JPS60237744A - Communication control equipment - Google Patents

Abstract

PURPOSE:To decides on the cause of a fault and to make its recovery effectively by providing a storage part which stores a processing state in the control equipment and reading its contents in case of the occurrence of the fault. CONSTITUTION:Plural communication control equipments linked to a synchronous station through transmission lines has a terminal device respectively. When one communication control equipment finishes obtaining the right for communication with another communication control equipment, a significant code, e.g. ''1'' is written in an address A+0 of a storage part. Then, the control equipment inquires of the opposite party communication control equipment whether it is busy or ready and then signifies the contents of an address A+1. Then, addresses A+2-A+N are signified successively every time each process of communication is completed. Consequently, if a failure in communication continues, a significant code is read out to check on records, thereby easily performing processes as the occurrence position and cause of a fault and its recovery.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a communication control device connected via a transmission path, and particularly to a device that transmits information with a partner using a communication procedure.

[Prior art]

Conventionally, there have been devices of this type that perform processing as shown in JI8C6362. FIG. 3 shows a connection diagram of the communication system. Sl is a synchronization station, and 82 to S4 are communication control devices, which are connected in series to the synchronization station S1 in a ring shape via a transmission line, and receive a synchronization signal from the synchronization station 81 and perform synchronization therewith. T1 to T3 are terminal devices connected to communication devices 82 to 84, respectively,
Send and receive data.

The communication devices 82 to S3 connected in this manner each execute a transmission process as shown in the flowchart of FIG. To simplify the explanation, a case will be described in which the communication device S2 transmits data to the communication device S3.

Process 1 is a communication right acquisition process, and is a process that is always performed before using the transmission path L2. In addition to this process 1, when the communication right is acquired, processing 2 is performed to adjust the status of the communication partner (communication device 83).The status of the other party is BUSY (communication impossible) or READY (communication possible). .This alignment is performed by placing a predetermined signal on the transmission path, and the communication control device S3 of the other party also makes a predetermined response to this alignment signal.During this time, the data alignment to be transmitted in process 3 Make preparations such as
Wait for SY or READY status return. In judgment 4, it is determined whether the return is READY or BUSY. If NO (N), that is, READY, process 5 is performed to send data, and after all data is sent in process 6, it waits for the return of an ACK signal or NAC signal from the other party. Here A
The CK signal is a signal sent back when data is received correctly.
The AC signal is sent back from the other party when an error is detected by K, such as in various data verifications. Although not shown below, the determination and processing according to each situation are executed. If the result of judgment 4 is yes (Y), B
Perform rematch processing 7 when USY is present.

Conventional equipment expansion As mentioned above, since various processes were executed sequentially and communication with the other party was performed, some kind of failure occurred during the processing process, causing abnormal processing to be executed and communication to be interrupted. If it becomes impossible, the cause of the failure is wide-ranging, including a failure of the device itself, an abnormality in the transmission path, an abnormality in the communication partner station, or electrical disturbance, so there may be a large amount of trouble in determining the cause or estimation. The disadvantages are that it requires a lot of time and special measuring equipment.

[Summary of the invention]

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and communicates while storing the status of each process of the communication control device, and remembers when a failure occurs. Check the processing status and find out what kind of failure occurred.
In addition to determining where the cause is, it is possible to provide a device that can minimize the time and effort required to repair a communication failure when it occurs.

[Embodiments of the invention]

The flowchart of the process of this invention is the same as that shown in FIG. FIG. 2 is a map diagram showing the allocation of storage units. When the acquisition of communication rights in process 1 is completed, a significant code, for example 11m, is written to address A+O in this storage unit.

When process 2 is completed, address A+1 is made significant. Addresses A-1-2 to A+N are sent to addresses A-1-2 to A+N each time each process of communication is completed.
make it significant.

At this time, for example, if a situation continues in which communication is not possible because the other party's response is BUSY, by reading the significant codes recorded after processes 4 to T from addresses A+4 to A+7, communication will be disabled because the other party is BUSY. You can know that it is possible.

In addition, by reading records such as the state of processing, such as the extent to which the processing on the transmitting side has been completed, and whether or not it was a real K BUSY, the location where the cause of the K BUSY occurred can be further clarified.

Note that (a) the storage unit is configured with addresses A+O-A+N and addresses are allocated for each processing stage; however, in order to reduce the storage capacity, it is also possible to allocate bits for each processing stage. 〇 (b) If you do not assign processing stages to each address or bit in the storage unit, but instead assign numerical values to each stage as the processing progresses, the numerical value at the time of a failure cannot be memorized. , it is possible to know the stage of the process.

(1) When checking the memorized contents, each communication control device 82
Although it is possible to provide a means for reading out in S3, it is also possible to transmit the contents of the storage section to the synchronization station s1 and determine at the synchronization station the location where the failure has occurred. As described above, 1. According to the present invention, a storage section for storing processing status is provided in a conventional communication control device, and the contents can be read out when a failure occurs, and can be used to determine the cause of the failure and repair it. It can be used effectively, and there is no need for special measuring equipment, and the communication control device itself can use the stored contents effectively for self-diagnosis.

[Brief explanation of the drawing]

Figure 1 is a flowchart showing the processing procedure of the communication control device;
The figure is a map diagram of a storage section of a communication control device according to an embodiment of the present invention, and FIG. 3 is a connection diagram of a communication system. 1-3, 5-1...processing, 4...judgment, A+O~^
10N...Address, Sl...Synchronization station, 8
2-s3... Communication control device. Patent applicant Mitsubishi Electric Corporation

Claims (1)

[Claims] A state storage section is provided corresponding to each step of the process for communication, and is set according to the execution of that step, and when an abnormality occurs in the above processing, the state information stored in the state storage section is stored. A communication control device includes a processing unit for checking, and controls communication between terminal devices.