JPH06350728A - Automatic reporting device - Google Patents

Abstract

PURPOSE:To prevent an incorrect report to a managing center from being originated by inhibiting the transmission of a reporting signal for a prescribed time by using a delay circuit when any fault is generated at the abnormality reporting device provided with a fault recovery function in a microcomputer. CONSTITUTION:When a microcomputer 2 is turned to a fault state by thunder or noise, a detection circuit 3 sends a detecting signal 31 to a reset circuit 4, and the microcomputer 2 is reset. During this processing, the incorrect report is prevented from being sent by inhibiting the transmission of a report signal St through a report circuit 6 to the managing center for a prescribed time by using a delay circuit 5. When the microcomputer 2 is restored normally and there is no abnormality, a sensor 1 does not generate a signal 11, but when there is any abnormality, the report signal St is generated and the abnormality is reported to the managing center after the lapse of a prescribed time. Thus, the incorrect report can be prevented from being transmitted to the managing center when the fault state is generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic notification device that automatically notifies a management center when an abnormality in a monitored system is detected.

[0002]

2. Description of the Related Art Conventionally, a gas leak alarm that sends a gas leak detection signal to a microcomputer when a gas leak is detected, a microcomputer that sends a notification signal when a gas leak detection signal is input, and a notification signal are sent. 2. Description of the Related Art There is known an automatic notification device including a notification circuit that notifies a management center via a public telephone line when input.

[0003]

However, the microcomputer may fail due to lightning or noise, and when the microcomputer goes into a fault state, no notification is given even if the gas leak alarm detects the gas leak.

To solve this problem, the inventor, as shown in FIG. 5, uses a microcomputer 102 incorporating a watchdog timer 101 to check whether or not the watchdog pulse 103 is normally transmitted. An automatic notification device E having a fault recovery function, which is constantly monitored by the fault detection circuit 104 and, when a fault state is detected, is reset by the reset circuit 105 to return the microcomputer 102 to a normal state, was prototyped.

However, in the automatic notification device E,
When the microcomputer 102 goes into a fault state, the notification signal 107 may remain output regardless of the presence or absence of the gas leak detection signal 106, and the notification circuit 108 notifies the management center before resetting. .

An object of the present invention is to prevent an erroneous notification from being made to the management center when a fault occurs in an automatic notification device having a fault recovery function that resets the microcomputer to normal when a fault condition is detected. There is something to do.

[0007]

[Means for Solving the Problems] In order to solve the above problems,
The present invention includes a monitoring means for monitoring the state of a system to be monitored, a watchdog timer for transmitting a watchdog pulse, and a microcomputer for transmitting a notification signal when the monitoring means detects an abnormality in the system to be monitored. A fault detection circuit that determines that the microcomputer has failed when the watchdog pulse is no longer sent normally; a reset circuit that resets the microcomputer when the fault detection circuit detects a fault of the microcomputer; In an automatic notification device having a notification circuit for reporting an abnormality of a monitoring system to a management center, the notification circuit reports to the management center until a predetermined time elapses from the time when the microcomputer starts transmitting the notification signal. Delay to avoid doing Adopting a structure in which a road.

[0008]

[Operation] [When the microcomputer is operating normally] When the monitored system is normal, the monitoring means does not detect an abnormality, the microcomputer does not send a notification signal, and the notification circuit does not notify the management center. .

When the monitored system becomes abnormal, the monitoring means detects the abnormality and the microcomputer sends a notification signal.

With the delay circuit, the notification circuit does not notify the management center until a predetermined time elapses from the time when the microcomputer starts transmitting the notification signal. Notify the management center that there is an abnormality.

[When the Microcomputer Fails] Since the microcomputer does not normally output the watchdog pulse, the fault detection circuit detects the fault of the microcomputer and the reset circuit resets the microcomputer.

Even if the notification signal remains for a short time from the time of the fault to the time when it is returned to the normal state by the reset, the delay circuit does not give an error notification to the management center.

When the microcomputer returns to normal by the reset, if the monitored system is normal, no notification signal is sent, so no notification is sent to the management center. If there is an abnormality in the monitored system, a notification signal is sent. A notification is sent to the management center after a predetermined time has passed from the time of sending.

[0014]

[Effects of the Invention] Even if the notification signal remains for a short time from the time of the fault to the time when it is reset and returns to normal, the delay circuit outputs the notification signal. Since the notification circuit does not notify the management center until a predetermined time has elapsed from the time when the transmission is started, the management center will not be erroneously notified when a fault occurs.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIG. The automatic notification device A is the monitoring means of the present invention, and is a gas leak sensor 1 for monitoring gas leaks of gas equipment (not shown), a microcomputer 2 incorporating a watchdog timer 21, and a fault of the microcomputer 2. A fault detection circuit 3 for detecting a failure, a reset circuit 4 for resetting the microcomputer 2, a delay circuit 5 for delaying transmission of the notification signal St, and a notification circuit 6 for reporting a gas leak to a management center (not shown). With.

The gas leak sensor 1 is installed near the ceiling near the gas equipment, detects a gas leak by a metal oxide semiconductor, and outputs a gas leak detection signal 11 to the microcomputer 2 when the gas leak is detected.

When the gas leak detection signal 11 is input, the microcomputer 2 sends a notification signal St to the delay circuit 5. Further, the microcomputer 2 incorporates a watchdog timer 21 for sending out a watchdog pulse (square wave) 211 having a cycle of 0.2 seconds by software.

The microcomputer 2 may be faulted by lightning, noise or the like. In the fault state, the watchdog timer 21 does not output the watchdog pulse 211, regardless of the gas leak detection signal 11, the notification signal St. Keeps coming out or not at all.

The fault detection circuit 3 comprises a digital logic IC and a clock pulse generation circuit for generating a clock pulse having a short pulse width and a longer period than the watchdog pulse 211.

The fault detection circuit 3 determines whether or not the watchdog pulse 211 is normally transmitted based on the clock pulse and the watchdog pulse 211.
When it is determined that the microcomputer 2 has not normally transmitted, it is considered that the microcomputer 2 has faulted, and the fault detection signal 31 (high level signal) is transmitted to the reset circuit 4.

The reset circuit 4 composed of FETs and the like,
When the fault detection signal 31 is input, the reset terminal 2
2 is temporarily set to low level and the microcomputer 2
Reset.

The delay circuit 5 is normally in a non-conducting state between the input and the output, and further, 3 times from the time of inputting the notification signal St.
For 0 seconds, the report signal S is maintained by continuing the non-conduction state between input and output.
The transmission of t to the notification circuit 6 is prohibited.

The notification circuit 6 is composed of a PB signal generation circuit or the like. When the notification signal St is input, the notification circuit 6 reports the gas leak of the gas equipment to the management center via the public telephone line.

Next, the operation of the automatic notification device A will be described. [When the microcomputer 2 is operating normally]
When the gas equipment does not leak gas, the gas leak sensor 1 does not send the gas leak detection signal 11, the microcomputer 2 does not send the notification signal St, and the notification circuit 6 does not notify the management center.

When a gas leak occurs in the gas equipment, the gas leak sensor 1 sends a gas leak detection signal 11 to the microcomputer 2, and the microcomputer 2 sends a notification signal St.
To the delay circuit 5.

When 30 seconds have elapsed since the notification signal St was input, the input and output of the delay circuit 5 become conductive, and the notification signal St sent from the microcomputer 2 is transmitted to the notification circuit 6.

The reporting circuit 6 reports to the management center via the public telephone line that the gas equipment is leaking gas.

[When the Microcomputer Faults] The microcomputer 2 causes the watchdog pulse 2
Since 11 is no longer sent normally, the fault detection circuit 3
Detects a fault of the microcomputer 2 and sends a fault detection signal 31 to the reset circuit 4, and the reset circuit 4 resets the microcomputer 2.

By resetting from the time of the fault,
Even if the notification signal St is left for a short time until the microcomputer is restarted, the delay circuit 5 is in a non-conducting state between the input and the output.
The t is not transmitted to the notification circuit 6, and the notification circuit 6 does not cause an erroneous notification to the management center.

When the microcomputer 2 returns to normal by resetting and there is no gas leak, the notification signal St is not sent and no notification is sent to the management center.

If there is a gas leak, the notification signal St is transmitted, and 30 seconds after the notification signal St is transmitted, the input and output of the delay circuit 5 become conductive and the notification signal St is transmitted to the notification circuit 6. The reporting circuit 6 reports to the management center via the public telephone line that the gas equipment is leaking gas.

The advantages of this embodiment will be described below. [A] The microcomputer 2 is in a fault state due to lightning or noise, and even if the notification signal St is left for a short time from the time of the fault until it is reset and returns to normal, the notification signal St is input. 3 from the time
Since the input / output of the delay circuit 5 is non-conductive for 0 seconds, the notification signal St is not input to the notification circuit 6 and the management center is not notified. Therefore, the management center is not mistakenly notified when a fault occurs. .

(Ii) When the microcomputer 2 is in a fault state due to lightning or noise, the fault detection circuit 3 detects the fault, and the reset circuit 4 resets the microcomputer 2 to restore the normal state. Therefore, even if the gas leak sensor 1 detects the gas leak during the fault of the microcomputer 2, the problem that the notification circuit 6 does not notify the management center does not occur.

Even the automatic notification device B (second embodiment of the present invention) as shown in FIG. 2 has advantages similar to those of the automatic notification device A. Normally, the delay circuit 5 of the automatic notification device B is in the grounded state, and when the notification signal St is input, the circuit is continuously grounded for 30 seconds and the transmission of the notification signal St to the notification circuit 6 is prohibited. Then, after 30 seconds, the grounded state is released.

Even the automatic notification device C (third embodiment of the present invention) as shown in FIG. 3 has advantages similar to the automatic notification device A. The delay circuit 5 of the automatic notification device C does not normally send the notification signal Sj, and when the notification signal St is input, the delay circuit 5 continues to be in the transmission prohibited state of the notification signal Sj for 30 seconds. The notification signal Sj generated by itself is sent to the notification circuit 6.

Even the automatic notification device D (fourth embodiment of the present invention) as shown in FIG. 4 has advantages similar to the automatic notification device A. The delay circuit 5 of the automatic notification device D normally stops the function of the notification circuit 6 by stopping the supply of the operating power, and when the notification signal St is input, the delay circuit 5 continues to be in the stopped state for 30 seconds, After the lapse of time, the function stop of the notification circuit 6 is released.

The present invention includes the following embodiments in addition to the above embodiments. a. In addition to the gas leak sensor, the monitoring means is incomplete combustion,
It may detect a fire, an intruder, forgetting to turn off the switch of gas, oil, electricity, or other equipment.

B. The predetermined time of the delay circuit may be appropriately determined by a time longer than the time from when the fault detection circuit detects the fault of the microcomputer to when the reset circuit resets the microcomputer. Further, the period of the watchdog pulse may be arbitrary.

C. A management center is a staff room at a school,
It may be an administrator's room such as an apartment, or a guardman's place such as a building.

[Brief description of drawings]

FIG. 1 is a block diagram of an automatic notification device according to a first embodiment of the present invention.

FIG. 2 is a block diagram of an automatic notification device according to a second embodiment of the present invention.

FIG. 3 is a block diagram of an automatic notification device according to a third embodiment of the present invention.

FIG. 4 is a block diagram of an automatic notification device according to a fourth embodiment of the present invention.

FIG. 5 is a block diagram of an automatic notification device for a prototype.

[Explanation of symbols]

 1 gas leak sensor (monitoring means) 2 microcomputer 3 fault detection circuit 4 reset circuit 5 delay circuit 6 notification circuit 21 watchdog timer 211 watchdog pulse St notification signal A, B, C, D automatic notification device

Claims (1)

[Claims] 1. A microcomputer that incorporates monitoring means for monitoring the state of a monitored system and a watchdog timer for sending a watchdog pulse, and sends a notification signal when the monitoring means detects an abnormality in the monitored system. A fault detection circuit that states that the microcomputer has faulted when the watchdog pulse is no longer transmitted normally; a reset circuit that resets the microcomputer when the fault detection circuit detects a fault of the microcomputer; In an automatic notification device comprising a notification circuit for reporting an abnormality in a monitored system to a management center, until the predetermined time elapses from the time when the microcomputer starts transmitting the notification signal, the notification circuit notifies the management center. Do not report An automatic notification device characterized by being provided with a delay circuit.