JPH0452900A - Apparatus for fire informing equipment - Google Patents

Abstract

PURPOSE:To output an abnormal signal only when a counter measure for operation abnormality is required or a microcomputer is not restored to a normal state by providing the apparatus with a watching timer and an abnormality deciding means. CONSTITUTION:During the normal processing of a monitoring program, the microcomputer (MPU) inverts the output of an output port OUT4 in each 10-step processing e.g. of the program. The rise of an inversion pulse is detected by the watch-dog timer (WD) and a capacitor C3 in an abnormality detecting circuit (TH) repeats charging/discharging. During the normal operation of the MPU, the WD does not output a reset signal. When the operation of the MPU is abnormal, the WD intermittently outputs reset signals. When the number of resets of th WD reaches a prescribed value within a prescribed time, an abnormality output means outputs an abnormal signal. In the case of temporary abnormality, no abnormal signal is outputted, and only when a countermeasure is required, the abnormal signal is outputted.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a device for fire alarm equipment that includes a built-in microcomputer (microprocessor).

[Traditional technique]

Among devices for fire alarm equipment, devices equipped with a microcomputer (microprocessor) for signal processing and transmission processing are known.

Fire alarm equipment equipped with such microcomputers, such as fire receivers and repeaters, is equipped with a watchdog timer to monitor the operating status of the microcomputer in order to detect equipment abnormalities due to malfunction or runaway of the microcomputer. I am trying to monitor.

〔Problems to be solved〕

By the way, in conventional equipment, when a watchdog timer detects an abnormality in the microcomputer, it immediately displays the abnormality.

However, some abnormalities in microcomputers include changes in the memory contents of the random access memory that constitutes the microcomputer due to power supply noise or noise signals from signal lines, which can cause abnormalities such as the microcomputer to stop operating. There are many cases.

In this case, by resetting the microcomputer, the abnormal operation is recovered and normal operation is resumed.

However, the conventional method has a problem of displaying an abnormality even in such a case.

[How to solve the problem]

In view of the above points, the present invention aims at a device for fire alarm equipment that outputs an abnormality signal when a microcomputer malfunctions and does not recover to a normal state or when countermeasures against the malfunction are required. A fire alarm equipment equipped with a microcomputer includes a watchdog timer that monitors an abnormality in the microcomputer and outputs a reset signal to the microcomputer when an abnormality is detected, and an abnormality in the watchdog timer. The apparatus is characterized by comprising an abnormality determining means that counts the number of detections and outputs an abnormality signal when the counted value reaches a predetermined value or when the counted value reaches a predetermined value within a predetermined time. It is something.

[For production]

When the microcomputer malfunctions, it is reset, and when the number of resets reaches a predetermined value or the number of resets reaches a predetermined value within a predetermined time, an abnormality signal is output, so the microcomputer returns to a normal state. It does not output an abnormal signal at all times, but outputs an abnormal signal only when countermeasures against abnormal operation are required or when the microcomputer does not return to its normal state.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a circuit diagram of one embodiment in which the present invention is used in a fire receiver, where RE is the fire receiver and DE is the fire receiver R.
This is a fire detector connected to E via a pair of power and signal lines.

In the fire receiver RE, MPU is a microcomputer, INI to IN4 are its input ports, and 0UTI to 0U.
T4 is its output port, and RES is its reset terminal.

CMI and CM2 are comparators for fire signal detection, SWl is a main sound stop switch, and SW2 is a fire recovery switch.

Ll, L2 are fire area indicator lights, MB is the main bell as the main sound device, B is the main bell MB for ft1lJ111 (7
) Relay b is its meter contact.

WD is a watchdog timer, and IVI and IV2 are inverters.

CT is resistance R1, R'2,': l 7 tear Cl,
A counting circuit consisting of a charging/discharging circuit consisting of a diode D1, TS is a comparator CM3 and a relay A for outputting an abnormal signal.
This charging/discharging circuit CT and the abnormality output circuit TS constitute an abnormality determining means.

LA is the abnormality indicator light, BZ is the buzzer, and a is the relay A meter contact.

FIG. 2 is a circuit diagram of one embodiment of the watchdog timer WD, which includes a first monostable multi-by-break MMI for detecting a rising edge consisting of a capacitor C2, a resistor R3, and a diode D2, inverters IV3 and IV4, and a resistor R.
4, R5, an abnormality detection circuit TH equipped with a charging/discharging circuit consisting of a capacitor C3 and a diode D3, and a comparator CM4.
and a second monostable multivibrator MM2 for outputting a reset signal, which includes a capacitor C4, a resistor R6, and a diode D4.

Note that the fire reception MIRE is also provided with other switches such as a test switch and other circuits such as a backup power supply circuit, but these are not shown.

Next, the operation will be explained with reference to FIG.

While the microcomputer MPU is normally processing a program such as a fire monitoring program, the output of the output port 0UT4 is inverted as shown in FIG. let

Watch tong timer W to watch the rising edge of this inverted pulse.
The first monostable multi-bibreak MMI of D detects,
The output causes inverter IV4 to generate a pulse output as shown in FIG. 3(2). Due to the pulse output of the inverter rV4, the capacitor C3 of the abnormality detection circuit TH repeats charging and discharging as shown in FIG. 3(3).

Due to the charging voltage of capacitor C3 at this time, comparator CM
4 maintains the L output and the second monostable multipipe rake MM2 is not triggered.

In this way, while the microcomputer MPU is operating normally, the watch tong timer WD does not output the set signal.

However, if the microcomputer MPU malfunctions due to, for example, changes in the memory contents of its random access memory due to noise signals, etc., the output port ○
The output inversion of UT4 is L or H as shown in Figure 3 (1).
Stops in this state. As a result, the first monostable multivibrator MMI of the watchdog timer WD no longer produces a pulse output, and the output of the inverter IV4 becomes an L output state as shown in FIG. 3(2).

Depending on the L output state of inverter IV4, capacitor C3
The charge tii is discharged through resistor R5. Comparator C
M4 produces an H output when the voltage at its inverting input drops below the reference voltage at its non-inverting input due to discharge, and this H output causes the second monostable multivibrator MM2 to operate and output a reset signal.

This reset signal causes the microcomputer MPU
is reset and performs initialization operations, etc.

As a result, the microcomputer MPU resumes the inverting operation of the output port 0UT4. And as a result of initialization,
When the microcomputer MPU returns to normal operation,
Continue the inverting operation of output port 0UT4.

On the other hand, if the microcomputer MPU does not recover to normal operation even after being reset, it stops the inverting operation of the output port 0UT4 again.

As a result, the watchdog timer WD outputs the reset signal again.

In this way, as a result of the reset by the reset signal, the microcomputer MPU will output the output port 0U if it is normal.
The reversing operation of T4 is restarted and continued, but if there is an abnormality, the reversing operation is stopped.

As a result, if the operation of the microcomputer MPU (7) is abnormal, the watchdog timer WD intermittently outputs a reset signal.

A reset signal intermittently output from the watchdog timer WD charges the capacitor C1 whose charging time constant of the counting circuit CT is selected to be shorter than the discharging time constant.

The charging voltage of the capacitor C1 charged by this intermittently outputted reset signal is higher than the reference voltage of the comparator CM3 of the abnormal output circuit TS (when this happens, the comparator CM3 generates an H output and operates the relay A. , outputs an abnormal signal.

As a result of this operation of relay A, the abnormality indicator lamp LA lights up and the buzzer BZ sounds to notify the abnormality.

Note that the abnormal signal may be transmitted to a sub-receiver, display, etc. provided at another location.

Alternatively, the abnormal signal may be held by itself by using the meter contact of relay A.

By the way, in the above embodiment, a watchdog timer that generates a pulse output is used, but a watchdog timer that generates a DC output may also be used, and a counter may be used as the counting means instead of the CR charging/discharging circuit. If a counter is used, a timer that starts operating by the reset output of the watchdog timer should be provided, and when this timer times up, an error output circuit should be used to determine whether the count value of the counter has reached a predetermined value. Bye.

Further, in the above embodiment, the abnormality output means outputs an abnormality signal when the number of resets of the watchdog timer, that is, the number of abnormality detections reaches a predetermined value within a predetermined time, but the number of resets may be counted by a counter or the like. However, an abnormality signal may be output when the number of resets reaches a predetermined value. In this case, an abnormality signal is output even when temporary malfunctions due to noise signals or the like often occur, so by taking countermeasures, malfunctions due to noise signals can be prevented.

In addition, in the above embodiment, the case of a fire receiver was explained, but a microcomputer controller, a repeater,
The same applies to other fire alarm equipment such as smoke control panels.

〔effect〕

According to this invention, the microcomputer is reset when an abnormality occurs, and when the number of abnormalities exceeds a predetermined value, an abnormality signal is output,
- Since the abnormality signal is not output when normal operation is restored by reset due to a temporary abnormality, it is possible to obtain a device for fire alarm equipment that outputs an abnormality signal only when countermeasures such as repair are required.

[Brief Description of the Drawings] Fig. 1 is a circuit diagram of an embodiment of the present invention applied to a fire receiver, Fig. 2 is a circuit diagram of an embodiment of a watchdog timer, and Fig. 3 is a timer circuit diagram of an embodiment of the present invention. It is a chart. RE...Fire receiver, MPU...Microcomputer, RES...Reset terminal, WD...Watchdog timer, CT, TS...Counting circuit and abnormality output circuit constituting abnormality determination means. Patent candidate Nomi Disaster Prevention Co., Ltd. No. 2111 Figure 3 1llOLj 411 L (21IV4th shift P

Claims (1)

[Claims] 1. A fire alarm equipment device equipped with a microcomputer, comprising: a watchdog timer that monitors an abnormality in the microcomputer and outputs a reset signal to the microcomputer when an abnormality is detected; and the watch. A device for fire alarm equipment, comprising: abnormality determining means for counting the number of abnormality detections of a dog timer and outputting an abnormality signal when the counted value reaches a predetermined value. 2. In a device for fire alarm equipment equipped with a microcomputer, a watchdog timer that monitors an abnormality in the microcomputer and outputs a reset signal to the microcomputer when an abnormality is detected; and the number of abnormality detections of the watchdog timer. 1. An equipment for fire alarm equipment, characterized in that it is provided with an abnormality determining means for counting the number of times and outputting an abnormality signal when the counted value reaches a predetermined value within a predetermined time.