JPH01288127A - Non-hit line changeover system - Google Patents

Abstract

PURPOSE:To switch a line with no-hit without restricting the information transmission of a terminal equipment side when a line is disconnected by providing a means storing tentatively the information to be sent and sending the information at a transmission speed faster than the signal speed at the terminal equipment side. CONSTITUTION:A transmission signal P1 from a terminal equipment 1 to a terminal equipment 2 is stored tentatively by a storage circuit 7, plural bits are used as one data, one data is converted into a transmission signal P2 at a speed faster than the speed of the transmission signal P1 and outputted to a changeover circuit 11. If a line 3 is interrupted during the transmission of a DATA 2, a control circuit 6 commands line changeover to a control circuit 5 to control a changeover circuit 12 thereby connecting a line 4 and a reception signal P5. On the other hand, the control circuit 5 controls the changeover circuit 11 to give the transmission signal P2 to a line 4. On the other hand, the control circuit 5 controls the changeover circuit 11 to connect the transmission signal P2 to the line 4. Then the control circuit 5 issues a command of transmitting the DATA 2 again to a storage circuit 7 and the DATA 2 of the transmission signal P2 is stored in a storage circuit 8. The DATA 1 is sent from the storage circuit 8 as a reception signal P6 and then the DATA 2 is read from the storage circuit 8 succeedingly and then sent.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a line switching system, and in particular, it is possible to switch a line to an alternate route in the event of a line break without affecting the terminal side. The present invention relates to an uninterrupted line switching system.

Conventional technology Conventionally, when switching a line when a line is disconnected, data transmission on the terminal side is simultaneously disconnected as soon as the receiving side detects the line disconnection. , a method of switching the line when the error rate exceeds a certain value (before the line is disconnected), and a storage transmission method that restricts the amount of information transmitted on the terminal side and retransmits after a detour route is taken when the line is disconnected. A method has been proposed.

Problems to be Solved by the Invention However, in the conventional line switching method described above, the line remains in a disconnected state until the line is switched to a detour route after detecting the line disconnection, and the method for monitoring code errors is difficult. If the line is suddenly disconnected due to a device failure or the like, the line will be disconnected until the line is switched, and the conventional storage and transmission method has disadvantages such as temporarily stopping information transmission on the terminal side.

The present invention has been made in view of the above-mentioned conventional situation,
Accordingly, an object of the present invention is to provide a new line switching system that makes it possible to eliminate the above-mentioned drawbacks inherent in the conventional technology.

Means for Solving the Problems In order to achieve the above objects, the uninterrupted line switching system according to the present invention includes means for temporarily storing information to be transmitted, and transmitting at a transmission speed faster than the signal speed on the terminal side. The device is configured to include means for detecting a line disconnection, and a means for switching the transmission route to a detour route for both opposing stations in the event of a line disconnection. It is characterized by switching lines.

Embodiment Next, a preferred embodiment of the present invention will be specifically explained with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the uninterrupted line switching system according to the present invention, and FIG. 2 is a time chart for explaining the circuit diagram of FIG. 1.

Referring to Figures 1 and 2, terminals 1 and 2 are devices that communicate with each other, and line 3 is the normal transmission route between terminals 1 and 2, and line 4 is the line 3 that is disconnected. This is a detour route used when

The transmission signal P1 from the terminal] to the terminal 2 is temporarily stored in the storage circuit 7, and is converted into a transmission signal P2 at a faster rate than the transmission signal P1 for each data piece, with multiple bits as one data, and is output to the switching circuit 11. The switching circuit II normally connects the transmission signal P2 to the line 3, and connects the transmission signal P3 to the line 3.
is output as the received signal P via the switching circuit 12.
It becomes 5. The storage circuit 8 restores the received signal P5 as data only at the rising edge after time t has elapsed, and thereafter reads out the accumulated data one by one and outputs it to the terminal 2 as the received signal P6.

Next, as shown in the transmission signal P3 in FIG. 2, when the concave line 3 is disconnected during the transmission of DATA1, the detection circuit 10 detects the line disconnection and notifies the control circuit 6. The control circuit 6 includes a switching circuit 12, a four-wire 4, and a switching circuit 11.
The controller 5 instructs the control circuit 5 to switch the line via the controller 5, and also controls the switching circuit 12 to connect the four wire 4 and the received signal P5. On the other hand, the control circuit 5 instructed to switch the line
also controls the switching circuit 11 and connects the transmission signal P2 to the line 4. After this, the control circuit 5 instructs the storage circuit 7 to transmit DATA1 again, and
TAL is stored in the N product circuit 8 via the line 4 and the switching circuit 12. In the storage circuit 8, after transmitting DATA1 to the terminal as the received signal P6, DATA1 is subsequently read out from the storage circuit 8 and transmitted.

By the above operation, even if the line is disconnected, the line can be switched to the detour route without momentary interruption. Also, from terminal 2 to terminal 1
The same applies to the transmission signals to.

As described in detail, according to the present invention, there is provided means for temporarily storing information to be transmitted, means for transmitting at a transmission speed higher than the signal speed on the terminal side, means for detecting line disconnection, and means for detecting line disconnection. By providing a means for switching the transmission route to a detour route together with the opposing station, the line can be switched without momentary interruption when the line is disconnected, and the terminal side has the advantage that the line does not disconnect and the amount of information transmitted is not restricted. is obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the uninterrupted line switching system according to the present invention, and FIG. 2 is a time chart 1 to 1 to capture and explain the circuit configuration of FIG. 1. 1.2...Terminal, 3.4...Line, 5.6...Control circuit, 7,8...Storage circuit, 9,10...Detection circuit, 11゜12...Switching circuit Patent applicant: Representative of NEC Corporation Patent attorney: Yutabe Kumagai

Claims (1)

[Claims] A means for temporarily storing information to be transmitted, a means for transmitting at a higher transmission speed than the signal on the terminal side, a means for detecting line disconnection,
A means for switching the transmission route to a detour route together with the opposing station when a line disconnection is detected, thereby switching the line without any momentary interruption without restricting information transmission on the terminal side when the line is disconnected. Line switching method.