JPH03256499A - Selection control circuit - Google Patents

Abstract

PURPOSE:To strengthen a malfunction proofing function and to improve reliability as a system by electrically monitoring the ON/OFF state of a contact to be really used in advance before executing selection control. CONSTITUTION:A confirming circuit is formed by a power source 8 for monitor, power supply relay contact 14, respective contacts 3a-3n for selection and diodes 13a-13n. Before operating selection relays 2a-2n and a control relay 4, when there is the closing state of the contact for the operation, namely, of contacts 7a-7n for selection and a contact 6 for control, the electric output can be obtained by the confirming circuit to detect such a state, and therefore, the presence/absence of an abnormal state can be confirmed. Thus, since the confirming circuit is provided to directly monitor the state of the contact to be really operated, a selection control circuit can be obtained with high reliability while strengthening the malfunction proofing function as the system.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention (Industrial Application Field) The present invention relates to a selection control circuit that is more supervised and controlled.

(Prior art) Monitoring circuits and fail-safes have long been taken into consideration when controlling external equipment using remote monitoring and control devices, but in recent years, the types and scope of control by remote monitoring and control devices have expanded. , more reliable monitoring circuits are becoming necessary.

However, the monitoring circuit in the selection control circuit of the conventional remote monitoring control device is generally the circuit shown in FIG. Generally, a remote monitoring and control device has a device selection control circuit, and is capable of indirectly monitoring the operating status of the selection control circuit from a distance.

That is, in the selection control circuit 1 that is monitored by the remote monitoring control device, the selection relays 2a to 2n (PR1 to
PRn) is a relay for selecting a device to be controlled from among many devices (not shown) connected to the outside of the remote monitoring and control device. When the selection relays 2a to 2n operate, the respective selection contacts 38 to 3n operate and close, establishing a connection with each device, and as described later, control is performed from the control output terminals S□ to Sn. Output can now be applied.

Reference numeral 4 denotes a control relay, which turns on and off the power from the control power source 5 to the external equipment selected by the selection relays 2a to 2n.When the relay 4 is activated, its control contact 6 is turned on and off. The relay operates and closes,
The external devices include each control terminal 5a to 5n and a common terminal S which is one pole of the control power source 5. A control output will be applied to the device via.

Reference numerals 78 to 7n are monitoring contacts that are closed by each selection relay 28 to 2n at the same time as the selection contacts 38 to 3n, and when the contacts 78 to 7n are closed, the monitoring power source 8
becomes energized, and this contact signal is transmitted to the transmission line 9. ■
0, and the remote monitoring and control device monitors the relay operating status via the input module. Similarly, reference numeral 11 denotes a monitoring contact which is operated and closed at the same time as the control contact 6 by the control relay 4, and the contact signal is also sent to the remote monitoring and control device via the input module.

(Problems to be Solved by the Invention) However, in the conventional selection control circuit shown in FIG. 2, the status of each relay was monitored by electrically monitoring a contact that operated simultaneously with the contact. For example, suppose selection relay 21. When trying to turn on the selection contact 3a by driving (PR), the selection contact 3a
The monitoring contact 7a may be electrically ON even when it is not electrically ON due to dust or the like adhering to contact 7a. However, in this case, the problem is that the external equipment does not work, so it is still OK, but in the following case, it will be a serious accident. That is,
When none of the selection relays 2a to 2n are driven, one or more of the selection contacts 3a to 3n of the selection relay may become electrically 0II due to dust, fusion, etc.
In the I state, the monitoring contacts 78 to 7n may not be electrically turned on. In this case, the selection control circuit 20 is considered to be in a state of no selection and no control, and determines that selection control may be performed. Therefore, please remove any garbage etc. in advance.
When selecting a desired selection relay other than the selection relay in NL and performing M#, driving control relay 4,
A problem may occur where another device may operate at the same time as the device you were trying to control. This results in multiple outputs, which poses a serious problem in remote monitoring and control equipment. In other words, the remote monitoring and control device becomes unable to accurately grasp the operating status of the selection control circuit whose original purpose is to select and operate one external device, and thus loses its normal function.

The present invention has been made in view of the above points, and prevents malfunction as a system by electrically monitoring the ON and OFF states of the contacts actually used before performing selection control. The purpose is to provide a highly reliable selection control circuit with enhanced functionality.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a selection relay that selectively connects a device to be controlled among devices connected to the outside in a circuit through a selection contact that operates as a relay. and a control relay that outputs a control output to the selected device via a control contact, and monitors the operation of each relay via respective monitoring contacts that operate simultaneously with the selection contact and the control contact. In the selection control circuit equipped with a monitoring circuit, the ON/OFF states of the selection contact and the control contact can be determined by energizing the contacts from a separate monitoring power supply, so that an electrical signal can be obtained if the selection contact and the control contact are in the ON state. In this way, a confirmation circuit is provided that can check the presence or absence of contact abnormality before each relay is activated.

(Function) Before operating the selection relay and control relay, if the operating contacts, that is, the selection contact and the control contact, are closed, the confirmation circuit that checks this will generate an electrical output. Therefore, it is possible to check whether there is an abnormal condition. Therefore, since the selection control operation is executed after confirming that there is no abnormality detection power, it is possible to reliably select and control one device. This allows the remote monitoring and control device to monitor the operating status of the selection control circuit completely.

(Example) The present invention will be described in detail below with reference to FIG. In FIG. 1, components that are the same as or equivalent to those of the conventional circuit shown in FIG. 2 are indicated by the same numbers.

What is added to the configuration compared to the conventional circuit is a monitoring power supply relay PWR12 and the same number of diode groups 13 as the selection relays 28 to 2n. The monitoring power relay 12 has a power relay contact 14 that operates as a relay.
Selection contacts 38 to 3 of each selection relay 2□ to 2n through
One of the terminals of n is commonly connected to one pole of the monitoring power supply 8. This power relay contact 14 and each selection contact 3
An input signal line 16 is drawn out from a common connection line 15 with the terminals 8 to 3n. On the other hand, in the diode group 13, the cathodes are commonly connected and connected to the input signal line 17, and the positive electrodes of each of the diodes 1.3a to 13n are connected to each selection contact 3.
8 to 30.

Then, the other power supply 1i of the two input signals 11X16, 17 and the monitoring power supply 8! Each signal from 18 can be detected through the input module to obtain a monitoring signal.

That is, a confirmation circuit is formed by the monitoring power source 8, the power relay contact 14, each of the selection contacts 38 to 3n, and the diodes 13a to 13n.

Next, contents that can be determined from the output states of these signals m16 and m17 will be explained. First, we will explain the case where the voltage or current of the input signal line 16 is monitored when all of the control relay 4 and the selection relays 2□ to 2n are OFF (hereinafter, the voltage or current will be monitored using the voltage), the control contact 6, and the power source. Confirm that both relay contacts 14 are OFF, drive the monitoring power relay 12, and turn the power relay contact 1
Turn on 4. If a voltage is applied to the input signal line 16 here,
It can be confirmed that the power relay contact 14 is turned on.

Next, if no voltage is applied to the input signal line 16, it can be confirmed that all of the selection contacts 31 to 3n are electrically OFF. That is, if the selection contacts 38 to 3n are OFF, the diodes 13a to 13n are all non-conductive, and no signal voltage is generated on the input signal line 16.

In this manner, it is possible to confirm whether or not there is an abnormal closing of the actually operating contacts before operating the selection relays 28 to 2n. Therefore, if there is dust or fusion that has been a problem in the past, the diode becomes conductive through the closed selection contact at this point, and a voltage is output to the input signal line 16, allowing the abnormality to be discovered.

In this way, when the selection relay 2 (PRz) 2a is driven after confirming that it is normal, a voltage is output to the input signal line 16 and the input signal 4!17. You can now confirm that you have successfully selected it.

[Effects of the Invention] As explained above, according to the selection control circuit of the present invention,
By simply adding a diode and a relay, we have created a confirmation circuit that can directly monitor the status of the actually operating contacts without making any major changes to the conventional circuit. (contact ON due to fusion)
can be detected, and it is possible to prevent control outputs from being output with incorrect multiple selections. Therefore, the malfunction prevention function as a system can be strengthened, and a highly reliable selection control circuit can be provided at low cost.

[Brief explanation of drawings]

FIG. 1 is a selection control circuit diagram showing one embodiment of the present invention, and FIG.
The figure is a conventional selection control circuit diagram. 1...Selection control circuit, 2a-2n...Selection relay, 3
8 to 3n...Selection contact, 4...Control relay, 6 Control contact, 78 to 7n...Selection relay operation monitoring contact,
11...Contact for monitoring the operation of the control relay. (7317) Agent, Patent Attorney Noriyuki Chika (8869) Agent, Patent Attorney No. Ken Maru KR) d-do? 82 ((daiko) bolt-dango

Claims (1)

[Claims] Among devices connected to the outside, a selection relay selectively connects the device to be controlled via a selection contact that operates as a relay, and a control output to the selected device via the control contact. In a selection control circuit comprising a control relay that outputs, and a monitoring circuit that monitors the operation of each relay via respective monitoring contacts that operate simultaneously with the selection contact and the control contact,
A monitoring power supply that energizes each of the selection contacts when pre-checking the state, and a diode connected in a circuit so that the monitoring power is applied to the ON selection contact and outputs an electrical signal. 1. A selection control circuit comprising a group of electrical signals and a confirmation circuit capable of detecting the presence or absence of a contact abnormality before relay operation based on the presence or absence of this electrical signal.