JPS62174862A - Control device by multiprocessor - Google Patents

Abstract

PURPOSE:To prevent the erroneous intervention in a control side and to improve the reliability of a plant control by preventing writing by a processor side for man machine to a memory device shared by two processors to separate completely the function for control and for man machine. CONSTITUTION:Two processors completely separate the function as for a processor 1B for plant control and a processor 2B for man machine communication. The processor 1B for the control fetches the plant information through a process input output device 8 and outputs the control information. Simultaneously, the processor simultaneously has the function to write the plant information and the control information into a sharing memory device 3. On the other hand, the processor 2B for the man machine reads and edits the plant information and the control information from the sharing memory device 3 and outputs them through respective interfaces to a CRT 10 and a printer 14. In order to prevent the man machine side complicate and redundant in processing destructs or rewrites the information of the control side by mistake, the man machine side only reads the information of the sharing memory device 3 and will not write it into the sharing memory device 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a control device using a multiprocessor, and particularly to a control device using a multiprocessor suitable for a device equipped with a shared storage device.

[Background of the invention]

FIG. 6 is a block diagram showing a conventional multiprocessor control device. The example shown here is for controlling a controlled object (A) 21 and a controlled object (B) that are inside a plant. In FIG. 6, 1 is a processor (A), 2 is a processor (A),
is a processor (B), 3 is a shared storage device that can be accessed by both processors 1 and 2, and 4 is a processor 1
5 is a private storage device exclusively used by processor 2; 6 is an interface bus connected to processor 1; 7 is an interface bus connected to processor 2; 8 is a controlled object (A) 21 9 is a keyboard interface that connects the keyboard 18 and the bus 6; 10 is a CR
T, 11 is a CRT interface that connects CRTIO and bus 7, 12 is a keyboard, 13 is a keyboard 12
and a keyboard interface connecting bus 7, 14
1 is a printer, 15 is a printer interface that connects the printer 14 and bus 7, 16 is a CRT, and 17 is a CRT.
16 and a CRT interface connecting bus 6, 18
is a keyboard, 19 is a printer, 20 is a printer interface that connects the printer 19 and the bus 6, 21 is a controlled object (A), 22 is a controlled object (B), and 23 is a process input/output that connects the controlled object 22 and the bus 7. It is a device.

Processor 1 controls a controlled object 21, and processor 2 controls a controlled object 22. Processors 1.2 via their respective process input/output devices @B, 23.

The plant information of the controlled objects 21 and 22 is taken in, control information is created by arithmetic processing, etc., and the control information is output to the controlled objects 21 and 22. In addition, each process 1-2 performs man-machine communication such as outputting plant information and control information to the CRTIO, 16, which is a display device, and the printer 14, 19, which is an output device, or displaying operation guidance. do.

Furthermore, in addition to their individual storage devices 4 and 5, the processors 1 and 2 have a shared storage device 3 that can be accessed by each other, and can read and write necessary plant information and control information to each other.

A system having such a shared storage device 3 has been commonly used in the past, and is disclosed in, for example, Japanese Patent Application Laid-Open No.
As shown in Japanese Patent No. 14364, there is a system in which two online processors communicate with a shared storage device simultaneously.

However, according to the control device as shown in FIG. 6, the shared memory iff! Since information is exchanged between the two processors on 3, there is a risk that important control information may be erroneously rewritten. In addition, because software for man-machine communication generally has to be complicated, the processor handles both plant control and man-machine (processing that edits information requested by the user from plant data and provides it to the user). In some cases, it is essential to increase the reliability of control software.

[Purpose of the invention]

An object of the present invention is to provide a multiprocessor control device that prevents control information from being erroneously rewritten in a shared storage device and improves the reliability of control software.

[Summary of the invention]

In order to achieve the above-mentioned object, the present invention has a shared storage device of a multiprocessor system in which functions are completely separated for plant control and man-machine communication. It is designed to perform only the following.

[Embodiments of the invention]

Examples of the present invention will be described in detail below.

FIG. 1 is a block diagram showing one embodiment of the present invention. In FIG. 1, the same reference numerals are used for the same parts as in FIG. 6, so redundant explanations will be omitted.

The two processors are processor IB for plant control.
and processor 2B for man-machine communication.
It functions as a complete portion. The control processor IB is a process input/output device i! 8, and outputs control information. At the same time, it has a function of writing plant information and control information into the shared storage device 3.

On the other hand, the man-machine processor 2B has a shared storage device 3.
The plant information and control information are read out, edited, and output to the CRTIO and printer 14 via each interface. Here, in order to prevent the man-machine side, which has complicated and redundant processing, from accidentally destroying or rewriting the information on the control side, the man-machine side only reads the information from the shared storage device 3, and the shared storage device l! 3 will not be included.

FIG. 2 shows an outline of the processing flow on the control side and the man-machine side, respectively.

The control processor IB can repeat a series of processes from taking in plant information to outputting control information in short cycles without being bothered by the complexity of man-machine processing.

The man-machine side performs communication processing such as inputting operator instructions from the operation guidance keyboard 12 in addition to the processing of reading, editing, and outputting information from the shared storage device 3.

The control processor IB is a shared memory bag! ! ! The man-machine processor 2B performs only reading.

No writing is performed. This makes it possible to prevent erroneous input of information from the man-machine side, and to greatly improve the reliability of control.

However, in a plant control system, an operator may need to change control-related set values such as control constants during control. If there is such a request, a shared memory bag from the man-machine processor 2B side! ! ! We will allow writing to 3.

For this purpose, as shown in FIG.
Key switch interrupt input device for control constant change request on B side!
! 25 will be provided.

When the operator wants to change the set value, first display the set value on the CRTIO on the man-machine processor 2B side,
Setting values are changed by input operations on the keyboard 12, etc. At this point, the setting values can be changed using the individual memory bag ff! of the man-machine processor 2B. 5 only.

Next, the operator turns on the key switch interrupt input device 25 for requesting a setting value change on the control processor IB side. As a result, the setting value change process is started on the control processor side, and the shared memory bag is sent from the man-machine processor 2B side! ! 3, the changed setting value is read out.

FIG. 3 is a flowchart showing the setting value changing process.

The control processor IB side notifies the man-machine processor 2 side that there is a change request by turning on the change request flag on the shared storage v13. On the man-machine side, after rewriting the setting values from the operator,
The change request flag is constantly monitored, and when the flag is confirmed to be ON, the total number of changed setting values, the unique numbers of those setting values, and the changed values are written to the shared memory bag [3.

Here, the unique number of the setting value is one-to-one for all setting values.
This is an identification number associated with . After writing the change value, the man-machine side notifies the control side of the completion of writing by turning off the change request flag.

The control side confirms that the change request flag is OFF, takes out the changed value, and rewrites the set value on its own private storage device.

Next, a specific example of the process of writing and reading information via the shared memory bag M3 will be explained based on FIG. 4.

On shared storage devices 1 and 3, each piece of information has a one-to-one relationship with an address.
is associated with. The software of the control processor IB and the man-machine processor 2B each recognize this correspondence, and the control side writes information to the corresponding address of the shared storage device 3, and the man-machine side reads the necessary information in correspondence with the addresses. put out. Such a method is generally used when writing and reading information is always performed at regular intervals.

When a change occurs in plant information or control information, the method shown in FIG. 5 is effective in transmitting and receiving only the information that corresponds to the change.

Information is not associated one-to-one with addresses in the shared storage device 3, but is associated with information-specific names (generally information numbers).For example, water level is number 1, pressure is number 5, etc. It is identified as follows.

The control side confirms that the change information write flag is OFF, and writes the total number of changed information, this information, and the information number to the shared storage device 3. Thereafter, by turning on the change information write flag, the man-machine side is notified that the change information has been written.

The man-machine side monitors the change information write flag.

After confirming ON, read out the change information and information number. After the successive output is completed, the change information write flag is set to ○FFL, and the control side is notified that the information has been read.

〔Effect of the invention〕

As explained above, according to the present invention, the man-machine processor side is prevented from writing to a storage device shared by two processors whose functions are completely separated for control and man-machine. , prevent erroneous intervention on the control side,
This has the effect of increasing the reliability of plant control.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a flowchart showing processing during normal plant control, and FIG.
The figure is a flowchart showing the process when there is a request to change the set value, FIG. 4 is an explanatory diagram showing the process of writing and reading information via the shared memory bag [3, and FIG. FIG. 6 is a block diagram showing a conventional multiprocessor-based control device. 1B... Processor for plant control, 2... Processor for man-machine, 3... Shared storage device, 4, 5...
・Private storage device, 6.7...Interface bus,
8... Process input/output device, 10... CRT, 11
... CRT interface, 12... Keyboard, 13... Keyboard interface, 14...
Printer, 15...Printer interface, 21
...Controlled object, 25...Key switch interrupt input device.

Claims (1)

[Claims] 1. A first processor that is responsible only for plant control, a second processor that is responsible for processes other than plant control, and a readable and writable shared storage device that is shared by these processors. A control device using a multiprocessor, characterized in that the control device includes means for inhibiting writing by the second processor to the shared storage device during normal times. 2. The multiprocessor control device according to claim 1, further comprising interrupt means that can arbitrarily cancel the write prohibition by operating a switch.