JPS62210769A - Subscriber's circuit testing system - Google Patents

Abstract

PURPOSE:To confirm the normalcy of a code decoding circuit in a subscriber's circuit being put in a vacant state, by transmitting a test tone of digital form to the subscriber's circuit through a channel network, after the power down state of the code decoding circuit is cancelled from the outside. CONSTITUTION:In the testing time of a code decoding circuit 23 in a subscriber's circuit 2 being put in the vacant state, a power supplying signal (p) is transmitted to the subscriber's circuit 2, and the power down state of the code decoding circuit 23 is cancelled. Next, the test tone of digital form is transmitted from a test tone generation circuit 4 to the subscriber's circuit 2 through a channel network 3, and the code decoding circuit 23 converts a transmitted test tone of digital form to the one of analog form, and transmits it to two-wire/four-wire conversion circuit 22. By receiving the test tone of digital form by a reception circuit 5, it can be confirmed that the code decoding function of the code decoding circuit 23 in the subscriber's circuit is executed normally.

Description

[Detailed Description of the Invention] [Summary] In a digital exchange, the power-down state of the code/decoder circuit of a subscriber circuit can be canceled from the outside, and power is supplied to the code/decoder circuit of the subscriber circuit in an idle state. , by sending the test tone through the communication channel network and returning it via the code/decoding circuit and the two-wire/four-wire conversion circuit.
Check the normality of the code/decoder circuit.

[Industrial application field]

The present invention relates to improvements in subscriber circuit testing methods in digital exchanges.

Digital switching equipment converts analog voice signals transmitted from telephones to each subscriber circuit into digital format and transmits them to the communication network, and also converts digital voice signals transmitted from the communication network into analog A code/decoder circuit is provided for converting the data into a format and transmitting the data to the telephone set.

Note that when the subscriber circuit is in an idle state, the encoder/decoder circuit is rarely provided with a so-called power-down function to reduce the power consumption.

Even for subscriber circuits equipped with such a power-down function, it is desired that the code/decoder circuit be reliably tested in an idle state.

[Conventional technology]

FIG. 3 is a diagram showing an example of a conventional subscriber circuit.

In FIG. 3, the subscriber circuit 2 supplies a communication current to the accommodated telephone 1, and also includes a power supply/monitoring circuit 21 that monitors the on-hook/off-footer state of the telephone 1, and a two-wire subscriber line and a four-wire communication circuit. Two-wire four-wire conversion circuit 2 connecting to road network 3
2 and a code/decoder circuit 23.

Furthermore, the subscriber circuit 2 has a power-down function, and when the telephone 1 is in an on-footer state and the subscriber circuit 2 is in an idle state, power is not supplied from the power supply/monitoring circuit 21 to the code/decoder circuit 23. The supply signal p is not transmitted, and the code/decoder circuit 23 is placed in a power-down state.

In this state, when the power supply/monitoring circuit 21 detects off-hook of the telephone 1, the power supply signal p is sent to the code/decoding circuit 23.
Communicate.

The code/decoder circuit 23 that has received the power supply signal p releases the power-down state and normally executes the code/decode function.

Next, in order to test the code/decoder circuit 23 of the subscriber circuit 2 which is in a vacant state, the central control unit 6 connects the test tone generating circuit 4 and the test tone receiving circuit 5 to the subscriber circuit 2 via the communication path N43.
Even if the digital test sound generated by the test sound generation circuit 4 is transmitted to the subscriber circuit 2, the code/decoding circuit 2
3 is in a power-down state, testing of the code/decoder circuit 23 cannot be performed.

[Problem that the invention seeks to solve]

As is clear from the above description, in a certain conventional subscriber circuit, the power down state of the code/decoder circuit 23 is canceled only by the power supply signal p transmitted by the power supply/monitoring circuit 21, so that the subscriber circuit in the vacant state It was not possible to test the encoder/decoder circuit 23 of the operator circuit 2.

[Means for solving problems]

FIG. 1 is a diagram showing the principle of the present invention.

In FIG. 1, 2 is a subscriber circuit of a digital exchange which has a power supply/monitoring circuit 21, a two-wire/four-wire conversion circuit 22, and a code decoding circuit 23, and also has a power-down function;
3 is a communication path network, 4 is a test sound generating circuit, and 5 is a test sound receiving circuit.

Reference numeral 100 is provided according to the present invention, and the power-down state of the code/decoder circuit 23 can be detected not only from the power supply/monitoring circuit 21, but also from the power supply/monitoring circuit 21.
This is a release means that can also be released from the outside.

[Effect]

When testing the code/decoder circuit 23 of the subscriber circuit 2 which is in an idle state, after canceling the power-down state of the code/decoder circuit 23 from the outside, the test tone generating circuit 4 connected via the communication channel network 3 The transmitted test tone in digital format is transmitted to the subscriber circuit 2. The code/decoder circuit 23 converts the transmitted test sound into an analog format, and converts the transmitted test sound into an analog format.
However, since the telephone 1 is in the on-footer state, the two-line and four-wire conversion circuit 22 returns the analog test tone transmitted from the code decoding circuit 23 to the code decoding circuit 23. The code/decoder circuit 23 converts the returned test sound in analog format into a digital format and transmits it to the test sound receiving circuit 5 via the communication channel network 3.

The normality of the code/decoding circuit 23 of the subscriber circuit 2 is confirmed by the test sound receiving circuit 5 receiving the digital test sound.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a diagram showing a subscriber circuit testing method according to an embodiment of the present invention. Note that the same reference numerals indicate the same objects throughout the figures.

In FIG. 2, a gate 24 is provided in the subscriber circuit 2 as a release means 100.

Further, in FIG. 2, it is shown that the two-line and four-line conversion circuit 22 is composed of amplifiers A1 and A2, a subtracter A3, and the like. The analog signal input from the code/decoding circuit 23 to the amplifier A1 is sent to the power supply/monitoring circuit 21.
and is transmitted to the inverting input terminal (-) of subtracter A3.

When the telephone 1 is in the off-footer state, the power supply/monitoring circuit 21 transmits the analog signal transmitted from the amplifier A1 to the telephone 1, and also transmits the analog signal transmitted from the amplifier A1 to the telephone 1 via the amplifier A2 of the two-wire/four-wire conversion circuit 22 to the off-footer state of the subtracter A3. Input to the inverting input terminal (+). As a result, in the subtracter A3, the analog signal transmitted from the amplifier A2 and the analog signal transmitted from the amplifier A1 cancel each other out, thereby preventing the analog signal from being transmitted back to the code/decoding circuit 23.

Also in FIG. 2, the subscriber circuit 2 has a power-down function, and when it is in an idle state, the code/decoder circuit 2
3 is placed in a power down state.

In this state, when the power supply/monitoring circuit 21 detects an off-footer of the telephone 1, the power supply/monitoring circuit 21 sends the code to the code/decoding circuit 2 via the gate 24.
3 to release the power-down state.

Next, when testing the code/decoder circuit 23 of the subscriber circuit 2 which is in an idle state, the central control unit 6 selects the communication path! Connecting the test sound generating circuit 4 and the test sound receiving circuit 5 to the subscriber circuit 2 via ii3, and giving instructions to the control circuit 7;
A power supply signal p is transmitted to the subscriber circuit 2.

The power supply signal p is transmitted to the code/decoder circuit 23 via the gate 24 and causes the code/decoder circuit 23 to be released from the power-down state.

In this state, when a digital test sound is transmitted from the test sound generation circuit 4 to the subscriber circuit 2 via the communication path network 3, the code/decoder circuit 23 converts the transmitted digital test sound into an analog format. The signal is converted and transmitted to the two-wire/four-wire conversion circuit 22.

In the two-wire/four-wire conversion circuit 22, the analog test sound received by the amplifier A1 is transmitted to the power supply/monitoring circuit 21 and the inverting input terminal (-) of the subtracter A3.
is in the on-footer state, the power supply monitoring circuit 21 does not transmit the test sound transmitted from the amplifier A1 to the amplifier A2.

As a result, the subtracter A3 returns the analog test sound input from the amplifier A1 to the return code decoding circuit 23.

The code/decoder circuit 23 converts the test sound in analog format returned from the two-wire/four-wire conversion circuit 22 into a digital format.
It is transmitted to the test sound receiving circuit 5 via the communication path network 3.

When the test sound receiving circuit 5 receives the digital test sound, it is confirmed that the code/decoding circuit 23 in the subscriber circuit 2 is normally performing the code/decoding function.

As is clear from the above description (according to this embodiment, after transmitting the power supply signal p from the control circuit 7 to the subscriber circuit 2 in the idle state and canceling the power-down state of the code/decoder circuit 23, By confirming that the digital test tone transmitted from the test tone generating circuit 4 is returned to the test tone receiving circuit 5, the normality of the code/decoding circuit 23 can be confirmed.

Note that FIG. 2 is only one embodiment of the present invention, and for example, the configuration of the subscriber circuit 2 is not limited to that shown in the figure, and many other modifications may be considered. The effect of the present invention does not change even in this case.

〔Effect of the invention〕

As described above, according to the present invention, in the digital exchange, it is possible to confirm the normality of the code/decoder circuit of an idle subscriber circuit, and the credibility of the digital exchange is improved.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the principle of the present invention, FIG. 2 is a diagram showing a subscriber circuit testing method according to an embodiment of the present invention, and FIG. 3 is a diagram showing an example of a conventional subscriber circuit. In the figure, 1 is a telephone, 2 is a subscriber circuit, 3 is a communication path network, 4 is a test sound generation circuit, 5 is a test sound reception circuit, 6 is a central control unit, 7 is a control circuit, and 21 is a power supply/monitoring circuit. ,2
2 is a two-wire/four-wire conversion circuit, 23 is a code decoding circuit, 24 is a gate, 1oo is a release means, A1 and A2 are amplifiers, and A
3 is a subtractor, 1 is a ram 2 is a mouth

Claims (1)

[Claims] Power supply/monitoring circuit (21) and two-wire/four-wire conversion circuit (22)
and a code/decoder circuit (23), and a subscriber circuit (2) having a power-down function, the power-down state of the code/decoder circuit (23) is determined by the subscriber circuit (2). 2) Cancellation means (1) that can be released from the outside
00) in the subscriber circuit (2), and after canceling the power down state of the vacant subscriber circuit (2) from the outside via the canceling means (100), the communication path network (3) The test sound generation circuit (4) and the test sound reception circuit (5) are connected via the Line conversion circuit (22
) A subscriber circuit testing method characterized in that the test sound can be returned to the test sound receiving circuit (5) via the test sound receiving circuit (5).