JPH0318165A - Backup system for digital multi-function telephone set - Google Patents

Abstract

PURPOSE:To backup a digital multi-function telephone set by monitoring a fault of a local area network and accommodating the digital multi-function telephone set to an analog line when a fault takes place. CONSTITUTION:A conversion circuit 28 of a node 15 connects a terminal interface circuit 23 to a digital interface circuit 24 when no fault of a local area network 11 is detected. On the other hand, when a fault of the network 11 is detected, the circuit 28 changes the connection of a digital line connecting a digital multi-function telephone set 21 and a time division electronic exchange 13 into an analog line. Then the circuit 28 changes the connection of the circuit 23 into the connection to an analog interface circuit 27 from the circuit 24. A digital signal coming from the telephone set 21 is converted into an analog signal by the circuit 28 and sent to the analog interface circuit 27. The circuit 27 sends the analog signal to an analog line circuit 26 to apply the transmission and reception with the time division electronic exchange.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a backup system for digital multifunction telephones, and more particularly to a backup system for digital multifunction telephones distributed over a local area network.

[Conventional technology]

Digital multifunction telephones are used as telephones that can provide various services.

Some digital multifunction telephones internally detect when power supply from a time-sharing electronic exchange has stopped, and function as analog telephones.

A digital multifunction telephone equipped with such a backup function is sometimes connected to a local air network and used as a terminal device.

[Problem to be solved by the invention]

In such a case, the digital multifunction telephone has the disadvantage that even if the digital multifunction telephone becomes unusable due to an abnormality in the local area network, it cannot function as an analog telephone unless the power supply is stopped. That is, when a digital multifunction telephone is connected to a time division electronic exchange via a local area network, the digital multifunction telephone cannot be sufficiently backed up.

SUMMARY OF THE INVENTION An object of the present invention is to provide a backup system for digital multifunction telephones that can back up digital multifunction telephones connected to a local area network.

[Means to solve the problem]

The digital multifunction telephone backup system of the present invention includes (i) a time division electronic exchange, (11) a plurality of digital multifunction telephones that communicate via the time division electronic exchange, and (iii) a time division electronic exchange. and (iv) a local area network that connects these digital multifunction telephones, and (iv) a time-sharing electronic exchange located at each node of this local area network to which the digital multifunction telephones are connected, and that connects the digital multifunction telephones via the local area network. (V) An analog interface circuit located at each node and connecting the digital multifunction telephone to the analog line circuit of the time-sharing electronic exchange without going through the local area network;
(vi) fault detection means arranged at each node for detecting a fault in the local area network; and (vi) fault detection means arranged at each node for detecting a fault in the local area network; A connection switching means is provided which connects to the interface circuit and otherwise connects to the digital interface circuit side.

That is, the digital multi-function telephone backup system of the present invention monitors abnormalities in the local area network and, if an abnormality occurs, accommodates the digital multi-functional telephone onto an analog line.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to Examples.

FIG. 1 shows the structure of a communication system in one embodiment of the present invention.

The backup system of this embodiment is a system related to a digital multifunction telephone using the local area network 11. local area network l1
is connected to a time division electronic exchange l3 via a digital line interface circuit 12. In addition, each node 15, l6 of this local area network 11
, 17, 18, and 19 are connected to accommodate terminal devices such as a personal computer, a word processor, and a printer.

Digital multi-function telephone 21-L 21-2,...
. . 21-9 is provided with a terminal control unit 22 for controlling the line with the time division electronic exchange. The terminal control unit 22 is a digital multifunction telephone 2l.
The terminal interface circuit 23 is equipped with a terminal interface circuit 23 for connecting and accommodating. The digital interface circuit 24 is connected to the local area network 11 and forms a digital line between the digital multifunction telephone 21 and the time division electronic exchange 13.

An analog line circuit 26 is connected to the time division electronic exchange 13. The analog interface circuit 27 of the terminal control section 22 is connected to the analog line circuit 26 of the time division electronic exchange 13 to form an analog line. That is, the analog interface circuit 27
is directly connected to the time division electronic exchange 13 by an intra-office cable.

The terminal control unit 22 includes a conversion circuit 28.

The conversion circuit 28 detects an abnormality in the local area network 1l and connects the time division electronic exchange 13 and the digital multifunction telephone 21 to the local area network 11.
Converts from digital line to analog line via .

Therefore, the converter 28 converts the connection of the terminal interface circuit 23 from the connection with the digital interface circuit 24 to the connection with the analog interface circuit.

Next, the operation of the backup system for the digital multifunction telephone configured in this way will be explained.

The conversion circuit 28 of the node 15 detects an abnormality in the local area network 11 connected via the digital interface circuit 24. The conversion circuit 28 is, for example, a CM I (Co
It monitors code rule errors such as code errors and synchronization errors, and detects abnormalities in the local area network 11. Also, conversion circuit 2
8 can also detect an abnormality from information indicating an abnormality in the local area network output from other terminal devices.

The conversion circuit 28 converts the terminal interface circuit 23 when no abnormality is detected in the local area network 1l.
is connected to the digital interface circuit 24.

Therefore, the digital multifunction telephone 21 is connected to the time division electronic exchange 13 via the terminal interface circuit 23, the conversion circuit 28, the digital interface circuit 24, the local area network 11 and the digital line interface l2. The digital multifunction telephone 8!21 and the time division electronic exchange 13 are connected through this digital line, and signals are exchanged between them using digital signals.

On the other hand, the conversion circuit 28 is connected to the local area network 1
When abnormality 1 is detected, the digital line connecting the digital multifunction telephone 21 and the time division electronic exchange 13 is changed to an analog line.

Therefore, the conversion circuit 28 is connected to the terminal interface circuit 23.
The connection is changed from the connection with the digital interface circuit 24 to the connection with the analog interface circuit 27.

In addition to changing the line connection, the conversion circuit 28 displays on the digital multifunction telephone 21 via the terminal interface circuit 23 that an abnormality has occurred in the local area network, and limits the functions to those that can be provided by an analog telephone. The display is performed by a visible display such as light emission from a lamp provided on the digital multifunction telephone 21 or a display.

A digital signal arriving from the digital multifunction telephone 21 is converted into an analog signal by the conversion circuit 28 and sent to the analog interface circuit 27. The analog interface circuit 27 sends the converted analog signal to the analog line circuit 26 and performs transmission and reception with the time division electronic exchange 13. That is, the analog interface circuit 27 functions as an analog telephone with respect to the analog line circuit 26. Therefore, when an incoming call is received on the analog line circuit 26, the analog interface circuit 27 is called as an analog telephone. When the analog interface circuit 27 detects a calling signal,
The conversion circuit 28 is notified of the incoming call using a digital signal. The conversion circuit 28 notifies the digital multifunction telephone 2l of the incoming call in accordance with a predetermined control signal format.

When the local area network I1 returns to a normal state, the conversion circuit 28 returns the connection of the terminal interface circuit 23 to the digital interface circuit 24 for each line as soon as the call using the analog line ends.

In the embodiment described above, an analog line is used from the analog line circuit to the analog interface circuit as a backup line for the digital line of the local area network, but it may also be connected to a digital multifunction telephone as an analog line. .

〔Effect of the invention〕

In this way, in the present invention, a conversion circuit is provided at the node of the network connecting the time-sharing electronic exchange and the digital multi-function telephone, and when an abnormality in the network is detected, the digital multi-function telephone is connected to the analog line circuit of the time-sharing electronic exchange. It was planned to connect to. Therefore, according to the present invention, it is possible to back up the digital multifunction telephone not only when the power supply to the digital multifunction telephone stops, but also when an abnormality occurs in the network.

[Brief explanation of drawings]

FIG. 1 is a system configuration diagram of a backup system for a digital multifunction telephone according to an embodiment of the present invention. 11...Local area network, 13.
... Time division electronic exchange, 15 ... Node, 23 ... Terminal interface circuit, 24 ...
...Digital interface circuit, 26...
... Analog line circuit, 27 ... Analog interface circuit, 28 ... Conversion circuit.

Claims (1)

[Scope of Claims] A time division electronic exchange; a plurality of digital multifunction telephones that communicate via the time division electronic exchange; and a local area network connecting the time division electronic exchange and these digital multifunction telephones; A digital interface circuit is arranged at each node of the local area network to which the digital multi-function telephone is connected, and connects the digital multi-function telephone to the time-sharing electronic exchange via the local area network; an analog interface circuit for connecting a functional telephone to an analog line circuit of a time-sharing electronic exchange without going through a local area network; a fault detection means disposed at each of the nodes for detecting a fault in the local area network; and connection switching means for connecting the digital multifunction telephone to the analog interface circuit when the fault detection means detects a fault in the local area network and to the digital interface circuit in other cases. A backup system for digital multifunction telephones featuring: