it will develop a logic "1" at its Q output at a twenty-four kilohertz (24 KHz) rate, and that signal is applied to the lower input of OR gate 380. As a result, whenever an Eout logic "0" is developed by encoder 346, the capacitor 378 discharges a logic "0" will appear at the upper input of OR gate 380. At that time the OR gate will respond to the signal at its lower input to develop a twenty-four kilohertz (24 KHz) signal at its output. Thereupon, the four-bit code which was being applied to the D1 through D4 inputs of that tri-state register will be applied to pins 0 through 3 of Port 4 of microprocessor 62 on the next positive-going transition of that clock. The tri-state register 374 of FIG. 6 will act as a latch; and hence it will--until it is subsequently re:set--continue to apply to pins 0 through 3 of Port 4 of microprocessor 62 the four-bit code whih had been applied to its D1 through D4 inputs. That register could be re-set by the "toggling" of comparator 326 of FIG. 4 which would apply a signal to the R input of that register. However, the register 374 will be re-set at the end of each vending transaction by having conductor 384 apply a signal to the A output disable pin thereof. That signal is developed by the decoder 134 of FIG. 1 during step 550 of FIG. 11 after a vending operation has been initiated or during step 566 of FIG. 11 after a coin returning operation has been initiated.

The application of the four-bit code to pins 0 through 3 of Port 4 of microprocessor 62 will be sensed, and responded to, by steps 510 and 516 of FIG. 10. During the latter step, a sub-routine of the microprocessor will respond to the four-bit code at pins 0 through 3 of Port 4 to cause the microprocessor to address the location in the EAROM where the price corresponding to the selected product is stored. Thereafter, that price will be loaded into the price register; and then the arithmetic unit of the microprocessor will compare the data in the credit register with the data in the price register. If the value of the data in the credit register at least equals the value of the data in the price register, the microprocessor will change the logic "1" at pin 3 of Port 5 to a logic "0". Conductor 106 will apply that "0" to the D and S inputs of flip-flop 318 of FIG. 4, and also to the input of inverter 296. That flip-flop will not be able to respond to that "0" until a clock signal is applied to the C input thereof by comparator 266.

The inverter 296 will respond to the "0" on conductor 106 to apply a "1" to the base of transistor 300, thereby rendering that transistor conductive. The resulting "shorting out" of resistor 304 will cause comparator 266 to "toggle" close to the midpoint of the next positive-going half-cycle. More specifically, the "shorting out" of resistor 304 will require the voltage across resistor 302--and hence the voltage between the non-inverting input of comparator 266 and ground--to be greater than the voltage which was developed across resistor 302 when transistor 300 was non-conductive and constituted a high impedance in parallel with resistor 304. Consequently, the voltage at the non-inverting input of comparator 266 will not reach the level of the reference voltage at the inverting input of that comparator--and hence the comparator will not toggle--until shortly before the midpoint of that next positive-going half-cycle of the A.C. from the secondary winding of transformer 254. However, as soon as the output of that comparator becomes a logic "1", flip-flop 318 will respond to the resulting "1" at its C input to develop a "0" at its Q output; and then NAND gate 286 will supply a "1" to driver 288. The resulting triggering of relay 290 will occur close to the midpoint of the half-cycle of the A.C., and it will supply a wide current pulse to vending device 392, as indicated by the hatched portion of FIG. 22. That vending device will respond to that pulse to become actuated and thereby initiate a vending cycle for the vending machine.

The logic "0" at the Q output of flip-flop 318 also will be applied to the EXT. INT. input of microprocessor 62 in FIG. 6 by conductor 104; and, via conductor 104, capacitor 386 and inverter 390, will be inverted and applied to the D7 input of encoder 348. The logic "0" on conductor 104 will indicate that a vend operation has been initiated, and the microprocessor will respond to the application of that "0" to the EXT. INT. input thereof to start a timing function. The control device will provide a "fixed vend" if switch 58 of FIG. 1 is left open; and it will provide a "short vend" if that switch is closed. The duration of the timing function will be set in accordance with the "open" or "closed" state of switch 58--providing a twelve millisecond (12 ms) time period when that switch is "open" and providing a potentially longer time period when that switch is "closed".

The logic .-+.1" which inverter 390 of FIG. 4 applies to input D7 of encoder 348 will cause that encoder to develop a four-bit code at its Q1 through Q2 and GS outputs, and also will cause it to provide an Eout signal which will be applied to the Ein of encoder 346. OR gates 350, 352, and 354 will apply, to the D1 through D3 inputs of register 374, the portion of the four-bit code which appears at the Q0 through Q2 outputs of encoder 348; and the GS output of that encoder will apply the fourth bit of that code to the D4 output of that register. The encoder 346 will respond to the signal at its Ein to re-set each of the Q0 through Q2 outputs thereof to zero (O), and also to provide a logic "0" at its Eout. As described hereinbefore diode 375, resistor 376 and capacitor 378 will cause, after a short delay, a logic "0" to appear at the upper input of the OR gate 380. The resulting clock at the output of that OR gate will be applied to the C input of register 374 to clock the four-bit code at its D1 through D4 inputs to its Q0 through Q3 outputs--and thence to pins 0 through 3 of Port 4 of microprocessor 62. During steps 510 and 516 of the next execution of the routine of FIGS. 10 and 11, the new states of those pins will be sensed; and then, the microprocessor 62 will determine that the four-bit code does not match any four-bit code which should be received from register 374. Thereupon, the microprocessor will disregard, and not respond to, that four-bit code--just as it would disregard and not respond to any other "invalid" code at pins 0 through 3 of Port 4. Also, the timing function which was initiated by the "0" at the EXT. INT. input will be permitted to control the duration of the logic level on conductor 106.

Transistor 300, comparator 266, multivibrator 276, flip-flop 318, and the associated resistors permit only a narrow, one millisecond (1 ms), current pulse to be supplied to each vending device and its associated transformer primary winding at the instant the corresponding selection switch is closed. Subsequently, transistor 300, comparator 266, flip-flop 318, and the associated resistors permit a wider, four millisecond (4 ms), current pulse to be supplied to that vending device if microprocessor 62 provides a logic "0" on conductor 106. The flow of current during the four millisecond (4 ms) current pulse and the consequent further flow of current through the immediately-succeeding, approximately eight millisecond (8 ms) negative-going half-cycle of the A.C. will heat the solid state relay 290 and also will heat the vending device--246, 392 or one of the eleven (11) vending devices, not shown--to which that current pulse will be applied. The heat which is generated in that relay by the overall twelve millisecond (12 ms) current pulse will be dissipated by the "heat sink" of that relay, and hence that relay can safely be used to supply such pulses to those vending devices. Also, the heat which is generated in each of those vending devices by such pulses will be safely dissipated, and hence those vending devices can safely receive, and respond to, such pulses--even though the resulting current flow through the relay 290 and through some of those vending devices can be in the order of several amperes.

Where the control device is used with a vending machine which responds to a "fixed vend" time signal, the triggering pulses for the relay 290 must be long enough to actuate the vending device selected by the closing of the selection switch, and yet must not be so long that the relay 290 or the vending device could be overheated. The sub-circuit of FIG. 5 provides current pulses--for the vending devices 246 and 392 and for the other eleven (11) vending devices, not shown--which are wide enough and of sufficiently-long duration to actuate those vending devices but are short enough to avoid overheating of those vending devices or of relay 290, by not "toggling" the comparator 266 at the beginning of each half-cycle. Where that comparator is not toggled until about the midpoint of the positive-going half-cycle, and where the switch 58 of FIG. 1 is open--to provide a "fixed vend"--the twelve millisecond (12 ms) "fixed vend" timing function will change the "0" at pin 3 of Port 5 back to "1" close to the next positive-going zero crossing of the A.C. The flip-flop 318 will respond to the next "1" at the output of comparator 266 to develop a "1" at its Q output--thereby causing NAND gate 286 and driver 288 to discontinue the triggering signal which that driver had been applying to relay 290. As a result, that relay will be non-conductive during the first part of the next-succeeding positive-going half-cycle of the A.C. This means that where switch 58 is open, the maximum duration of a current pulse for a vending device will be the remainder of the positive-going half-cycle--during which that pulse was initiated--plus the succeeding negative-going half-cycle of the A.C.; and hence will be about twelve milliseconds (12 ms). A current pulse of that width and duration will be able to actuate a vending device without overheating it or the relay 290.

Where a vending machine is designed to receive a "short vend" signal from a control device, the vending device of that vending machine will be designed so the value of the current flowing through that vending device will be low enough to avoid overheating of that vending device. Because that value of current will be less than the value of current required by "fixed vend" time vending machines, that relay and that vending device can operate during the longer vend time without becoming overheated. Specifically, the control device will provide triggering signals for just three-quarters of the first A.C. cycle, subsequent to microprocessor supplying a "0" on conductor 106, and continuously thereafter, when switch 58 is closed; and it will supply those signals only as long as a "0" appears on conductor 106. The "short vend" timing function, which will be indicated when flip-flop 318 supplies a "0" to the EXT. INT. input of FIG. 6, will cause pin 3 of Port 5 to maintain the logic "0" on conductor 106 until the vending machine develops a LINE 6 signal, the opto-coupler 154 of FIG. 1 supplies a resulting signal to pin 6 of Port 4, the next execution of steps 510 and 516 of FIG. 10 enables that signal to be sensed, the next execution of step 546 of FIG. 11 provides further de-bouncing of that signal, and will cause a "1" to re-appear on conductor 106. This logic "1" on conductor 106, is applied to the S input of flip-flop 318 and that flip-flop will immediately re-establish logic "1" at its Q output; and NAND gate 286 and driver 288 will discontinue the triggering signal which that driver has been applying to relay 290. Until the "short term" vend signal is discontinued, the vending device will receive and respond to current during each negative-going, as well as during each positive-going, half-cycle of the A.C.; because the relay 290 is able to pass current in both directions.

At the time pin 3 of Port 5 of microprocessor 62 applied a "0" to conductor 106, that microprocessor set a flag in the R1FLG register to indicate that a vending operation had been initiated. Also, it addressed the register in EAROM 142 which stores data representing the number of products--selected by selection switch 240 and vended by vending device 246--which have been vended, and then incremented that data. Further, the microprocessor addressed the register in EAROM 142 which stores data representing the total of all sales of products by the vending machine and then incremented that data by the price of the vended product.

These various actions during step 550 require finite amounts of time; and hence the program will excecute the rest of the steps of FIG. 11, jump to the routine of FIG. 12, via connectives 574 and 576, exit at step 582 via connective 584, and then loop through the routines of FIGS. 10-12. During the last portion of step 550, the program will respond to the flag in the R1FLG register to execute the step 552.

A device, not shown, which is referred to as a data acquisition unit and which is not, per se, a part of the present invention, is mounted within the vending machine and is connected to pins 4 and 7 of Port 5 by conductors 92 and 94 of FIG. 1. That device also is connected to resistor 162 by conductor 163, to the output of opto-coupler 154 by conductor 161, and to plus twelve (+12) volts by conductor 31, all as shown by FIG. 1. A plug and socket 33 are used to connect those conductors to correspondingly-numbered conductors which extend to that device, which is shown and described in Hasmukh R. Shah et al application for Data Acquisition Unit that is filed of even date and that bears U.S. Pat. No. 4,350,238 issued Sept. 21, 1982.

That device receives a serial bit stream on conductor 92 whenever a vending operation is initiated by the application of a logic "0" to conductor 106 of FIG. 6, and thereafter receives a serial bit stream on conductor 94 if that vending operation was not a "free" vending operation. That device will respond to those serial bit streams to record the data represented by the bits of those serial bits streams, to accumulate two sets of totals representing (a) the number of vends initiated by the closing of each selection switch, (b) the total cash represented by those vending operations, and (c) the total cash represented by all of the vending operations initiated by all of those selection switches. Those totals can be printed on a printout at any time by a printer therein. One set of totals is non-resettable, and hence provides an unalterable, running count which can be used for statistical purposes over a long period of time. The other set of totals is re-settable and represents the vending operations and total cash corresponding to vending operations which occurred subsequent to the last printing of totals.

The data acquisition unit has relay contacts therein which normally complete a circuit from opto-coupler 154 to resistor 162 of FIG. 1. However, during the time the printer of the data acquisition unit is printing a printout, those relay contacts will be permitted to open and thereby keep the coin changer of the present invention from accepting further coins. The opening of those contacts provides the same action that is provided when a Line 6 signal is applie to conductor 158.

The reading of the various data in the EAROM and the updating of the corresponding data in the data acquisition unit require finite amounts of time; and hence the program will jump via connective 554--which is entitled CRET0P and which corresponds to line 2665 of the program--and connective 685, respectively, of FIGS. 11 and 18 to the routine of FIG. 18. After executing steps 686 and 688 in the manner described hereinbefore, the program will jump, via connectives 690 and 692, respectively, of FIGS. 18 and 19 to the routine of FIG. 19. During the execution of that routine, the change, if any, that was required as a result of the vending function of step 550 will be dispensed. Thereafter, the program will jump, via connectives 734 and label 508, respectively, of FIGS. 20 and 10, to the routine of FIGS. 10 and 11. During the next execution of step 550, a NO will be produced, because that step has been completed; and hence the program will execute the rest of the steps of FIG. 11, jump to the routine of FIG. 12 via connectives 574 and 576, and then execute step 578 of FIG. 12. A determination will be made, during that step, of whether data is still being read from the EAROM and is still being used to update the data in the data acquisition unit. If that step produces a YES, the program will jump, via connective 582--which is entitled DEBNCE and which corresponds to line 3118 of the program--and label 508 of FIG. 10 to execute the routines of FIGS. 10 and 12, jump to connective 576 of FIG. 12, and again execute step 578. The program will loop in this manner until the comparing function of step 578 provides a NO, and then it will execute steps 580 and 582 to exit at connective 584 and loop through the routines of FIGS. 10-12. At this time, the control device and the vending machine will be in the "standby" condition in the product-vending mode.

Nickels, dimes and quarters can be dispensed from the nickel, dime and quarter tubes, and dollars can be dispensed from the passageway therefor, in response to the pressing of the cancel sale button or in response to a vending transaction wherein the value of inserted coinage exceeds the price of the selected product. If it is assumed that the cancel sale button is pressed, sensor 803 of FIG. 8 will change the state at pin 7 of Port 4; and, during the next executions of steps 510 and 516 of FIG. 10, the difference between the state and states in the Port 4 status register will be stored in the Port 4 change register. During the next execution of step 566 of FIG. 11, a YES will be provided; and then step 678 will change the state of the Q register to the state representing "standby", step 680 will reset the price verification flag in the RFLG register, the CRETP connectives 682 and 684, respectively, of FIGS. 11 and 18 will cause step 686 of FIG. 18 to change the state of the Q register to the state representing "pay", and step 688 will clear the 7-segment displays 232, 234 and 236 of FIG. 3 by causing them to exhibit "0.00". Thereafter, connective 690 of FIG. 18 and connective 692 of FIG. 19, which is entitled PAY and which corresponds to line number 2672 of the program, will initiate step 694 which is entitled PAY OUT DOLLARS IF REQUIRED and which corresponds to lines 2697 through 2702 of the program.

The microprocessor 62 will, in response to the data in the Port 4 status register, cause data corresponding to zero (0) to be loaded into the price register, and then will cause the arithmetic unit thereof to subtract the value of the data in the price register from the value of the data in the credit register, and to store data representing the difference in the credit register. The program will then cause that arithmetic unit to check the data in the dollar coin register. As described hereinbefore, that coin register stores the running count of all inserted dollar coins during one transaction. If the data stored in that register represents zero, then no dollar coin is payed. But if that data stored in that register represents a non-zero number, the arithmetic unit will then load data, representing the value of one dollar ($1) value of the data in the change register, the selector motor 366 of FIG. 9 will be actuated in the dollar-returning direction, but the motor 230 will be left de-energized, all as described in said Johnson application. Also, the value of the data in the change register will be subtracted from the value in the credit register, and the difference will be stored in the credit register. Also the number stored in the dollar coin register will be decremented by one. Thereupon, a dollar will be released from the passageway in which it was being held, and will be directed to the coin cup at the exterior of the vending machine. The arithmetic unit will again check the data in the dollar coin register and if that data represents a non-zero number, it will load data, representing the value of one dollar ($1), into the change register and will compare that data with the new data in the credit register--which represents the difference obtained by subtracted the dollar-value data from the original data in the credit register. If the value of the data in the credit register at least equals the one dollar ($1) value of the data in the change register, the selector motor 366 will again be actuated in the dollar-returning direction, and the motor 230 will again be left-de-energized. Thereupon, a further dollar will be released from the passageway in which it was being held, and will be directed to the coin cup at the exterior of the vending machine. Again, the value of the data in the change register will be subtracted from the value in the credit register, and the difference will be stored in the credit register. Also the number stored in the dollar coin register will be decremented by one. The process of checking the dollar coin register, the loading of the change register with data representing the value of one dollar ($1), the comparing of the value of that data with the value of the data in the credit register, and the dispensing of dollars, will be repeated until the arithmetic unit determines that the number stored in the dollar coin register is zero, or the value of the residual data in the credit register does not at least equal the value of the data in the change register. Thereafter, in the concluding operation of step 694, the selector motor 366 would be actuated in the opposite direction to cause any dollar which might still be in the dollar passageway--because a dollar which was dispensed during the execution of step 694 had been inserted during a vending transaction but had not fallen from the dollar passageway to the cash box--to pass to the cash box of the vending machine.

In the assumed situation where a route man inserted a quarter and then pressed the cancel sale button, the first process of checking the dollar coin register will show that the number in that register is zero, and hence the selector motor 366 will not be actuated. Thereupon any dollar which might still be in the dollar passageway--because a dollar which was dispensed during the execution of step 694 had been inserted during a vending transaction but had not fallen from the dollar passageway to the cash box--would be permitted to pass to the cash box of the vending machine.

In the step 695, which is entitled RESET TUBE EMPTY REGISTERS, the program will cause the 25.cent. tube empty register and 10.cent. tube empty register to be reset to zero. The program will then pass, via label 696, which is entitled PAY CHG. to step 697 which is entitled UPDATE TUBE EMPTY REGISTERS. During this step the bit in the word in the tube level status register which corresponds to the quarter coin tube will be sensed to determine whether that tube is "full". Since a route man customarily "fills" all of the coin tubes before he closes the vending machine, that bit represents that quarter tube is "full" and cause the 25.cent. tube empty register to be set to represent a count of four. In the same step 697 the bit in the word in the tube level status register which corresponds to the dime coin tube will be sensed to determine whether that tube is "full". Since a route man customarily "fills" all of the coin tubes he closes the vending machine, that bit will represent that dime tube is "full" and cause the 10.cent. tube empty register to be set to represent a count of eight.

The program will then pass to step 698 which is entitled IS REMAINING CHG.<25.cent. and which corresponds to lines 2735 through 2756 of the program. During that step, data having a value of twenty-five cents (25.cent.) will be loaded into the change register and then will be compared with the value in the credit register.

In the assumed situation where a route man inserted a quarter and then pressed the cancel sale button, that comparing operation will cause step 698 to provide a NO, because the values of the data in the change register and credit register will be equal. During step 700--which is entitled IS 25.cent. TUBE EMPTY REG.=0? and which corresponds to lines 2762 through 2765 of the program--the comparing function of step 700 will provide a NO, because this register was set to represent a count of four in the step 697. During step 702--which is entitled IS THE 5.cent. TUBE FULL? and which corresponds to lines 2775 through 2777 of the program--the bit in the word in the tube level status register which corresponds to the nickel coin tube will be sensed to determine whether that tube is "full". Since a route man customarily "fills" all of the coin tubes before he closes the vending machine, the comparing function of step 702 will provdie a YES, thereby branching the program to step 706. That step is entitled PAY OUT A QUARTER and it corresponds to line 2792 of the program; and, during that step, the motor 230, the relay coil 808 and the selector motor 366 of FIG. 9 will be energized to effect the dispensing of a quarter from the quarter tube--all as described in said Johnson application. Also, during step 706, the value in the credit register was reduced by twenty-five cents (25.cent.) to reflect the paying out of the quarter. The program will then start the step 707 which is entitled DECR. THE 25.cent. TUBE EMPTY REG. In this step the count in the twenty-five cent tube empty register is decremented by one. At the conclusion of step 707, connective 708, which is entitled PAY CHG. and which corresponds to line 2810 of the program, will cause the program to jump to label 696 of FIG. 19. In the ensuing execution of step 697 the bit in the word in the tube level input status register which corresponds to the quarter coin will be sensed to determine whether that tube is still "full" and if that tube is "full", the twenty-five cent tube empty register will again be set to a count of four. In the execution of the next step 698, data having a value of twenty-five cents (25.cent.) will again be loaded into the change register, and it will be compared with the value in the credit register. In the assumed situation where a route man inserted a quarter and then pressed the cancel sale button, the value of the residual data in the credit register will be zero (0), and hence that comparing operation will cause step 698 to provide a YES. During the next-succeeding step 724--which is entitled IS REMAINING CHG.<10.cent.? and which corresponds to lines 2766 through 2772 of the program--data having a value of ten cents (10.cent.) will be loaded into the change register and then will be compared with the value in the credit register. In the assumed situation where a route man inserted a quarter and then pressed the cancel sale button, the value of the residual data in the credit register will be zero (0) and hence the comparing function of step 724 will provide a YES. Thereupon, during step 730 of FIG. 20--which is entitled IS REMAINING CHANGE=TO0? and which corresponds to lines 2772 and 2818 through 2823 of the program--data having the value of five cents (5.cent.) will be loaded into the change register and then will be compared with the value in the credit register. In the assumed situation where a route man inserted a quarter and then pressed the cancel sale button, the value of the residual data in the credit register will be zero (0), and hence the comparing function of step 730 will provide a YES. Step 732, which is entitled SET MACH. STATE BACK TO STANDBY (STBY) and which corresponds to lines 2976 and 2984 of the program, will change the state of the Q register to "standby". Connective 734--which is entitled DEBNCE and which corresponds to line 3020 of the program which jumps to lines 0799 through 0868 of the program--and label 508 of FIG. 10 will cause the program to loop at steps 510 and 512 until the timer in the latter step times out. Thereafter, the program will loop through the routine of FIGS. 10 and 11, jump to the routine of FIG. 12, and exit from the latter routine via step 582 and connective 584. The program will continue to loop through those routines until a customer inserts money. At this time, the control device and the vending machine are again in the "standby" condition of the product-vending mode.

If the cancel sale button is pressed at a time when the value in the credit register constitutes an integral multiple of twenty five cents (25.cent.), the program will respond to the YES from step 566 of FIG. 11 to execute steps 678 and 680, jump via CRETP connectives 682 and 684, respectively, of FIGS. 11 and 18, execute steps 686 and 688, jump via connectives 690 and 692, respectively of FIGS. 18 and 19, and execute steps 694, 695, 697 and then step 698 to provide a NO. Thereafter, the program will execute steps 700, 702, 706 and 707 in the manner described hereinbefore; and it will effect the dispending of a quarter and the reduction of the value of the data in the credit register by twenty-five cents (25.cent.). Thereafter the program will branch, via connective 708 and label 696, to step 697 of FIG. 19. Further executions of steps 697, 698, 700, 702, 706 and 707 will effect further dispensings of quarters and further subtractings of twenty-five cent (25.cent.) values from the value of the data in the credit register--until a comparison shows that the value of the data in the credit register does not at least equal the twenty-five cents (25.cent.) value in the change register. Thereafter, the YES from step 698, a YES from step 724, and a YES from step 730 of FIG. 20 will enable step 732 to change the state of the Q register to the state representing "standby". The program will then jump, via connective 734 of FIG. 19 and label 508 of FIG. 10 to the routine of FIGS. 10 and 11; and it will loop through that routine and the routine of FIG. 12. At this time, the control device and vending machine will again be in the "standby" condition of the product-vending mode.

In the event the cancel sale button is pressed at a time when the value of the data in the credit register is twenty cents (20.cent.), the YES from step 566 of FIG. 11 will cause the program to execute steps 678 and 680, jump via CRETP connectives 682 and 684, respectively of FIGS. 11 and 18, execute steps 686 and 688, jump via connectives 690 and 692, respectively, of FIGS. 18 and 19, execute steps 694, 695, 697 and 698, and then respond to the YES from the latter step to execute step 724. During that step, data having a value of ten cents (10.cent.) will be loaded into the change register; and a comparison will be made to determine whether the value of the data in the credit register at least equals the value of the data in the credit register. The resulting NO, because the value in the credit register will be twenty cents (20.cent.) and the value in the change register will be ten cents (10.cent.), will cause the program to execute step 714, wherein the count in the ten cent (10.cent. ) tube empty register will be checked to determine whether there are any coins in the dime tube. If that comparison provides a NO, the program will execute step 270 wherein the motor 230 and the selector motor 366 of FIG. 9 will be energized to effect the dispensing of a dime, all as explained in said Johnson application. In addition, the value of the data in the change register will be subtracted from the value of the data in the credit register, and the ten cent (10.cent.) difference will be written into the credit register. The program will then start the step 707 which is entitled DECR. THE 10.cent. TUBE EMPTY REG. In this step the count in the ten cents (10.cent.) tube empty register is decremented by one. Thereafter, the program will jump, via connective 722 and label 696, to step 697. In this step the bit in the word in the tube level input status register which corresponds to the dime coin will be sensed to determine whether that tube is still "full", and if that tube is "full", the ten cents tube empty register will again be set to a count of eight. The program will then cause the execution of step 698. The resulting YES from that step will cause step 724 to again load data having a value of ten cents (10.cent.) into the change register and again compare the value of the data in the credit register with the value of the data in the change register. The resulting NO from step 724 will again cause step 714 to be executed; and, since the ten cents tube empty register is not zero, step 720 will effect the paying out of a second dime, and will again effect the subtraction of the value of the data in the change register from the value of the data in the credit register. The step 721 will cause the count in the ten cent tube empty register to be decremented by one. The program will then jump, via connective 722 and label 696, to step 697 and then 608. The resulting YES will co-act with a YES from step 724--because the dispensing of two dimes reduced the value of the data in the credit register to zero (0)--will cause the program to execute step 730 of FIG. 20. The resulting YES from that step will cause the program to execute step 732 and then jump, via connective 734 of FIG. 20 to label 508 of FIG. 10--with subsequent looping of the program through the routines of FIGS. 10 and 12. Again, the control device and vending machine will be in the "standby" condition of the product-vending mode.

If the cancel sale button is pressed at a time when the value of the data in the credit register equals ten cents (10.cent.), the program will effect the dispensing of a dime in the manner in which that program effected the dispensing of the first dime in response to the closing of the cancel sale button when the value of the data in the credit register equalled twenty cents (20.cent.). Also, the value of the data in the change register will be subtracted from the value in the credit register to produce a zero (0)--in the same manner in which the value in the change register was subtracted from the ten cents (10.cent.) value corresponding to the second dime to produce a zero (0). During the subsequent execution of each of the steps 697, 698, 724 and 730 of FIGS. 19 and 20 a YES will be obtained; and hence step 732 will change the state of the Q register to the state representing "standby". Thereafter, the program will execute the routines of FIGS. 10-12 and again be in its "standby" condition in the product-vending mode.

If the cancel sale button is pressed at a time when the value of the data in the credit register equals fifteen cents (15.cent.), the YES from step 566 in FIG. 11 will cause the program to execute steps 678 and 680, jump via CRETP connectives 682 and 684, respectively, of FIGS. 11 and 18, execute steps 686 and 688, jump via connectives 690 and 692, respectively, of FIGS. 18 and 19, execute steps 694, 695, 697, 698, 724, 714, 720 and 721 in the manner described hereinbefore in the dispensing of the first dime when the cancel sale button was pressed when the value in the credit register equalled twenty cents (20.cent.). The execution of those steps will effect the dispensing of a dime and a reducing of the value in the credit register by ten cents (10.cent.) to five cents (5.cent.). Thereafter, the program will jump via connective 722 and label 696, to steps 697, 698 and 724. The resulting YES from step 724 will cause the program to execute step 730 of FIG. 20, wherein data having a value of five cents (5.cent.) will be loaded into the change register, and a comparison will be made between the value of the data in the credit register and the nickel value in the change register. That comparison will cause step 730 to provide a NO; and, thereupon step 726--which is entitled PAY OUT A NICKEL and which corresponds to lines 2792 through 2794 of the program--will cause motor 230 of FIG. 9 to be energized while both selector motor 366 and relay coil 808 are left de-energized. A nickel will then be dispensed in the manner described in said Johnson application. Also, during step 726, the value of the data in the change register will be subtracted from the value of the data in the credit register to make the latter value zero (0). The program will then jump, via connective 728--which is entitled PAY CHG. and which corresponds to line 2810 of the program--to label 696. The succeeding execution of each of steps 697, 698, 724 and 730 will provide a YES; and step 732 will change the machine state back to the state representing "standby". The subsequent jumping of the program via connective 734 of FIG. 20 to label 508 of FIG. 10 will cause the program to loop through the routines of FIGS. 10-12; and, again, the control device and the vending machine will be in their "standby" conditions in the product-vending mode.

In the event the cancel sale button is pressed at a time when the value of the data in the credit register equals five cents (5.cent.), the program will effect the dispensing of a nickel in the same manner in which the program effected the dispensing of a nickel when the cancel sale button was pressed while the value of the data in the credit register was fifteen cents (15.cent.). Also, the nickel value of the data in the change register will be subtracted from the nickel value of the data in the credit register to provide zero (0). Thereafter, the program will execute steps 697, 698, 724, 730 and 732 of FIGS. 19 and 20, and then jump to label 508 of FIG. 10 to resume the looping through the routines of FIGS. 10-12. Once again, the control device and the vending machine will be in the "standby" condition in the product-vending mode.

The cancel sale button can be pressed at times when widely-different values will be stored in the credit register; and hence the control device can be required to dispense many different combinations of coins to enable patrons to receive coinage which aggregates the value of the inserted coinage. In each instance, the control device will attempt to dispense the fewest number of coins which can aggregate the value of the inserted coinage.

In the foregoing Operation Of Selection Switches section, it was pointed out that the microprocessor 62 applies a logic "0" to conductor 106 when it determines that the value of the data in the credit register at least equals the value of the data in the price register. Thereafter, a delay of about one-half of a second is provided to permit any coin which might have been inserted by a customer but had not yet been sensed by the corresponding one of sensors 149, 486, 520 and 574 of FIG. 8, to reach that sensor so its value would be added to the value of the data in the credit register. At the end of that delay, the arithmetic unit will subtract the value of the data in the price register from the value of the data in the credit register and then store the data corresponding to the remainder in the credit register. These various actions take place during step 550 of FIG. 11; and, thereafter, step 552--which is entitled UPDATE SALES TOTALIZER and which corresponds to lines 2535 through 2665 of the program--will be executed. During that step a register, which stores the number of vending transactions that effect the dispensing of a product of the type that was just dispensed, will be incremented. Also another register, which stores a running count of the total sales of products of the type that was just dispensed, will be incremented. Moreover, a further register, which stores a running count of the total sales of all products vended by the vending machine, will be incremented. In addition, serial bit streams will be applied to conductors 92 and 94 of FIG. 1 by pins 2 and 3 of Port 0; and those serial bit streams will be supplied to the data acquisition unit--all as described hereinbefore in the Totalizer section.

At the conclusion of step 552, the program will jump, via connective 554--which is entitled CRETOP and which corresponds to line 2665 of the program--and connective 685 of FIG. 18--which is entitled CRETOP and which corresponds to lines 2480 and 2481 of the program--to step 686 of FIG. 18. The execution of steps 686 and 688 will change the states of the Q register to the state representing PAY, and the displays 232, 234 and 236 of FIG. 3 will be caused to exhibit "0.00", all as described hereinbefore. Connectives 690 and 692, respectively, of FIGS. 18 and 19 will cause the program to execute the routine of FIG. 19.

During step 694, it will be determined whether a dollar should be dispensed, all as described hereinbefore. If a dollar should be dispensed, and if the customer had inserted one or more dollars, step 694 would effect the dispensing of that dollar and the subtraction of a dollar value from the value in the credit register, all as described hereinbefore. If, however, a dollar should be dispensed but the customer had not inserted any dollars, step 694 would not attempt to pay out a dollar and also would not attempt to subtract a dollar value from the value in the credit register.

During steps 697, 698, 700, 702, 706 and 707, it will be determined whether any quarters should be dispensed, all as described hereinbefore. If any quarters should be dispensed, and if the quarter tube has enough quarters therein, steps 697, 698, 700, 702, 706 and 707 will effect the dispensing of those quarters and the corresponding reducing of the value in the credit register, all as described hereinbefore.

During steps 724, 714, 720 and 721, it will be determined whether any dimes should be dispensed, all as described hereinbefore. If any dimes should be dispensed, and if the dime tube has enough dimes therein, steps 724, 714, 720 and 721 will effect the dispensing of those dimes and the corresponding reducing of the value in the credit register, all as described hereinbefore.

During steps 730 and 726 of FIG. 20, it will be determined whether any nickels should be dispensed, all as described hereinbefore. If any nickels should be dispensed, and if the nickel tube has enough nickels therein, steps 730 and 726 will effect the dispensing of those nickels and the corresponding reducing of the value in the credit register, all as described hereinbefore.

Except for the fact that during change-making operations, the values in the credit register represent the differences between the values of the inserted coinage and the prices of the selected products, whereas during cancel sale operations the values in the credit register represent the values of the inserted coinage, the executions of the routine of FIG. 19 during those operations are essentially the same. As a result, the foregoing detailed descriptions of the executions of that routine during cancel sale operations will largely serve to describe the executions of that routine during change-making operations. However, step 704--which is entitled IS REMAINING CHG.=30.cent. OR 40.cent. and which corresponds to lines 2778 through 2782 of the program--is seldom, if ever, executed during cancel sale operations, but can be executed from time to time during change-making operations.

If the level of nickels in the nickel tube falls far enough for the sensor 308 of FIG. 8 to supply an "empty" signal to pin 4 of Port 1, the next execution of steps 510 and 516 of FIG. 10 will recognize and respond to that fact; and then step 556 of FIG. 11 will provide a YES. Similarly, if the level of dimes in the dime tube falls far enough for the sensor 310 of FIG. 8 to supply an "empty" signal to pin 5 of Port 1, the next execution of steps 510 and 516 of FIG. 10 will recognize and respond to that fact; and then step 556 of FIG. 11 will provide a YES. In either event, step 558 of FIG. 11--which is entitled TURN ON EXACT CHANGE LAMP and which corresponds to lines 0645 through 0650 of the program--will cause pin 1 of Port 5 of microprocessor 62 to apply a signal to conductor 96.

EXACT CHANGE LAMPS are provided for the protection of customers, but many customers do not pay any attention to the illuminating of those lamps. As a result, even though the EXACT CHANGE LAMPS are illuminated, customers frequently insert coinage and seek products which have prices that are below the value of that coinage--thereby requiring the dispensing of change. Some control devices for vending machines will dispense insufficient change if the nickel tubes thereof are empty and if the value of the change is thirty cents (30.cent.) or forty cents (40.cent.). In contrast, the control device of the present invention will dispense exact change even if the required amount of change is thirty cents (30.cent.) or forty cents (40.cent.) and all five (5) of the nickels--which must be in the lower portion of the nickel tube to keep sensor 308 of FIG. 8 from providing an "empty" signal--have been dispensed during prior vending transactions.

For example, if at a time when the nickel tube has no nickels therein but sensor 310 indicates that the dime tube is "full", a customer ignores the EXACT CHANGE LAMP, inserts a dollar coin, and then presses a selection switch calling for the dispensing of a product having a price of sixty cents (60.cent.), the control device will be required to dispense forty cents (40.cent.) as change. Steps 510 and 516 of FIG. 10 and step 562 of FIG. 11 will cause a dollar value to be stored in the credit register. Thereafter, step 550 of FIG. 11 will respond to the closing of the appropriate one of selection switches 240, 242 and 244 to successively (a) draw from EAROM 142 the price data into the price register, (b) compare the value of the data in the credit register with the value of the data in the price register, (c) supply a vend-initiating logic "0" to conductor 106 if the value of the data in the credit register at least equals the value of the data in the price register, (d) update the data in the appropriate registers of step 552, and (e) execute the routine of FIG. 19 to effect the dispensing of change.

The comparing function of step 698 of FIG. 19 will provide a NO, the comparing function of step 700 will provide a NO, and the comparing function of step 702 will provide a NO. Step 704--which is entitled IS REMAINING CHG=30.cent. OR 40.cent. and which corresponds to lines 2778 through 2782 of the program--will cause data having the value of a quarter to be loaded into the change register and also will cause a comparison to be made between that data and the data in the credit register. At this time, the data in the credit register has a value of forty cents (40.cent.); and the comparison will determine that the difference represents a value of fifteen cents (15.cent.); and the resulting YES of step 704 will execute steps 724 and 714. During the latter step, the count in the ten cent tube empty register will be checked, and, since in step 697 it was set to represent a count of ten, the comparing function of step 714 will provide a NO. Thereupon, step 720 will effect the dispensing of a dime, and also will cause the value of that time to be subtracted from the value in the credit register--thereby reducing that value to thirty cents (30.cent.). The step 721 will cause the count in the ten cent tube empty register to be decremented by one. The program will then exit through connective 722 and re-enter at label 696 to again execute steps 697 and 698, 700, 702, 704, 724, 714, 720 and 721. Those steps will again initiate the paying out of a dime and the subtracting of the value of that dime from the value in the credit register--thereby reducing that value to twenty cents (20.cent.). At this time, the program will loop via connective 722, label 696, and steps 697, 698, 724, 714, 720 and 721 to effect the paying out of a third dime and the subtracting of the value of that dime from the value in the credit register--thereby reducing that value to ten cents (10.cent.). Thereupon, the program will again loop via connective 722, label 696 and steps 697, 698, 724, 714, 720 and 721 to effect the paying out of a fourth dime and the subtracting of the value of that dime from the value in the credit register--thereby reducing that value to zero (0). The succeeding looping of the program via connective 722, label 696, steps 697, 698, 724, 730 and 732, connective 734 of FIG. 20 and label 508 of FIG. 10 to step 510 will cause the program to loop at steps 510 and 512 until the timer of the latter step times out. At this time, the control device and vending machine will be in "standby" condition in the product-vending mode.

If, in the preceding example, the price of the selected product had been seventy cents (70.cent.) rather than sixty cents (60.cent.), the comparing function of step 704 would again provide a YES; and steps 724, 714, 720 and 721 would again initiate the dispensing of a dime and the subtracting of the value of that dime from the value in the credit register--thereby reducing that value to twenty cents (20.cent.). The program will then exit through connective 722 and re-enter at label 696 to execute steps 697, 698, 724, 714, 720 and 721. Those steps will again initiate the paying out of a second dime and the subtracting of the value of that dime from the value in the credit register--thereby reducing that value to ten cents (10.cent.). Thereupon, the program will again loop via connective 722, label 696, and steps 697, 698, 724, 714, 720 and 721 to effect the paying out of a third dime and the subtracting of the value of that dime from the value in the credit register--thereby reducing that value to zero (0). The succeeding looping of the program via connective 722, label 696, steps 697, 698, 724, 730 and 732, connective 734 of FIG. 20, and label 508 of FIG. 10 to step 510 will cause the program to loop at steps 510 and 512 until the timer of the latter step times out. At this time, the control device and vending machine will be in "standby" condition in the product-vending mode.

The foregoing illustrations show that instead of dispensing quarters prior to the dispensing of any smaller-denomination coins--as some prior control devices invariably do, the control device of the present invention determines whether the dispensing of quarters prior to the dispensing of any smaller-denomination coins could short-change a customer. If the dispensing of quarters prior to the dispensing of any smaller-denomination coins would not short-change the customer, the control device of the present invention will dispense a quarter as part of the thirty cents (30.cent.) or forty cents (40.cent.) which is to be delivered to the customer. However, if the dispensing of a quarter prior to the dispensing of any smaller-denomination coins could short-change the customer, the control device of the present invention will automatically use dimes to dispense the required thirty cents (30.cent.) or forty cents (40.cent.).

By anticipating the potential loss of a nickel to any customer who is entitled to thirty cents (30.cent.) or forty cents (40.cent.) at a time when the nickel tube is devoid of nickels, and then dispensing the full amount that is due, the control device of the present invention merits the confidence of customers. Also, that control device can provide this desirable result even where the amount due the patron is greater than thirty cents (30.cent.) or forth cents (40.cent.). Thus, if the difference between the credit and the selected price is fifty-five cents (55.cent.) or sixty-five cents (65.cent.), the paying out of a quarter would reduce the amount due to thirty cents (30.cent.) or forty cents (40.cent.)--with consequent potential loss to the customer if the nickel tube was devoid of nickels. As a result, the protections offered by step 704 of FIG. 19 can be of considerable value.

It will be noted that the present invention enables the control device to continue to effect the dispensing of coins from a coin tube during any given coin-dispensing operation even if, shortly after the beginning of that operation, the level of the coins in that tube were to fall below the level at which the sensor for that tube indicates an "empty" condition. This is desirable; because it makes those coins in that coin tube, which are located below the "empty" level, available for change-making purposes--thereby minimizing the dispensing of lower-denomination coins to effect the paying out of the required amount of money. For example, if it is assumed that the quarter tube contains the minimum number, namely five (5), of quarters which is needed to enable sensor 306 to sense a "full" condition, if it is assumed that both the dime and nickel tubes are "full" and if it is assumed that a patron inserts a dollar ($1) and then selects a product priced at twenty-five cents (25.cent.), the execution of step 706 will result in dispensing of the first of the five (5) quarters. In the next step 707 the count in the twenty-five cents tube empty register will be decremented from four to three. Also, the dispensing of the first of the five (5) quarters in the quarter tube will enable sensor 306 to change the state of the signal at pin 6 of Port 1. During the succeeding execution of steps 510 and 516 of FIG. 10, that change of state will be sensed as an "empty" signal, and it will change a particular bit in the tube level status register to represent that the quarters tube in "empty". In the step 697 this bit will cause the twenty-five cents tube empty register to reamin unchanged and then direct the program to steps 698 and 700. The step 700 will determine if the twenty-five cents tube empty register has been decremented to zero. Since in step 707 it was decremented to three and in step 697 it remained unchanged, the step 700 will provide a NO. Thereupon, step 702 will determine whether the nickel tube is full; and, in the assumed situation, the comparing function of that step will provide a YES. Step 706 will then effect the paying out of a quarter even though sensor 306 is providing an "empty" signal and even though step 697 recognized that such a signal had been provided. The program will then loop through steps 697, 698, 700, 702, 706 and 707 to dispense another quarter, thereby providing the required seventy-five cents (75.cent.) in change--even though sensor 306 continued to provide the "empty" signal.

It will be noted that none of the dimes in the dime tube was used to effect the paying out of the seventy-five cents (75.cent.) in change. Further, it will be noted that none of the nickels in the nickel tube was used to effect the paying out of that change. Consequently, the supplies of coins in the dime tube and in the nickel tube were not reduced, and hence will be available for further coin-dispensing operations.

Step 697 anbd 707 of FIG. 19 are provided to permit the continued paying out of quarters in a currently-executed transaction wherein sensor 306 changes the state of pin 6 of Port 1; but steps 697 and 707 will keep more than four (4) quarters from being dispensed during that transaction after that sensor provides the "empty" signal. It is very unlikely that there would ever be a need to pay out more than four (4) quarters during a transaction after sensor 306 has provided an "empty" signal; because if a patron had inserted dollars and then (a) pressed the cancel sale button or (b) selected a product that was inexpensive enough to require more than a dollar in change, one or more of the inserted dollars would be available to provide the required value of returned coins of the required amount of change. Similarly, if a patron inserted a considerable number of quarters and then (a) pressed the cancel sale button or (b) selected a product that was inexpensive enough to require more than a dollar in change, those inserted quarters would be available to provide the required value of returned coins or the required amount of change. However, if a patron had an extremely large number of dimes and nickels, and if he wanted to use them to effect the purchase of a relatively high-priced product and then, after inserting that large number of nickels and dimes, decided to select a product which was offered at a substantially-smaller price, the control device could be called upon to pay out more than four quarters after sensor 306 had provided an "empty" signal. For example, if it was assumed that a patron inserted a dollar and sixty-five cents ($1.65) in dimes and nickels and then pressed a selection button corresponding to a product priced at forty cents (40.cent.), the value which would be stored in the change register would be a dollar and twenty-five cents ($1.25). If, at that time, the quarter tube had only five (5) quarters in it, the first execution of the routine of FIG. 19 would execute steps 697, 698, 700, 702, 706 and 707--with the dispensing of a quarter and with the development of an "empty" signal by the sensor 306. The first execution of step 697 causes the twenty-five cents empty register to be set to the count of four. The next execution of steps 697, 698, 700, 706 and 707 would effect the dispensing of a quarter and a decrementing of the count in the twenty-five cents tube empty register to three. Simimlarly, the next two executions of the routine of FIG. 19 would execute steps 697, 698, 700, 702, 706 and 707 with two (2) further dispensing of quarters and two (2) further decrementings of the count in the twenty-five cent tube empty register. Those four (4) executions of the routine of FIG. 19 would effect (a) the dispensing of four (4) quarters, (b) four (4) decrementings of the count in the twenty-five cent tube empty register. The next execution of the routine of FIG. 19--which would be needed to pay out the remaining twenty-five cents (25.cent.) in change--would include steps 697, 698, 700, 724, 714, 720 and 721 to effect the paying out of a dime; because the twenty-five cents tube empty register would have been decremented to zero, and step 700 will provide a YES. A further execution of the routine of FIG. 19 would include steps 697, 698, 724, 712, 720 and 721 to effect the dispensing of a second dime. The next-to-last execution of the routing of FIG. 19 would include steps 697, 698, 724, 730 and 726 to effect the dispensing of a nickel; and the last execution of that routine would include steps 697, 698, 724, 730 and 732--with consequent setting of the machine state to "standby". It thus should be apparent that the development of an "empty" signal--during a transaction which requires the dispensing of a number of quarters--will not halt the dispensing of quarters. Instead, up to four (4) quarters can be dispensed during that transaction. It should also be apparent that if quarters can no longer be dispensed from the quarter tube, the program will automatically dispense two (2) dimes and a nickel to aggregate the required twenty-five cents (25.cent.).

If a subsequent transaction--which requires the dispensing of a quarter--is initiated before any further quarters are introduced into the quarter tube--by a route man or by the introduction of quarters into the coin slot of the vending machine--no quarters will be dispensed; and, instead, dimes and nickels will be dispensed to provide the money value of coinage that otherwise would be provided by the dispensing of one or more quarters. Specifically, steps 697, 698 and 700 will direct the program to step 724. Steps 714, 720 and 721 will then dispense a dime with a consequent corresponding reduction of the value in the credit register. The program will then cause those steps to dispense a further dime, with a further consequent corresponding reduction of the value in the credit register. The next execution of the routine of FIG. 19 would cause steps 697, 698, 724, 730 and 726 to dispense a nickel, with a consequent corresponding reduction of the value in the credit register. The action of step 697 and 700 of FIG. 19 in distinguishing between an "empty" condition of the quarter tube which develops during a currently-executed transaction and an "empty" condition of that tube which developed during a prior transaction is important; because quarters can be dispensed in the former condition without any risk of short-changing a customer, whereas the dispensing of quarters in the latter condition could easily short-change a customer.

Steps 697 and 721 of FIG. 19 are provided to permit continued paying out of dimes in a currently-executed transaction wherein sensor 310 changes the state of pin 5 of Port 1; but steps 697 and 721 will keep more than eight (8) dimes from being dispensed during that transaction after that sensor provides the "empty" signal. It is very unlikely that there would ever be a need to pay out more than eight (8) dimes during a transaction after sensor 310 provided an "empty" signal; because if a patron had inserted dollars and then (a) pressed the cancel sale button or (b) selected a product that was inexpensive enough to require more than a dollar in change, one or more of the inserted dollars would be available to provide the required value of returned coins or the required amount of change. Similarly, if a patron inserted a considerable number of quarters and then (a) pressed the cancel sale button or (b) selected a product that was inexpensive enough to require more than a dollar in change, those inserted quarters would be available to provide the required value of returned coins or the required amount of change. Further, if a patron inserted a considerable number of dimes and then (a) pressed the cancel sale button or (b) selected a product that was inexpensive enough to require a substantial amount of change, those inserted dimes would be available to provide the required value of returned coins or the required amount of change. However, if a transaction were to occur wherein more than eight (8) dimes should be dispensed after the sensor 310 develops an "empty" signal, steps 697 and 721 will be effective in dispensing only eight (8) dimes after that sensor develops an "empty" signal. For example, if it was assumed that prior transactions had completely emptied the quarter and the dime tubes, and if it was assumed that a customer had inserted five (5) quarters, nine (9) dimes and two (2) nickels and then pressed the cancel sale button, the first execution of the routine of FIG. 19 would execute steps 697, 698, 700, 702, 706 and 707--with consequent dispensing of a quarter, and decrementing of twenty-five cent tube empty register to a count of three. During the second execution of the routine of FIG. 19, step 697 will sense that quarter tube is still "full" and set the twenty-five cent tube empty register to a count of four. Next, steps 698, 700, 702, 706 and 707 will be executed with consequent dispensing of a second quarter, a decrementing of the twenty-five cent tube empty register to a count of three, and the immediate development of an "empty" signal by sensor 306 of FIG. 8. During each of the three (3) succeeding executions of the routine of FIG. 19, steps 697, 698, 700, 702 and 706 would again be executed-- with consequent dispensing of three (3)further quarters, and with three further decrementings of the twenty-five cent tube empty register. During the sixth execution of the routine of FIG. 19, steps 697, 698, 700, 724, 714, 720 and 721 would be executed, because the comparing function of step 700 would provide a Yes. During the execution of that routine, a dime would be dispensed. During the seventh execution of the routine of FIG. 19, steps 697, 698, 700, 724, 714, 720 and 721 would be executed--with consequent dispensing of a second dime, a decrementing of the ten cent tube empty register. During the next six (6) executions of the routine of FIG. 19, steps 697, 698, 700, 724, 714, 720 and 721 would be executed--with consequent dispensing of six (6) dimes, six (6) decrementings of the ten cent tube empty register. During the fourteenth execution of the routine of FIG. 19, steps 697, 698, 724, 714, 720 and 721 would be executed--with consequent dispensing of a ninth dime, an eighth decrementing of the ten cent tube empty resigter. During the fifteenth execution of the routine of FIG. 19, steps 697, 698, 724, 714, 730 and 726 would be executed, because the comparting function of step 714 would provide a YES. During the execution of that routine, a nickel would be dispensed. During the sixteenth execution of the routine of FIG. 19, steps 697, 698, 724, 730 and 732 would be executed--with consequent dispensing of a second nickel.

The foregoing illustration shows that the control device of the present invention (a) makes it possible to continue to pay out quarters during a transaction even after the sensor 306 of FIG. 8 has developed an "empty" signal during that transaction, (b) limits the number of such after-"empty" quarters to four (4) and then automatically causes any further credit to be met by dimes or nickels, (c) makes it possible to continue to pay out dimes during a transaction even after the sensor 310 of FIG. 8 has developed an "empty" signal during that transaction, and (d) limits the number of such after-"empty" dimes to eight (8) and then automatically causes any further credit to be met by nickels. As a result, that control device provides a large change-making capability.

A control device for vending machines customarily is equipped with "inventory" switches--usually one switch for each coin tube. Further, these "inventory" switches usually are single function switches. The present invention makes it possible to use just two (2) "inventory" switches to control the dispensing of coins from three (3) coin tubes, and also enables either or both of those "inventory" switches to perform dual functions, namely, placing the control device in the price verification mode, and controlling the emptying of the coin tubes.

The slide 608 preferably is identical to the correspondingly-numbered slide of the said Johnson application. When that actuator is in position to close only switch 150, that switch will apply a signal to pin 2 of Port 0 of microprocessor 62. During the next execution of steps 510, 516 and 534 of FIG. 10, the change in the state of that pin will be sensed. During step 570 of FIG. 11, a comparing function will determine whether either or both of the switches 150 and 152 is closed; and, in the assumed instance, step 570 will provide a YES. The program then will jump via connectives 634 and 636, respectively, of FIGS. 11 and 16, to the routine of FIG. 16. During the execution of step 638, the price verification flag is set; and during steps 640 and 642 nickels will be paid out as long as switch 150 is held closed. In this way, the closing of that switch initiated two functions.

When the actuator 608 is in position to close only switch 152, that switch will apply a signal to pin 3 of Port 0 of microprocessor 62. During the next execution of steps 510, 516 and 538 of FIG. 10, the change in the state of that pin will be sensed. During step 570 of FIG. 11, a comparing function will determine whether either or both of the switches 150 and 152 is closed; and, in the assumed instance, step 570 will provide a YES. The program then will jump via connectives 634 and 636, respectively, of FIGS. 11 and 16, to the routine of FIG. 16. During the execution of step 638, the price verification flag is set; and during steps 640 and 642, dimes will be paid out as long as switch 152 is held closed. In this way, the closing of that switch initiated two functions.

When the actuator 608 is in position to close both switches 150 and 152, those switches will apply signals to pins 2 and 3 of Port 0 of microprocessor 62. During the next execution of steps 510, 516 and 538 of FIG. 10, the changes in the states of those pins will be sensed. During step 570 of FIG. 11, a comparing function will determine whether either or both of the switches 150 and 152 is closed; and, in the assumed instance, step 570 will provide a YES. The program then will jump via connectives 634 and 636, respectively, of FIG. 11 and 16, to the routine of FIG. 16. During the execution of step 638, the price verification flag is set; and during steps 640 and 642 quarters will be pair out as long as switches 150 and 152 are held closed. In this way, the closing of those switches initiated both functions. Moreover, in this way, the present invention makes it possible to use just two (2) switches to effect the selective dispensing of three-individually different kinds of coins from three individually-different tubes. Such an arrangement not only saves a further connection to microprocessor 62, but it obviates a need for a third switch and the cost and size requirements which such a switch would entail.

Whenever the control device and program are to be used with a mechanical slug rejector, a driver 133 will have the input thereof connected to pin 6 of Port 0 of microprocessor 62. A pull-up resistor 135 will be connected between the input of that driver and plus five (+5) volts. Conductor 83 will extend from the output of that driver to the CREM for that slug rejector.

When that control device and the vending machine, with which it is used, are in the "standby" condition in the product-vending mode, pin 6 of Port 0 of microprocessor 62 will apply a signal to the driver 133, and that driver will energize the CREM to permit the insertion and acceptance of authentic coins of desired denominations. However, during a vending operation, during a cancel sale operation, or during a change-making operation--when it is not desirable for coins to be accepted--pin 6 of Port 0 will not supply that signal to driver 133; and hence the CREM will be de-energized. At such time, even authentic coins of desired denominations will not be accepted. Step 530 of FIG. 10 will, during each execution of the routine of FIGS. 10 and 11, make certain that the CREM is in its proper condition.

The control device and the program can be used with mechanical slug rejectors or with electronic slug rejectors--each of which receives, and determines the denominations of, various combinations of nickels, dimes, quarters and dollar coins. A mechanical slug rejector utilizes a CREM to selectively reject all inserted coins before they can be fully tested by that slug rejector; but an electronic slug rejector can test all inserted coins and then utilize an accept-reject gate to effect the acceptance of acceptable coins. Where the control device and the program are to be used with an electronic slug rejector, the switch chip 416, the capacitor 420, the sensors 574, 520, 486 and 149, the resonating capacitors 444, 448, 452 and 456, and the resistors 446, 450, 454 and 458 of FIG. 8 will be deleted, and conductors 108, 110, 112 and 114 will be connected directly to the outputs of the electronic slug rejector. Also, the sensor 803, resonating capacitor 472 and resistor 474, or counterparts thereof, will be mounted on the board of the electronic slug rejector, and conductor 122 will be disconnected from switch chip 418 and grounded. In addition, the driver 133 of FIG. 1 will be removed, and sensor 802, or its counterpart, will be connected to circuitry which will be connected directly to pin 6 of Port 0 of microprocessor 62. That sensor and circuitry will respond to the pressing of the cancel sale button to apply a signal to that pin. Also, pin 6 of Port 0 will be directly connected to the circuitry of that electronic slug rejector.

The electronic slug rejector will respond to the insertion of authentic dollar coins, quarters, dimes and nickels to supply signals to pins 0 through 3 of Port 1 of microprocessor 62 in the same way in which sensors 149, 486, 520, 574 and switch chip 416 respond to the insertion of such coins to supply signals to those pins. As a result, where the control device and the program are used with an electronic slug rejector, rather than with a mechanical slug rejector, the execution of the various routines of FIGS. 10 through 20 will, with the exception of steps 526 and 530 of FIG. 10 and step 566 of FIG. 11, be identical. Where the control device and program are used with a mechanical slug rejector, step 526 will always provide an essentially-immediate output which will cause the program to execute step 530. Where, however, that control device and program are used with an electronic slug rejector, step 526 will sense the state of pin 6 of Port 0 to determine whether that pin is being used to send a signal to the circuitry of the electronic slug rejector to keep that electronic slug rejector from accepting further coins. If that pin is not being so used, step 526 will respond to that state as indicating whether the cancel sale button has been pressed--setting an appropriate flag if that button has been pressed. If, at the time step 526 is initiated, pin 6 of Port 0 is being used to send a signal to the circuitry of the electronic slug rejector to keep that electronic slug rejector from accepting further coins, a check will be made of the Port 0 status register to determine whether the cancel sale button had been pressed after the last execution of step 526 but before pin 6 of Port 0 was used to send the signal to the circuitry of the electronic slug rejector to keep that electronic slug rejector from accepting further coins. Thereafter, a flag will be set in that appropriate register to indicate whether the check of the Port 0 status register had indicated a pressing of the cancel sale button.

Step 530 will, when the control device and program are used with an electronic slug rejector, operate somewhat differently than it will when that control device and program are used with a mechanical slug rejector. Specifically, it will supply a signal on pin 6 of Port 0 which is connected to the circuitry of the electronic slug rejector. A logic "0" on that pin will be used by that electronic slug rejector to keep the accept-reject gate in reject position and logic "1" will be used by that electronic slug rejector to energize that solenoid if inserted coin is acceptable.

Step 566 will, when the control device and program are used with an electronic slug rejector, operate somewhat differently than it will when that control device and program are used with a mechanical slug rejector. Specifically, it will sense for the presence of the flag which might have been set during step 526 of FIG. 10. When the control device and program are used with a mechanical slug rejector, the state of pin 6 of Port 1 is directly sensed. However, by using the conductor, which connects pin 6 of Port 0 to sensor 803, to connect that pin to the circuitry of the electronic slug rejector to keep that electronic slug rejector from accepting further coins, the present invention obviates the need of an additional conductor.

Referring particularly to FIGS. 23 and 24, portions of a control device, for a vending machine which responds to the pressing of selection switches to display the prices corresponding to those selection switches, are shown. Those portions illustrate how credit, corresponding to the values of inserted coins is exhibited. Also, FIGS. 23 and 24 illustrate a simple and direct way of placing that control device in a price verification mode, and additionally illustrate a simple and direct way of taking that control device out of that mode and placing it in the product-vending mode.

The numerals 150 and 152 denote inventory switches that preferably are identical to the similarly-numbered switches of FIG. 1. The numerals 902, 908 and 920 denote HEX tri-state buffers, which preferably are identical to the buffer 136 of FIG. 1; and conductors 900, 906 and 918 connect the outputs of comparators, not shown, such as comparators 340 and 408 of FIG. 4, to the clocking inputs of those buffers. All of the data inputs of those buffers are connected to six-position dip switches 904, 910 and 922, of standard and usual design, which have the outputs thereof connected to a six-bit price bus 952. Pull up resistors 924 are connected to the six (6) conductors of that bus, and are connected to plus five (+5) volts. The numeral 914 denotes additional HEX tri-state buffers, the numeral 916 denotes additional six-position dip switches, and the numeral 912 denotes additional conductors which are connected to the outputs of additional comparators.

The numeral 932 denotes a standard and usual binary counter, which has its outputs connected to a six-bit credit bus bar 953. That counter has an OR gate 931 connected to it; and one input of that gate is connected to the output of inverter 296 of FIG. 5, and the other input of that gate is connected to conductor 122 of FIG. 8. That conductor also is connected to the lower input of a five-input OR gate 934. Conductors 108, 110, 112 and 114 of FIG. 8 are connected to the other four inputs of OR gate 934; and conductor 108 is directly connected to the input of counter 932, but conductor 110 is connected to that input by a pulse generator 926 which will supply two (2) pulses to that input when it receives an input from conductor 110. Conductor 112 is connected to the input of counter 932 by a pulse generator 928 which will supply five (5) pulses to that input when it receives an input from conductor 112; and conductor 114 is connected to that input by a pulse generator 930 which will supply twenty (20) pulses to that input when it receives an input from conductor 114.

Pull up resistors 938 and 940 connect the inputs of a NAND gate 936 to plus five (+5) volts. An inverter 942 connects the output of NAND gate 936 to the upper input of an AND gate 946, the middle input of that AND gate is connected to the Q output of a set-reset flip-flop 944, and the lower input of that AND gate is connected to conductor 124 of FIG. 8. A conductor 947 extends from the output of OR gate 934 of FIG. 23 to the select input of MUX 948. The numeral 948 in FIG. 24 denotes two Motorola 4053 multiplexer/de-multiplexers (hereafter MUX); and the output of AND gate 946 is connected to the "select" input thereof. The output of that MUX is connected, by a six-bit bus bar 949 to a gate array 950 which consists of three MMI PAL10H8 Dual Octo Ten-Input AND/OR Gate Arrays. The numerals 236, 234 and 231 denote seven-segment displays which preferably are identical to the similarly-numbered displays of FIG. 3.

In its normal state, the MUX 948 will connect the six-bit bus bar 953 to six-bit bus bar 949, while simultaneously disconnecting six-bit bus bar 952 from six-bit bus bar 949. The insertion of coins will cause conductor 108, conductor 110 and pulse generator 926, conductor 112 and pulse generator 928, and conductor 114 and pulse generator 930 to supply signals to counter 932. Those signals will represent the values of inserted coins; and the gate array 950 of FIG. 24 will cause the sum of those values to be exhibited by the displays 236, 234 and 232.

When a customer presses one of the selection switches, not shown, of the control device, the corresponding one of the buffers 902, 908, 914 and 920, and the corresponding one of the six-position dip switches 904, 910, 916 and 922, will apply a code to six-bit bus bar 952 which will represent the price of the desired object. Thereupon, a comparator, not shown, of standard and usual type, which senses the price-based signals on six-bit bus bar 952 and the credit-based signals on six-bit bus bar 953, will (a) determine whether the value of the credit at least equals the value of the price, and (b) initiate a vending of the desired product if that value does at least equal the value of the price. At this time the control device of FIGS. 23 and 24 will be, and will operate, in the product-vending mode.

To place the control device of FIGS. 23 and 24 in the price verification mode, a route man will close one or the other of switches 150 and 152 of FIG. 23 by moving the actuator 608. Thereupon, a zero (0) will be applied to the corresponding input of NAND gate 936; and will thereby cause a "1" to appear at the S input of flip-flop 944. The logic "0" at the Q output of that flip-flop will change to a "1". NAND gate 936 and inverter 942 will apply a "0", to the upper input of AND gate 946, which will continue as long as either or both of switches 150 and 152 are closed. Payout motor 230 of FIG. 9 will respond to the closing of either or both of switches 150 and 152 to become energized, and to rotate the gears connected to its rotor, thereby causing sensor 312 of FIG. 8 to apply a "0" to the lower input of AND gate 946 via conductor 124.

At this time the AND gate 946 will have only one logic "1" at its input; and hence that AND gate will apply a logic "0" to the select input of MUX 948. Because that 948 must receive a logic "1" at its select input to connect the six-bit bus bar 952 to the six-bit bus bar 949, and because those six-bit bus bars must be connected to each other to place the control device in the price verification mode, that control device will not, at this time, be able to enter the price verification mode. Consequently, it will be noted that closing switches 150 and 152 will not immediately place the control device in the price verification mode.

When both of the switches 150 and 152 are permitted to re-open, inverter 942 will again apply a "1" to the upper input of AND gate 946. When the motor 230 completes its cycle and comes to rest, conductor 124 will again apply a "1" to the lower input of that AND gate. At this time, the Q output of flip-flop 944 will still be applying a "1" to the middle input of AND gate 946; and hence that AND gate will apply a "1" to the select input of MUX 948 via conductor 947. That MUX will then connect the six-bit bus bar 952 to six-bit bus bar 949 while disconnecting six-bit bus bar 953 from the latter bus bar. At this time, the control device will be in the price verification mode.

That control device will automatically be changed from the price verification mode to the product-vending mode as soon as a coin is inserted or the cancel sale button is pressed. Specifically, as soon as a signal appears on any of the conductors 108, 110, 112 or 114, due to the insertion of a nickel, dime, quarter or dollar, the OR gate 934 will respond to that signal to re-set flip-flop 944. The resulting "0" at the Q output of that flip-flop will cause a "0" to appear at the output of AND gate 946, and hence at the select input of MUX 948. Thereupon, the six-bit bus bar 953 will be connected to six-bit bus bar 949, and six-bit bus bar 952 will be disconnected from the latter six-bit bus bar. At this time, the control device and the vending machine will again be in the product-vending mode.

In this simple and direct way, without any requirement of a microprocessor or program, the control device can be placed in the price verification mode and then removed from that mode. As in the case of the control device of FIGS. 1 through 20, the present invention ideally arranges an operation which the route man should perform, namely, the closing of one of the switches 150 and 152, so it is automatically performed during an operation which the route man must perform, namely, the emptying of the coin tubes. Additionally, the present invention ideally precludes the performance of an operation which should be performed, namely, the verification of prices, until a prior operation which must be performed, namely, the re-opening of switches 150 and 152, has been completed. Moreover, the present invention obviates all of the initial cost of an extra switch, all of the cost of wiring such a switch into the circuit, and all of the problems of servicing and maintaining such a switch.

Referring particularly to FIG. 25, a simple circuit is shown for placing the control device of a vending machine in the price-setting mode and then taking that control device out of that mode. Switches 185 and 183 are identical to the similarly-numbered switches of FIG. 1. The left-hand terminals of those switches are connected to ground, and the right-hand terminals thereof are connected to the lower inputs of NAND gates 970 and 972. The outputs of those NAND gates are connected, respectively, to the UP and DOWN inputs of an UP DOWN counter 974 of standard and usual design. Pull up resistors976 and 978 are connected, respectively, between the right-hand terminals of switches 185 and 183 and plus five (+5) volts. The upper inputs of NAND gates 970 and 972 are connected to an oscillator 980 which supplies signals at a frequency of two hertz (2 Hz).

The numerals 184 and 182 denote switches which preferably are identical to the similarly-numbered switches in FIG. 1. The left-hand terminals of those switches are connected to ground; and the right-hand terminals of those switches are connected, respectively, to the lower inputs of NAND gates 984 and 986. The outputs of those NAND gates are connected, respectively, to the UP and DOWN inputs of an UP DOWN counter 990 of standard and usual design. Pull up resistors 977 and 979 are connected, respectively, between the right-hand terminals of switches 184 and 182 and plus five (+5) volts. The middle inputs of NAND gates 984 and 986 are connected to oscillator 980. Although different counters could be used as the UP DOWN counters 974 and 990, it is preferred to use two CD 4029A counters as each of those counters.

The numeral 992 denotes an R/W 256X8 RAM, which has an eight-bit bus bar 996 connected to it. Although various RAMs could be used, it is preferred to use two Motorola 5101 RAMs as the RAM 992. A back-up battery 993, of standard and usual design, is connected to that RAM. The numeral 994 denotes a decoder to which the eight-bit bus bars 996 and 998 are connected. Although various decoders could be used, eight MMI PAL10H8 dual octal 10 input AND/OR gate arrays are preferred. The eight-bit bus bar 996 is connected to the output of UP DOWN counter 974; and the eight-bit bus bar 998 is connected to the inputs of a tri-state buffer 999 and also to the outputs of a tri-state buffer 1000. Although different buffers could be used as the buffers 999 and 1000, Motorola 14503 buffers are preferred. An eight-digit display 1002 can, and preferably will, be the same as the display 168 of FIG. 2; and an eight-bit bus bar 993 is connected between a decoder 994 and that display.

The numeral 1004 denotes a one-shot multivibrator, of standard and usual design, which has the input thereof connected to the output of NOR gate 1008. The inputs of that gate are connected to the right-hand terminals of switches 184 and 182. An eight-bit bus bar 1010 connects the output of UP DOWN counter 990 to the inputs of register 1000. An eight-bit bus bar 1011 connects the outputs of register 999 to the UP DOWN counter 990. An AND gate 1005 has one input thereof connected to the output of NAND gate 1008, and has the other input thereof connected to the output of inverter 1001. The output of that AND gate is connected to the R/W input of RAM 992. The input of inverter 1001 is connected to the output of the multivibrator 1004; and the output of that inverter also is connected to the enable input of register 1000. The output of that multivibrator also is connected to the enable input of register 999 and to the upper inputs of NAND gates 984 and 986.

A NAND gate 1012 has two of the four inputs thereof connected to the right-hand terminals of switches 184 and 182, and has the other two inputs thereof connected to the right-hand terminals of switches 185 and 183. The output of that NAND gate is connected to the S input of a set-reset flip-flop 1014; and the Q output of that flip-flop is connected to the enable input of the display 1000 by a conductor 1018. An OR gate 1016 has four of the inputs thereof connected to conductors 108, 110, 112 and 114 of FIG. 8, and has the other input thereof connected to conductor 122. The output of that OR gate is connected to the R input of flip-flop 1014.

Because the inverting functions of NAND gates 970, 972, 984 and 986 occur at the inputs of those gates, a "1" at any input will provide a "0" output, and all inputs must be "0" to provide a "1" output. Because the inverting functions of NAND gates 1008 and 1012 occur at the inputs of those gates, a "0" at any input will provide a "1" output, and all inputs must be "1" to provide a "0" output.

Closing of switch 185 will apply a "0" to the lower input of NAND gate 970 and also to the the lower input of NAND gate 1012. During the next time the oscillator 980 applies a "0" to the upper input of that NAND gate, that gate will apply a "1" to the UP input of counter 974, and will thereby cause that counter to increment the line number. NAND gate 1012 will respond to the "0" from switch 185 to apply a "1" to the S input of flip-flop 1014, and will cause that flip-flop to apply a "1" to the ENABLE input of display 1002. The output of counter 974 will be applied to decoder 994 and also to RAM 992. At this time, the location in that RAM which corresponds to the incremented line number will be addressed; and the data in that location will be decoded by decoder 994 and supplied to the display 1002. Consequently, the actuation of switch 185 effected an incrementing of the selection line number and also effected the displaying of that line number and of the corresponding data. As long as that switch is held closed, oscillator 980 will cause the line number to be changed twice each second, and will cause the corresponding data to be decoded by decoder 994 and exhibited by the display 1002. This is due to the fact that the "1"'s from that oscillator will disable NAND gate 970, and will thereby simulate the opening of switch 185.

If switch 183 is closed, NAND gate 1012 will receive a "0" and apply a "1" to the S input of flip-flop 1014; and NAND gate 972 will respond to the "0" from switch 183 and the next "0" from oscillator 980 to supply a "1" to the DOWN input of counter 974--with decrementing of the line number and with consequent exhibiting of that decremented line number and of the corresponding data on display 1002. As long as that switch is held closed, oscillator 980 will cause the line number to be changed twice each second, and will cause the corresponding data to be decoded by decoder 994 and exhibited by the display 1002. This is due to the fact that the "1"'s from that oscillator will disable NAND gate 972 and will thereby simulate the opening of switch 183.

If switch 184 is closed, NAND gate 1012 will respond to the resulting "0" to apply a "1" to the S input of flip-flop 1014. NAND gate 1008 will respond to the "0" from that switch to apply a "1" to the upper input of AND gate 1005 and to the input of multivibrator 1004. The resulting "1" at the output of that multivibrator will enable buffer 999, will disable NAND gates 984 and 986, and will cause inverter 1001 to provide a "0" which will disable AND gate 1005 and buffer 1000. Because the AND gate 1005 is unable to develop a "1" at its output, RAM 992 will continue to be in its "read" mode. The buffer 999 will respond to the data which is addressed in the RAM to load that data into the UP DOWN counter 990, thereby initializing that counter. When the multivibrator 1014 "times out", the resulting "0" at its output will no longer enable buffer 999; and hence the data at the input of that buffer will no longer be applied to UP DOWN counter 990. Inverter 1001 will apply a "1" to AND gate 1005 which will cause that AND gate to supply a "1" to the R/W input of RAM 992 to place that RAM in its "write" mode. The "0" which multivibrator 1004 applies to the upper input of NAND gate 984 will coact with the "0" from switch 184 and the next "0" from oscillator 980 to cause that NAND gate to apply a "1" to the UP input of counter 990. Thereupon, that counter will increment--by a five cent (5.cent.) value--the data which was loaded into it by RAM 992 and buffer 999. Also, the "1" at the output of inverter 1061 will enable buffer 1000; and that buffer will respond to the incremented data within the UP DOWN counter 990 to write that incremented data into the RAM, and also to cause decoder 994 to decode that data and apply it to display 1002. The "1" from the Q output of flip-flop 1014 will effect the exhibiting of that data. In this way, the closing of switch 184 enabled the data which corresponded to the currently-addressed location in the RAM 992 to be loaded into the UP DOWN counter 990, to be incremented by a five cent (5.cent.) value, to be written back into that location in incremented form, and to be exhibited by the display 1002. As long as that switch is held closed, oscillator 980 will cause the data in the currently-addressed RAM location to be changed twice each second, and will cause that changed data to be written into that RAM location and decoded by decoder 994 and exhibited by display 1002. In this way, the data corresponding to the currently-addressed RAM location can be progressively incremented.

If switch 182 is closed, NAND gate 1012 will apply a "1" to the set input of flip-flop 1014. NAND gate 1008 will respond to the "0" from that switch to apply a "1" to the upper input of AND gate 1005 and to the input of multivibrator 1004. The resulting "1" at the output of that multivibrator will enable buffer 999 and disable NAND gates 984 and 986, and it will cause inverter 1001 to disable AND gate 1005 and buffer 1000. The data in the currently-addressed RAM location will be loaded into the UP DOWN counter 990 by buffer 999; and then, as the multivibrator 1004 times out, the resulting "0" at its output will disable buffer 999, will coact with the next "0" from oscillator 980 to cause NAND gate 986 to apply a "1" to the DOWN input of UP DOWN counter 990, and will cause inverter 1001 to apply an enabling "1" to AND gate 1005 and buffer 1000. The " 1" at the DOWN input of counter 990 will decrement--by a five cent (5.cent.) value--the data that was loaded into that counter by buffer 999. Thereafter, that decremented value will be written into the RAM location by buffer 1000, and also will be decoded by decoder 994 and applied to display 1002 by bus bar 993. The "1" from the Q output of flip-flop 1014 will cause display 1002 to exhibit the corresponding value. As long as that switch is held closed, oscillator 980 will cause the data in the currently-addressed RAM location to be changed twice each second, and will cause that changed data to be written into that RAM location and decoded by decoder 994 and exhibited by display 1002. In this way, the data corresponding to the currently-addressed RAM location can be progressively decremented.

It will be noted that the circuit of FIG. 25 permits the control device to be placed in its price-setting mode in a simple and direct manner. Further, that circuit enables any desired location within the RAM to be addressed, and then have the data therein incremented or decremented to any desired value. That control device is automatically taken out of its price-setting mode by releasing the switches 185, 183, 184 and 182.

If desired, a digital technique, rather than the analog technique of FIGS. 4 and 5, could be used to provide narrow and wide current pulses for the solid state relay 290. Specifically, the microprocessor 62 could load a first scratch pad register with data representing seven and eight-tenths millisecond (7.8 ms) and then sense a positive-going zero crossing of the A. C. to start decrementing that data. When that data had been decremented to zero (0), a logic "0" would be applied to pin 3 of Port 5, and that "0" would be inverted and applied directly to the input of gate 286 of FIG. 4. About four-tenths of a millisecond (0.4 ms) later, a further scratch pad register, which had been loaded with data corresponding to eight and two-tenths milliseconds (8.2 ms) would "time out", and would change the "0" at pin 3 of Port 5 back to a "1". Because each half-cycle of the A. C. has a duration of about eight and three-tenths milliseconds (8.3 ms), that driver would apply a triggering pulse to relay 290 which would terminate before the negative-going zero crossing of the A. C. In this way, a four-tenths millisecond (0.4 ms) current pulse would be applied to relay 290 during each positive-going half-cycle but would be terminated before the end of that half-cycle.

The four-tenths millisecond (0.4) ms current pulse would be supplied to the relay 290 during each positive-going half-cycle of the A.C. until a selection switch was closed. Thereafter, the microprocessor would compare the price of the product selected by the closing of that selection switch with the inserted credit to determine whether that credit at least equalled that price. If that microprocessor determined that the credit at least equalled the price, data representing four and three-tenths milliseconds (4.3 ms) would be loaded into the first scratch pad register and then the next positive-going zero crossing of the A. C. would be sensed to start the decrementing of that data. When that data had been decremented to zero (0), a logic "0" would be applied to pin 3 of Port 5; and that "0" would be inverted and applied directly to the input of driver 288 of FIG. 4. The resulting current pulse would be applied to relay 290 through the rest of that half-cycle, so that current pulse could continue throughout the immediately-following negative-going half-cycle. The overall width of the resulting current pulse would be about twelve milliseconds (12 ms); and such a pulse would be long enough to actuate the corresponding vending device but would be short enough to prevent overheating of the solid state relay 290 or that vending device.

The numeral 60 denotes a switch which can be closed to place the control device in a "declining balance" mode. That mode has been used in a number of coin changers, and hence is not unique. The closing of that switch enables the control device to permit varying numbers of products to be selected and vended--as long as the price of any selected product is matched or exceeded by the un-used credit. The operation of the control device in the "declining balance" mode is provided for in lines 2535 through 2665 of the program.

The attached program enables the control device to provide a considerable number of operations and functions which are not shown on the flow chart of FIGS. 10 through 20. Those operations and functions are of the type generally performed by coin changers and control devices for vending machines, and they are performed in a manner known to those skilled in the art. As a result, those operations and functions are not parts of, and are not necessary for an understanding of, the present invention.

The control device of the present invention is particularly adapted for use with slug rejectors that respond to U.S. coins and is particularly adapted for use with coin-dispensing devices that accommodate U.S. coins. However, that control device can be used with slug rejectors and coin-dispensing devices that respond to, and that accommodate, coins of different nations.

Whereas the drawing and accompanying description have shown and described different embodiments of the present invention, it should be apparent to those skilled in the art that various changes could be made in the form of the invention without affecting the scope thereof. ##SPC1## ##SPC2## ##SPC3## ##SPC4## ##SPC5## ##SPC6## ##SPC7## ##SPC8## ##SPC9##