JPS6046650A - Communication line control system - Google Patents

Abstract

PURPOSE:To attain switching of a communication line in spite of the absence of a terminating subscriber by executing switching from a private line to a public line and its reverse switching automatically when any one of the private and public communication lines is used for the mutual communication between two communication devices. CONSTITUTION:Modulation/demodulation devices 1, 2 connected to communication devices respectively are connected to line control devices 3, 4 respectively and both devices 3, 4 are coupled with each other by private lines 5, 6 and public lines 8-11 through an exchange 7. When an operation part 19 applies an indication to connect the public lines 8, 10 and 9, 11 to a control part 17a in the control device 3 at the data communication through the normal private lines 5, 6, the control part 17a applies a dial sending indication to a dial signal generating part 12, and when the device 3 is connected to the device 4 by sending the dial signal and the relays 15a, 16a are actuated, data communication parts 13 are connected, and after transmitting and receiving an identification code and a response code, are switched. When a line switching indication is applied from the operation part 19, a switching code is applied to the control device 4 through the lines 8, 10, and after detecting and responding the code, the lines 8, 10 are switched to the lines 5, 6.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a communication line control system, and in particular, to communication between two communication devices by selectively using either a private or public communication line. This relates to line control methods.

Conventionally, when a dedicated line becomes disconnected, the method of switching to a public line is to have each person go to the location where the modem, which is communication equipment, is installed, and one of them performs the same operations as connecting to the public line. After confirming that the public line is connected, both parties switch the private line connected to the modem to the public line. This conventional method has the disadvantage that the communication line cannot be switched unless there is a person on the other end.

SUMMARY OF THE INVENTION An object of the present invention is to provide a communication line control system that makes it possible not only to automatically switch from a private line to a public line, but also to switch vice versa.

In the communication line control system according to the present invention, first and second line control apparatuses that connect a private line and a public line are installed on each line side of the first and second communication apparatuses. This is a communication line control method in which mutual communication is performed between communication devices by selectively using either a private line or a public line, and its characteristics are that the first line control device The system includes a means for generating a dial signal for connecting a public line and a second line control device, and a means for instructing the second line control device to switch to a public line and return to a dedicated line. means for transmitting the instruction signal and receiving a response signal from the second line control device in response to the instruction signal; and means for connecting the first communication device to either the private or public communication line. The second line control device includes: means for detecting a calling signal from the public line network in response to the dial signal; means for receiving the instruction signal and transmitting a response signal thereto;
means for connecting the second communication device to any of 10,000 private and public lines, and the communication line between the first and second communication devices is automatically switched. It is in.

Embodiments of the present invention will be described below with reference to the drawings. There are first and second line control devices 3 and 4 between modulation and modulation devices 1 and 2, which are first and second communication devices, and a dedicated line 5 for sending data from modulation and demodulation devices 1 to 2.
A dedicated line 6 for transmitting data from the modem 2 to the modem 1 is provided. Further, public lines 8 and 9 are provided to connect between the modem 1 and the exchange Ia7, and a public line 10 is provided to connect between the exchange 7 and the modem 2.
and 11 are provided. The line control device 3 includes a dial signal generator 12 that generates a dial pulse for connecting the public lines 8 and 10 and the public lines 9 and 11, and a dial signal generator 12 that connects the line control device 4 via the public lines 8 to 11. a data communication unit 13a for transmitting and receiving data; relays 14a, 15a for connecting either the dedicated line 5.6 or the public lines 8, 9 to the modem 1; Relay 16a connected to 9, each of the above blocks 12, 132 and relays 14a, 15a
, 16a is provided.

The line control device 4 includes a tone detection section 18 for detecting a calling signal from the exchange 7, a data communication section 13b similar to the line control device 3, and IJ relays 4b and 15b.
, 16b, and a control section 17b are provided. Connected to the control section 17a of the line control device 3 is an operation section 19 for instructing line switching.

In the above configuration, when data communication is normally performed between the modem devices 1 and 2 via dedicated lines 5 and 6,
A method for switching the data communication line to the public lines 8 to 11 and a method for returning to the private lines 5 and 6 based on instructions from the operation unit 19 will be described below.

The operation unit 19 gives an instruction to the control unit 17a of the line control device 3 to connect the public lines 8 and 10 and 9 and 11. Upon receiving this instruction, the control section 17a gives an instruction to the dial signal generation section 12 to send out the dial number of the public line 1°, and the dial signal generation section 12 sends out this dial signal to the public line 8. This dial signal is input to the exchange 7, and the exchange 7 sends a calling signal to the public line 1o. When the tone detection section 18 detects this calling signal, the tone detection section 18 notifies the line control device 40 control section 17b of the detection. Upon receiving this information, the control unit 17b instructs the tone detection unit 18 to connect the public line. As a result, public lines 8 and 1
0 is connected. Public lines 9 and 11 are connected in a similar manner.

After both the public lines 1° and 11 are connected, the control unit 17b of the modem 4 operates the relays 15b and 16b to connect the public line 10.11 and the data communication unit 132, and transmits data from the line control device 3 to the data communication unit 132. to be able to receive data.

On the other hand, the control unit 17a of the line control device 3 controls the public line 8,
After transmitting dial signals to both relays 15a and 9, relay 15a
, 16a to operate the public line 8.9 and the data communication section 13.
Connect a. Next, in order to check whether the line control devices 3 and 4 are connected by the public lines 8 to 11,
The identification code is sent from the data communication unit 13a of the line control device 3 via the public line 8. This code is used by line controller 4.
When the data communication unit 13b detects this, it notifies the control unit 17b, and the control unit 17b instructs the data communication unit 13b to send a response code. Upon receiving this instruction, the data communication section 13b sends out a response code via the public line 11. This code is sent to the data communication unit 13a of the line control device 3.
When detected, the control unit 17a is notified of this, and the control unit 17a notifies the operation unit 19. Here, if the line control device 4 does not receive the above identification code within a certain period of time, the public lines 10 and 110 are disconnected. This prevents the public line 10 or 11 from being connected to the wrong telephone.

Next, by giving an instruction to switch the line from the operation unit 19, the control unit 17a of the line control device 3 causes the data communication unit 13 to
a. A switching code indicating that the line is to be switched is sent to the line control device 4 via the public lines 8 and 10. The control unit 17b of the line control device 4 that received this instruction instructs the data communication unit 13b to transmit a response code indicating that the line switching instruction has been received, and after sending the response code, the relay 14b and 16b are operated to connect the modem 2 and the public circuit 10.11.

On the other hand, when the control unit 17a of the line control device 3 is informed that the data communication unit 13a has received the response code from the line control device 4, the control unit 17a transmits the relay 14a.

16a is operated to connect the modem 1 and the public line 8.9. Further, the control unit 17a notifies the operation unit 19 that the line has been switched.

According to the above method, modem devices 1 and 2 are connected to public lines 8 to 1.
Data communication becomes possible via 1.0 When restoring the public lines 8 to 11 to the dedicated lines 5 and 6, an instruction to restore the line is given from the operation unit 19 to the control unit 17a of the line control device 30. . Upon receiving this instruction, the control section 17a activates the relay 14a.

16a to connect the data communication unit 13a to the public line 8,
Connect to 9. Next, the data communication unit 13a sends out a return code indicating line recovery via the public line 8. When the data communication section 13b of the line control device #4 detects this return code, it notifies the control section 17b of this, and the control section 1
7b operates relays 14b and 16b to connect data communication section 13b to public line 10.11. Thereafter, the data communication unit 13I) sends a response code indicating that the line has been switched via the public line 11. When the data communication section 13a of the line control device 3 detects this response code, this is notified to the control section 17a, and the control section 17a notifies the operation section 19 that the line has been restored.

As a result, the data communication line is restored to the dedicated lines 5 and 6, and after confirming that data communication is being performed normally on the dedicated lines 5 and 6, the operation unit 19 issues an instruction to disconnect the public line. It is given to the line control device 3.

Upon receiving this instruction, the data communication unit 13 sends out a disconnection code instructing disconnection of the line. The data communication unit 13b of the line control device 4 detects this disconnection code, and the control unit 17b
After transmitting a response code from the data communication unit 13b, the control unit 17b disconnects the public line 10.11 and returns the relay 15b to its original state. On the other hand, after receiving the above response code, the control unit 17a of the line control device 3 disconnects the public lines 8 and 9 and restores the relay 15a. By the above method, public lines 8 to 11 are disconnected.

As explained above, according to the control method of the present invention, data communication lines can be switched without the need for a human being on the other end, which has the effect of reducing manpower and significantly shortening work time. In addition, connection of public line, switching to public line,
Since the processes of returning to the dedicated line and disconnecting the public line can be executed independently, even if data communication cannot be performed on the dedicated line after returning to the dedicated line, the route of the public line can be changed. It is also possible to immediately switch to a public line and perform data communication without having to do so.

[Brief explanation of drawings]

The figure is a block diagram of an embodiment of the invention. Explanation of symbols of main parts 1.2...Modulation/demodulation device, 3.4...Line control device, 5,6......Dedicated line, 7...
...Exchange, 8-11...Public line, 13...
...Data communication section, 14-16... Relay, 17... Control section, 19... Operation section.

Claims (1)

[Claims] First and second line control devices that connect a dedicated line and a public line are installed on each line side of the first and second communication devices, and between the first and second communication devices, the dedicated and public lines are connected to each other. A communication line control system in which mutual communication is performed by selectively using one of two public lines, wherein the first line control device connects the public line and the second line control device. means for generating a dial signal to connect the second line to the public line, and sending an instruction signal to the second line control device to switch to the public line and return to the private line; means for receiving a response signal from the second line control device in response to an instruction signal, and means for connecting the first communication device to either one of the dedicated and public lines, The line control device comprises means for detecting a calling signal from the public line network in response to the dial signal, means for receiving the instruction signal and transmitting the response signal thereto, and the second communication device. and means for connecting to either one of the dedicated and public lines, and the communication line between the first and second communication devices is automatically switched. Line control method.