JPH0887938A - Latch relay monitoring device - Google Patents

Abstract

(57) [Abstract] [Purpose] One of the two contact output latch relays is used for signal monitoring, and the connection state of the latch relay is constantly monitored to enable detection and correction of malfunctions. A CPU that outputs a control signal based on an alarm signal or a sensor signal that is input, a relay control circuit that supplies a strobe pulse to an output side designated by the control signal, and a CPU that inputs the strobe pulse Latch relay with 2-contact output that switches the connection state,
An I / O circuit for converting an output data signal of the latch relay into a predetermined data format that can be input by a CPU, one of the outputs of the latch relay is an output to be originally used, and the other is for signal monitoring. Since the output for signal monitoring is constantly monitored by the CPU, malfunction of the latch relay can be easily detected and corrected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a latch relay monitoring device for monitoring the connection state of a latch relay used in a communication system or the like.

[0002]

2. Description of the Related Art In a communication system, a relay is used for switching a circuit based on an alarm output of insulation monitoring and outputs of various sensors. When there are many types of alarms and a large number of sensors, a large number of relays are required. For example, one package may have 30 or more relays and have an output function of 30 or more contacts. As a relay used for switching the circuit, etc., if a normal relay is used, it must be energized at all times to maintain the connection state, but power consumption is very large, but if a latch relay is used, it will be set. Alternatively, the connection is switched and the connected state is maintained only by supplying a strobe pulse of about 10 [ms] to one of the two reset inputs, so that the power consumption is relatively small. Therefore, when a large number of relays are required as described above, latch relays are often used. However, it is not constant whether the connection state of the latch relay is set or reset when the power is turned on.Therefore, when the power is turned on, a pulse must be generated by that reaction to force the set or reset state. It was

However, while the latch relay does not require electric power for maintaining the operating state, it has a weak maintaining force in the connected state, and the connected state may be erroneously switched due to large vibration even during energization. Therefore, the circuit configuration is very unstable, and it is difficult to confirm the malfunction state from the outside, so that it is difficult to detect and correct the malfunction.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a latch relay monitoring device capable of constantly monitoring the connection state of a latch relay and detecting / correcting a malfunction.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, a latch relay monitoring device according to the present invention includes a CPU that outputs a control signal based on an input alarm signal or sensor signal, and a predetermined output side according to the control signal. A relay control circuit for supplying a strobe pulse, a latch relay having a two-contact output for switching the connection state by inputting the strobe pulse, and an output 1 of the latch relay is used as an output to be originally used, while an output 2 Is used for signal monitoring, and is composed of an I / O circuit that converts the data signal output from each relay into a data format that can be input by the CPU. Output 2 is used for signal monitoring to the CPU via the I / O circuit. The CPU compares the contents of the data signal output from the I / O circuit with the data signal before the relay input, and if they do not match, the CPU returns Over detects a malfunction of the relay by determines that not the correct connection state, is to modify the connection relay outputs a relay control signal again.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the embodiments shown in the drawings. FIG. 1 is a block diagram showing the configuration of a latch relay monitoring device according to the present invention. In the figure, C
The PU 1 outputs a control signal based on an alarm signal or a sensor signal that is input, and its output end is connected to the relay control circuit 2 via an address bus and a data bus. The relay control circuit 2 supplies a strobe pulse to a predetermined output end according to the control signal, and the output end is connected to the relay 3. The relay 3 is a two-contact output latch relay, and the output 1 is used as an output that should be used originally, while the output 2 is used for signal monitoring and the output end 2 is connected to the I / O circuit 4. The I / O circuit 4 outputs the output from each relay to the input format of the CPU.
The conversion end is connected to the CPU 1 via the address bus and the data bus.

The latch relay monitoring device having the above-mentioned configuration is
It works as follows. That is, the CPU 1 that receives the alarm signal or the sensor signal outputs a control signal for switching the connection state of the required relay based on the signal, and the control signal is sent to the relay control circuit 2 via the address bus and the data bus. Is entered. The relay control circuit 2 generates a strobe pulse having a pulse length of about 10 [ms] based on the control signal, and further supplies the strobe pulse to a predetermined output side according to the control signal. The relay 3 connected to each output of the relay control circuit 2 inputs a data signal from each unit (not shown) and inputs a strobe pulse from the relay control circuit 2 to switch the connection state. Output 1 is input to each device as the output that should be used originally,
The output 2 is input to the I / O circuit 4 for signal monitoring,
The I / O circuit 4 converts the data signal output from each relay into data in a format that can be input to the CPU 1, and the data is input to the CPU 1 via an address bus and a data bus. The CPU 1 constantly compares the data signal output from the I / O circuit 4 with the data signal before input to the relay 3, and if they do not match, determines that the relay is not in the correct connection state. Therefore, even when the connection state of the relay is erroneously switched due to vibration or the like, the CPU 1 constantly monitors the connection state, so that the error in the connection state of the relay can be detected. When the CPU 1 detects a malfunction of the relay, the CPU 1 outputs the relay control signal again to correct the relay connection.

[0008]

According to the present invention, by using the latch relay monitoring device having the above-mentioned structure, even if a malfunction occurs in the latch relay, the output of the latch relay is monitored by the CPU to detect the malfunction. The state of the relay can be modified. In addition, since the latch relay connection status is monitored even when the power is turned on, it is not necessary to generate a pulse by the reaction when the power is turned on and forcefully set or reset the state. Alternatively, a circuit for switching to the reset state is unnecessary.

[0009]

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a latch relay monitoring device according to the present invention.

[Explanation of symbols]

1 ... CPU 2 ... Latch relay control circuit 3 ... Latch relay 4 ... I / O circuit

Claims (1)

[Claims] 1. A CPU that outputs a control signal based on an alarm signal or a sensor signal that is input, a relay control circuit that supplies a strobe pulse to an output side designated by the control signal, and the strobe pulse that is input. A latch relay having a two-contact output that switches its connection state by an I / O circuit that converts the output data signal of the latch relay into a predetermined data format that can be input by the CPU, and one of the outputs of the latch relay The other one is used as an output to be used originally, and the other is used for signal monitoring. The output data signal for signal monitoring is input to the CPU via the I / O circuit, and the CPU outputs the data signal output from the I / O circuit. Always compare the data signal before inputting the latch relay, and if the data does not match the control signal, check that the latch relay is not connected correctly. Latching relay monitoring device for detecting a malfunction of the latching relay by determining the things.