JPH07321914A - Codec testing device - Google Patents

Abstract

PURPOSE:To provide a testing device testing a PCM codec mounted to a speech path board in a PCM terminal station equipment built in a communication line network. CONSTITUTION:Switches 13 and 14 respectively connected to an oscillation circuit 11, a detection circuit 12 and a control line 24 are provided between a signal conversion circuit 22 and the PCM codec 23 and between the PCM codec 23 and a sound signal line 25. At the time of receiving an on-hook detection signal from the control line 24, the switch 13 connects the oscillation circuit 11 or the detection circuit 12 to the PCM codec. Further, at the time of receiving the on-hook signal from the control line 24, the switch 14 connects the detection circuit 12 or the oscillation circuit to the PCM codec.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a codec tester, and more particularly to a codec tester for testing a codec mounted on a speech path board of a PCM terminal equipment connected to a general subscriber line or a public telephone line. .

[0002]

2. Description of the Related Art As shown in FIG. 2, a speech path board in a PCM terminal device includes a signal conversion circuit 22 connected to a subscriber line 21 and a PCM codec (CODEC) connected to the signal conversion circuit 22. And 23. The signal conversion circuit 22 detects an on-hook / off-hook signal from the subscriber line 21 and outputs an on-hook / off-hook detection signal to the control line 24. Further, the signal conversion circuit 22 outputs the analog voice signal from the subscriber line 21 to the PCM codec 23 and the analog voice signal from the PCM codec 23 to the subscriber line 21. In addition, the signal conversion circuit 22
Is the subscriber line 2 based on the incoming call signal from the control line 24.
The call signal is sent to 1.

The PCM codec 23 includes a signal conversion circuit 2
The analog voice signal from 2 is PCM encoded and output to the voice signal line 25, and the PCM encoded digital voice signal from the voice signal line 25 is decoded and the analog voice signal is output to the signal conversion circuit 22.

Conventionally, the speech path board in the PCM terminal equipment as described above is positioned as a part of the transmission path in the communication network, and there is no apparatus that tests only the voice function of the PCM codec.

A failure detection circuit for detecting a failure of a digital signal processing circuit in a callless state is disclosed in Japanese Patent Laid-Open No. 62-62.
It is disclosed in Japanese Patent No. 266934.

[0006]

As described above, conventionally, there is no test device for performing a function test of the PCM codec mounted on the speech path board in the PCM terminal equipment. Further, the failure detection circuit disclosed in Japanese Patent Laid-Open No. 62-266934 cannot be applied to the test of a codec for bidirectional transmission.

The present invention is a PCM incorporated in a communication network.
An object of the present invention is to provide a test device for testing a PCM codec mounted on a speech path board in a terminal device.

[0008]

According to the present invention, there is provided a signal conversion circuit which is connected to a subscriber line and which detects an on-hook / off-hook signal from the subscriber line and outputs a detection signal. The signal conversion circuit is connected to the signal conversion circuit. The analog voice signal from the subscriber line input through the signal conversion circuit is converted into a digital voice signal and output to a voice signal line, and the digital voice signal input from the voice signal line is converted into an analog voice signal. A codec test device provided on a speech path board having a codec for converting and outputting to the signal conversion circuit, the test executing means for transmitting and receiving a test signal, and the test executing means based on the detection signal. Alternatively, a codec test apparatus comprising: the signal conversion circuit and a switch unit that selectively connects the audio signal line to the codec. Obtained.

[0009]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 shows an embodiment of the present invention. The codec test apparatus according to the present embodiment includes an oscillator circuit 11 that outputs a test signal, a detection circuit 12 that receives the test signal, a signal conversion circuit 22 and P.
The switch 13 is connected between the CM codec 23 and the oscillation circuit 11 and the detection circuit 12, and is connected between the PCM codec 23 and the audio signal line 25, and is connected to the oscillation circuit 11 and the detection circuit 12. It has a switch 14. Here, the switches 13 and 14 are also connected to the control line 24.

The operation of the codec test apparatus of this embodiment will be described below. When the communication ends and the on-hook signal is output to the subscriber line 21, the signal conversion circuit 22
The on-hook signal is detected and the on-hook detection signal is output to the control line 24. The signal conversion circuit 22 monitors the transmission direction of the voice signal, and outputs the data indicating the transmission direction of the voice signal immediately before the detection of the on-hook signal by including the data in the on-hook detection signal.

Upon receiving the on-hook detection signal from the signal conversion circuit 22, the switch 13 connects the oscillation circuit 11 or the detection circuit 12 to the PCM codec 23 according to the on-hook detection signal. Also, switch 1
When the on-hook detection signal from the signal conversion circuit 22 is input, the signal P 4 receives P in accordance with the on-hook detection signal.
The CM codec 23 includes a detection circuit 12 or an oscillation circuit 11.
Connect. For example, when the communication is completed after the voice signal is transmitted from the subscriber side (during transmission), the switch 13
Connects the oscillator circuit 11 to the PCM codec 23, and the switch 14 connects the detection circuit 12 to the PCM codec 23. On the contrary, when the communication is terminated after the subscriber receives the voice signal (at the time of reception), the switch 13 switches the PCM.
The detection circuit 12 is connected to the codec 23, and the switch 14
Connects the oscillator circuit 11 to the PCM codec 23.

At the time of transmission, the oscillator circuit 11 outputs a test analog audio signal to the switch 13. The test analog voice signal input to the switch 13 is output to the PCM codec 23 and digitally converted. PC
The digital test signal output from the M codec 23 to the switch 14 is input to the detection circuit 12. The detection circuit 12 analyzes the input digital test signal to analyze the PC.
Know the operating status of the M codec.

When receiving, the oscillator circuit 11 outputs a test digital audio signal to the switch 14. The analog test audio signal input to the switch 14 is the PC
It is output to the M codec 23 and converted into an analog signal. PC
The analog test signal output from the M codec 23 to the switch 13 is input to the detection circuit 12. Detection circuit 12
Knows the operating state of the PCM codec by analyzing the input digital test signal.

When the signal conversion circuit 22 detects an off-hook signal from the subscriber line 21, it outputs an off-hook detection signal. The switches 13 and 14 are the signal conversion circuit 2
When the off-hook detection signal is input from 2, the signal conversion circuit 22 and the audio signal line 25 are connected to the PCM codec 23, respectively.

As described above, the codec test apparatus of this embodiment can always perform the PCM codec operation test when the line is not used, without setting a special test time.

[0016]

According to the present invention, the PCM codec is disconnected from the transmission line and connected to the test circuit by using the switch for switching connection based on the on-hook / off-hook detection signal output from the signal conversion circuit. By doing so, the operation test of the PCM codec can be performed when the line is not used.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is a partial block diagram of a speech path board of a conventional PCM terminal device.

[Explanation of symbols]

 11 oscillation circuit 12 detection circuit 13 switch 14 switch 21 subscriber line 22 signal conversion circuit 23 PCM codec 24 control line 25 voice signal line

Claims (3)

[Claims] 1. A signal conversion circuit connected to a subscriber line for detecting an on-hook / off-hook signal from the subscriber line and outputting a detection signal, and an input connected to the signal conversion circuit via the signal conversion circuit. The analog voice signal from the subscriber line is converted into a digital voice signal and output to a voice signal line, and the digital voice signal input from the voice signal line is converted into an analog voice signal to the signal conversion circuit. A codec test device provided on a speech path board having a codec to output and performing an operation test of the codec, a test execution means for transmitting and receiving a test signal, the signal conversion circuit based on the detection signal, and A codec test apparatus comprising: switch means for connecting the test execution means to the codec instead of the audio signal line. 2. The codec test apparatus according to claim 1, wherein the test execution means includes an oscillation circuit that generates the test signal and a detection circuit that detects the test signal. 3. The first switch for connecting any one of the signal conversion circuit, the oscillation circuit, and the detection circuit to the codec based on the detection signal, and the detection means. The codec test apparatus according to claim 2, further comprising a second switch that connects any one of the audio signal line, the oscillation circuit, and the detection circuit to the codec based on a signal.