Method and Apparatus for Alarm Signal Processing

This application make reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. .sctn.119 from an application entitled APPARATUS AND METHOD FOR ALARM SIGNAL PROCESSING earlier filed in the Korean Industrial Property Office on 18 Aug., 1995 and assigned Ser. No. 25486/1995.

1. Field of the Invention

The present invention relates to a remote-controlled safety control system, and more particularly to a method and apparatus for informing an operator of the correct status upon the activation of an alarm.

2. Description of the Related Art

Generally a remote-controlled safety control system is used for crime prevention, disaster prevention, and gas leak detection, and for continuous sensing for changes in other unattended operations, and an operator is needed for the maintenance of the system. U.S. Pat. No. 4,092,643 entitled Security Device, U.S. Pat. No. 4,160,246 entitled Wireless Multi-Head Smoke Detector System, U.S. Pat. No. 4,994,787 entitled Remote Intrusion Alarm Condition Advisory System, and U.S. Pat. No. 5, 422,626 entitled Electrical Monitoring System for example, each endeavor to construct wireless remote control alarm systems. Since these conventional remote-controlled control systems are usually equipped merely with a line-printer and a cathode ray tube for maintenance, an operator can not recognize the correct cause of an alarm activation and even may not realize that an alarm activation has occurred if the operator stays at locations, such as a night-duty room other than a control room.

Accordingly, it is an object of the present invention to provide an improved alarm signal processing method and apparatus.

It is another object to provided process and apparatus for informing an operator with an alarm signal through an external speaker for the maintenance of a remote-controlled safety control system.

It is still another object to provide a process and apparatus able to continually assure transmission of an alarm signal to a human operator, independently of the location of the operator relative to the apparatus. To achieve these and other objects, the invention provides a remote safety control system that analyzes alarm signals from subscriber lines to generate alarm data, analyzes alarm signals from safety monitoring lines to generate alarm data, checks related X.25 processors periodically to generate alarm data in case of the need of a service call, and generates an alarm by sending alarm data over a serial communication line.

A more complete appreciation of the invention, and many of the attendant advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, wherein:

FIG. 1 is a block diagram of maintenance apparatus constructed in accordance with the principles of the present invention, which is used in conjunction with a remote-controlled monitoring system;

FIG. 2 is a flowchart illustrating an operation of processing an alarm signal according to the principles of the present invention; and

FIG. 3 is a flowchart illustrating a timer interrupt processing routine for the practice of the present invention.

Turning now to the drawings, FIG. 1 is a block diagram of a maintenance apparatus constructed according to the principles of the present invention, used in conjunction with a remote-controlled monitoring system. A central processing unit, CPU 10 (e.g.--an 8-bit microprocessor such as part No. 80C31BH from the INTEL Corporation) has three I/O ports, an interrupt port, a reset port, a control port, and a transmission and reception port (T.times.D and R.times.D). An I/O port 1 is a data bus line connected to a random access memory RAM 12a and a read only memory ROM 12b of a memory unit 12. Data is exchanged through this data bus line 1. An I/O port 2 is an address line used for RAM and ROM from A0 to A13 by buffer control (not shown). An I/O port 3 is used for controlling relay driver 14 to display alarm status. A reset unit 26 is connected to the reset port of CPU 10. The reset unit 26 is divided into a power-on reset and a manual reset, and resets the CPU 10 when reset time T.sub.c is approximately 326.65 ms. An interrupt unit 24 connected to the interrupt port of CPU 10 is an alarm sound cut-off interrupt, uses chatter elimination elements to enable an operator to turn an alarm on and off. The relay driver 14 receives alarm control signals and an alarm-on display signal from CPU 10, and then turns on four photoMOS relays 16.

FIG. 2 is a flowchart illustrating an operation of processing an alarm signal according to the practice of the present invention. In FIG. 2, alarm signals from subscriber lines are analyzed to generate alarm data, alarm signals from safety monitoring lines are analyzed to generate alarm data, related X.25 processors (not shown) are checked periodically to generate alarm data in case of a service call, and an alarm is activated by sending the alarm data over a serial communication line.

FIG. 3 is a flowchart illustrating a process control operation of the timer interrupt routine according to the practice of the present invention. For a use in monitoring periods, a timer interrupt processing routine controls a counter and flags: the count in the counter is increased by one every ten millisecond interval; a 200 ms-flag is set to "1" whenever the counter counts to 20; a 1500 ms-flag is set to "1" each time the counter counts to 150.

The CPU 10 accepts received information from an information transceiver 30, or checks related X.25 processors at short intervals (about every twenty seconds) to directly collect alarm signals. The collected alarm signals are transmitted to the relay driver 14 through an RS232C standard port at 9600 bps using a predetermined protocol. The CPU 10 receives an alarm signal by an interrupt from the interrupt unit 24, and then stores the alarm signal in internal buffers. The alarm signal is analyzed for 100 ms in the next monitoring period. The stored alarm signal is analyzed if the 1500-milliseconds flag is "1" in the monitoring period. Upon the completion of the alarm signal analysis, the relay controller 14 controls the photoMOS relays 16 to control light emitting diodes 22: in case of the service request, the corresponding light emitting diode is turned on; the corresponding light emitting diode is turned off in case the automatic recovery mode is the selected mode; if the selected mode is the manual recovery mode, the corresponding light emitting diode is not turned off. However, the 200 ms-flag is set to "1" at an interrupt generated when the manual recovery mode is converted to the automatic recovery mode, so that the light emitting diode is turned off as the value stored in the internal buffers. Referring now to FIG. 2, once the system is turned on and the program is activated, the CPU 10 initializes the stored data and the state of input and output of the relay driver 14 in step 101, and activates the ten milliseconds timer. Then, CPU 10 increases the count in the counter every ten milliseconds in step 201 of FIG. 3, and if the counter reaches a count of 20, then proceeds to step 203 to set the 200 ms-flag to "1". When the counter reaches a count of 150 in step 204, CPU 10 proceeds to step 205 and set the 1500 ms-flag to "1". In addition, when the counter reaches a count of 300 in step 206, the 3000 ms-flag is set to "1". The CPU 10 checks the counter during monitoring periods to determine whether the 200 ms-flag is set to "l". The CPU 10 turns on the light emitting diodes to display the operating state the first time that the 200 ms-flag is set to "1", and activates the relay driver 14, the second time that the 200 ms-flag is set to "1", to turn off the light emitting diodes. In step 104, the CPU 10 determines whether the automatic recovery mode is the selected mode, and proceeds to step 105 if the automatic recovery mode is the selected mode. The CPU 10 checks for service requests in step 105, and if there is any service request, proceeds to step 106 to turn on light emitting diodes 22 in the alarm apparatus 32 in order to indicate the service request. The CPU 10 checks the 1500 ms-flag to determine whether it is "1" in step 107, and then proceeds to step 108 if the 1500 ms-flag is set to "1". In step 109, the CPU 10 checks alarm data for disorders and if there is no disorder, proceeds to step 113. In step 113, the CPU 10 determines whether there is any disorder recovery alarm, and proceeds to step 114 if there was any disorder recovery alarm. In step 114, the CPU 10 determines whether the system is in the automatic recovery mode, and proceeds to step 115 if the system is in automatic recovery mode. In step 115, the CPU 10 drives the alarm apparatus 32 to turn off light emitting diodes 22. If there is any disorder in step 109, then CPU 10 proceeds to step 110 and drives the alarm apparatus 32 to turn on light emitting diodes 22. The CPU 10 determines whether any alarms for audible alarm processing occurred in step 116, and then proceeds to step 117 if there are any alarms for audible alarm processing. In step 117, the CPU 10 determines whether the system is in a speaker enabled mode and if the system is in a speaker disabled mode, proceeds to step 118, and then turns off the speaker. If the speaker mode is the speaker enabled mode however, then the CPU 10 turns on the speaker to generate alarm sounds in step 119. In step 111, the 3000 ms-flag is checked for whether it is set to "1", and if it is set to "1", the program proceeds to step 112 for transmission of a program alive signal, and returns to the main flowchart after the transmission. The speaker and the display unit can be located in a night-duty room or an office, so that an operator can operate the system.

As discussed previously, in the present invention, upon the system disorder, the operator for the system maintenance is informed of alarm signals through the speaker and can maintain the safety monitoring system properly, even when staying in a night-duty room located far from the office where the host computer is installed.

It should be understood that the present invention is not limited to the particular embodiment disclosed herein as the best mode contemplated for carrying out the present invention, but rather that the present invention is not limited to the specific embodiments described in this specification except as defined in the appended claims.