JPS59117602A - Backup controller of n:1 - Google Patents

Abstract

PURPOSE:To back up every group surely by providing an input/output switching part which switches the output to a process from a control unit at the abnormal output time and executing a processing for an abnormal control unit. CONSTITUTION:The signal from a detecting end 14 of the process is inputted to a terminal board 5 of an input/output signal switch 3 and is inputted to a control unit 1a through a cable 4a. A backup controller 2 is connected to the switch 3 through a cable 4 similarly to the control unit 1a. The switch 3 is divided for every control unit 1a and backup controller 2, and divided parts correspond to individual measuring instruments in 1:1 to make the maintenance of each element possible.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a controller used for process control, and particularly relates to an N:1 backup controller that backs up a plurality of controllers with one controller.

[Prior art]

Conventionally, when backing up a plurality of controllers with one backup controller, the backup controller shared the input/output section of each process, and only the control calculation section was separated. Another method for wiping is to share the storage section for the contents of control calculations between the /C pickup controller and the plurality of controllers, and to separate the control calculation section and the input/output section.

Although this method has the advantage of simplifying the transition procedure from the controller to the backup controller in the event of an abnormality, it also has the following disadvantages.

(11. Since a part of the controller and backup controller are shared, if this part breaks down, backup will not be possible in the event of an abnormality. (2) If the shared part breaks down, it is not possible to replace only this part. Countermeasures in the event of failure become large-scale and costly.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of the prior art described above and to provide an N:1 backup controller that is relatively simple but capable of independently and reliably backing up each control loop.

[Summary of the invention]

The present invention is characterized by a plurality of control units having a communication unit that transmits the contents of control calculations and a self-diagnosis function unit that outputs all abnormality signals in the event of an abnormality in the controller; One backup controller that has an instrument abnormality input section that inputs the output, a storage section that holds the calculation contents that control the abnormal output, and an input/output switching section that switches the output to the above process from the control unit in the event of an abnormal output. The problem lies in the fact that the system is configured to connect the two through data transmission and act as a substitute for a control unit that is in an abnormal state.

[Embodiments of the invention]

FIG. 1 is an external view of an N:l backup controller that is an embodiment of the present invention. Reference numeral 1 denotes a controller having a plurality of microcomputers, a control unit 1a, etc., and is connected to the input/output switch 3 by a cable 4a.

The signal from the detection end 14 of the process is transmitted to the input/output signal switch 3
is input to the terminal board 5 of the terminal board 5, and is input to the control unit 1a via the cable 4ai. This input is outputted again to the operating valve 13 connected to the terminal board 5 via the cable 4a' after the control calculation process.

Each control unit (1a) has an LED display lamp 6 that lights up when arithmetic processing is being executed, and an LED display lamp 7 that lights up when there is an abnormality in the instrument. Reference numeral 2 denotes a backup controller, which is connected to the input/output switch 3 via a cable 4 similarly to the control unit (la). The input/output switch 3 is separated for each control unit la and backup controller 2, and 1=1 for each assembly.
1 to enable maintenance of each element ~
There is.

The input/output switch 3 has a L E that lights up during backup.
It has a D indicator lamp 8 and a changeover switch 9 that forcibly switches the input/output to either the control 1 or the backup controller 2 and transfers control during maintenance. 10 is an electrode unit that supplies power to the controller 1, backup controller 2, and input/output switch 3. Still 1
2 is a communication unit green unit, which is connected to the cathode tube CRT 11 via a cable 4b, and is connected to the controller 1 by CR and Tll.
It also monitors the status of the controller 2 and the backup controller 2 and issues instructions.

Figure 2 is a structural explanatory diagram of the input/output switching unit in Figure 1.
It consists of a pair of boards 15 to which mechanical relays 16 are attached for each input/output point, and a panel 19 and cables 17
and is connected via a connector 18. The mechanical relay 16 is provided for each input/output point and for each board 15, so that it has a duplex configuration and can be replaced without turning off the input/output for each board 15.

FIG. 3 is a block diagram of the N:1 backup controller shown in FIG. 1, in which the same parts as in FIG.

1b, backup controller 2, and input/output switch 3a
, 3b and the state of connection to the plant are shown. The controlled variable signal PV from the detection end 14 of the plant is sent to the input/output switch 3
to the controller 1 via the mechanical relay 16 of a.
Further, the operation output MV similarly controls the state of the operation valve 13 via the input/output switch 3ai. The controller 1 and the backup controller 2 are connected by a data transmission line 20. The backup controller 2 is connected to the low contact side of the mechanical relay 16, and is connected to the switching signal line 21.
It is connected to the mechanical relay 16 via.

FIG. 4 is a signal transition diagram between the controller in FIG. 3 and the backup controller. FIG. 4(a) shows a normal state in which the controller 1 outputs MVe to the operating valve 13, and the controller receives the PV multiplication signal from the detection end 14, performs control calculations, and outputs the MV value to the operating valve 13. The backup controller 2 receives and stores backup data.

Figure 4(b) is a signal transition diagram in the event of an abnormality.
In response to the abnormal output of the cutter, a switching signal is output to the input/output switch 3, and a control calculation is executed on the PV from the detection end 14 based on the backup data stored during normal operation, and the operating valve 1
Output MVi to 3. Also, the fact that the backup has been performed is displayed on the screen.

When the grasshopper returns, backup data is sent from the CRTll to the controller by a return command, and a switching signal is sent! As kOFF, the state returns to the normal state shown in FIG. 4(a).

Fig. 5 is a system diagram of the N:1 backup controller shown in Fig. 1, where the control unit ia converts the analog input of the control amount into a digital amount) A CPU 22 using a microprocessor that performs control calculation processing, a storage unit 24 that stores the results of the control calculation processing and parameters such as P, I, D, etc., a D/A conversion unit 25 that outputs the calculation processing results, and a storage unit. 24 to the backup controller 2 via the data transmission line 20, and an instrument abnormality output circuit 27 that outputs an instrument abnormality when the control 22) 1a has a self-diagnosis abnormality.

The backup controller 2 includes an A/D converter 23 that converts analog input into a digital signal, and performs predetermined control arithmetic processing on the input signal and backs up the arithmetic processing results and parameters stored in the storage section 24 of the control unit (la). CPL collects data and monitors instrument abnormalities
122, a D/AX conversion unit 25 that outputs calculation results, a storage unit 24 that stores backup data of the control unit 1a, a communication unit 26 that receives data from the control unit 1a, and inputs instrument abnormalities. a meter abnormality output 1 circuit 29 to switch the input signal from the detection end 14 and the output signal to the operation valve 13 in the event of an abnormality, and a switching command unit 29 which inputs the signal from the switch 9 of the input/output switch 3;
It is composed of yoυ.

The input/output signal switch 3 includes a mechanical relay 16 that switches input/output signals from the plant, a switching driver 31 that switches the mechanical relay 16 in response to a signal from the switching signal line 30 from the backup controller 2, and a device that forces the transition to backup. It consists of a selector switch 9. Note that a power source is indicated at the corner of each control unit 1a and backup controller 2. FIG. 6 is a diagram of backup operation in the system of FIG. 5. When the self-diagnosis is normal, the control unit 1a turns off the abnormal meter output, performs arithmetic processing, and outputs the result to MV'. Also, backup data is output to the backup controller 2 via a data transmission line 20. The backup controller 2 monitors the abnormal output of the control unit (7) la (7), and if it is OFF, it turns off the arithmetic processing, turns the switching signal OFF, turns the MV ratio output OFF, and inputs only backup data to handle the abnormality of the instrument. Prepare for backup.

Turn it on and hold the arithmetic processing 'kOFFXMV output.

The backup controller 2 inputs the instrument abnormal output and moves to backup transition processing. Backup data input during normal operation is used as backup data, and reliable data from one cycle before the instrument is used when the instrument is normal. The output is held at the MV value input as MV ratio output backup data. After switching, switch signal eON and back up LED.
Turn on the display lamp 8, execute arithmetic processing, and
Notify and display the transition to backup.

After this, the output to the operating valve 13 is from the backup controller 2 to perform backup. Returning from backup is performed by a return command from the CRTII, and the backup controller 2 turns off the calculation process and holds the MV output.

After that, return to the loop controller. Send the results of the arithmetic processing executed before receiving the command and the parameters of P, I, and D to the controller. 5. After controller 1 receives the data normally, it turns the switching signal eOFF and is in the process of backing up. Turn off the LED indicator lamp 8 and report the return to CR and Tll.

After inputting the backup data, the controller 1 resets the operation output using the MV value of the backup data, turns the switching signal eOFF, turns the arithmetic processing ON, executes the arithmetic processing, and turns on the instrument abnormality LED display rung 6? Turn on the white light. The backup controller 2 turns the M V output fzOFF upon input of the backup data from the controller 1, and returns to normal operation.

FIG. 7 is an operational flowchart of the system shown in FIG. control unit) la is A that takes in the control amount signal by A/D conversion
Perform I input processing. A predetermined control calculation process is performed on the input signal to determine the manipulated output Mv, but this manipulated output is D
/A conversion processing and output. The self-diagnosis includes a readback check that takes in the AO high output of controller 1 and the AI high input again, a parity check of the storage section, and a sum check of the program.If there is an abnormality, an instrument abnormality is output.
Turn on the ED lamp 7.

In the communication transfer processing, when the controller is normal, N:1 backup data is created from the storage section 24, and when the controller is abnormal, the data received by the N:1 backup data transfer processing is stored in the storage section 24. In the N:1 backup data transfer process, the backup data is retired between the backup controllers 2. When receiving backup data, M of the received backup data is
MV is output based on the V value, and the entire process is completed after 20 m5 has elapsed. The above processing is carried out for a certain period of time in each calculation cycle.
A also receives the backup data and performs N:1 backup transfer processing to store it in the storage unit 25.The MV output reset resets the MV ratio output to zero. Next, as a meter abnormal input, a meter abnormal input is received from a plurality of controllers 1, and all judgments are made to determine whether or not there is an abnormality.If normal, the backup data of the next controller 1 is subsequently requested and this process is repeated.

If there is an abnormality at this time, the process moves to the backup migration sequence, and the M in the backup data input during the previous normal operation is
Performs MV output operation to output the V value. After the output, a switching signal is output from the controller that outputs the instrument abnormality, and the LED
'r lights up to report backup migration to CRTll. Next, the process moves to control processing, and the control amount signal is converted to A/
A, 1 input processing for D conversion, arithmetic processing for executing a predetermined control calculation with the input control amount and outputting a manipulated output, and AO output processing for outputting the manipulated output to the operating valve 13 are performed.

Next, a self-diagnosis is performed in the same way as the controller 1, and if the backup controller 2 is abnormal, the output is held and the meter abnormal LED is turned on. Furthermore, it is determined whether a return command from Cl or Tll is issued, and if there is no command, the content of the calculation process or P is determined.

N:1 formed by the tuning parameters of I, I)
Performs backup data creation processing.

Furthermore, perform all the calculations expected and repeat the above operation at regular intervals υ
return. If there is a command, the process moves to the return sequence. The MV ratio output is held, the arithmetic processing is turned off, and the N:1 pack “r” stored in the storage unit 24 during backup is
Extract the block data and set the corresponding controller unit) la
-<Send. If communication is normal, switching signal "k OF"
After reporting the return to F Toji CRTll, we will move on to support for normal operation.

In the N:1 backup controller of this embodiment, the controller and the backup controller are each provided with an arithmetic section and an input/output section independently, and the controller and the backup controller are connected through data transmission.
The effect is that a plurality of controllers can be completely and relatively easily backed up with one backup controller.

[Effects of the Invention] The N:1 backup amplifier controller of the present invention has the advantage that it is possible to reliably back up each control loop, and that it can be achieved through relatively simple and inexpensive improvements.

[Brief explanation of drawings]

Fig. 1 is an external view of an N:1 backup controller which is an embodiment of the present invention, Fig. 2 is a structural explanatory diagram of the input/output switch of Fig. 1, and Fig. 3 is an N:1 backup controller of Fig. 1. A block diagram of the backup controller, Figure 4 is a signal transition diagram between the controller in Figure 3 and the backup controller, Figure 5 is a system diagram of the N:1 backup controller in Figure 1, and Figure 6 is a diagram of the N:1 backup controller in Figure 5. Backup operation diagram in the system, 7th
The figure is an operation flowchart of the system shown in FIG. ■... Controller, 2... Backup controller, 3... Input/output switch, 4.17... Cable, 5... Terminal board, 6, 7.8... LED indicator lamp, 9 ... Selector switch, lO... Power supply unit, 1
Engineering...CRT. 12...Communication unit l-113...Operation valve, 14.
...Detection end, 15... Board, 16... Mechanical relay, 18... Connector, 19... Panel, 20...
...Data transmission line, 21...Switching signal line, 2
2...CP[J. 23... A/D converter, 24... Storage section, 25...
・IJ/A conversion unit, 26... Communication unit, 27... Instrument abnormality output circuit, 28... Instrument abnormality input circuit, 29...
・Switching command department, (1 other person) 20th

Claims (1)

[Claims] 1. In a controller that inputs a control type signal from a process, executes a predetermined control calculation, and outputs the output as an operation signal to the above process, when there is an abnormality in the communication section that transmits the contents of the control calculation and the above controller, A plurality of control units each having a self-diagnosis function section that outputs an abnormality signal, an instrument abnormality input section that inputs abnormality outputs from the plurality of control units, and holding calculation contents for controlling the abnormality outputs. A backup controller is provided which has a storage unit and an input/output switching unit that switches the output to the process from the control unit when the abnormal output occurs, and the two are connected by data transmission to detect the abnormal control unit. N:1 characterized by being configured to perform agency work
Backup controller.