JPS60264146A - Detecting and restoring device of communication error - Google Patents

Abstract

PURPOSE:To avoid trouble to a customer due to system-down by discriminating the state of a reception signal, taking it as a fail state if a normal block signal is not received until a prescribed time is elapsed and controlling the system to release the fail state when the normal block signal exists afterward. CONSTITUTION:A timer 7 is started after the detection of the block signal is awaited, the signal is decoded and the display in response to the content of the signal is executed. In the normal communication state, the next block signal is detected before the time informs the elapse of 500msec. When the timer informs the elapse of 500msec while no block signal is detected because of a fault or noise, the state is in the fail state and error display is executed. The error display is consecutive until the next new block signal is detected. Since the normal block signal is detected again when the error is due to a temperature cause such as simple noise, the fail state is released and the state is returned to the original normal state.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to abnormal processing of data communication in a multi-CPU control system.

Prior art If information is serially transferred from the main microcomputer to the sub-microcomputer using a communication system, if an abnormality occurs in the communication, the cause may be due to a malfunction or temporary noise due to noise, etc. It is also possible that this is due to some kind of malfunction.

Conventionally, when there is an abnormality in communication, the microcomputer on the receiving side detects the abnormality in the received signal 12. The task was in a fail state with an error message displayed and task processing was also stopped.

Therefore, even if the abnormality in the received signal is temporary due to noise, etc., the abnormality will remain displayed, and even if a normal signal is sent later, it will return to the original state and continue task processing. could not.

In this case, the hardware itself is not malfunctioning, and the operator must turn off the power and then turn it on again.
It's an unnecessary hassle.

Problems to be Solved by the Invention The present invention eliminates these drawbacks, and aims to solve them by automatically setting up the automatic communication system when a failure occurs due to a communication abnormality and a normal signal is subsequently received. The point is to cancel the fail state.

problem! The structure of the present invention will be explained based on FIG. 1.

A is a main microcomputer, B is a submicrocomputer, and information is transferred in blocks from the main microcomputer A to the submicrocomputer B in a serial manner.

In the sub-microcomputer B on the receiving side, O is a fail state setting means for setting a fail state due to a communication abnormality, and η is a fail state canceling means for canceling the fail state.

E is a block signal detection means for detecting the block signal transmitted from the main microcomputer A, and F is a time elapse detection means for detecting the passage of a predetermined time from the time when the block signal is detected by the block signal detection means. .

G & If there is no block signal, an instruction is given to the fail state setting means 0 to set the fail state, and when a normal block signal is received afterwards, an instruction is given to the fail state canceling means to cancel the fail state. Fill with things to do. .

Therefore, once a fail state 2 occurs, T- and Hole receive a normal signal and are able to release the fail state and return to the original normal communication state.

EXAMPLE Hereinafter, an example of the present invention illustrated in FIGS. 2 to 4 will be described.

This embodiment is an example of application to a copying machine, in which a main microcomputer is built into the main body of the copying machine, and a sub microcomputer is built into the display device, and information displayed by the main microcomputer is stored in the main microcomputer. This is a block transfer to the secondary microcomputer.

FIG. 2 is a block diagram of this embodiment, where l is the main body of the copying machine, 2 is the display device, 3 is the main microcomputer t, and 4 (
It is a secondary microcomputer.

Other display driver 5 on the display device 2 side. Various indicators 6
and a timer 7.

The display information signal transmitted from the main microcomputer 3 is decoded by the microcomputer 4, and a display instruction signal is output to the display driver 5, which drives the required display device and displays the required display. 'ru.

The communication signal is 50 m, as shown in Figure 3. sc y2
Block transfer is performed in units of one unit, and one block contains approximately (9) bytes of display information f2-? , has been.

While the required display is turned on for the required time, information with the same content is repeatedly transferred, and when the display state changes, corresponding information is transmitted.

In Fig. 2, the timer 7 starts with a signal for each block and notifies when 500 mθec time has elapsed, but in normal communication state, it starts with a signal of one block and resets with a signal of the next block. Repeatedly starting again.

Therefore, an abnormality occurs in the communication, and the block signal disappears.T'' continues to measure the time when the block signal cannot be detected due to the disturbance and the power is on.
After 500 msec has elapsed and no signal is detected, the secondary microcomputer 4iC issues a warning signal at 5 o'clock.

Based on the configuration described below, the operating procedure will be explained with reference to the flowchart shown in FIG.

First, wait for a block signal to be detected (step ■), then the timer 7 will start (step ■), and the signal will be decoded (step ■) 2. The electric display will change depending on the content of the signal (step ■) .

Timer 7 determines whether to issue a warning after 500 m sec has elapsed (step ■) or whether the next block signal is detected (step ■), and if it fails, repeat steps ■, ■, and ■. . When the communication is in a normal state, the next block signal is detected before the timer notices the passage of 500-vsc, so the process returns from step ■ to step ■, and timer 7 restarts T-, and the signal decoding is completed. (step ■), a display is made according to the content of the signal (step ■), and steps ■, ■, and ■ are repeated again.

At this point, if the timer is activated for 500 m sec without detecting a block signal due to a failure or the like due to noise etc., the process moves from step p to step ■, and a fail state occurs and the error display power is activated. □ The error display continues until the next new block signal is detected (step ■). The error will still be displayed, but if it is due to a temporary cause such as simple noise, a normal block signal will be detected again, so the program will return from step ■ to step ■, and the fail state will be cleared. , 1' which returns to the original normal operation.

As mentioned above, even if an error display state occurs, the error display state can be automatically canceled and normal operation can be restored by detecting a subsequent block signal, so there is no need to turn off the power and then turn it on again as in the past. No hassle.

Effects of the Invention In this way, the present invention can automatically release the fail state and return to normal operation even if the communication goes into a fail state due to a communication abnormality, and sometimes the fail state can be automatically canceled and normal operation can be restored. Inconvenience to customers can be avoided.

[Brief explanation of the drawing]

Fig. 1 is a diagram corresponding to the claims of the present invention, Fig. 2 is a block diagram of an actual example of the present invention, Fig. 3 is a diagram showing the signal state of the nose embodiment, and Fig. 4 is the operation of the present embodiment. It is a flowchart showing the procedure. L... Copying machine body, 2... Display device, 3... Main microcomputer, 4... Sub microcomputer, 5... Display driver, 6... Various displays, 7...
...Timer agent Patent attorney Nozomi Ehara (2 people) Figure 3

Claims (1)

[Claims] A multi-PU system that transfers blocks of information serially from the secondary microcomputer to the secondary microcomputer.
In the communication control by K, the receiving loop i[l is sent from the main microcomputer to a fail state setting means for setting a fail state due to a communication abnormality on the microcomputer side and a fail state canceling means for canceling the fail state. A block signal detection means for detecting a block signal, a time elapse detection means for detecting the elapse of a predetermined time from the time when the block signal is detected by the block signal detection means, and information from the time elapse detection means and the block signal detection means. First, determine the state of the received signal.1 If a normal block signal is not received by the time a predetermined period of time has elapsed, an instruction is given to the fail state setting means to set the fail state and a normal block signal will be received after a period of time. A communication abnormality detection and recovery device comprising information processing means for instructing the fail state canceling means to control the fail state to be canceled when the fail state is detected.