JPH05327722A - Data transmitter device for a plurality of inter-operation terminals - Google Patents

Abstract

PURPOSE:To automate a procedure for inspection of the operation terminals where an uncommunicatable state is caused in regard to a data transmitter device which transmits the data among plural terminal. CONSTITUTION:A data transmitter device which transfers the data among plural operation terminals is provided with a calling means 40 which acquires affirmative answers to the calling commands given to the operation terminals by the external instructions and an answer processing control means 41 which decides whether an affirmative answer is received from each called operation terminal within a prescribed time or not and performs the control to store the deciding result, and a fault deciding means 42 which decides the fault of each operation terminal based on the presence or absence of the stored affirmative answer data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data transmission device between a plurality of terminals which combines a plurality of terminals and transmits data between them. In particular, according to the present invention, which terminal is used when communication is impossible between the terminals. It relates to the one that automates the procedure for investigating whether communication is lost between two.

[0002]

2. Description of the Related Art Conventionally, as a technique in such a field, when the amount of data is relatively small and there is a direction for installing a terminal,
There is a line data transmission device that utilizes a branching device. The economic effect of using a branching device is greater when the number of branches is large and the distance between the center and the terminal group, that is, the shared portion of the line is longer, but it is considerably economical even if the distance between the center and the terminal group is relatively short. Since it can be expected to be effective, it is actually widely used in systems where the geographical spread of the communication network is relatively narrow. For data transmission to the terminal via this branching device, there are a polling / selecting method, a contention method, and the like. The former asks whether the master machine can send or receive to each terminal in order. That is, it performs two functions of polling and selecting. More specifically, in polling, the master machine asks the terminal if there is any data to send,
On the other hand, if there is data to be transmitted from the terminal, an affirmative response ACK (Acknowledge) is sent and the content is transmitted, and if there is no data, then there is no response NAK (N
Execute an eager acknowledgment. In selecting, the master unit wants to send data to the terminal, but it asks whether it can receive it. If the terminal can receive it, it sends a positive response ACK and receives the data, and cannot receive it. In the case of (the terminal is doing other work), a negative response NAK is issued. On the other hand, in the contention method, unlike the above method, the terminals independently control the line without going through the master unit, and for example, the sending side can ask whether the data can be sent to the receiving side and confirm it. After that, the transmission right is established and the actual data is transmitted.

[0003]

However, in the data transmission device between a plurality of terminals as described above, when a part of the line fails, the master machine accesses each terminal machine by the polling / selecting method. It is possible to quickly determine which terminal is malfunctioning, but the terminal itself independently determines which terminal is malfunctioning by the contention method by sending and receiving to and from each terminal individually. It has to be time-consuming and difficult.

Therefore, in view of the above problems, the present invention provides a data transmission device between a plurality of terminals, which allows a terminal to quickly and surely investigate which device has a failure when a system goes down due to communication failure. The purpose is to do.

[0005]

In order to solve the above problems, the present invention provides a means for calling each operation terminal in a data transmission device between a plurality of operation terminals which transmits and receives data between the operation terminals. A response processing control means for each operation terminal and a failure determination means for each operation terminal are provided. The calling means of each operating terminal requests an affirmative response to the calling command to each of the other operating terminals according to an instruction from the outside.

The response processing control means of each operation terminal determines whether or not a positive response has been received from each operation terminal called by the calling means of each operation terminal within a predetermined time and stores the result. I do. The failure determination means of each operation terminal determines the failure of each operation terminal based on the presence or absence of positive response data stored by the response processing control means of each operation terminal.

[0007]

According to the data transmission device between a plurality of operation terminals of the present invention, each operation terminal responds to a call command from the calling means of each operation terminal to each of the other operation terminals according to an instruction from the outside. Requires a positive response. Further, the response processing control means of each of the operation terminals determines whether or not a positive response is received from each of the operation terminals called by the calling means of each of the operation terminals within a predetermined time and stores the result. Can go.

Further, the failure judging means of each of the operating terminals judges the failure of each of the operating terminals from the presence / absence of the positive response data stored by the response processing control means (41) of each of the operating terminals. Therefore, it becomes possible to quickly determine which operating terminal is out of order from one operating terminal.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a plurality of branch type terminal lines according to an embodiment of the present invention. The lines of a plurality of terminals shown in the figure are a master machine 1 as a host computer, a branching device 2 connected to the master machine 1, branching devices 3, 4, 5 connected to the branching device 2, and an operating terminal. 6, a line terminal 7 connected to the branching device 3, operation terminals 8, 9, and 10,
A line terminal 11 that wirelessly communicates with the line terminal 7, an operation terminal 12 connected to the line terminal 11, and the branching device 4
And operating terminals 17, 14, 19, 16 connected to the branching device 5, and operating terminals 17, 18, 19, 20 connecting to the branching device 5.

Although the modem is omitted here, each of the branching devices 2 is an AC branching device for branching the modulated signal, and each of the branching devices 3, 4, 5, 6 is an AC branching device for branching the modulated signal. Or a DC branching device for branching the DC level after demodulation by a modem. The latter is suitable when the operating terminal is installed near the branching device.

FIG. 2 is a diagram showing a schematic configuration of signal processing of the terminal. The terminal shown in this figure includes an interface 31 for transmitting and receiving signals to and from the branching device and for converting between analog and digital signals, and each phase of the transmission control procedure, for example, line connection and transmission side when using a public line. To establish a data link that establishes a path for sending and receiving data between the receiver and the receiver, to perform error control to detect and correct an error that occurs in the transmission path, and to detect the failure point of the line at the time of failure described later. A central processing unit 32 (CPU) that transfers information, releases the data link when the data link transfer ends, terminates, and finally disconnects the line, and normal signal processing for the central processing unit 32. A ROM 33 that stores a program for making a terminal failure determination, an address of a terminal that constitutes a line, and the like, and temporarily stores data processed by the central processing unit 32. Including the AM34, a key input unit 35 for performing such giving an instruction for detecting an operation terminal failure in the central processing unit 32, and a display 36 for displaying the status of the operation terminal failure.

FIG. 3 is a diagram showing the configuration of signal processing performed by the central processing unit of the operating terminal. The central processing unit 32 shown in the figure comprises a calling means 40 for each operating terminal that requests each operating terminal that constitutes the line to call. When there is an instruction to detect an operating terminal failure from a key input, the calling means 40 of each operating terminal reads out the address of each operating terminal from the ROM 33 and sends it to each operating terminal via the interface 31 to call and receive the call. It then asks to send a positive response ACK. Specifically, in FIG. 1, for example, a call command is sent from the operation terminal 6 to A6-8, A6-9, A6-10, A6-1.
2, A6-13, A6-14, A6-15, A6-1
6, A6-17, A6-18, A6-19, A6-20
The operating terminals 8, 9, 10, 12, 13, 14, 15,
16, 17, 18, 19, 20 and the positive response from these operating terminals is ACK8-6, ACK9-6, AC
K10-6, ACK12-6, ACK13-6, ACK
14-6, ACK15-6, ACK16-6, ACK1
7-6, ACK18-6, ACK19-6, ACK20
-6 is transmitted to the operation terminal 6.

Next, the central processing unit 32 is provided with a response processing control means 41 for each operation terminal which controls the response from each operation terminal. Response processing control device 4 of each operation terminal
1 determines whether an affirmative response ACK from each operation terminal called by the calling means 40 of each operation terminal has been received within a predetermined time, and the result is temporarily stored in the RAM 34 corresponding to each operation terminal. Remember.

Further, the central processing unit 32 is provided with a failure judging means 42 for each operating terminal for judging a failure of each operating terminal. The failure judgment means 42 of each operation terminal judges a failure from the positive response result from each operation terminal processed by the response processing control means 41 of each operation terminal, and displays the result on the display 36. The details of the failure judgment of each operation terminal will be described below.

FIG. 4 is a flow chart for explaining failure judgment of each operation terminal. As shown in the figure, in step 1, the failure determination means 42 of each operation terminal sends an affirmative response ACK to the call from each operation terminal from the RAM 34 via the response processing means 41 of each operation terminal.
To determine if all exist. When there is no affirmative response ACK within a predetermined time from the call from the calling means 40 of each of the operation terminals, it is determined that the corresponding operation terminal has a failure.

In step 2, all positive acknowledgments ACK
If there is, all the operating terminals are judged to be normal, and that fact is displayed. In step 3, it is determined whether all positive acknowledgment ACKs are not present. In step 4, if there is no positive response ACK, it is determined that the master machine has failed or its own failure. This is because the probability that all operating terminals will fail at the same time is very small, because there is one master machine or itself and one master line.

In step 5, it is determined whether there is a positive response ACK from all the operating terminals belonging to the same branching device. In step 6, if there is no positive response ACK from all operating terminals belonging to the same branching device, it is determined that the branching device has failed. This is because the probability that a plurality of operating terminals will fail at the same time is small. For example, the positive response AC
K17-6, ACK18-6, ACK19-6, ACK
If 20-6 does not exist, the branching device 5 has failed.

In step 7, if there is only a part of the positive response ACK of all the operating terminals belonging to the same branching device, it is determined that the operating terminal is out of order. The failure of the operating terminal includes a transmitting device of the operating terminal, a communication line, and the like.

[0019]

As described above, according to the present invention, since the procedure for investigating which communication terminals are incapable of communication is automated, the failure location can be determined quickly and reliably.

[Brief description of drawings]

FIG. 1 is a diagram showing a line between a plurality of branch type terminals according to an embodiment of the present invention.

FIG. 2 is a diagram showing a schematic configuration of signal processing of a terminal.

FIG. 3 is a diagram showing a configuration of signal processing performed by a central processing unit of a terminal.

FIG. 4 is a flowchart illustrating failure determination of each terminal.

[Explanation of symbols]

1 ... Master machine 2, 3, 4, 5, 6 ... Branching device 8, 9, 10, 12, 13, 14, 15, 16, 17,
18, 19, 20 ... Terminal 32 ... Central processing unit 40 ... Calling means of each operation terminal 41 ... Response processing control means of each operation terminal 42 ... Failure determination means of each operation terminal

Claims (1)

[Claims] 1. A data transmission device between a plurality of operation terminals for transmitting and receiving data between a plurality of operation terminals, wherein an affirmative response to a call command to each of the other operation terminals is given by an external instruction. A call means (40) for each operating terminal to be sought and a judgment as to whether or not a positive response has been received from each of the operating terminals called by the calling means (40) for each operating terminal within a predetermined time, and the result is stored. The failure determination of each operation terminal is performed based on the response processing control means (41) of each operation terminal that controls the operation and the presence or absence of positive response data stored by the response processing control means (41) of each operation terminal. A data transmission device between a plurality of operation terminals, comprising: failure determination means (42) for each operation terminal.