JPH03254552A - Communication controlling system - Google Patents

Abstract

PURPOSE:To prevent disturbance caused in any transmission line from giving effect onto a data through other transmission line by providing a switch closed only for a setting period having a response on the way of a reception data line through which a response outputted from a communication controller at a secondary station side returns to a communication control circuit. CONSTITUTION:A response is inputted to a communication control circuit 3 via a transmission line 5a, an interface circuit 4a, a reception data line 7a, a switch 9a and an OR gate 10. When a stationary disturbance takes place in the transmission line 5a, the communication of a command to a communication controller 2a or of the response to the communication control circuit 3 is not implemented. However, when other communication controllers 2b-2d receive a command and send a response independently respectively, any of relevant switches 9b-9d is closed and the switch 9a is opened, then the effect of the disturbance on the transmission line 5a is not caused at all and normal communication is maintained.

Description

[Detailed description of the invention] [Industrial application field]

This invention includes one primary station side communication control device and a plurality of two
The present invention relates to a communication control system that controls data transmission and reception performed with a communication control device on the next station side.

[Conventional technology]

FIG. 2 is a block connection diagram showing a conventional communication control system. In the figure, 1 is a communication control device on the side of one primary station, and 2a, 2b, 2c, and 2d are a plurality of communication control devices that communicate with this device. A communication control device on the secondary station side, 3 is a communication control circuit provided in the communication control device 1, 4a, 4b, 4c, and 4d are interface circuits, and 5a, 5b, 5c, and 5d communicate with each interface circuit 4a to 4d. Transmission lines connecting corresponding control devices 2a to 2d; 6 is a transmission data line; 7a, 7b, 7c, and 7d are reception data lines; 1;
0 is an OR gate that inputs each received data on the received data lines 7a to 7d to the communication control circuit 3. Next, the operation will be explained. First, in the communication control device 1 on the primary station side, the communication control circuit 3
outputs a command through the transmission data line 6. This command is sent to the communication control devices 2a to 2a on the secondary station side through interface circuits II, 4a to 4d, and transmission lines 5a to 5d.
2d. Therefore, 2a to 2d for each communication #
checks whether the command is addressed to its own station, and if, for example, the communication control device 2a recognizes that the command is addressed to its own station, it returns a response to the communication control device 1. This response is sent via the transmission path. Receive data line 7a through 5a
is inputted to the communication control circuit 3 from there, and this is confirmed. Similarly, each communication control device 2b follows. By sequentially sending commands to 2c and 2d, communication between these and the communication control device 1 is performed.

[The problem that the invention tries to solve! ! 1. Since the conventional communication control system is configured as described above, for example, if there is a steady disturbance in the transmission path 5a,
Erroneous data is constantly input to the communication control circuit 3 via the reception data line 7a and the OR gate 10, and therefore, the reception data from the communication control devices 2b, 2c, and 2d are also input to the communication control circuit 3 by mistake. , there were problems such as communication between the communication control device 1 and the communication control devices 2b, 2c, and 2d becoming impossible. Note that technology similar to the conventional communication control system is described in Mitsubishi Electric Technical Report Vol. 1.61.
N11121987 P14-17. This invention was made to solve the above-mentioned problems, and even when disturbances occur regularly on a specific transmission path, communication control devices connected to other transmission paths can The purpose is to obtain a communication control system that can connect communications between [! l! Means for Solving the Problem] In the communication control system according to the present invention, the communication control circuit is connected to the communication control circuit on the secondary side in the middle of each data line connecting the communication control circuit on the primary station side and each interface circuit. A switch is connected that is turned on only for a set period of time while waiting for a response from each communication control device.

[Effect]

The switch of the present invention is turned on only for a certain period of time when the communication control device on the secondary station side corresponding to the switch returns a response to the communication control circuit of the communication control device on the primary station side.
Even if there is a disturbance in the transmission path, it will be turned off after this period has elapsed, so that subsequent communication between the communication control device of the other secondary station and the communication control circuit can be performed without being affected by the disturbance. do it like this.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, 1 is one communication control device on the primary station side, 2a
, 2b, 2c, and 2d are a plurality of 2s that communicate with each other.
Communication control device on the next station side, 3 is a communication control circuit provided in the communication control device 1, 4a, 4b, 4c, 4d are interface circuits, 5a, 5b, 5c, 5d are communication control with each interface circuit 4a to 4d. A transmission line connecting corresponding devices 2a to 2d, 6 a transmission data line, 7
Reference numerals a, 7b, 7c, and 7d are reception data lines, and IO is an OR gate for inputting each reception data of the reception data lines 7a to 7d to the communication control circuit 3. Further, 8 is a switching circuit connected in the middle of the reception data lines 7a to 7d.
Switches 9a and 9b that turn on and off the received data passing through the
, 9c, and 9d. In addition, each of these switches 93
~9d are turned on only for a predetermined period when responses are received from the corresponding communication intermediaries f2a~2d. Next, the operation will be explained. First, the communication control device 1 on the primary station side sends a command addressed to, for example, the communication control device f2a on the secondary station side from the communication control circuit 3 through the transmission data line 6, and turns on the switch 9a of the switching circuit 8. Make it. This command is applied to each interface circuit 4a to 4d and transmission line 5a to 5d.
is supplied to all communications equipment f2a-2d through
Each command is checked to see if it is addressed to its own station. Then, the station that recognizes the command as being addressed to its own station, here the communication intermediary device f2a, returns a response to the communication control circuit 3. That is, this response is sent to the transmission path 5a, the interface circuit 4a, the reception data line 7a, switch 9a
and is manually input to the communication control circuit 3 via the OR gate 10. After this, the switch 9a is turned off. Thereafter, commands are sent to each communication control device 2b to 2d and responses are received from these devices in the same manner. By the way, if a steady disturbance occurs in the transmission WI 5a, commands to the communication intermediary F12a and responses to the communication control I11 circuit 3 cannot be communicated from now on. However, other communication control devices 2b to 2d
When receiving a command and transmitting a response independently, one of the corresponding switches 9b to 9d is closed and the switch 9a is opened, so the response from the communication control device 2b to 2d is The above transmission wi
This means that normal communication can be maintained without being affected by the disturbance in 5a. In addition, in the above embodiment, four secondary side communication intermediaries W2a
Although the case of ~2d has been described, the number may be four or more. Further, in the above embodiment, the interface circuits Ni4a to 4d
Although a modem or high-speed digital line interface circuit is shown, it may be a modem or a high-speed digital line interface circuit.

【Effect of the invention】

As described above, according to the present invention, during the reception data line in which a response output by the communication control device on the secondary station side is returned to the communication control circuit, the communication control circuit is turned on for a set period of time during which it waits for the response. Since the configuration is equipped with a switch, it is possible to prevent disturbances that occur in one transmission path from affecting data passing through other transmission paths, and the system can continue to respond to data through other transmission paths. This has the effect that stable communication can be performed between the communication control device on the secondary station side and the communication control circuit.

[Brief explanation of drawings]

FIG. 1 is a block connection diagram showing a communication control system according to an embodiment of the present invention, and FIG. 2 is a block connection diagram showing a conventional communication control system. 1 is a communication control device on the primary station side, 2a to 2d is a communication control device on the secondary station side, 3 is a communication control circuit, 4a to 4d are interface circuits, 5a to 5d are transmission paths, 6 is a transmission data line, 7a to 7d are reception data lines, and 9a to 9d are switches. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. 1I11 Figures 2a-2d 4a-4d 5a-5d 7a-7d 9a-9d Primary station Il+l communication system 4ITI Song setting 2; missing ﾾ 6iiil+liri mausoleum iiiword #Il+ 4 wholesale 1 layer (
1 message ^ 11 (11 []μ

Claims (1)

[Claims] Generated from multiple secondary station side communication control devices connected to one primary station side communication control device via a unique transmission path, and the communication control circuit of the above primary station side communication control device. A transmission data line that supplies commands to each communication control device on the secondary station side through an interface circuit, and a response output by the communication control device on the secondary station side that has recognized the command, via the corresponding interface circuit. In the communication control system, each of the received data lines is connected in the middle of each of the received data lines to be turned on only for a set period during which the communication control circuit waits for the response. A communication control system characterized by: