JPS63120302A - Multiplexed controller - Google Patents

Abstract

PURPOSE:To secure a constitution where the bypass is always possible with a single controller only by using both a selection switch and an operation switch to energize a bypass control relay and then de-energizing this relay by release of the selection switch. CONSTITUTION:A selection switch 46 is changed over so that a movable contact 46F of the switch 46 is connected to a fixed contact 46B for maintenance of a controller 34. Then a resetting type operation switch 45 is pushed. As a result, a relay 44 is energized to secure connection among fixed contacts 44A, 44C, 44E and 44G and movable contacts 44B, 44D, 44F and 44H respectively. In this case, however, only a relay 40 is energized owing to connection secured between a fixed contact 40E and a movable contact 40F. Therefore the relay 40 is continuously energized even though the switch 45 is released. Thus a fixed contact 40A is detached from a movable contact 40B and connection is secured between a fixed contact 40C and a movable contact 40D. Thus the signal received from a signal setting means 47 is outputted to a signal selecting circuit 38. While pilot lamps 55-58 show the selected bypass parts respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a multi-IZ control device, and particularly relates to a multiplex control device having a bypass mechanism to ensure redundancy during maintenance of the control device. .

[Conventional technology]

Important control devices used in large power plants, chemical plants, railways, etc. require extremely high reliability in order to increase overall system availability. For important control systems of such plants.

BACKGROUND ART Conventionally, multiplexed, for example, double, triple, or quadruple control devices have been used to improve reliability and safety. For example, the control/protection system disclosed in Japanese Patent Application Laid-Open No. 58-221403 has 23 control devices, and when maintaining one control device to confirm its health, the output signal of the control device is A bypass mechanism is provided to prevent output to the controlled object.

This system has the configuration shown in FIG. 2, and the bypass mechanism described above is controlled by a keyed switch. Detector (or transmitter) in the figure] - ~ 3
The output signals are given to signal processing sections 4-6. The signal processing sections 1 to 6 compare whether or not the input signal No. 4 exceeds a predetermined value, and if it does, output a trip signal to the bypass sections 9 to 11-. This signal is normally applied to the logic section 7 through the bypass section.

The logic section 7 generally takes a majority vote on the input signals and outputs the operation signal 8 to a controlled object (not shown). By the way, when maintaining the signal processing units 4 to 6 to check their health, the signals of the signal processing units to be maintained are not output to the logic unit 7. Bypass sections 9 to 1-1- perform this function. For example, when maintaining the signal processing section 4, the bypass request signal 15 (or operation of the manual bypass switch 18) is applied to the bypass section 9. To grant this request, there is a bypass permission switch 12, and this switch is managed by a nail. In other words, the switch 12 managed by the key is selected.

Maintenance of the 1M processing unit 4 is possible only when the bypass request signal ]-5 (or the operation of the manual bypass switch 18) is input to the bypass unit 9.

The maintenance of other signal processing units is the same, 16.17 is a bypass request signal, 19.20 is a manual bypass switch, i
3 and 14 are bypass permission switches.

[Problem that the invention seeks to solve]

” - In the above example, the bypass permission switch 12, 13゜14
Since the signal processing unit is managed using a key, there is a problem that if the key is lost, bypass operation becomes impossible and maintenance of the signal processing unit becomes impossible. The present invention has been made in view of the above points, and an object thereof is to provide a configuration in which only one control device can be reliably bypassed at any time when bypassing a control device.

[Means for solving problems]

The problem mentioned above is that in order to bypass one of the multiplexed controllers for maintenance, the rotary switch is installed in each output stage of the multiplexed controller so that only one bypass mechanism can be selected at any time. The bypass control relay is energized by both the selection switch, which is 1, and the operation switch, which is a return type switch.The relay is also energized when the operation switch is released, and the relay is activated by the release operation of the 1 selection switch. This can be solved by configuring a bypass mechanism so that it is demagnetized.

[Effect]

By configuring the bypass mechanism as described above, it is possible to bypass the system to be maintained even without a key, and moreover, it is possible to bypass two or more control devices at the same time, so the system Reliability is greatly improved, and man-machine performance is also high.

〔Example〕

Hereinafter, specific embodiments of the multiplex control device with a bypass mechanism according to the present invention will be described.

□Figure 1 shows an embodiment of the present invention, in which the control system is a quadruple system. In the case of a triple system, one of the control devices 34 to 37 can be removed and the input/output section connected to it can be removed.In the case of a double system, the J-thread All you have to do is remove the system. Conversely, in the case of a quintuple system or more, the necessary systems may be added to the configuration shown in FIG.

In the first @, the control devices 34 to 37 input the input signals 30 to
31 and executes arithmetic processing to output signals 64 to 67.
Bypass parts 40a, 41a.

It outputs to 42a and 43a. Bypass section output signal 51
-54, the most probable signal is selected by the signal selection circuit 38 and output to the controlled object (not shown).

Here, when the signal 39 applied to the controlled object is a digital signal, the signal selection circuit 38 selects 2 out of 4 signals.
It becomes the majority circuit of the circuit.

The bypass sections 40a to 43a are normally connected to the control device 34.
The signals 64 to 67 output from ~37 are sent to the signal selection circuit 38.
Output to. However, when one control device is bypassed for maintenance, the contacts of the bypass section of this system are switched to output the signal from the signal setting device to the signal selection circuit.

Now, (number 52 is a, signal 52 is a, signal 53 is C1.
The signal 54 is set to d, and the signal selection circuit 38 selects the logic it O+
2 out of 4 circuits giving priority to t, signal 39
When Z is 2, 2 is given by the following equation.

z==abe+bcd+eda+dab-(1)
The reason why the signal selection circuit is made into a 2-ara 1-of-4 circuit that gives priority to the logic 110 tr is that the system 11 operates on the safe side (the system operates even when a signal is lost).

In the above case, for maintenance, for example, the control device 3
4, the bypass section can be selected by switching the contacts of the bypass section 40a. By the way, when the signal 2 is expressed by equation (1), each No. 44 setter outputs a signal of logic rt 1 pp.

Therefore, in the above case, the signal a becomes 1'1'', and (1
), we obtain equation (2). In other words, the signal Z is the signal S,
It is given by majority logic of 2 out of 3 for c and d. This is an attempt to increase the reliability of the system by configuring the system so that a majority vote can always be established.

z=b e+c d+d b...(
2) However, in the above case, the bypass section 40a
and 41a, a=′″
1. , 11, b=ul II, and the signal Z is expressed as equation (3).

z=c+d...(3)
Cocote, ffi control bag f! t36 (7) IPs Power Control” 1 ' 1!l: If a failure occurs, z = u l lj, and the controlled object will not be able to be controlled. Make sure that this does not happen. These are the switch group and relay group shown on the lower side of FIG. There are four, because the system is a quadruple system.The system has n (n is 2
above natural numbers) If the system is a multiple system, it is sufficient that the number of these is n.

Now, in order to maintain the control table M34, the bypass section 40
Consider operating the signal setter 47 to send the output of the signal setting device 47 to the signal selection circuit 38. This operation can be achieved as follows.

First, the selection switch 46, which is a rotary switch, is switched so that its movable contact 46F is connected to the fixed contact 46B. Then, the operation switch 45, which is a return type switch, is pressed, and as a result, the relay 45 is energized, and the fixed contacts 44A, 44C, 44, which are the contacts of the relay 45, are energized.
E, 44G and movable contacts 44B, 44D, 44F, 44
H are connected to each other. Movable contact 46 of operation switch 45
Since F is connected to fixed contact 46B, only relay 40 is energized. When the relay 40 is excited, the fixed contact 40E and the movable contact 40F, which are the contacts of the relay, are connected. As a result, the relay 40 continues to be energized even if the switch 45 that has been pressed until now is released. The response time of the relay is from several tens of milliseconds to several hundred milliseconds, which is sufficiently short compared to the period during which a person presses the switch 45, and the series of relay switching operations described above are performed without any problem.

As a result, the fixed contact 40 which is the other contact of the relay 40
A and the movable contact 40B are separated, and the fixed contact 40c and the movable contact 40D are connected. As a result, the signal from the signal setter 47 is output to the signal selection circuit 38. This state is maintained until the selection switch 46 is switched. In the above state, the movable contact 46F of the selection switch 46 is connected to the fixed contact 46.
When switching to a contact other than B, the relay 40 is demagnetized.

Further, since the operation switch is not pressed, the other relays 41 to 43 are not excited. As a result, the bypass section 40
A to 43a supply signals from each control device to the signal selection circuit.

In other words, according to this method, it is possible to always select only one bypass section.

By the way, 55 to 58 are display lamps that indicate which bypass section is selected.These display lamps improve the man-machine performance, and the fixed contact 46A of the selection switch 46 is controlled. By switching the movable contact 46F to this contact when bypassing the device is not required, it is possible to prevent any bypass portion from being selected even if the operation switch is pressed by mistake.

By providing this function, operational reliability is further improved.

Note that 59 to 63 are power supplies, and it is easy to understand that these may be implemented with one power supply.

Although the above example deals with the bypass of the control device 34, it is easy to understand that the bypass of other control devices can be similarly operated.

In addition, 4], A~41. F is a contact point of the relay 41, 42A to 42F are contact points of the relay 42, and 43A to 42F are contact points of the relay 42.
43B is a contact point of the relay 43.

In this embodiment, the selection switch 46 and the operation switch 45 are
Relays 40 to 43 are energized under ND conditions. If you try to do this using only the selection switch, for example, when switching the movable contact 46F of the selection switch 46 to the fixed contact 46E, the contact 46B.

4f; C and 46D are temporarily selected, and the bypass sections 40a to 42a are temporarily operated, and the control device that is not to be maintained is bypassed. - It is undesirable for something like this to occur, even if it is temporary. For this reason, as described above, the bypass section is selected based on the AND condition of the two switches.

In addition, in this embodiment, the relays 40 to 43 and the bypass parts 40a to 43a driven by them are configured to be independent for each system, so there is no common mode failure and the reliability of the system is further increased. can.

〔Effect of the invention〕

As mentioned above, according to the present invention, in a multiplex control device, only one bypass section is always selected in the output stage of each control device by a combination of a rotary switch and a reset switch. Because it is not possible, the system as a whole
Redundancy can always be maintained and system reliability can be increased7.

When the control device is bypassed, the corresponding indicator lamp automatically lights up, making it highly man-machine friendly.

Therefore, the present invention has great industrial value when applied to a multiplexed control system in which the control device is bypassed for maintenance.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional multiplex control device. 34-37... Control device, 40a-43a... Bypass section, 38... Signal selection circuit, 46... Selection switch, 45... Operation switch, 40-44... Relay, 47- 50...Signal setting device.

Claims (1)

[Claims] 1. In a multiplex control device in which a signal setting device is provided for each control device, and a bypass section is provided that outputs a signal from the signal setting device when bypassing the control device, one of the plurality of bypass sections is When the AND condition of the selection switch to be selected and the operation switch is satisfied, the relay that controls the operation of the bypass section is energized, and the relay is energized to maintain the energization at the contacts of the relay, and the selection switch is switched. 1. A multiplex control device, characterized in that the bypass section that has been selected is canceled, and an indicator lamp indicating the bypassed control device is lit by the contact of the energized relay.