JPS63142914A - Relay contact input circuit - Google Patents

Abstract

PURPOSE:To offer a fail safe collation pulse type input circuit of multiple constitution by providing a photocoupler switched by an N collation pulse given to a contact N at the operating position of a relay, a photocoupler whose conduction is switched by an R collation pulse given to a contact at the position of restoration and a sensor sensing the conducting state of the photocouplers. CONSTITUTION:In applying the N, R collation pulses respectively to transistors 7, 8, photo TRs 4a, 4b are conducted respectively and their conducting state is sensed by a sensor 3. When the output of the sensor 3 changes from '1' to '0', it represents the operating position contact N is active and when the output changes from '0' to '1', it depicts that the restorating position contact R is active. If the sensor output changes differently from the above, it shows that a fault takes place in the input circuit. Thus, a fault in the input circuit as well as the information input is sensed by monitoring the sensor output appearing at contact information input terminal 9. Moreover, even when the operating position contact N and the restoration position contact R of the relay are connected in parallel with other system, since the pulses of its own system are not bypassed to the other system, the constitution of a multiple system is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a relay contact input circuit used as an input circuit for, for example, automatic train control systems (ATC) of railways that require fail-safe performance.

Conventional technology such as ATC requires fail-safe performance for operational safety. Conventionally, a relay contact input circuit as shown in FIG. 6 has been employed as an input circuit for such an ATC or the like.

That is, FIG. 6 is a so-called reference pulse type relay contact input circuit, in which a first reference pulse (hereinafter referred to as "
A second verification pulse (hereinafter referred to as "N verification pulse") is alternately applied to the recovery side contact R, and a second verification pulse (hereinafter referred to as "N verification pulse") is applied alternately to the contact R on the recovery side. This is to identify whether the relay contact is configured on the N or R side based on the combination of the presence or absence of an output signal. In this way, simply turn on the contact,
○Do not input information only with FF, use check pulse to enter N,
If information is input while simultaneously checking the configuration status of both R contacts, contact abnormalities, etc. can be detected, resulting in a fail-safe input circuit.

Problems to be Solved by the Invention When the conventional relay contact input circuit described above is used, fail-safe operation as an input circuit is achieved, but it is difficult to construct multiple input circuits. That is, generally A.T.
In order to increase the safety level of the equipment, in order to increase the safety level of the equipment, multiple identical circuits and equipment are operated in parallel (a so-called multi-system configuration is often used, but in the case of the circuit configuration shown in Figure 6, the input information If the common contact C that captures the There was a problem that the system configuration was difficult.

The present invention was invented based on the above-mentioned circumstances, and provides a reference pulse type relay contact input circuit that is fail-safe and capable of multiple configuration.

Means for Solving the Problems The present invention provides a relay contact input circuit having a configuration as shown in FIG. 1 in order to solve the above problems. That is, the photocoupler 1 is a first switching element whose passage is controlled to open and close by N inspection pulses, the photocoupler 2 is a second switching element whose passage is controlled to open and close by N inspection pulses, and the first
and a sensor 3 for detecting the conduction state of the second photocoupler 1.2, the first and second photocoupler 1.
One end of the second phototransistor 4a, 4b is connected to the 7th side (OV) through the sensor 3, and the other end of the phototransistor 4a of the first photocoupler 1 is connected to the working side contact N of the relay contact. At the same time, the other end of the phototransistor 4b of the second photocoupler 2 is connected to the recovery side contact R of the relay contact, and the common contact C of the relay contact is connected to the positive pole (24V) of the power supply. Light emitting diodes 5a of the first and second photocouplers 1.2.

5b through the transistor 7.8, N inspection pulses and N inspection pulses are applied alternately to the first and second pulses at that time.
Phototransistors 4a and 4b of photocoupler 1 and 2 of
The sensor 3 is configured to detect the conducting/non-conducting state of the.

Operation As shown in FIG. 2, when N illumination pulses and N illumination pulses are alternately applied to the transistor 7.8, the photocouplers 1 and 20 light emitting diodes 5a and 5b emit light, and the phototransistors 4a and 4b emit light. are respectively conductive.

By the way, if we assume that the relay (path shown) is operating and the common contact C of the relay contacts is in contact with the operating contact N, and the operating contact N is configured, in this state the N reference pulse and the When N scanning pulses are applied alternately, when the N scanning pulses are applied, the phototransistor 4a
is conductive and the operating side contact N is configured, so a current flows through the sensor 3 and the sensor output becomes "1". Next, when applying the N illumination pulse, the phototransistor 4
b is conductive, but the recovery side contact R is not configured, so
No current flows through the sensor 3, and the sensor output becomes "O". Therefore, in the state where the operating side contact N is configured, N
In response to the arrival of the inspection pulse and the N inspection pulse, the output of the sensor 3 generated at the contact information input terminal 9 changes from "1' to "0".

On the other hand, when the relay (path shown) is in the recovery state and the common terminal C of the relay contact contacts the recovery side contact R to form the recovery side contact R, in this state, the N check pulse and the N check pulse When N inspection pulses are applied, the phototransistor 4a becomes conductive, but since the operating side contact N is not configured, no current flows through the sensor 3, and the sensor output becomes "0".

Next, when the N inspection pulse is applied, since the phototransistor 4b is conductive and the recovery side contact R is configured, a current flows through the sensor 3, and the sensor output becomes "1". Therefore, when the recovery side contact R is configured,
The output of the sensor 3 generated at the contact information input terminal 9 changes from "0" to "1n" in response to the arrival of the N reference pulse and the N reference pulse.

As is clear from the above, when the N and N reference pulses are applied alternately, when the sensor output changes from "1" to "O", it indicates that the operating side contact N is configured, and " When the change changes from “0” to “1”, the recovery side contact R
is configured. If the sensor output changes from "0" to "O" or from "1" to "1" other than the above, it indicates that an abnormality has occurred in the input circuit.

Therefore, by monitoring the sensor output appearing on the contact information input terminal 9, it is possible to detect not only information input but also abnormalities in the relay contact input circuit, resulting in a fail-safe input circuit.

Furthermore, in order to configure the input circuit as a multiplex system, even if the operating side contact N and recovery side contact R of the relay contact are connected in parallel with other systems, the N reference pulse and the N reference pulse of the own system will be transmitted to the other system. Therefore, the input circuit can be freely constructed in a multiplex system.

Note that the transistors 7 and 8 in FIG. 1 are for amplifying the illumination pulse and can be omitted. Also,
Although photocoupler 1.2 was used as the first and second switching elements to ensure electrical insulation, the switching elements are not limited to this, and semiconductor elements having the same function as the photocoupler 1.2 are used, for example. It is obvious that it can be replaced with a transistor or the like.

Embodiment FIG. 3 shows an embodiment of the relay contact input circuit according to the present invention. The illustrated example shows an example in which verification using a verification pulse is executed by a microcomputer in a security department that takes in input information. Note that the same reference numerals as in FIG. 1 indicate the same elements and elements.

The flip-flop 10 is a circuit for applying N inspection pulses and N inspection pulses to the base of the transistor 7.8, and is controlled by a microcomputer in the security department. Further, the flip-flop 11 is a circuit for reading contact information input obtained by the sensor 3 to the security department side, and is controlled by a micro combinator. 12 is an inverter.

In the above configuration, first, the operation when the relay contact is configured as the operating side contact N will be described with reference to FIG. 4.

Data bus DBQ- from the security department's microcomputer
When the verification pulse information is sent from the DB 7, the information is read into the flip-flop 10 by the write signal WHO, and N verification pulses and N verification pulses are alternately generated from the flip-flop 10 as shown in FIG. are respectively applied to the bases of transistors 7.8.

When the transistor 7.8 is activated by the N test pulse and the R test pulse at the respective times, the photocoupler 1.2
The light emitting diodes 5a and 5b emit light, and the phototransistors 4a and 4b are respectively conductive. When the N reference pulse is applied, the phototransistor 4a becomes conductive, and since the relay contact is configured as the active contact N, the phototransistor 4 of the photocoupler 1 serving as the sensor
Current flows through a, and output = “1” to contact information input terminal 9.
occurs. In addition, when the R inspection pulse is applied, the phototransistor 4a becomes conductive, but since the relay contact is configured as the operating side contact N, no current flows through the photocoupler 3, which is the sensor, and the contact information An output=“0” is generated at the input terminal 9.

The microcomputer supplies a read signal RDO for reading information to the flip-flop 11, and the flip-flop 11 generates a signal RDO at the contact information input terminal 9 at the timing shown in FIG. The sensor outputs "1" and "O" are read out sequentially and sent to the microcomputer. Then, the microcomputer determines that the relay contact is configured as the operating contact N because the input information changes from "1" to "0", and takes this as contact input information.

When the relay is in the recovery state and the relay contact is configured as the recovery side contact R, the sensor output “0” → “1” generated at the contact information input terminal 9 changes as shown in FIG. Read out. Then, the microcomputer determines that the relay contact is configured as the recovery side contact R because the input information changes from "O" to "1", and takes this in as contact input information.

Contact information input terminal 9 read into the microcomputer
The output generated at “1”→’0” or “O”→“
When the value is other than 1'', that is, from 1 to 1 or from 0 to 0, it indicates that an abnormality has occurred in the relay contact, the photocouplers 1 and 2, or other circuit elements.

Accordingly, by identifying this, the microcomputer can learn of a failure in the input circuit, thereby preventing erroneous input of abnormal contact input information, and achieving fail-safety of the circuit.

Effects of the Invention The present invention achieves the excellent effect of providing a highly reliable relay contact input circuit by enabling a fail-safe, multi-system configuration with the structure and operation described above. It is.

[Brief explanation of the drawing]

Fig. 1 is a principle block diagram of the relay contact input circuit according to the present invention, Fig. 2 is its operation time chart, Fig. 3 is a circuit diagram showing one embodiment of the present invention, and Figs. 4 and 5 are its operation time chart. The operation time chart in FIG. 6 is a circuit diagram of a conventional reference pulse type relay contact input circuit. 1: Photocoupler (first switching element), 2: Photocoupler (second switching element), 3: Sensor (photocoupler),
9: Contact information input terminal, N: Relay operating side contact, R
: Relay recovery side contact, C: Relay common contact.

Claims (1)

[Claims] In a relay contact input circuit that inputs information through a relay contact that turns on and off according to external information, the first
A first switching element whose opening/closing of the passage is controlled by the reference pulse, a second switching element whose opening/closing of the passage is controlled by the second reference pulse, and a conduction state of the first and second switching elements is detected. one end of the first and second switching elements are each connected to one pole of a power source via the sensor, and the other end of the first switching element is connected to the operating side contact of the relay contact. and the other end of the second switching element is connected to the recovery side contact of the relay contact, and the common contact of the relay contact is connected to the other pole of the power supply, and the first and second switching elements A first inspection pulse and a second inspection pulse are applied alternately to the switching element, and the first and second inspection pulses at that time are
A relay contact input circuit characterized in that the sensor detects the conduction/non-conduction state of the switching element.