JPS6048937B2 - Duplex line switching device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a duplex line switching device that can quickly and reliably switch a duplex line in order to improve reliability.

A conventional device of this type is shown in FIG.

In the figure, 1 is the working line, 2 is the protection line installed on the same route as the working line 1, and 3 is the working line 1 and the protection line 2.
4 is the switching contact that switches the line 1 through the switching contact 3.
or 2, d is a switching control signal output from the receiving circuit 4 when the receiving circuit 4 receives a switching command, or when the receiving circuit 4 cannot receive correct information for a predetermined time, 5 is a relay circuit that is driven by this switching control signal d and switches the switching contact 3; 6 is an output circuit that outputs the information received by the receiving circuit 4 to another device; 7 is the switching contact 3, the receiving circuit 4, and the relay circuit 5. and an output circuit 6. Next, the operation will be explained.

Normally, information transmitted through the working line 1 is received by the receiving circuit 4 via the switching contact 3, sent to the output circuit 6, and outputted from the output circuit 6 to other devices. In addition, when the receiving circuit 4 receives a switching command, if J or the receiving circuit 4 cannot receive correct information for a predetermined period of time, the receiving circuit 4 sends a switching control signal d to the relay circuit 5.
is output, the relay circuit 5 is driven, the switching contact 3 is operated, and the backup line 2 is connected to the receiving circuit 4. i Since conventional equipment is configured as described above, even if an attempt is made to switch from working line 1 to protection line 2 by a switching command, there is no guarantee that the switching command will be correctly received if working line 1 itself is abnormal. Moreover, the need to switch the line only arises when the telephone line 1 becomes abnormal.
cannot achieve its original purpose.

Therefore, as a backup, when the receiving circuit 4 cannot receive correct information for a predetermined period of time, it determines that the working line 1 has become abnormal and drives the relay circuit 5 to switch the line to the protection line 2. There was a drawback that it took a predetermined amount of time to switch to the protection line 2 after an abnormality occurred on the line 1. Furthermore, when the working line 1 and the protection line 2 are arranged on the same route, there is a drawback that when a fault occurs in the working line 1, there is a high possibility that a fault will also occur in the protection line 2 at the same time.

As a method to solve the above-mentioned drawbacks, for example, as shown in Japanese Patent Application Laid-open No. 53-58705, the working line and the protection line are provided on separate routes, and a switching method is used to send a switching command in the event of a fault in the working line. It is conceivable to provide a command line, but in this case, the structure becomes complicated due to the switching command line. The present invention has been made in order to eliminate the drawbacks of the conventional circuits as described above, and includes first and second working lines disposed on different routes and first and second working lines tangentially connected thereto. If you have a terminal device,
Routes that are different from the first and second working lines. 1st and 2nd
At the same time, a switching command is sent through the second and first working lines, and the lines of the first and second terminal devices are switched, thereby ensuring that the lines can be quickly and reliably switched in the event of an abnormality in the working line. The purpose of the present invention is to provide three duplex line switching devices capable of switching.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows a duplex line switching device according to an embodiment of the present invention, in which 11 and 21 are arranged on routes A and B3-, and first and second lines 11 and 21 are arranged to transmit information or switching commands for other stations, respectively.
The second working lines 12, 22 are arranged on routes B and A, and the first,
The second protection line, 13 and 23 are the first and second working lines 1
The first and second switching contacts 14 and 24 switch the first and second protection lines 12 and 22, respectively. The first and second receiving circuits receive information from the second working lines 11 and 21 or the protection lines 12 and 22, respectively, and A and b are the first receiving circuits.
, the second receiving circuits 14 and 24 connect to the working line 11 for a predetermined time,
When correct information cannot be received from 21, the first and second
The first and second switching control signals output from the receiving circuits 174 and 24, C and d are the first and second switching control signals output from the first and second receiving circuits 14 and 24.
the first and second other station switching control signals output from the first and second receiving circuits 14 and 24 when receiving the switching command via the first and second working lines 11 and 21; , 15 is the first switching control signal a or the second other station switching control signal d.
The first relay circuit 25 operates the second switching contact I23 driven by the second switching control signal b or the first other station switching control signal c. a second relay circuit for actuation, 16;
26 are first and second output circuits that output the information received by the first and second receiving circuits 14 and 24 to other devices (not shown); 17 and 27 are first and second switching contacts 13, 23, receiving circuits 14, 24, relay circuits 15, 25, and output circuits 16, 26, respectively.

Next, the operation will be explained. Usually, terminal devices 17, 27
The receiving circuits 14, 24 are connected to the working lines 11, 21 by switching contacts 13, 23, and the receiving circuits 14, 24 are connected to the working lines 11, 21 so that the . The received information is sent to receiving circuit 1.
4, 24 and sent to output circuits 16, 26, from which they are output to other devices.

Now, when an abnormality occurs in the first working line 11 and a switching command is transmitted to the second terminal device 27 via the second working line 21, this switching command is received by the second receiving circuit 24. be done.

Then, the second receiving circuit 24 receives the second other station switching control signal d.
The first relay circuit 15 is driven by the second other station switching control signal d to operate the first switching contact 13 and switch the transmission line from the first working line 11 to the first reserved line. Switch to Kama line 12. Therefore, from now on, this first Senbi line 1
Transmission is performed by 2. Further, when the first receiving circuit 14 cannot receive information from the first working recirculating spring 11 for a predetermined time, the receiving circuit 14 receives the first switching control signal a.
The first relay circuit 15 outputs this switching control signal d.
This drives the first switching contact 13, and the first switching contact 13 is activated.
The line connected to the receiving circuit 14 of the first working line 11
to the first protection line 12.

On the other hand, if an abnormality occurs in the second working line 21, a switching command is transmitted via the first working line 11, and the first receiving circuit 14 and second relay circuit 25 switch the second working line 21 to the second protection line 22.

If the second receiving circuit 24 cannot receive correct information for a predetermined time via the second working line 21, the second receiving circuit 2
4 and the second relay circuit 25, the lines are switched in the same manner as above. According to the duplex line switching device of this embodiment having the configuration and operation as described above, the first working line 1
When an abnormality occurs in the first receiving circuit 1, Yang He transmits a switching command via the second working line 21, receives this at the second receiving circuit 24, and switches the line on the first receiving circuit 14 side to the working line 11. Since the line is switched from the line to the protection line 12, the line can be switched quickly and reliably.

As described above, according to the present invention, in a station having two lines and a terminal device, each working line and protection line are arranged on different routes, and a switching command is sent via the working line of the other station. Since the other terminal device receives this and switches the line of its own station, the switching command can be reliably sent and the line can be switched quickly and reliably.

[Brief explanation of the drawing]

Figure 1 is a block diagram of a conventional duplex line switching device;
The figure is a block diagram of a duplex line switching device according to an embodiment of the present invention. 11, 21...first and second working lines that also serve as second and first switching command lines, 12,22...first and 52nd protection lines, 13,23...first , second switching contact, 1
4, 24...first and second receiving circuits, 15,25...
- First and second relay circuits (first and second contact switching circuits), 17, 27...first and second terminal devices.

Claims (1)

[Claims] 1. First and second working lines arranged on different routes and for respectively transmitting information and switching commands for the other line, and the above-mentioned first working line arranged on a different route from the first and second working lines. , first and second protection lines for respectively transmitting information in the event of an abnormality in the second working line, and the first and second protection lines.
first and second switching contacts that respectively switch between the working line and the first and second protection lines, and the first and second working lines or the protection line via the first and second switching contacts. When information from the first and second working lines cannot be received for a predetermined time, outputs first and second switching control signals and receives switching commands from the first and second working lines. a first, which outputs the first and second other station switching control signals when
the first and second switching contacts by the second receiving circuit and the first switching control signal or the second other station switching control signal, or the second switching control signal or the first other station switching control signal; What is claimed is: 1. A duplex line switching device comprising: first and second terminal devices each having first and second contact switching circuits that respectively operate the double line switching device.