JPH06325002A - Synchronizing method for plural computers - Google Patents

Abstract

PURPOSE:To unnecessitate a synchronizing signal from a master computer when a slave computer is singly used and, on the other hand, to prevent system down caused by automatically switching a system to the single start of the slave computer when the synchronizing signal is stopped being supplied in the middle of the operation of the slave computer corresponding to the synchronizing signal from the master computer. CONSTITUTION:In place of the conventional method for periodically starting a slave computer 2-i only corresponding to a synchronizing signal 4-i from a master computer 1, a start trigger switch processing part 8 is added inside the slave computer 2-i, and an interrupting signal 7 from an internal timer 6 of the master computer 1 is automatically switched to a trigger for the periodical start of an application program 5 and used corresponding to the form of use and the interruption of the synchronizing signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of synchronizing computers in a system including a plurality of computers in its components.

[0002]

2. Description of the Related Art A conventional method for synchronizing a plurality of computers will be described with reference to FIG. In FIG. 4, this system includes one master computer 1 and n slave computers 2-i (i
, 1, 2, ..., N), and the master computer 1 sends a synchronization signal 4-i (i = 1, 2, ..., N) to each slave computer 2-i via the synchronization signal line 3. Output.
On the slave computer 2-i side, the application program 5 is cyclically activated using the corresponding synchronization signal 4-i in all the usage patterns.

[0003]

In the conventional synchronization method,
Since the application program 5 in the slave computer 2-i is cyclically activated only by the synchronization signal 4-i given from the master computer 1, the following problems occur. (1) Even when the slave computer, for example, 2-1 is used alone, it is necessary to operate the master computer 1 and supply the synchronization signal 4-1 in order to start the application program 5, which results in high operating cost. . (2) When the synchronization signal 4-i is not supplied due to a failure of the master computer 1 during the operation of the system, the slave computer 2-i cannot be started and the system goes down.

The present invention solves the above-mentioned problems of the prior art and eliminates the need for a synchronization signal from the master computer when the slave computer is used alone, while the slave computer is operating while the synchronization signal from the master computer is operating. It is an object of the present invention to provide a synchronization method capable of automatically switching to the independent activation of a slave computer and preventing the system from going down even if the synchronization signal is no longer supplied.

[0005]

A method of synchronizing a plurality of computers according to the present invention which achieves the above object, is a system including a slave computer and a master computer for giving a synchronization signal to the slave computer. An activation trigger switching processing unit having an interrupt processing unit, an internal timer interrupt processing unit, a flag for managing the usage pattern of the system, and a counter for monitoring the interruption of the synchronization signal is provided. The part (1) receives both the synchronization signal from the master computer and the interrupt signal from the internal timer, and (2) monitors the state of the flag and activates the application program using the synchronization signal. Whether to use an interrupt signal or (3) a synchronization signal to the application program. When used as dynamic trigger,
The counter is updated each time the sync signal is received, and the interruption of the sync signal is monitored depending on whether the counter is updated at regular intervals.When the interruption occurs, the interrupt signal from the internal timer is used as a start trigger for the application program. It is characterized by being used.

[0006]

With the above configuration, instead of the conventional method in which the slave computer is synchronously activated only by the synchronization signal from the master computer, an activation trigger switching processing unit is added in the slave computer to cope with the usage pattern and the interruption of the synchronization signal. Then, the internal timer of the slave computer is automatically switched to a trigger for cyclic activation of the application program and used.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of a multi-computer system to which the present invention is applied. The master computer 1 and slave computers 2-i are shown in FIG.
(I = 1, 2, ..., N). The master computer 1 outputs a synchronization signal 4-i (i = 1, 2, ..., N) to each slave computer 2-i via the synchronization signal line 3. In addition to the application program 5 and the internal timer 6, the slave computer 2-i has an activation trigger switching processing unit 8. In addition to the synchronization signal interruption processing unit 9 and the internal timer interruption processing unit 10, the activation trigger processing unit 8 has a switching flag unit 11 and an interruption monitoring counter 12, and the synchronization signal and the period equal to the synchronization signal are provided. Both of the set interrupt signals 7 from the internal timer 6 are received via the interrupt processing units 9 and 10, and the switching flag unit 11 and the counter 12 determine the usage pattern of the system and the presence or absence of interruption of the synchronization signal. Then, the start trigger for the application program 5 is used as a synchronization signal, or the interrupt signal 7 from the internal timer 6 is used.
Switch whether or not.

Next, the operation of the activation trigger switching processing section 8 will be described with reference to FIGS. 1, 2 and 3.

First, in the switching flag section 11, the switching flag F is set by the application program 5 in accordance with the usage pattern of the system, and the switching flag F uses the activation trigger as a synchronization signal from the master computer 1 or It specifies whether to use the interrupt signal 7 from the timer 6.

The synchronization signal interrupt processing unit 9 is activated each time a synchronization signal is received. As shown in FIG. 2, the switching flag F is read (step S1), and the switching flag F indicates activation by the synchronization signal. If (step S2), counter 1
2 is updated or incremented (step S3), and the application program 5 is started using the synchronization signal from the master computer 1.

The internal timer interrupt processing unit 10 is activated by an interrupt signal 7 from the internal timer 6, reads the switching flag F (step S10), and the switching flag F receives the interrupt signal 7 as shown in FIG. If the activation is indicated (step S11), the application program 5 is activated using the interrupt signal 7 (step S17). When the switching flag F indicates the activation by the synchronization signal from the master computer 1, the interruption monitoring counter 12 is read (step S12), and it is checked whether or not it is normally updated (incremented) at a constant interval ( Step S1
3) If not updated normally, the number of times the counter 12 is updated is counted (step S14), and when the value reaches the adjustable value A, it is determined that an abnormality has occurred (step S15), and the application program 5 is started by using the interrupt signal 7 from the internal timer 6 (step S1
7). At this time, the occurrence of an abnormality is notified to the application program 5 as necessary (step S16).

[0012]

According to the present invention, it is possible to automatically switch the start trigger of the application program inside the computer according to the usage pattern of the system and the presence / absence of an abnormality. The following effects can be achieved. (1) When the slave computer is used alone, it is possible to automatically switch to the internal timer of the slave computer, and it is not necessary to move the master computer, so the operating cost can be reduced. (2) Even when the supply of the synchronization signal is interrupted due to a failure of the master computer or the like, the activation trigger of the application program can be switched to the internal timer, and the system down can be avoided.

[Brief description of drawings]

FIG. 1 is a diagram showing a multi-computer system according to an embodiment of the present invention.

FIG. 2 is a diagram showing a flow of synchronization signal interrupt processing.

FIG. 3 is a diagram showing a flow of internal timer interrupt processing.

FIG. 4 is a diagram showing a conventional example.

[Explanation of symbols]

 1 master computer 2-i (i = 1,2, ... n) slave computer 3 synchronization signal line 4-i (i = 1,2, ... n) synchronization signal 5 application program 6 internal timer 7 interrupt signal 8 start trigger Switching processing unit 9 Synchronization signal interrupt processing unit 10 Internal timer interrupt processing unit 11 Switching flag unit 12 Counter

Claims (1)

[Claims] 1. In a system including a slave computer and a master computer for providing a synchronization signal to the slave computer, the slave computer is provided with a synchronization signal interrupt processing unit, an internal timer interrupt processing unit, and a usage pattern of the system. An activation trigger switching processing unit having a flag to be managed and a counter for monitoring interruption of the synchronization signal is provided, and by this activation trigger switching processing unit, (1) a synchronization signal from a master computer and an interrupt from an internal timer. Receiving both of the signals, (2) monitoring the state of the flag, and switching between activation of the application program using a synchronization signal or an interrupt signal, (3) ) When the sync signal is used as a start trigger for the application program, the counter is updated each time the sync signal is received. Newly, multiple computers characterized by monitoring the interruption of the synchronization signal depending on whether or not the counter is updated at regular intervals and using the interrupt signal from the internal timer as a start trigger for the application program when the interruption occurs. Synchronization method.