JPS6361682B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention comprises a main controller that performs process control;
A process consisting of a sub-controller that takes over process control when a failure occurs in the main controller, and a switching device that mediates between the main controller and the sub-controller and has backup memory. This relates to a backup method in a control device.

[Conventional technology]

FIG. 1 is a block diagram showing an example of such a process control device, showing a main controller MCT and a sub-controller.
SCT is provided, and a switch CG is provided as an intermediary between these controllers.
It is equipped with a CPUc, and memories MMm, MMs, and MMc for storing process value data and parameter data used for control calculations.
The processor CPUm of the main controller MCT is the memory
Process control is executed while accessing the necessary data to MMm.

In addition, when a failure occurs in the main controller MCT,
The processor CPUs of the sub-controller SCT start operating according to a command via the switch CG, and the processor CPUs of the main controller MCT
Similarly, process control is performed on behalf of the memory MMs while accessing the necessary data, but the sub-controller SCT is used for multiple main controllers MCT.
Only one processor is installed, and the processor CPUc of the switching device CG installed corresponding to the main controller operates at all times, and the data is temporarily stored and sent from the main controller MCT by the buffer BFm. Memory for process values and parameter data
After being sequentially stored in MMc, the contents of memory MMc are transferred to memory MMs of sub-controller SCT in response to a failure in main controller MCT.

Therefore, the contents of memory MMm and memory
It always matches the contents of MMc, and the memory MMc
Since the contents of the memory MMs are transferred to the memory MMs via the buffer BFs as necessary, the processor CPUs can take over control of the main controller MCT in the event of a failure.

[Problem to be solved by the invention]

However, in the past, the main controller
All data of MCT is stored in memory via buffer BFm.
Since the data is transferred to MMc, if the amount of data handled by the main controller MCT becomes large,
The amount of data that can be stored simultaneously in the buffer BFm must be increased, and the configuration of the buffer BFm using registers and the like becomes large-scale, resulting in the disadvantage that the cost of the device becomes an effect.

[Means to solve the problem]

The present invention provides the above-mentioned process control device, which includes:
Depending on the type of data, process value data that constantly changes is stored in memory from the main controller via a buffer, and a steady operation is repeated, while parameter data that does not change constantly is controlled by the main controller only when there is a change in the data value. The data is stored from the device to the memory via a buffer.

[Effect]

This reduces the operating load on the buffer in the main controller, making it possible to greatly simplify the configuration of this buffer.

〔Example〕

The details of the present invention will be explained below with reference to the flowchart of FIG. 2 showing an example.

FIG. 2 shows the operational status of data storage resulting from data transfer by the processors CPUm and CPUc of the main controller MCT and the switch CG.

First, the processor CPUm performs a "data check" to check whether the data is constantly changing process value data or constantly changing parameter data, depending on the bit indicating the type of data. ?”
If YES, in response to this, the processor CPUc immediately "transfers to buffer" and sends the data to the switching device CG, so the processor CPUc stores the data in memory MMc using "store in memory" and stores these data. Repeat steady motion.

On the other hand, if the type is a parameter and the answer is NO for "Constantly changing data?", the processor CPUm determines "Is there any change?"
If this is YES, "transfer to buffer" is performed and "storage to memory" is performed. On the other hand, if the answer to ``Is there a change?'' is NO, the process immediately returns to the first ``data check,'' and ``transfer to buffer'' and ``storage to memory'' are not performed.

Among the types of data, data that constantly changes indicates process quantities and constantly changes, while data that does not constantly change is a parameter for control calculations and cannot be changed due to changes in commands from a host controller or artificial setting values. Changes only when changes are made. Therefore, the amount of data that constantly changes is extremely small compared to the amount of data that does not change constantly, and according to the method shown in FIG. 2, the amount of data that must be simultaneously stored in the buffer BFm is greatly reduced.

Therefore, the configuration scale of the buffer BFm can be easily simplified, the device cost can be significantly reduced, and the time devoted to transferring data that does not change constantly is extremely reduced. Also,
Memory for data that constantly changes due to steady operation
Since the transfer to MMc is repeated, the contents of memory MMm and memory MMc match,
There is no problem with backup.

The method described above can be applied to any device equipped with a main controller MCT and a backup memory MMc, regardless of the presence or absence of a sub-controller SCT and a switch CG. Various modifications can be made depending on the situation.

〔Effect of the invention〕

As explained above, according to the backup method of the process control device according to the present invention, the configuration of the buffer that mediates between the main controller and the backup memory is greatly simplified due to the simple configuration. In addition to achieving a reduction in cost, the time required to transfer parameter data that does not change all the time is greatly reduced, and the operating load on processors that handle large amounts of data is reduced. Significant effects can be obtained in process control equipment.

[Brief explanation of drawings]

Figure 1 is a block diagram showing an example of the configuration of the device;
The figure is a flowchart showing an embodiment of the invention. MCT...Main controller, SCT...Sub controller, CG
...Switcher, CPUm, CPUs, CPUc...Processor, MMm, MMs, MMc...Memory, BFm,
BFs...batshua.

Claims (1)

[Claims] 1. A main controller, a backup memory for storing future process value data and parameter data to be used in control calculations, and a backup memory for temporarily storing the data when transferring the data from the main controller to the memory. In a process control device equipped with a buffer, depending on the type of data,
The constantly changing process value data is stored in the memory from the main controller via a buffer, and a steady operation is repeated, and the constantly changing parameter data is stored in the main controller only when there is a change in the data value. A backup method for a process control device, characterized in that data is stored in the memory via a buffer.