JPH0664668B2 - Alarm output release circuit - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an alarm output system of a communication device, and more particularly to an alarm output canceling circuit of an alarm output circuit in a station building.

[Conventional technology]

Conventionally, this type of alarm output cancellation circuit drives a first relay having a contact that is closed when a device failure occurs, and an alarm output circuit that allows a closed circuit to be configured, and a contact that opens when the alarm output is canceled. It is composed of two relays and a switch for manually driving the second relay to release the alarm output.

[Problems to be Solved by the Invention]

The above-mentioned conventional alarm output canceling circuit has only means for manually closing the switch to cancel the alarm output. Therefore, the alarm output is canceled only at a certain place such as a device that is outputting the alarm. However, there is a problem that the alarm output cancellation is stopped only when the failure state of the device or the like is restored, so that the alarm is not output even if a new failure occurs.

[Means for Solving the Problems]

The alarm output canceling circuit of the present invention is closed at the time of alarm output 2
A first relay having two contacts, a relay drive circuit that drives the first relay when a device failure occurs, and a contact that opens and closes when the alarm output is released and one contact of the first relay A second relay connected in series,
An alarm output circuit capable of forming a closed circuit at alarm output by connecting the other contact of the first relay and a contact opened when the alarm output of the second relay is released in series, and by remote control in the alarm output state. A first photocoupler for driving the second relay to release the alarm output, and a second photocoupler for stopping the alarm output by remote control when the alarm output is released.
A second photocoupler for driving the relay of FIG. 1, an input buffer for a remote alarm output control signal, and a push button switch connected in parallel between the collector and the emitter of the light receiving transistor of the first photocoupler. is there.

[Action]

In the present invention, the alarm output is released by remote control,
Also, the alarm output cancellation is stopped by remote control.

〔Example〕

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

The figure is a block diagram showing an embodiment of the present invention.

In the figure, 1 is two contacts 4, 6 that are closed when an alarm is output.
A relay drive circuit for driving the relay 1 when a device failure occurs, and a relay 3 having a contact 7 that opens and a contact 5 that closes when the alarm output is released and connected in series with one contact 4 of the relay 1, Reference numeral 8 is an alarm output circuit that connects the other contact 6 of the relay 1 and contact 7 that opens when the alarm output of the relay 3 is released in series to configure a closed circuit at the time of alarm output, and 9 is a remote control at the time of alarm output. A photocoupler for driving the relay 3 so as to release the alarm output. The photocoupler 9 has a light receiving transistor (not shown) in an off state when the device or the like is in a normal state. Reference numeral 10 is a photo coupler that drives the relay 3 so as to cancel the alarm output release by remote control when the alarm output is released.
Reference numeral 10 indicates that the light receiving transistor (not shown) is in the ON state when the device or the like is in the normal state. Reference numerals 11 and 12 are remote input buffers for alarm output control signals, and 13 is a pushbutton switch connected in parallel between the collector and the emitter of the light receiving transistor of the photocoupler 9. The pushbutton switch 13 is for manually releasing the alarm output. It is a switch.

Reference numeral 14 is an alarm input terminal, 15 is an alarm output terminal, 16 and 17 are alarm output control signal input terminals, 18 is a primary side power supply terminal, 19 is a primary side ground terminal, and 20 is a secondary side power supply terminal.

Next, the operation of the embodiment shown in this figure will be described.

First, when the device is in a normal state, the contacts 4 and 6 of the relay 1 and the contact 5 of the relay 3 are open, and the contact 7 of the relay 3 is open.
Is closed and no alarm is output.

Next, if the device or the like is in a failure state, the relay 1
The contacts 4 and 6 of are closed and the alarm output state is set. Here, if the pushbutton switch 13 is manually turned on temporarily or a pulse signal for canceling the alarm output is input from the alarm output control signal input terminal 16 side, the light receiving transistor of the photocoupler 9 is temporarily turned on. , A current flows through the relay 3 to open the contact 7 of the relay 3 and close the contact 5, so that the alarm output is released.

Then, when the failure of the device is recovered, the relay 1
Since the contacts 4 and 6 of the relay 3 are opened and the current flowing through the relay 3 stops flowing, the contacts 5 and 7 of the relay 3 are respectively opened and closed like the case where the device is in the normal state. The alarm output cancellation is canceled.

Also, from the alarm output control signal input terminal 17, input a pulse signal for canceling the alarm output cancellation,
Since the current of the relay 3 is cut off by temporarily turning off the light receiving transistor of No. 3, the alarm output can be canceled as in the case of the failure recovery of the above-mentioned device.

〔The invention's effect〕

As described above, the present invention has a relay having a contact that opens and a contact that closes when an alarm output is released, a first photocoupler that drives the relay to release an alarm output by remote control, and an alarm output when released. By providing a second photocoupler for driving the relay so as to stop the alarm output cancellation by remote control in the alarm output cancellation circuit, it is possible to cancel the alarm output by remote control, and also the alarm output by remote control. Since cancellation can be canceled, there is an effect that an alarm can be output when a new fault occurs even in the alarm output canceled state.

[Brief description of drawings]

The figure is a block diagram showing an embodiment of the present invention. 1 ... Relay, 2 ... Relay drive circuit, 3 ... Relay,
4,6 …… Relay 1 contacts, 5,7 …… Relay 3 contacts, 8 ・ ・ ・
… Alarm output circuit, 9,10 Photo coupler, 11,12 Input buffer, 13 Push button switch.

Claims (1)

[Claims] 1. A first relay having two contacts that are closed when an alarm is output, a relay drive circuit that drives the first relay when a device failure occurs, and a contact that is opened and a contact that is closed when an alarm output is released. Mochi A second relay connected in series with one contact of the first relay, another contact of the first relay and a contact opened when the alarm output of the second relay is released are connected in series. An alarm output circuit capable of forming a closed circuit at alarm output, a first photocoupler for driving the second relay so as to release the alarm output by remote control during alarm output state, and an alarm by remote control at alarm output release A second photocoupler for driving the second relay so as to cancel the release of the output, an input buffer for a remote alarm output control signal, and a collector transistor for the light receiving transistor of the first photocoupler. Alarm output canceling circuit, by comprising a push-button switch connected in parallel between the emitter and said.