JPH0418282Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] This invention relates to a level frequency characteristic measuring device for measuring the level frequency characteristic of a transmission line connecting subscriber lines.

[Background of the idea]

The configuration shown in FIG. 2 is a conventional method for measuring the level frequency characteristics of a transmission line. Connected. On the other hand, for the input terminal 5 on the remote exchange 2 side,
A level meter 6E is connected, and the frequency characteristics of the transmission line 7 to be measured are measured by reading the indication of the level meter 6E while changing the frequency of the oscillator 4.

However, this conventional method requires two workers, one on the exchange 1 side and one on the remote exchange 2 side, and if the remote exchange 2 is an unmanned station,
It was necessary for the worker to go to remote exchange 2 with measuring equipment. Moreover, it is necessary to select the same transmission line to be measured on both the exchange 1 side and the remote exchange 2 side. This task becomes quite complicated as the number of measurement transmission lines increases.

In order to solve this difficulty, a system has been proposed in which a split device is provided in parallel with the remote exchange 2 at the input terminal 5 shown in FIG.
No. 171247). In this proposed method, a signal at a measurement frequency of a specific level is transmitted from the oscillator 4 to one of the transmission lines 7 to be measured. When the splitting device detects that this signal exists for a certain period of time or more, it operates the transmission line switching relay in the splitting device in accordance with the transmission line on which the signal has arrived. With this operation, the measurement transmission line is automatically drawn into the level meter, and the level meter displays a level value corresponding to the measurement frequency.

However, in this proposed system, the transmission line to be measured is selected on the exchange 1 side shown in FIG. 2, and cannot be selected on the remote exchange 2 side, which is the measuring side. Therefore, it is not possible to confirm the current transmission of the measurement frequency signal from the oscillator 4 and the reception status of that signal on the corresponding transmission line on the remote exchange 2 side.

[Purpose of invention]

This invention solves the difficulties of the previously proposed methods, selects the transmission line to be measured on the measuring side, checks the incoming call on the selected transmission line between the lines, and at the same time checks the level of the selected transmission line. It is an object of the present invention to provide a level frequency characteristic measuring device capable of measuring frequency.

[Summary of the idea]

To achieve this objective, the present invention provides level frequency characteristics of a transmission line connecting a first subscriber line to which a first terminal is connected and a second subscriber line to which a second terminal is connected. a level frequency characteristic measuring device for measuring a level frequency characteristic, the transmitting device being connected to the first joining line and outputting a measurement signal and a detection signal; a first splitting device that disconnects the first subscriber line from the first terminal and connects it to the transmitting device during the operating time when the time is received, and measures the level frequency characteristics of the transmission line with respect to the measurement signal; When connected to the level meter and the second joining line and receiving the detection signal,
a second split device that disconnects the second subscriber line from the second terminal device and connects it to the level meter during the duration of the measurement signal; and transmission means for transmitting the start signal to the line.

[Example of idea]

FIG. 1 is a block diagram showing the configuration of an embodiment of this invention, in which a telephone 12-T is connected to a first subscriber line 12 as a first terminal, and a telephone 12-T is connected to a second subscriber line 13 as a second terminal. A telephone 13-T is connected, and the first and second subscriber lines 12 and 13 are connected by a transmission line 7.

Between the transmission line 7 and the first joining line 12, a portion of the transmitting side measuring device 8 is configured. A first splitting device 10 is connected to the first joining line 12 via a bandpass filter 14 through the terminal 20 of the transmitting measuring device 8 . The transmitting device 4 is connected to the terminal 20 via the relay contact 21 of the first splitting device 10 .

A reception-side measurement device 9 portion is configured between the transmission line 7 and the second joining line 13. A second splitting device 11 is connected to a second joining line 13 via a bandpass filter 16 through a terminal 22 of the receiving measuring device 9 . The level meter 6 is connected to the terminal 22 of the second split device 11 through the relay contact 23.

Bandpass filters 14 and 16 are both configured to have high input impedance.

When measuring the level frequency characteristics of the transmission line 7, from the second addition line 13 to the first addition line 12
A start signal of a first frequency is transmitted.

In the embodiment, the line number of the first line 12 to be measured is called from the second subscriber line 13 using a telephone. Terminal 15 of transmitting measuring device 8
When the subscriber telephone calling signal, which is the start signal, is input for more than a predetermined time, the bandpass filter 1
The first splitting device 10 connected to 4 is activated.

The first split device 10 has a relay contact 21
By switching the transmission line 7 corresponding to the line number to be measured from the telephone 12-T to the transmitting device 4.
switch to the side. At the same time the first splitting device 10
An excitation signal is given to the transmitter 4 from the transmitter 4 .

A detection signal of a second frequency and a measurement signal are emitted from the transmitting device 4 excited by the first splitting device 10, and are inputted to the receiving side measuring device 9 through the transmission line 7 to be measured. When a detection signal is applied to the input terminal 17 of the receiving measuring device 9 for a predetermined period of time, this state is detected by the second splitting device 11 connected to the bandpass filter 16.
is detected, and the second splitting device 11 is activated.

Since the second split device 11 switches the relay contact 23, the transmission line 7 corresponding to the line number to be measured is connected to the level meter 6. Following the detection signal, a measurement signal is transmitted through the transmission line 7, and the level meter 6 displays the input level corresponding to the measurement signal. Although not shown, a printer linked to the level meter 6 is provided, and the level value corresponding to the measurement signal detected by the level meter 6 is recorded on this printer.

After the first splitting device 10 has been activated for a predetermined activation time, it returns and the relay contact 21 is switched to its home position. Therefore, the transmitting device 4 is disconnected from the first line 12, and the first line 12 is connected to the transmission line 7.
and returns to the state before measurement.

In the embodiment, the first splitting device 10
A timer (not shown) is provided, and the operating time is set to a predetermined time from the time when the transmitting device 4 is activated. When this operating time has elapsed, the first splitting device 10 inputs a stop signal to the transmitting device 4, returns itself, and switches the relay contact 21 to its original position.

When the second splitting device 11 detects that the transmitting device 4 has stopped and the measurement signal has been cut off, it performs a return operation and the relay contact 23 is switched to its original position. Therefore, the second line 13 is connected to the transmission line 7, and the state before the measurement is restored.

In this manner, as soon as the measurement of the level frequency characteristics of the transmission line 7 is completed, the line returns to its original state, so that subsequent calls can be made as a normal telephone line.

By selecting the transmission line 7 to be measured on the second subscriber line 13 side and transmitting a start signal to the first subscriber line 12 side using a telephone, for example, the incoming call can be confirmed and the level frequency characteristics of the transmission line can be measured. Measurements are taken simultaneously.

[Effect of idea]

As explained in detail above, according to this invention, by transmitting a start signal from the measurement side to the transmission line, the incoming call is automatically confirmed and the level frequency characteristics of the selected transmission line are measured. It is possible to provide a level frequency characteristic measuring device that can manually and accurately measure the level frequency characteristic of a transmission line between lines.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of this invention, and FIG. 2 is a block diagram showing the configuration of a conventionally used level frequency characteristic measuring device. 4... Transmitting device, 6... Level meter, 7... Transmission line, 8... Transmitting side measuring device, 9... Receiving side measuring device, 10... First split device, 11... Second split device Device, 12...first subscriber line,
13...Second joining line, 14...Band pass filter, 15, 17, 20, 22...Terminal, 16
...Bandpass filter.

Claims (1)

[Claims for Utility Model Registration] 1. Measuring the level frequency characteristics of a transmission line connecting a first subscriber line to which a first terminal is connected and a second subscriber line to which a second terminal is connected. In the level frequency characteristic measuring device, the first
a transmitting device that is connected to a subscriber line and outputs a measurement signal and a detection signal; and a transmitting device that is connected to the first subscriber line and transmits a signal to the first subscriber line during the activation time when the start signal is received for a time exceeding a predetermined time. a first splitting device which is disconnected from the first terminal and connected to the transmitting device; a level meter which measures the level frequency characteristic of the transmission line with respect to the measurement signal; and a level meter which is connected to the second subscriber line. , upon receiving the detection signal, disconnects the second subscriber line from the second terminal device and connects it to the level meter during the connection time of the measurement signal; A level frequency characteristic measuring device comprising: transmission means for transmitting the start signal from the subscriber line to the first subscriber line. 2. The level frequency characteristic measuring device according to claim 1, wherein the operating time is a preset time from the start of the transmitting device, which is set by a timer of the first splitting device.