JPH0537634A - Private branch of exchange - Google Patents

Abstract

PURPOSE:To detect a connection abnormality of an extension line with simple configuration. CONSTITUTION:When a maintenance terminal equipment 5 enters an extension number to start an extension line test, a call signal generated in a call signal generating circuit 6 is given to an extension telephone set 2-x connecting to an extension circuit 1-x because a controller 4 drives an RG relay in the extension circuit 1-x corresponding to the extension number inputted from the maintenance terminal equipment 5. In this case, when the extension telephone set 2 is connected to the extension circuit 1-x, the call signal current flows thereto and when the extension telephone set 2 is not connected to the extension circuit 1-x, no call signal current flows. The controller 4 monitors a call signal current detection circuit 7 to display it that the extension line to be tested is normal when the call signal current flows and to display it that the extension line to be tested is not normal when no call signal current flows.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a private branch exchange which accommodates an extension telephone via an extension circuit, and more particularly to a private branch exchange having a function of testing a connection abnormality of an extension line.

[0002]

2. Description of the Related Art In a conventional private branch exchange, a line test circuit is added to each extension circuit to which an extension telephone is connected, and a maintenance terminal connected to a control device conducts the line test via a switch network. The normality of the extension line was tested by activating the service circuit.

[0003]

In the above-mentioned conventional private branch exchange, it is necessary to add a line test circuit that is not used in normal operation to the extension circuit, which increases the overall cost and increases the cost of the line. Since a volume for mounting the test circuit is required, there is a problem that the overall size becomes large.

The present invention has been made in view of the above problems, and an object thereof is to provide a private branch exchange capable of detecting an abnormal connection of an extension line with a configuration as simple as possible.

[0005]

In order to achieve the above object, the invention according to claim 1 comprises a switch circuit network for switching the extension connection path, and a control means for controlling the switching of the extension connection path in the switch circuit network. A private branch exchange comprising an extension circuit for connecting an extension telephone to the switch circuit, and a ringing signal transmission circuit for transmitting a ringing signal to the extension telephone through the extension circuit when the extension circuit is in a ringing state, Extension circuit selecting means for controlling switching of the switch network to connect extension lines to bring a predetermined extension circuit into a ringing state, and ringing signal current when the extension circuit selecting means puts the extension circuit into the ringing state Ringing signal current detecting means for detecting whether or not
When the ringing signal current detecting means detects that the ringing signal current flows, the selected extension line is determined to be normal, and when it is detected that the ringing signal current does not flow, the extension line is abnormal. And a determination means for determining that there is.

[0006]

In the invention according to claim 1 configured as described above, when the extension circuit selecting means controls the switching of the switch network to connect the extension lines to bring a predetermined extension circuit into a ringing state, At this time, the ringing signal current detecting means detects whether or not the ringing signal current has flowed, and when the ringing signal current detecting means detects that the ringing signal current has flowed, the selected extension line is normal. When it is detected that the ringing signal current does not flow, it is determined that the extension line is abnormal.

That is, at the time of the test, the extension line to the extension circuit to which the extension telephone is supposed to be connected is connected, and the ring signal is sent from the ring signal sending circuit. Then, if the extension telephone is connected, the ringing signal current will flow through the extension circuit, and if the extension telephone is not connected, the ringing signal current should not flow.
The normality of the extension line is judged by detecting whether or not the ringing signal current flows.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a private branch exchange according to an embodiment of the present invention. In the figure, extension circuits 1-1 to 1-1
Extension telephones 2-1 to 2-n are provided for each 1-n.
Are connected, and the extension circuits 1-1 to 1-n are housed in the switch circuit network 3.

A control device (extension circuit selection means, determination means) 4 for controlling connection switching of extension lines in the switch circuit network 3 is connected to the switch circuit network 3,
A maintenance terminal 5 for maintenance is connected to the control device 4.

On the other hand, a ringing signal generating circuit (RGU) 6 for sending a ringing signal to each of the extension circuits 1-1 to 1-n.
And a ringing signal current detection circuit (RGS) for detecting whether a ringing signal current flows between the ringing signal generating circuit 6 and each of the extension circuits 1-1 to 1-n.
(Call signal current detecting means) 7 is interposed.

FIG. 2 is a circuit diagram showing the internal structure of the extension circuit 1. When the RG relay is driven, the call signal output from the call signal generation circuit 6 directly flows to the extension telephone set 2, When the RG relay is not driven, a signal line for conversation between the switch network 3 and the extension telephone 2 is formed.

Next, the operation of this embodiment having the above structure will be described. Now, it is assumed that an extension number is input from the maintenance terminal 5 to start the extension line test.

Then, the control device 4 causes the RG in the extension circuit 1-x corresponding to the extension number input from the maintenance terminal 5 to be generated.
Activate the relay. When the RG relay is driven,
The call signal generated from the call signal generation circuit 6 flows to the extension telephone set 2-x connected to the extension circuit 1-x.

At this time, if the extension telephone set 2 is connected to the extension circuit 1-x in which the RG relay is driven, then the extension telephone set 2 shown in FIG.
As shown in FIG. 3, a ringing signal current flows to the extension telephone 2 through the ringing signal current detection circuit 7, but if the extension telephone 2 is not connected to the extension circuit 1-x, the ringing signal current does not flow.

The control device 4 monitors the ringing signal current detection circuit 7 for a certain period of time after driving the RG relay in the extension circuit 1-x. When it is detected that the ringing signal current flows, the control device 4 notifies the maintenance terminal 5 and the maintenance terminal 5 displays that the extension line under test is normal.

However, if the ringing signal current detection circuit 7 cannot detect the ringing signal current within a fixed time after driving the RG relay in the extension circuit 1-x, the control device 4 performs maintenance. The terminal 5 is notified, and the maintenance terminal 5 displays that the extension line under test is abnormal.

[0017]

As described above, the present invention does not add a line test circuit to each extension circuit and detects whether a ringing signal current flows from a ringing signal transmitting circuit used in normal operation. Therefore, since the normality of the extension line is determined, it is possible to provide the private branch exchange capable of detecting the connection abnormality of the extension line with a simple configuration.

[Brief description of drawings]

FIG. 1 is a block diagram of a private branch exchange according to an embodiment of the present invention.

FIG. 2 is a circuit diagram of an extension circuit and a call signal transmission circuit.

[Explanation of symbols]

 1 ... extension circuit 2 ... extension telephone 3 ... switch circuit network 4 ... control device 5 ... maintenance terminal 6 ... call signal generation circuit 7 ... call signal current detection circuit

Claims (1)

Claim: What is claimed is: 1. A switch circuit network for switching an extension connection path, a control means for controlling switching of the extension connection path in the switch circuit network, and an extension circuit for connecting an extension telephone to the switch circuit. In a private branch exchange comprising a ringing signal sending circuit for sending a ringing signal to the extension telephone through the extension circuit when the extension circuit is in the ringing state, switching of the switching circuit network is controlled to connect the extension line Extension circuit selection means for connecting and making a predetermined extension circuit a ringing state, and ringing signal current detection means for detecting whether or not a ringing signal current flows when the extension circuit selecting means puts the extension circuit in a ringing state And when the ringing signal current detecting means detects that a ringing signal current has flowed, it is determined that the selected extension line is normal. Rutotomoni, private branch exchange, characterized by comprising a judgment means for abnormality on the extension line is determined to be in when it is detected that the calling signal current does not flow.