JPH07281702A - Stop backup device for controller - Google Patents

Abstract

PURPOSE:To stop a controller without affecting the state of an instrument as a controlled system without affecting the operating conditions of this instrument. CONSTITUTION:Normally, the signal of a sensor 1 is inputted to a controller A and this controller A controls an instrument 21 as the controlled system. When stopping the controller A, the signal of a changeover switch 14 is transmitted to an input switching device 2, output hold logic 19 and coincidence deciding means 11. Then, the device 2 transmits the signal of the sensor 1 to a controller B for backup, and the value of an arithmetic logic 7a (the output value of the controller A) just before the switching of the device 2 is held and transmitted through a transmission bus 15 to the coincidence deciding means 11 by the output hold logic 19. When the signal from the switch 14 is received and the value from the bus 15 is equal with the value of 7b, the coincidence deciding means 11 switches the state of an output switching device 12. Afterwards, this device 12 starts transmitting the output of the controller B to the instrument 21 of the controlled system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus capable of stopping the control device while continuously controlling the controlled object when the control device is inspected and the like. .

[0002]

2. Description of the Related Art Conventionally, when stopping a control device for controlling equipment or the like for inspection or the like, it is necessary to select a time when the equipment to be controlled may be stopped or continuous operation is required. For the equipment, an operator manually operates the equipment to be controlled in place of the stopped control device.

[0003]

When inspecting the control device by stopping the equipment to be controlled, it is possible to find the time to stop the equipment to be controlled or make an adjustment to create that time. Very difficult,
In addition, even if the time was obtained, it was often very short, and the burden on the inspector was heavy. Further, in the case of the method in which the operator operates the device to be controlled, the operator had to perform the operation while observing the state of the device, which imposes a heavy burden on the operator.

The present invention has been made in view of the above points, and an object thereof is to affect the state of a device to be controlled regardless of the state of the device. It is an object of the present invention to provide a device that can stop the control device without the need.

[0005]

In order to solve the above problems, the present invention provides a control device for controlling a device to be controlled by obtaining a sensor signal from the device to be controlled. A backup control device that is provided in parallel with the control device via the device and has the same functional unit as the control functional unit that needs to continuously control the device to be controlled inside the control device, Means for generating a switching signal at the time of switching, the input switching device for switching the sensor signal to be input from the control device to the backup control device, and the input switching signal generated by the switching signal generating device for receiving the input switching signal. Means for holding the output signal of the control device as it is, and the output signal after switching and the signal sent to the backup control device via the switching relay. Matching determination means for determining the same and outputting the signal as an output signal of the backup control device when both are the same, and a control signal input to the device to be controlled after switching from the output signal of the control device. And an output switching device for switching to an output signal of the backup control device.

Further, in the above structure, the coincidence determining means is provided inside the backup control device and outputs the output signal sent from the control device and the signal sent to the backup control device via the input switching device. The input of the coincidence determination unit and the output signal of the coincidence determination unit and the input switching signal sent from the switching signal generation unit are input, and when the both are input, the output of the same determination unit It is characterized in that it is configured by an AND operation unit that outputs a signal.

[0007]

When the control device is stopped, the control function units that need to continue to control the equipment to be controlled are selected in advance, and the configuration of these indispensable parts is also applied to the backup control device. Mount. When the control device is stopped, the input switching device switches the input signal from each sensor and the control parameter of the control device to be stopped to the backup control device. By the coincidence determination means, the control calculation value of the control function unit of the control device to be switched, that is, the control device to be stopped is equal to the control calculation value of the control function unit of the backup control device,
In addition, it is determined whether the output of the control calculation value of both control function units is synchronized, and if so, the output switching device sends the control signal of the backup control device to the device to be controlled. Will be available. After that,
The control device can be stopped without affecting the device to be controlled.

In particular, if the AND operation unit is provided in the coincidence determining means, the output values of the control function units in the switching source and backup control devices are equal to each other, and at that time, the input switching signal is determined to be coincident. Since the AND operation unit determines whether or not it has been sent to the means, it can be easily determined whether or not the output of the control operation value is synchronized.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a block diagram of a commonly used digital control device. In the figure, a digital control device A
Is an input signal converter 6a, an A / D converter 4a, an arithmetic logic 7a, a D / A converter 5a, and an output signal converter 10.
It consists of a. The signal of the sensor 1 input to the digital control device A is an analog current signal of, for example, 1 to 20 mA, but since the arithmetic logic 7a of the digital control device A is a device for arithmetically processing a voltage signal, the current The signal is processed by the input signal converter 6a by the operation logic 7a.
It is converted to a voltage signal level for input. The converted signal is digitally converted by the A / D converter 4a and input to the arithmetic logic 7a, which is a device that generates a control signal for the device 21 of the control device. The output signal of the arithmetic logic 7a is converted into an analog signal by the D / A converter 5a, and then converted into a current signal again by the output signal converter 10a. The signal output from the output signal converter 10a is the device 21 to be controlled.
The control signal 18 is input to the device 21.

The sensor 1 and arithmetic logic 7a in FIG.
The control signal 18 to the control target device 21 is singular, but depending on the control target device, there may be a plurality of the sensor 1 and the arithmetic logic 7a having the above-described configuration. The arithmetic logics 7a and the like which have received the input signal from the sensor 1 exchange necessary data and the like between the arithmetic logics and output the control signals of the number necessary for controlling the device 21.

FIG. 1 is a block diagram of a backup control device of a control device according to the present invention. In the figure, the changeover switch 14 is connected to the input changeover device 2, the digital control device A, and a backup digital control device B, which will be described later, and inputs to each device only immediately before the digital control device A is stopped. This is a device that outputs the switching signal 16.

In the figure, a sensor 1 and a device 2 to be controlled
The control signal 18 and the device 21 to be controlled are the same as those in FIG. Further, the input signal converter 6a, the A / D converter 4a, the arithmetic logics 7a and D in the digital control device A are provided.
The A / A converter 5a and the output signal converter 10a are the same as those in FIG. An output hold logic 19 is installed between the arithmetic logic 7a and the D / A converter 5a in the digital control device A. Normally, the output hold logic 19 outputs the output value of the control logic 7a as it is. However, when the input changeover signal 16 from the changeover switch 14 is input to the output hold logic 19, the output hold logic 19 outputs. Continuing to hold the value of the arithmetic logic 7a when the input switching signal 16 is input,
The stored value is output without being affected by the output value of the arithmetic logic 7a thereafter.

In the present invention, the digital control device A
This is true even if a plurality of digital control devices are installed as a backup control device for stopping the backup. However, in this embodiment, one digital control device B is used as the backup control device. The backup digital control device B is composed of an input signal converter 6b, an A / D converter 4b, an arithmetic logic 7b, a D / A converter 5b, an output signal converter 10b and a coincidence determination means 11 described later. Input signal converter 6b and A / D converter 4
b, the operation logic 7b, the D / A converter 5b and the output signal converter 10b are the input signal converter 6a, the A / D converter 4a, the operation logic 7a of the digital control device A,
It is the same as the D / A converter 5a and the output signal converter 10a. The coincidence determination means 11 continues to the changeover switch 14 and is configured to receive the input changeover signal 16 at the same timing as the output hold logic 19.

The digital control device A and the backup digital control device B are connected via a transmission bus 15. The transmission bus 15 is connected between the output hold logic 19 and the D / A converter 5a inside the digital control unit A, and inside the digital control unit B, the coincidence determining means. 11 is connected.

The changeover relay 3 inside the input changeover device 2 is controlled by a changeover switch 14 so that the signal from the sensor 1 is inputted to either the digital control device A or the backup digital control device B. To work. The changeover relay 3 transmits the signal of the sensor 1 to the digital control unit A when the changeover switch 14 does not output the input changeover signal 16, that is, during the normal device control operation. When the changeover switch 14 outputs a signal, that is, immediately before the digital control device A is stopped, the changeover relay 3 is switched to transmit the signal of the sensor 1 to the backup digital control device B.

A switching relay 13 inside the input switching device 12
Serves to transfer the output of either the digital control device A or the backup digital control device B to the device 21 to be controlled. The switching relay 13 normally transmits the output of the digital control device A to the device 21 to be controlled, but when receiving the output switching signal 17 from the coincidence determination means 11 inside the backup digital control device B which will be described later. The output of the digital control device B is used as a control signal 18 for the device 2 to be controlled.
Switch to tell 1.

Here, in the present invention, the operation of each device for controlling the equipment to be controlled in a normal case will be described. At this time, the changeover switch 14 changes the input changeover signal 1
Since 6 is not output, as described above, the switching relay 3 inside the input switching device 2 transmits the signal of the sensor 1 to the digital control device A. In addition, the digital control device A
The internal output hold logic 19 outputs the output value of the arithmetic logic 7a as it is as described above. The switching relay 13 in the output switching device 12 also transmits the output of the digital control device A as the control signal 18 to the device 21 to be controlled, as described above, so that the control device 21 eventually receives the signal from the sensor 1. The series of device control operations until the transfer is performed is the same as in FIG.

Next, in the present invention, the equipment to be controlled needs to be continuously controlled, and the operation of each device when the digital control device A is stopped in the same situation will be described. At this time, immediately before the digital control device A is stopped, the changeover switch 14 changes the input changeover signal 1
6 is output to the switching relay 3 inside the input switching device 2, and the switching relay 3 is switched. When the switching relay 3 is switched, the signal of the sensor 1 is input to the backup digital control device B. A signal value output from the sensor 1 and output from the arithmetic logic 7b via the input signal converter 6b, the A / D converter 4b, and the arithmetic logic 7b inside the backup digital control apparatus B. Is input to the D / A converter 5b and also to the coincidence determination means 11.

Further, the changeover switch 14 outputs the input changeover signal 16 to the changeover relay 3 and at the same time, sends the input changeover signal 16 to the output hold logic 19 inside the digital control unit A. Same output hold logic 19
When receiving the input switching signal 16, the input switching signal 1
The output value of the operation logic 7a immediately before receiving 6 is continuously held. The value held by the output hold logic 19 is transmitted through the transmission bus 15 and input to the coincidence determination means 11 inside the backup digital control device B.

The match determining means 11 is composed of a match determining section 22 and an AND operation section 20. The coincidence determination unit 22 of the means 11 compares the signal value sent from the output hold logic 19 by the transmission bus 15 with the signal value from the operation logic 7b, and performs AND operation while both signal values match. A signal is sent to the arithmetic unit 20. The changeover switch 14 includes the changeover relay 3 and the output hold logic 1.
The input switching signal 16 is sent to the AND operation section 20 at the same time as the input switching signal 16 is sent to the AND operation section 20. The AND operation section 20 switches the input when the signal from the coincidence determination section 22 is obtained. When the signal 16 is obtained, the output switching signal 17
Is output to the switching relay 13 inside the output switching device 12.
By this action, when the digital control device A is switched to the backup digital control device B, the input signal converter 6b, the A / D conversion 4b and the arithmetic logic 7b in the backup digital control device B are changed. It is possible to prevent the signal output from the backup digital control unit B from fluctuating due to the processing delay.

A switching relay 13 inside the output switching device 12
Is the D inside the backup digital control device B.
The signal output from the A / A converter 10b is switched by the output switching signal 17 from the coincidence determination means 11 so as to be sent to the device 21 to be controlled. After that, the backup digital control device B controls the device 21 to be controlled in exactly the same manner as the digital control device A. Therefore, the digital control device A can be stopped without affecting the device 21 to be controlled.

[0022]

According to the present invention, when the control device is stopped in order to inspect the control device or the like, the state of the control device is affected regardless of the operating condition of the device. It is possible to stop the control device without doing so. Further, when the control device is switched to the backup control device, the control signal can be automatically switched without fluctuation. Therefore, it becomes unnecessary for the operator to control the device when the control device is stopped, so that the burden on the operator can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a backup control device of a control device according to an embodiment of the present invention.

FIG. 2 is a block diagram of a commonly used digital control device.

[Explanation of symbols]

 1 Sensor 2 Input Switching Device 3, 13 Switching Relay 4a, 4b A / D Converter 5a, 5b D / A Converter 6a, 6b Input Signal Converter 7a, 7b Arithmetic Logic 10a, 10b Output Signal Converter 11 Match Judgment means 12 Output converter 14 Changeover switch 15 Transmission bus 16 Input changeover signal 17 Output changeover signal 18 Control signal 19 Output hold logic 20 AND mental arithmetic section 21 Controlled device 22 Matching decision section

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G05B 23/02 C 7531-3H

Claims (2)

[Claims] 1. A control device for controlling a device to be controlled by obtaining a sensor signal from the device to be controlled, the sensor signal being provided in parallel with the control device via an input switching device. A backup control device having the same function unit as the control function unit that needs to continuously control the device to be controlled inside the control device, means for generating a switching signal at the time of switching, and the sensor signal After the switching, the input switching device that switches the control device so that it is input to the backup control device, the means that receives the input switching signal generated from the switching signal generating means, and holds the output signal of the control device as it is. When the output signal and the signal sent to the backup control device via the input switching device are determined to be different from each other, the output signal and the backup signal are returned to the same when both are the same. Match determination means for outputting as an output signal of the backup control device, and an output switching device for switching the control signal input to the device to be controlled after switching from the output signal of the control device to the output signal of the backup control device. A stop backup device for a control device, comprising: 2. A coincidence judging unit and a coincidence judging unit for inputting an output signal sent from a control device and a signal sent to a backup control device through an input switching device to judge whether they are different or not. It is characterized by comprising an AND operation unit for inputting the output signal of the determination unit and the input switching signal sent from the switching signal generating means, and outputting the output signal of the coincidence determination unit when both are input. The stop backup device for the control device according to claim 1.