Flowchart-based control system with active diagnostic objects

[0001] This application claims the benefit of U.S. Provisional Application No. 60/310,257, filed Aug. 6, 2001, which is hereby incorporated by reference.

[0002] The present invention relates to programming and control systems. More particularly, this invention relates to flowchart-based programming and control systems that include active diagnostic objects.

[0003] Programming and control systems are generally used for controlling processes that involve devices such as relays, solenoids, motors, valves, switches, and other electrical and electromechanical devices. The processes that are controlled include machining, drilling, welding, spraying paint, mixing materials, assembling parts, handling materials, and other similar processes.

[0004] Conventional programming and control systems generally employed ladder diagrams and relay ladder logic (RLL) to control the operation of the devices that are associated with the processes. In practice, however, programmers tend to use a flowchart to initially define the operation of the devices in the process. Then, the programmers manually translated the flowchart into the ladder diagrams. The programmers employ the flowcharts as a first step because the flowcharts emulate human thought processes whereas the ladder diagrams do not. Subsequently, developers created programming and control systems that control the process directly from the flowchart logic. One flowchart-based system is disclosed in Continuous Flowchart, Improved Data Format and Debugging System For Programming and Operation of Machines, U.S. Pat. No. 4,852,047, which is hereby incorporated by reference.

[0005] Flowcharts generally include action blocks that represent an operation or action based on current input and output data. Action blocks generally have one entry point that is usually located at the top and one exit point that is usually located at the bottom. A branching or decision block is a diamond-shaped block that represents a branch in the control path based on the results of a decision. Decision blocks generally have one entry point that is usually located at the top and two exit points that are usually located at the side and the bottom. Using combinations of the action and decision blocks, a programmer creates a flowchart that controls one or more devices that are associated with a process.

[0006] Even though the flowchart object code functions correctly, there are other problems that should be diagnosed quickly to maximize process output. For example, in a material handling process, a continuous material supply may stop supplying material. If the process runs continuously, it can be several hours before an operator notices.

[0007] A machine programming and control system according to the present invention includes a computer with a processor, memory and a display and a device that is associated with a process. A flowcharting module executed by the computer generates and edits a flowchart that contains action and decision blocks that define logic for operating the device to further the process. The flowcharting module allows active diagnosis objects to be associated with at least one of the action and decision blocks.

[0008] In other features, the active diagnosis objects facilitate diagnosis of non-coding process problems. The active diagnosis objects include an icon that is added to the flowchart to visually identify the active diagnosis object. Alternately, the active diagnosis object includes a visual identification selected from the group of special fonts, shading, boldfacing, italicizing and underlining to visually identify the active diagnosis object.

[0009] In yet other features, the active diagnosis object automatically initiates a message when the action or decision block is executed. The message includes at least one of an e-mail, a pager message, an operator alert and an alarm.

[0010] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

[0011] The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0012] FIG. 1 is a functional block diagram of an exemplary process for illustrating the present invention;

[0013] FIG. 2 is a functional block diagram of a flowchart-based programming and control system according to the invention;

[0014] FIG. 3 is a more detailed functional block diagram of the flowchart-based programming and control system of FIG. 2;

[0015] FIG. 4 illustrates a graphical user interface (GUI) screen view of an exemplary flowchart that is generated by the flowchart-based programming and control system and that includes active diagnostic objects that are added to the flowchart according to the invention;

[0016] FIG. 5 illustrates a scrolled view of the GUI screen view of the exemplary flowchart of FIG. 4; and

[0017] FIG. 6 illustrates an exemplary dialog box for setting active diagnostic object properties.

[0018] The ensuing detailed description provides preferred exemplary embodiments only and is not intended to limit the scope, applicability or configuration of the present invention. Rather, the ensuing detailed description of the preferred exemplary embodiments will provide those skilled in the art with an enabling description for implementing the preferred exemplary embodiments of the present invention. It being understood that various changes may be made in the function and arrangement of the elements without departing from the spirit and scope of the invention as set forth in the appended claims.

[0019] Active diagnostic objects according to the invention are provided in the flowchart of a machine programming and control project to facilitate diagnosis of problems in a machine programming and control process. The active diagnostic objects automatically send e-mails, pager messages, and operator alerts to notify the appropriate personnel that the process is operating in a particular mode. Active diagnostics decrease the amount of time that is required to identify problems with the process other than flowchart coding bugs. Active diagnostics also improve process uptime.

[0020] Referring now to FIG. 1, an exemplary process 10 will be employed to illustrate the invention. The process 10 heats and mixes two materials until their conductivity reaches a pre-selected conductivity. Then, the process delivers the materials to a holding tank. The process 10 includes a supply 12 for a first material and a supply 16 for a second material. A first solenoid valve 20 is positioned in line with a conduit 22 to control the delivery of the first material. A second solenoid valve 26 is positioned in line with a conduit 28 to control the delivery of the second material. The first and second solenoid valves 20 and 26 are operated electronically. A fan 30 includes fan blades 32 and a fan motor 36.

[0021] A material container 40 contains the first and second materials 41 that have been delivered by the first and second supplies 12 and 16. A first mixer 42 includes a first mixer motor 44 and a first mixing device 45 that is located inside the container 40. A second mixer 46 includes a second mixer motor 48 and a second mixing device 50 that is also located inside the container 40 on an opposite side of the container 40. A conductivity sensor 54 is located inside the container 40 in fluid contact with the first and second materials 41. A temperature sensor 56 is likewise located inside the container 40 in fluid contact with the first and second materials 41.

[0022] A furnace 60 is positioned adjacent to the container 40 and is connected to a gas supply 64. The furnace 60 heats the first and second materials. The furnace 60 includes a solenoid valve 66 for supplying gas to the furnace 60. The furnace 60 includes a pilot 68 and an ignition device 70 that lights the pilot when triggered by an electronic signal. A pilot sensor 72 generates a signal indicating whether a pilot flame is present or absent. A conduit 76 is connected to the container 40 and a finished product container 80. A solenoid valve 78 controls movement of fluid between the containers 40 and 80. After mixing and heating the two materials, a finished product is delivered to the finished product container 80 by actuating the solenoid valve 78.

[0023] Referring now to FIG. 2, a flowchart-based programming and control system is illustrated at 110. The programming and control system 110 includes a computer 116, a display 118, an input/output card (I/O) 120 and one or more I/O devices such as a keyboard 124 and/or a mouse 126. The I/O card 120 is connected to a communications network 130. The I/O card 120 can be an Ethernet card and the communications network 130 can be an Ethernet network. Skilled artisans can appreciate that other I/O cards and communications networks can be employed without departing from the spirit of the invention.

[0024] The communications network 130 is connected to the first and second mixers 42 and 46 (both of which are identified at 140 in FIG. 2). The communications network 130 is similarly connected to the fan 30, the pilot sensor 72, the ignition device 70, the temperature sensor 56, the conductivity sensor 54, one or more relays 144, one or more switches 146, and the solenoid valves 20, 26 and 66 (collectively identified at 148). The flowchart-based programming and control system 110 allows a user to create a flowchart 149 that includes active diagnostic objects as will be described further below.

[0025] Referring now to FIG. 3, the flowchart-based programming and control system 110 is illustrated in further detail. The computer 116 includes an I/O interface 150 that is connected to a processor 152 and memory storage 154 that can include floppy drives, hard drives, optical storage, etc. Memory 160 is connected to the processor 152 and the I/O interface 150. The memory 160 includes random access memory (RAM) and read only memory (ROM). When the computer 116 is booted up, the computer 116 loads an operating system (OS) module 170 which is preferably a multi-tasking OS, such as Windows 95, Windows 98, Windows 2000, Windows NT), and Windows NTE.

[0026] After being selected and launched by the user, the computer 116 loads a flowchart module 174 into memory 160. As a user creates a flowchart, the flowchart module 174 generates flowchart source code 178 that can be stored in memory 160 or memory 154. When the user validates and debugs the flowchart source code 178, the user compiles the flowchart source code 178 and generates flowchart object code 180 that is executed by a flowchart run time engine 186 during operation of the process 10. During creation or editing of the flowchart 149, the user adds active diagnostic objects as will be described below. The I/O interface 150 can also be connected to a local area network (LAN) 196, a wide area network (WAN) 197, and one or more other I/O devices 198 such as scanners, printers, etc.

[0027] Referring now to FIG. 4, the exemplary flowchart 149 is created using a pull-down menu 204, toolbar 210, and tools 212 and using a cursor 213 that is moved using the keyboard 124 and/or the mouse 126. Scroll bars 214 and 216 allows a user to navigate a flowchart design window 218. The exemplary flowchart 149 includes enable blocks, decision blocks, and action blocks.

[0028] Control begins at enable block 300 where variables are initialized. For example, Flag A and Flag B are set equal to zero. Control continues with decision block 302 where control determines whether a first switch is on. If the first switch is not on, control turns on a flasher at action block 304 and control returns to step 302. Otherwise, control continues with action block 306 where control turns on a relay associated with the furnace 60 and a relay associated with the mixer 42. Control waits five minutes at wait block 307 until the furnace 60 is operating and the mixer 42 has had sufficient time to mix the first and second materials. Then, control continues with decision block 310 where control determines whether Flag A is equal to one. If Flag A equals one, control turns on an alarm relay (not shown in FIG. 1) in step 311. Otherwise, control continues with decision block 312 where control determines if the temperature of the first and second materials 41 is less than 80 F. If the temperature is less than 80, control continues with decision block 314 where control determines whether a pilot is present by scanning an output of the pilot sensor 72.

[0029] If the pilot is not present, control turns on the pilot using the ignition device 70, waits five minutes at wait block 317, and then returns to step 310. Otherwise, control continues with action block 318 where control turns off the furnace 60, the mixer 42, and the first switch, sets Flag A equal to 1, and continues with step 310.

[0030] If the temperature is greater than 80 F., control continues with decision block 326 where control determines whether the conductivity of the first and second materials 41 is less than 0.8 and a Flag B is equal to zero. If not, control continues with action block 330 where control turns on a relay associated with the second mixer 46, and sets the Flag B equal to one. In wait block 331, control waits 2 minutes. Control continues with decision block 334 where control determines whether the conductivity of the materials 41 is less than 0.8. If it is, control continues with step 338 where control turns on the solenoid valve 20 that is associated with the first material supply 12. Control waits two minutes in wait block 339. Control turns off the solenoid valve 20 and the relay that is associated with the second mixer 46 in action block 340 and continues with step 310. Otherwise, control continues with step 341 where control turns off the relay associated with the second mixer 46.

[0031] Referring now to FIG. 5, if the conductivity is greater than 0.8 or the flag is equal to zero, control continues from step 326 to step 350 where control determines if the conductivity is less than 0.8 and the flag equals one. If both conditions are met, control continues with step 352 where control shuts down the furnace relay, the mixer relay, and the first switch and continues with step 310. Otherwise, control continues with step 356 where control determines whether the temperature of the first and second materials 41 is greater than 110 F. If the condition is true, control continues with action block 360 where control turns on a fan relay to start the fan 30 to cool the first and second materials 41 and waits four minutes in wait block 361.

[0032] Control continues with decision block 362 where control determines whether the temperature still exceeds 110 F. If not, control turns off the fan relay associated with the fan 30 and continues with step 310. Otherwise, control continues with step 368, where control turns off the furnace relay, the mixer relay, and the first switch, sets Flag A equal to one, and continues with step 310. If the temperature does not exceed 110 F. in step 356, control continues with decision block 372 where control determines whether the first switch is off. If it is, control continues with action block 376 where control turns off the furnace relay and the mixer relay. Control turns on the fan relay associated with the fan 30. Control waits five minutes in wait block 377. Control turns off the fan relay in action block 378 and continues with step 302. Otherwise, control continues with step 310.

[0033] Referring now to FIG. 6, an active diagnostic object dialog box 550 that is provided by the flowchart module 174 is illustrated. The active diagnostic object dialog box 550 allows programmers to associate action or decision blocks with active diagnostic objects. The active diagnostic object dialog box 550 is actuated by left clicking on the action and/or decision block with the mouse or by using the pull-down menu 204, the toolbar 210 and/or the tools. The active diagnostic object dialog box 550 includes an e-mail option that is selected using a check box 552, a pager option that is selected using a check box 554 and an operator alert option that is selected using a check box 556. Other suitable options will be apparent to skilled artisans. The user selects one or more of the check boxes 552, 554, and 556 for initiating an active diagnosis action.

[0034] The e-mail check box 552 is located within a frame 558 that contains an address text box 560 for entering an e-mail address of a user who is paged when the action or decision block with the active diagnostic object is executed. ActiveX components are preferably employed to execute the selected diagnosis action. A text box 564 allows a user to enter a textual message that forms part of the e-mail that is sent to the designated e-mail address that is specified in the address text box 560. A lookup command button 566 triggers a dialog box for looking up e-mail address from a contact list such as Microsoft Outlook or other similar contact lists. The flowchart programming and control system 110 can also include stand-alone contact lists.

[0035] The pager check box 554 is contained in a frame 568. A phone number text box 570 contains a phone number of the pager that is to be paged when an action or decision block that contains the active diagnostic object is executed during runtime. A text box 574 contains a message that is to be sent along with the page. A lookup command button 576 allows a user to look up pager numbers from a contact list such as Microsoft Outlook or other similar contact lists. The operator alert check box 556 is located within a frame 580 that includes a device name text box 584 for specifying a device such as a light or a buzzer that is associated with the flowchart programming and control system and that is used to alert an operator. The device name text box 584 can be a combo box or drop-down list for selecting devices that are associated with the flowchart programming and control system 110. A lookup command box 590 allows a user to lookup devices that are associated with the flowchart programming and control system 110. Command buttons 592, 594 and 596 perform conventional OK, cancel, and clear functions.

[0036] Special fonts, shading, boldface, italicized or underlined typefaces, icons or other techniques are used to visually identify action or decision blocks that are associated with active diagnostic objects. Alternately, icons such as icons 600, 602 and 604 in FIGS. 4 and 5 can be added and placed adjacent the action or decision block that triggers the active diagnostic object. If the icons 600, 602 and/or 604 are employed, the active diagnostic object dialog box 550 preferably includes an icon selection box and an input for identifying the action or decision block that triggers the active diagnostic object. The active diagnostic objects are preferably implemented using ActiveX components. In other words, when action or decision blocks are executed and are associated with active diagnostic objects, the ActiveX component is automatically executed. Preferably, the icon illustrates the type of diagnosis action that is to be performed. For example, the icon 600 illustrates an alarm action, the icon 602 illustrates an e-mail action, and the icon 604 illustrates a pager action. Skilled artisans can appreciate that other formats for adding diagnostic objects can be employed without departing from the present invention.

[0037] Active diagnostic objects according to the invention are provided in the flowchart of a machine programming and control project to facilitate diagnosis of problems in a machine programming and control process. The active diagnostic objects automatically send e-mails, pager messages, and/or operator alerts to notify the appropriate personnel that the process is operating in a particular mode. Active diagnostics objects decrease the amount of time that is required to identify problems with the process other than flowchart coding bugs. Active diagnostics also improve uptime of the process.

[0038] Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the present invention can be implemented in a variety of forms. Therefore, while this invention has been described in connection with particular examples thereof, the true scope of the invention should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, the specification and the following claims.