JPS6357801B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multiple computer synchronization device for synchronizing program processing when a plurality of computers are assembled into a composite type.

For example, in power generation plants, conventional sequence control devices with logic using electromagnetic relays,
Analog control devices combined with analog circuits have been used as plant monitoring and control devices. Recently, however, with advances in computer technology, these devices have come to be implemented using computers, particularly microcomputers (hereinafter referred to as microcomputers), through software program processing.

FIG. 1 is an explanatory diagram of a plant monitoring and control device using a microcomputer. In the figure, 7 is a power generation plant such as hydropower, thermal power, nuclear power, etc., 5 is a process input device 6 is a process output device, and 1 is a microcomputer. The state of the plant process 7 is read into the memory of the microcomputer 1 via the process input device 5, and the plant monitoring and control logic is executed by the program of the microcomputer 1 according to the process state, and the process is output as the final output. An output signal is sent to the plant 7 via the output device 6.

For example, some plant process quantities require the status to be captured at very fast intervals, such as pulse input to detect the rotational speed of a turbine generator, and others that require measurements over a period of several seconds to several seconds, such as the temperature of steam generated in a boiler. There are some cases where it is sufficient to capture the state at a cycle of minutes.

When applying the system shown in Figure 1 to parts of a plant process that need to be monitored and controlled at relatively short intervals, the program in microcomputer 1 first loads the necessary process inputs into the microcomputer's memory. In many cases, the program processes the plant state stored in the memory, processes the process output, and when the process is completed, reads the process input again, repeating a cycle. This is sufficient if there is no need to monitor or control at a fast cycle (several tens of milliseconds or less).

By the way, as these microcomputer-based monitoring and control devices are widely applied, higher reliability is required due to their importance in plant operation, and this microcomputer also needs to be multiplexed. In the case of multiplexing, the problem is synchronization of program processing executed by each computer. In the case of a device that only needs to repeat the cycle of operation from the process input to the process output described above, if this is multiplexed, the input or It is sufficient to synchronize the output, and an example of this is shown in the second example.
This will be explained with a diagram.

In Figure 2, 1, 2, and 3 are microcomputers that repeatedly execute the same round of processing, 4 is a synchronization device, and 1
1, 12, and 13 are synchronization request signals issued to the synchronizer 4 from the microcomputers 1, 2, and 3, respectively.
41, 42, 43 are from the synchronizer 4 to the microcomputer 1,
This is a synchronous interrupt signal issued at 2 and 3. The plant process input device and process output device explained in FIG. 1 are omitted in FIG.

The programs in microcontrollers 1, 2, and 3 are each
Read the process input from the process input device,
It processes programs and outputs them to the process output device repeatedly.
2 and 3 only need to be synchronized at the time of reading the process input, the time of outputting the process, or both. Taking synchronization at the time of reading process input as an example, when microcontroller 1 among microcontrollers 1, 2, and 3 reaches the timing to read process input, microcontroller 1 issues a synchronization request signal 11 to synchronizer 4, and synchronizes. The progress of the program is stopped until an interrupt signal 41 is received. Synchronizer 4 receives synchronization request signal 1 from microcontrollers 1, 2, and 3.
When 1, 21, and 31 are present, the synchronous interrupt signal 4
When signals 1, 42, and 43 are sent to the microcomputers 1, 2, and 3 at the same time, the microcomputers 1, 2, and 3 resume program progress and simultaneously start reading process inputs.
This allows for synchronization.

However, with this method, if the microcomputer 2 suddenly breaks down for some reason (for example, due to a failure in the power supply line to the microcomputer 2,
If the power supply to the microcomputer 2 suddenly stops), the synchronization request signal 21 from the microcomputer 2 will no longer be output, and the program progress of this system will stop.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a multiple computer synchronization method that allows system processing to continue even if one microcomputer fails and cannot issue a synchronization request signal.

The present invention will be explained below with reference to the drawings. FIG. 3 is a block diagram showing an embodiment of the present invention. Here, a case of a multi-computer system with three microcomputers is shown as an example, but the same applies to a case of four or more microcomputers.

The same parts as in FIG. 2 are given the same reference numerals, and the description of the same parts will be omitted. 4 is a synchronizer, 44, 45, 46 are OR circuits, 47 is an AND circuit, and 48 is a synchronous interrupt signal generator. 14,
15 and 16 are failure signals sent from the microcomputers 1, 2, and 3. 17, 18, 19 are OR circuit 4
These are signals transmitted from 4, 45, and 46.

OR circuit 44 receives synchronization request signal 1 from microcomputer 1
1 or the fault signal 14 is transmitted, the signal 17
is transmitted to the AND circuit 47. OR circuit 45 receives synchronization request signal 12 or failure signal 1 from microcomputer 2.
5 is transmitted, a signal 18 is transmitted to the AND circuit 48. OR circuit 46 sends signal 19 to AND circuit 47 when synchronization request signal 13 or failure signal 16 is sent from microcomputer 3 . AND circuit 4
7 transmits a signal 20 to the synchronous interrupt signal generator when all the signals 17, 18, and 19 are present.
Upon receiving the signal 20, the synchronous interrupt signal generator 48 sends synchronous interrupt signals 41, 42, 43 to the microcomputer 1,
2 and 3 respectively, and an interrupt is issued to cause the microcomputers 1, 2, and 3 to perform processing at the same time.

As explained above, the present invention provides OR circuits 44, 4
5 and 46, and even if a failure signal 14, 15, or 16 occurs, a synchronization command is issued to each microcontroller, so even if one microcontroller fails, the processing of the entire system continues as normal. It can be continued with a microcomputer. Of course, the control output signal of the faulty microcomputer is 2OUT from the three microcomputer configurations.
This is blocked because it uses the of 3 method.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of the plant monitoring and control system, Figure 2
The figure is a block diagram of a conventional device, and FIG. 3 is a block diagram showing an embodiment of the present invention. 1...Microcomputer, 2...Microcomputer, 3...Microcomputer,
4...Synchronization device, 5...Process input device, 6...Process output device, 7...Plant, 11...Synchronization request signal, 12...Synchronization request signal, 13...Synchronization request signal,
14... Failure signal, 15... Failure signal, 16... Failure signal, 17... Signal, 18... Signal, 19... Signal, 20
... Signal, 41... Synchronous interrupt signal, 42... Synchronous interrupt signal, 43... Synchronous interrupt signal, 44... OR circuit, 45
...OR circuit, 46...OR circuit, 47...AND circuit,
48...Synchronized interrupt signal generator.

Claims (1)

[Claims] 1. In a multi-computer system having multiple computers that execute the same round of program processing, a synchronization request signal that indicates the completion of one round of program processing on a computer, a failure signal that indicates a computer failure, and the transmission of these signals. It is equipped with the same number of OR circuits as there are computers, an AND circuit that takes the logical product of the output signals of each OR circuit, and a synchronous interrupt signal that receives the output signal of the AND circuit and outputs a synchronous interrupt signal to each computer. A synchronization device for multiple computers consisting of a signal generator and a signal generator.