JPH02210546A - Back-up method for on-line dual processing system - Google Patents

Abstract

PURPOSE:To obtain an output signal having high accuracy by comparing the difference of the output times of output signals outputted to an output device from a main arithmetic processor and a back-up arithmetic processor with the difference of the data transmission times and detecting the presence or absence of the processing abnormality of the main arithmetic processor. CONSTITUTION:The comparison is carried out between the difference of transmis sion times of data which are transmitted to a main arithmetic processor (master) 2 and a back-up arithmetic processor (slave) 3 from an input device 1 and the difference of output times of output signals which are outputted to an output device 4 from the master 2 and the slave 3. Thus, the presence or absence of abnormality is detected for the arithmetic process of the master 2. When the abnormality of the master 2 is confirmed, the output signal of the slave 3 is decided correct and can be quickly outputted to the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a backup method for an online dual processing system using a microcomputer or the like.

<Conventional technology> Traditionally, online processing systems using computers have to be built on the premise of continuous operation, for example, 24 hours a day, so dual systems have been adopted to improve their reliability. (For example, the document ``Real-time Reservation System J
See P. 76 (Sangyo Tosho Co., Ltd., published in June 1972).

Such an online dual processing system, for example, as shown in FIG.
It consists of a mask (hereinafter referred to as a mask) 2, a backup arithmetic processing unit (hereinafter referred to as a slave) 3 which is the same model as the master 2 and operates according to the same program, and an output device 4.

An input signal S1 such as field data inputted to the input device 1 is amplified by the input device 1, inputted to the master 2 and slave 3 as SiM+Stll, and is subjected to predetermined arithmetic processing in the master 2 and slave 3, respectively. is executed, the output signal S. +4+s
, g to the output device 4.

The output device 4 then performs the following determination process to determine whether there is an abnormality in the processing of the re-output signal.

■ Master 2 output signal S. H and the output signal 5oil of the slave 3 are compared at a fixed timing to determine whether or not the master 2 has the highest level of processing.

■ Re-output signal S. ) I+Sol, it is determined that the mask 2 is normal, and its output signals So and I are output as the output signal S0 to the outside.

■ Also, the output signal S of master 2. ) I and the output signal S of slave 3. If there is a difference between B and B, the system self-detects that an abnormality has occurred in the entire system to prevent the system from running out of control.

■ Output signal 5 from master 2 (
When IN is not output, it is determined that an abnormality such as a failure has occurred in the master 2, and the output device 4 outputs the output signal 5 (IB) of the slave 3 as an output signal S0 to the outside.

In this way, when an abnormality occurs in the master 2, it is immediately switched to the slave 3 in an attempt to minimize system stoppages due to failures or failures.

<Problems to be Solved by the Invention> However, the conventional online dual processing system as described above has the following drawbacks.

■ Master 2 output signal S. 9 and slave! It is unclear which of the three output signals SOB will be output to the output device 4 first, and therefore it is difficult to determine the timing to compare them.

■ When the number of points of the input signal S8 increases, the mask 2 . Since the number of signal wires to the slave 3 increases, the cost required for wiring work increases.

■ If slave 3 is triplexed or quadruplexed in order to improve system reliability, construction costs will further increase, signal wiring will become complicated, and maintenance and inspection will be burdened.

An object of the present invention is to provide a backup method for an online dual processing system suitable for solving the above problems.

<Means for Solving the Problems> The gist of the present invention is to input field data signals and the like to a main processing unit and a backup processing unit through an input device, perform processing in parallel, and then output the data. A backup method for an online dual processing system that outputs signals to each device, determines whether there is a processing abnormality in the output device, and then outputs a correct output signal. A difference is given in advance to the data transmission time to be transmitted, and the main calculation is performed by comparing the difference in the output time of the output signal output from the main processing unit and the backup processing unit to the output device with the difference in the data transmission time. In order to achieve the above purpose, the presence or absence of a processing abnormality in the processing unit is detected, and when it is determined that there is an abnormality in the output signal of the main processing unit, the output signal of the backup processing unit is immediately output. It is something to do.

<Function> According to the present invention, the difference in data transmission time from the input device to the main processing unit (mask) and the backup processing unit (slave) and the output signal output from the mask and slave to the output device By comparing the difference in the output time of can do.

<Examples> Examples of the present invention will be described in detail below with reference to the drawings. FIG. 1 schematically shows an embodiment of the method of the present invention.

As shown in FIG. 1, an input device 1, a master 2, and a slave 3 are connected by a loop-shaped data communication line 5. By looping the line, the data communication line 5 can constitute a network having a so-called broadcast communication function that transmits one piece of information to a plurality of computers in chronological order.

Here, the input device 1 and the master 2 . The connection position of slave 3 is always fixed,
Therefore master 2 and slave 3 from input bag W1
Transmission distance fl+, t! Assuming that z remains unchanged and the transmission speed of the data communication line 5 is constant, such as 10 Mbps, the input signal S from field data etc. amplified by the input device 1 is as shown in FIG. After a time t2, it is inputted to the master 2 as an input signal S1, and after a time t2, it is inputted to the slave 3 as an input signal Si8, and the time difference Δ1 (-12L, ) is also always constant.

Then, from master 2 and slave 3 to output device 4
Each output signal S is output to. , 4SoB output timing is, in a normal state, the output signal S from the master 2 first. , 4 is outputted and a time Δ after that, the output signal S from slave 3 is output. B will be output.

Therefore, in the output device 4, by setting the time difference Δm in advance and performing the following judgment process, it is possible to quickly detect a failure in the master 2 and back it up.

■ First, based on the output time of the output signal 5 (18) of the master 2, the slave 3
It is determined whether or not the output signal Son is output, and it is determined whether or not there is an abnormality in the processing of the master 2.

■ And re-output signal S. When there is no difference between M+SOB, it is determined that master 2 is normal, and its output signal S. M is output as an output signal S0 to the outside.

■ Also, the output signal S of master 2. H and slave 3 output signal S. If there is a difference between B and B, it is determined that an abnormality has occurred in the entire system, and the system is prevented from running out of control.

■ Output signal S of slave 3. After B is output, the output signal S of master 2 is output. , l is output, or when it is not output at all, it is determined that an abnormality has occurred in the master 2, and the output device 4 selects the output signal 5oil of the slave 3 and outputs the output signal S to the outside.

Output as .

In this way, the output signal S of master 2. The output signal S of the master 2 after a time difference Δt has elapsed with reference to M. M and slave 3 output signal S. 6, it is possible to obtain a highly reliable output signal S0.

Note that if a plurality of slaves 3 are set, the output signal S of the slave 3 itself. It goes without saying that the abnormality in B can also be detected using the same procedure as above. The timing of comparison at this time is n・Δt (where n is the number of slaves 3 and n≧2), so
An increase in the number of slaves 3 does not cause confusion in comparison operations.

<Effects of the Invention> As explained above, according to the present invention, the following effects are expected.

■ Since the output signals of the mask and slave can be compared at accurate timing, highly accurate output signals can be obtained.

■ Since slave multiplexing can be easily configured, a non-stop online control system can be realized.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram schematically showing an embodiment of the method of the present invention, FIG. 2 is an explanatory diagram showing the transmission time of an input signal, and FIG.
The figure is a schematic diagram schematically showing a conventional example. 1... Input device. 2...Mask (main processing unit). 3...Slave (backup processing unit). 4...Output device. 5...Data communication line.

Claims (1)

[Claims] Field data signals and the like are input to the main processing unit and the backup processing unit through the input device, and arithmetic processing is executed in parallel, and then outputted to the respective output devices.The output device determines whether or not there is a processing abnormality. This is a backup method for an online dual processing system that outputs correct output signals from an input device, in which a difference is given in advance to the data transmission time from an input device to a main processing unit and a backup processing unit. The difference in the output time of the output signal output from the backup processing unit to the output device is compared with the difference in the data transmission time to detect the presence or absence of a processing abnormality in the main processing unit, and the output signal of the main processing unit is detected. When it is determined that there is an abnormality in
A method for backing up an online dual processing system, characterized by promptly outputting an output signal from a backup arithmetic processing unit.