JPH01159740A - Duplex computer system - Google Patents

Abstract

PURPOSE:To enable a computer which received the right of control to perform the control with continuity by storing equalizing data in the memory of a waiting side when the computer of the waiting side detects an end mark inserted by the computer of an executing side. CONSTITUTION:The computer 1 of the executing side executes sequence control according to a control program, and updates the data base of the memory 12. As for the data to make the memory contents of the waiting side computer equivalent among the updated data, an equalizing data frame is generated, and is stored in the FIFO 32 of the duplex control device 3. Here, a mark inserting means 13 inserts a start mark and the end mark at the start time and the finish time of the executing side. In the case that the waiting side computer 2 stores the data from the FIFO 32 in the memory 22, when it detects the end mark by an end mark detecting means 24, it stores the data 63 interposed between the marks 61-64 in a designated address.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an aS, a redundant type of duplex computer system, and more specifically, to a computer system in which one computer fails and the other computer takes control. 6 Concerning a redundant computer system that enables smooth transfer of v-rights (Prior technology) One method of increasing the reliability of a computer system has traditionally been a redundant computer system of standby redundancy type. computers and a redundant control device that monitors and controls the operations of these computers.

This redundant control device monitors the operation of the computers, makes one of them engage in actual work, and leaves the other in a standby state.When a failure occurs in the computer used for actual work, the standby side takes over the actual work. It will be taken over by Total XR. Total nR who took over
While the worker is engaged in actual work, the broken computer is repaired, and once the repair is completed, the computer's dual system is restored.

Here, the duplex control device includes a buffer memory that temporarily stores data to be equalized so that the contents of the memories of the two computers match and the control right can be smoothly transferred from one computer to the other computer. is provided.

(Problems to be Solved by the Invention) In the conventional duplex computer system with such a configuration, when the control right is transferred from one computer to the other computer,
The extent to which the actual work has been executed is not managed, so the computer that has taken over will have to execute the actual work from the beginning. In this case, there was a problem that the continuity of control was not very high. This means that when a redundant computer system is executing sequence control, for example, the operation signal is sent twice before and after the transfer of W control.
This causes the problem that the data is output twice.

The present invention has been made in view of these problems, and its purpose is to provide a redundant computer system in which actual work can be executed continuously during transfer of control rights.

(Means for Solving the Problems) The present invention for solving the above-mentioned problems includes two computers,
A standby redundant system having a monitoring means for monitoring the operation of these computers, and a redundant control device having a buffer memory for temporarily storing the equalized data transferred from the computer on the actual work side to the memory of the standby computer and its address. In the duplex computer system, the computer system includes mark insertion means for inserting a start mark and an end mark at the start and end points of the actual work in each of the computers, and an end mark for inserting an end mark from among the signals read from the buffer memory. The apparatus includes end mark detection means for detecting an end mark, and data storage means for storing data from the start mark to the end mark at the address when an end mark is detected.

(Effect) Total X* on the actual work side inserts a start mark and an end mark at the start and end points of the actual work while it is being executed, and when control is transferred, the work mark is It will no longer be inserted. When the end mark is detected, the standby computer stores the start mark and the data sandwiched between the end mark in its own memory, and when control is transferred, the start mark is inserted just before the transfer. The actual work begins with the work corresponding to the acquired data.

(Example) Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a conceptual diagram showing an embodiment of the present invention.
In the figure, 1 and 2 are computers, 3 is a redundant control device,
A monitoring means 3 for monitoring the operation of the double-handed counter 1.2 is provided inside thereof.
1 and a first-in first-out buffer (FIFO) 32 for temporarily storing data to be equalized.

In the computer 1.2, 11.21 is a processor, and 12.22 is a main memory, which stores various databases, control programs, equalization request programs started based on requests from the control programs, etc. Stored.

13.23 is mark storage means for storing a start mark and an end mark in the FIFO 32 in the redundant control device 3 at the start and end of actual work, and 14.24 is data read from the FIFO 32. end mark detection means for detecting whether there is an end mark in the 15.
25 stores the data from the start mark to the end mark in its own main memory 1 when the end mark is detected.
2.22 is a data storage means.

Reference numeral 4 denotes switching means for input/output buses from each Sat, 2, which is switched by a signal from the duplex control device 3. Reference numeral 5 denotes an input/output device connected to either of the two terminals X and a1.2 via the switching means 4.

(motion) The operation of the apparatus configured in this way will be explained next.

Here, computer 1 is assumed to be the actual working side, and computer 2 is assumed to be the standby side. The computer 1 on the actual work side executes, for example, feedback control or sequence control according to the control program, and updates the database in the main memory 12. Regarding the updated data that is necessary to equalize the memory contents of the standby hand xn, an equalized data frame is created according to a request from the equalization request program, and this is sent to the duplex control device 3. Store in FIFO32.

Here, the mark insertion means 13 inserts a start mark and an end mark at the start and end points of the actual work. That is, when the computer 1 is working to control multiple control loops, for example, a start mark and an end mark are inserted at the time when control of one loop starts and when it ends. Furthermore, when sequence control is performed based on a plurality of sequence tables, a start mark and an end mark are inserted each time one sequence table is processed.

FIG. 2 is a conceptual diagram showing an example of the equalized data frame stored in the PIFO 32.

It consists of a start mark 61, a write address 62 in the memory of the standby computer, a plurality of updated data 63, and an end mark 64.

The standby computer 2 reads the data from the PIFO 32 and stores it in its own memory 22.

When storing the data in the memory 22, the end mark detection means 24 detects whether or not there is an end mark in the data read from the FIFO 32, and if an end mark is detected, the data is read from the start mark 61 to the end mark. The data 63 sandwiched by 64 is stored at the address designated by 62.

FIG. 3 is a flowchart when the total XR1 on the actual work side performs sequence table processing in process control, for example.

In this sequence processing, before processing one sequence table, a start mark and table number l are stored at the beginning of the sequence table in the FIF 032 of the duplex control device 3.

In table execution processing, memory 1 of computer 1 on the actual work side
2 database is updated, and for data that requires equalization, addresses and data are stored in the FIFO32. At the end of table processing, set the end mark to FI
Store in FO32.

FIG. 4 is a flowchart showing the operation for equalization performed by the computer 2 on the standby side.

The standby computer 2 reads data from the PIFO 32, detects whether there is an end mark in the data, and if an end mark is detected, stores the data from the start mark to the end mark in the memory 22, and calculates the equal value. complete the process.

By performing the above operations for all tables for each table, the data updated in the computer 1 on the standby side is sequentially stored in the designated address of the memory 22 of the computer 2 on the standby side through the PIFO 32.

When calculation R1 fails during execution of the sequence table and control is transferred to computer 2 on the standby side, computer 1 uses FIF
No longer inserts an end mark in O32. For this reason, the database that was being updated by the table being processed is
It is no longer stored in the memory 22 of the standby side calculation a2. Therefore, the computer 2 that has taken control starts processing from the table whose table number is +1 that has been equalized up to that point (the table that was being executed before the transfer of control). This ensures continuity of control.

Note that the redundancy control device 3 drives the switching means 4 to perform 1. The input/output device 5 is connected to the computer 2 which has received control authority.

(Effects of the Invention) As described in detail above, according to the present invention, a start mark and an end mark are inserted at the start and end points of the actual work, and the standby computer detects the end mark. In this case, the data to be equalized is stored in its own memory.

Therefore, according to the present invention, the computer receiving the control right can know the control state immediately before receiving the control right from the presence or absence of the end mark, and can perform continuous control.

[Brief explanation of the drawing]

FIG. 1 is a configuration block diagram showing one embodiment of the present invention, and FIG.
The figure is a frame configuration diagram of equalized data stored in the FIFO buffer, and FIGS. 3 and 4 are flowcharts showing an example of the operation. 1.2... Total X, machine 11.21... Processor 12.22... Main memory 13.23... Mark insertion means 14.24... End mark detection means 15.25...
・Data storage means 31... Monitoring means 32... Buffer memory 4... Switching means 5... Input/output device Figure 1 Figure 2 ￥3 Figure 4

Claims (1)

[Claims] The computer has two computers, a monitoring means for monitoring the operations of these computers, and a buffer memory for temporarily storing the equalized data and its address transferred from the computer on the actual working side to the memory of the standby side computer. In a standby redundant type duplex computer system having a duplex control device, the computer system comprises mark insertion means for inserting a start mark and an end mark in each computer at the start and end points of an actual work; An end mark detection means for detecting an end mark from a read signal, and a data storage means for storing data from the start mark to the end mark at the address when the end mark is detected, and the control right is transferred. This computer is a redundant computer system characterized by starting the actual work from the work corresponding to the data in which the start mark has been inserted.