JPS6298835A - Supervisory control system - Google Patents

Abstract

PURPOSE:To allow a center equipment to independently check the restoration of its own circuit by installing a circuit loop-back means to a supervisory control center equipment at the side of a supervisory control terminal equipment in terms of an information transfer line and looping back transmission/reception signals when a line between the center equipment and said equipment is witched to a pay station circuit. CONSTITUTION:A loop-back part 11 for exclusively used circuits 3 and 4 is installed at the side of the terminal equipment 2. When said circuits 3 and 4 develop troubles, a circuit connecting both lines is switched to the pay station circuits 5 and 6, and simultaneously the loop-back part 11 applies looping-back to the circuits 3 and 4. Namely a signal line 3 from the center equipment 1 and a signal line 4 to the center equipment 1 are directly connected by the loop-back part 11 and signal lines 12 and 13. Thus a signal transmitted from the center equipment 1 returns to the center equipment itself through the signal line 4 irrespective of the terminal equipment 2 of the supervisory controller, whereby the center 1 equipment alone can detect the restoration of the circuits 3 and 4.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a supervisory control system, and more particularly to a supervisory control system comprising a supervisory control terminal device and a supervisory control center device.

BACKGROUND ART Conventionally, in this type of system, as the block diagram is shown in FIG. , private lines 3 and 4 for information transfer, and public lines 5 and 6 as backup lines.

The terminal device 2 has a central processing section 7, an interface section 8 for the private lines 3 and 6 for information transfer, an interface section for the public lines 5 and 6, and a path line 10 between these sections.
It consists of

In J3 with such a configuration, when the dedicated lines 3 and 4 for information transfer between the center device 1 and the terminal device 2 fail, switching to public lines (telephone lines) 5 and 6 prepared as auxiliary lines and connecting both devices 1 and communication between the two.

In this case, it is necessary to know whether the dedicated lines 3 and 4 for information transfer have been restored, so the terminal device 2 synchronizes with the center device 1 and connects the communication line in a time-sharing manner to the information transfer loop FA3.
and 4, and confirms the recovery.

More specifically, in normal times, the terminal device 2 communicates with the center device 1 using the dedicated lines 3 and 4, and receives the signal (3) from the center device 1 at the interface section 8. The data is analyzed by the central processing unit 7, and the result is sent as a signal (
Send as 4).

Here, if the dedicated lines 3 and 4 break down for some reason, the center device 1 detects this and uses the signal line 5 of the public line to send the signal line 5 to the terminal 2 of the supervisory control device to the public lines 5 and 6. command to switch. After that, this terminal 2
exchanges signals with the center device 1 exclusively through the interface section 9 of the public lines 5 and 6.

Detection of recovery of the dedicated lines 3 and 4 is carried out by time-sharing both the center device 1 and the terminal device 2, which is a supervisory control device, switching back to the dedicated lines 3 and 4 and attempting communication between them. . If communication between the two parties is possible at this point, the dedicated lines 3 and 4 will be used as is; if not, communication will be performed by switching again to the public lines 5 and 6 according to a command from the center device 1.

In such a method, the procedure for restoring the leased lines 3 and 4 includes communication with the terminal device 2, which makes the procedure complicated. Furthermore, if the leased lines 3 and 4 have not been recovered,
During this procedure, communication between the two parties will be disabled.
Communication between the two parties will no longer be smooth. In addition, dedicated line 3
4 and public lines 5 and 6 requires accurate synchronization between the two, and this procedure is more difficult.

Purpose of the Invention The present invention has been made to eliminate the drawbacks of the above-mentioned conventional devices, and its purpose is to provide a dedicated An object of the present invention is to provide a supervisory control system that can easily and quickly confirm that a line has been restored.

Configuration of the Present Invention The supervisory control system according to the present invention provides a loopback section in the interface section of the dedicated line, so that when the connection with the center device is switched to a public line, the dedicated line can be connected to the ink interface of the supervisory control terminal device. It has the feature that the center device can independently check the recovery of the dedicated line, regardless of the visual control terminal device, by looping back the transmitted and received signals at the center.

Example Hereinafter, the present invention will be explained in detail using FIG.

FIG. 1 is a block diagram of an embodiment of the present invention, and parts equivalent to those in FIG. 2 are designated by the same reference numerals.

In the figure, on the terminal device 2 side, dedicated lines 3 and 4
A loopback section 11 is provided for the.

This loopback section 11 is provided at the input section of the interface section 8 for the dedicated lines, and is connected to the dedicated lines 3 and 4.
This loopback section applies loopback to the data.

When the dedicated lines 3 and 4 fail, the lines between them are switched to public lines 5 and 6 by a command from the center device 1, and at the same time, a loopback unit 11 loops back the dedicated lines 3 and 4.

That is, the signal line 3 from the center device 1 and the center device 1
The signal line 4 to the loopback section 11 and the signal line 12.1
3 connects directly. Then, since the signal (3) sent from the center device 1 always returns to the center device itself through the signal line 4 regardless of the terminal 2 of the supervisory control device, the center device 1 alone can restore the dedicated lines 3 and 4. Detection can be performed.

As a result, there is no need for any communication with the terminal device 2 to detect recovery of the dedicated lines 3 and 4, and communication between the terminal device 2 and the center device 1 will not be disabled due to this detection. do not have. Moreover, complicated timing control for switching and switching back between the dedicated lines 3 and 4 and the public lines 5 and 6 is not required at all. Therefore, recovery of the dedicated lines 3 and 4 can be detected with a simple procedure.

As described in detail, according to the present invention, a loopback unit for the dedicated line is provided on the supervisory control terminal device side connected to the central center equipment, so that the connection between the dedicated line and the center equipment can be prevented even if the dedicated line fails. When switching to a public line, the transmission and reception signals are looped back to the dedicated line, thereby making it possible to detect recovery of the dedicated line easily and quickly.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional supervisory control system. Explanation of symbols for main parts 1...Center device 2...Terminal device 3.4...Dedicated line 5.6...Public line

Claims (1)

[Claims] A supervisory control system comprising a supervisory control terminal device and a supervisory control center device, wherein a line loop to the supervisory control center device is provided in an information transfer line between the supervisory control center device and the supervisory control terminal device. A supervisory control system characterized in that a back means is provided on the supervisory control terminal device side.