JPS63193653A - Method and equipment for switching private line/backup line - Google Patents

Abstract

PURPOSE:To confirm a terminating subscriber by the return of a terminal code, to automatically switch a current data circuit to a backup subscriber's line and to simplify the constitution of an equipment by automatically calling a previously set backup subscriber's line from either one of the terminal equipment side or the center side. CONSTITUTION:The center equipment 1 is connected to the terminal equipment 2 through a private data line 9 and a subscriber's line 10, the equipment 1 is provided with a center switching equipment 7 and the equipment 2 is provided with a terminal switching equipment 8. The equipments 7, 8 are respectively provided with switching circuits 12, 16 and a communication control equipment 4 and a data communication terminal equipment 6 are respectively connected to one changeover switches of the circuits 12, 16 respectively through MODEMs 3, 5. On other hand, the line 10 is connected to the other changeover switches of the circuits 12, 16 respectively through network control circuits 11, 15, the circuits 12, 16 are controlled by respective control circuits 14, 18 and previously set terminal code transmitting/receiving circuits 13, 17 are called through the line 10. Thus, the constitution of the switching circuit can be simplified.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a modulation/demodulation system in which a modem on the center equipment side and a modem on the terminal equipment side are connected to each other via a data line. The present invention relates to a line switching method and a line switching device for switching modem connections on a center device side and a terminal device side from a data line to a backup line.

(Prior art) Conventionally, as a line switching method of this type, when switching the modem connection on the terminal device side and the center device side from the current data line to the backup line, the connection between the center device side and the terminal device side is changed. Either the terminal devices communicate with each other and switch manually, or the center device uses a control line to control the switching on the terminal device side.

(Problems to be Solved by the Invention) The conventional line switching method described above requires operations on the center equipment side, but in general, this type of modem system has a large number of terminal equipment, and the operator on the center equipment side The problem was that it was difficult to deal with.

(Means for Solving the Problem) The present invention has been made to solve the above problem, and is intended to solve the problem when a failure occurs in the dedicated data line that connects the modem on the center device side and the modem on the terminal device side. When it occurs,
In a line switching system that uses a subscriber telephone line for backup, a center switching device connected to the backup subscriber telephone line is provided on the center equipment side, and a terminal connected to the backup subscriber telephone line is provided on the terminal device side. A switching device is provided, and by making a call from the terminal device side to the subscriber telephone line of the center device side, the call is automatically received at the center switching device, and the dedicated data line is switched to the backup subscriber telephone line, and Conversely, by making a call from the center device side to the subscriber telephone line on the terminal device side, the call is automatically received at the terminal switching device, and the dedicated data line can be switched to the backup subscriber telephone line. .

(Example) Next, the present invention will be explained by way of example with reference to the drawings.

FIG. 1 is a block diagram of a modulation/demodulation system having a line switching device according to an embodiment of the present invention.

This modulation/demodulation system includes a modem 3, a communication control device 4, and a center switching device 7 included in the center device 1 side.
A modem 5, a data communication terminal device 6, and a terminal switching device 8 included in the terminal device 2 side, and a dedicated data line 9 and a backup shipboard telephone line that interconnect the center device 1 side and the terminal device 2 side. 10. The center switching device 7, which is a main part of the present invention, includes the network control circuit 11.
The terminal switching device 8 is composed of a switching circuit 12, a terminal code transmitting/receiving circuit 13, and a control circuit 14, and a network control circuit 15, a switching circuit 16, a terminal code transmitting/receiving circuit 17, and a control circuit 18.

In normal times, the modem 3 on the center device 1 side is connected to the dedicated data line 9 via the contact a1 of the switching circuit 12, and further via the dedicated data line 9 to the contact a2 of the switching circuit 16 on the terminal device 2 side. and is connected to the modem 5 via the switching circuit 16.

For example, assume that data communication between the communication control device 4 on the center device 1 side and the data communication terminal device 6 on the terminal device 2 side is interrupted due to a malfunction of the dedicated data line 9. At this time, on the terminal device 2 side, the control circuit 18 sends the backup subscriber telephone number information of the center device 1 side to the network control circuit 15, and initiates a call to the center device side via the subscriber telephone line 10. On the center device 1 side, when the call is automatically received at the network control circuit 11 in response to the above-mentioned call, the terminal device 2
The network control circuit 15 on the side detects an incoming call response from the center device side. This detection output is then sent to the control circuit 18, which activates the terminal code transmission/reception circuit 17.
The terminal code is sent from the terminal code transmitting/receiving circuit 17 to the subscriber telephone line 10. On the center device 1 side, when the terminal code is received by the terminal code transmitting/receiving circuit 13 via the network control circuit 11, the control circuit 14 transmits the same terminal code as received from the terminal code transmitting/receiving circuit 13 to the terminal device 2 side. Thereafter, the contacts of the switching circuit 12 are switched to the bl and d1 sides, respectively.

On the other hand, on the terminal device 2 side, the terminal code sent back from the center device 1 side is received by the terminal code transmitting/receiving circuit 17, and it is determined whether it matches the previously sent terminal code. If the code is the same, the control circuit 18 The contacts of the switching circuit 16 are switched to the b2 and d2 sides. In this way, the modem 3 on the center device 1 side and the modem 5 on the terminal device 2 side are connected via the backup subscriber telephone line 10.

Furthermore, when a call is made from the center device 1 side to the backup subscriber telephone line on the terminal device 2 side, the dedicated data line 9 is similarly switched and connected to the subscriber telephone line 10.

(Effects of the Invention) As explained above, the present invention automatically makes a call to a preset backup subscriber telephone line from either the terminal device side or the center device side, confirms the other party by returning the terminal code, Since it is configured to have a means to automatically switch the connection from the working data line to the backup subscriber telephone line, it has the effect of being able to switch the connection line without requiring any human intervention on the other party's side. be.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a modulation/demodulation system having a line switching device according to an embodiment of the present invention. 1... Center device, 2... Terminal device, 3.5...
Modem, 4... Communication control device, 6... Data communication terminal device, 7... Center switching device, 8... Terminal switching device, 9... Dedicated data line, 10... Joining Telephone line, 11.15...Network control circuit, 12.16...
Switching circuit, 13.17...Terminal code transmission/reception circuit, 14.18.
...Control circuit.

Claims (2)

[Claims] (1) When a failure occurs in the dedicated data line that connects the modem on the center equipment side and the modem on the terminal equipment side, the dedicated line is backed up using the subscriber telephone line.
In the backup line switching method, a line switching section connected to the subscriber telephone line is provided on the center device side and the terminal device side, respectively, and the terminal device side makes a call to the subscriber telephone line on the center device side, thereby switching the center The line switching section on the device side automatically receives the call, or conversely, the center device makes a call to the subscriber telephone on the terminal device side, and the line switching section on the terminal device side automatically receives the call. A line switching method characterized by switching to a subscriber telephone line. (2) A line switching circuit for switching and connecting the dedicated data line and the subscriber telephone line to each of the center device and the terminal device which are connected to each other by the data dedicated line and the backup subscriber telephone line, and the subscriber telephone line. A modulation/demodulation system characterized by having a terminal code transmitting/receiving circuit that automatically transmits and receives a terminal code via a line, and a control circuit that confirms the other party by transmitting and returning the terminal code and controls switching and connection of the line switching circuit. System line switching device.