JPH04151923A - Self-diagnostic system for pcm line unit - Google Patents

Abstract

PURPOSE:To simplify the test content at LIU shipping and to find out a fault early automatically by implementing the confirmation of the UB conversion of a line interface unit LIU and the B/U conversion function automatically at power application and at a routine period. CONSTITUTION:A pattern generator PG in a line interface unit LIU generates an optional pattern including a BPV error or the like and the pattern is looped back through a relay contact RL1 closed in the loopback mode. Then the pattern is looped back to a B/U through a relay contact RL2 closed in the mode. Then a pattern detection section PD in the inside of an LSI confirms, that the result of detection tells it that the received pattern is equal to a pattern generated by the pattern generator PG. The result of the confirmation of the function is displayed on a display device DISP. Then the indication of the normal state SVCE and the fault state FAIL is implemented on the display device DISP by means of, e.g. blinking.

Description

[Detailed Description of the Invention] [Summary of the Invention] Regarding the self-diagnosis method of the PCM line interface unit, the U/B conversion function, B/U conversion function, and line monitoring function among the various functions of the LIU are The purpose is to automatically perform this at the time of transmission and periodically, by converting the multiplexed unipolar signal into a bipolar signal and transmitting it, converting the received bipolar signal into a unipolar signal and sending it to the separation section, and further Also performs line monitoring
In the self-diagnosis method of the CM line interface unit, the unit is equipped with a pattern generator, and loopback paths are provided on the demultiplexing section side and the bipolar signal transmission/reception side, and the loopback paths are closed by program control when power is turned on, etc. , the pattern generator is configured to generate various test patterns and check the output of the pattern detection section.

[Industrial application field]

The present invention relates to a self-diagnosis method for a PCM line interface unit i.

For transmission equipment equipped with a line interface unit I-(LIU), the LIU is
Perform a self-diagnosis of U. The present invention relates to this self-diagnosis method.

[Conventional technology]

Some digital multiplexers have the configuration shown in FIG. In this figure, TEL is a telephone, CU is a channel unit that performs A/D conversion, and MLDX is a multiplexing/demultiplexing unit. The audio output of the telephone "f゛I!
The multiplexed unipolar signal RZ is multiplexed by
It is converted into a bipolar signal NRZ by the CM line interface unit LIU and sent out. The bipolar signal NRZ from the other party is converted into a unipolar signal RZ by the LIU, separated by the MLIIX, D/A converted by the CU, and sent to the corresponding telephone TI 15.

In this way, 11U performs CU/f3 conversion, ■B/U conversion, and also monitors the line status and displays the display section (RC
V) -”- is displayed.

Conventionally, the diagnosis of various functions of your LIU was performed by connecting a measuring device to the appropriate location, inputting correct signals, signals containing errors, etc.
This is done manually by checking the line status display section RCV (Figure 1).

(Problems to be Solved by the Invention) As described above, conventionally, the various functions of L i U have been manually diagnosed.

The present invention improves this point and automatically performs the U/B conversion function, B/U conversion function, and line monitoring function among the various functions of LIU at power-up and at regular intervals. Goshichi)".

[Means to solve the problem]

As shown in No. 11a, in the present invention, the line monitoring section I of the PCM line ink face unit l-LTU.

M is provided with a pattern generator PC. In addition, return paths are provided on the demultiplexing unit side and the bipolar signal N RZ O) transmitting/receiving side. RL, , R1-z are relay contacts that turn on/off the return path.

[Effect]

In the present invention, when the power is turned on and periodically under program control, the loopback mode is set, and the relay contacts RL, RL. is closed to complete the return path, and also causes the pattern generator PC to generate various test patterns. The generated test pattern signal passes through the path of ■■■■ to the pattern detection unit FD.
P enters and is checked.

Assuming that the generated pattern is a normal pattern and the U/B converter and B/U converter are also normal, the pattern detector PD
The detection result is normal. With this, each U/B and B/U conversion section can be used as usual. If the generated pattern includes an error, the detection result of the pattern detection unit PD will be abnormal (error). With this, it is possible to assume that the pattern detection section 1)D is operating normally.

(Embodiment) Fig. 1 will be further explained in detail.The line monitoring unit r-M is normally LS
It is controlled by the processor CPU, monitors the B/U converted bipolar signal NRZ of the receiving side PCMIN, and performs line break detection, BPV (bipolar violation) error detection, etc. This invention? The surroundings of the line monitoring unit LM are placed in loopback mode at power up and through regular software operations, and the U/B
.

Verify B/U and line monitoring system operations U (1').

The procedure for confirming operation is as follows.

(2) Generate an arbitrary pattern including 1-3 PV errors etc. using the pattern generator PG inside the LSI.

■ The pattern is folded back through relay contact RL, which closes in loopback mode.

■It passes through tJ/B and is looped back to B/U through relay contact RLz, which closes in loopback mode.

(6) Confirm that the pattern detection unit PD inside the LSI obtains a detection result that the received pattern is the same as that generated by the pattern generator I)G.

If these ■～■ are performed in patterns such as line breaks, BPV errors, and Al5 (8 alarm Indication Signal), these detection functions can be confirmed and B/
U.

You can check the U/B conversion function. The confirmation results of these functions are displayed on the display device DISP. Normal 5VCE and abnormal FAIL are displayed by, for example, flashing or blinking on the display device SP. Figure 2 shows a state transition diagram during self-diagnosis.

The CPU instructs relays RL and RL2 to loop back.■
, and pattern generator 1) G with an arbitrary pattern (normal,
■ Instructs the occurrence of AIS, BPV).

The pattern generator PC generates the instructed pattern, the pattern detection unit PD monitors this, and notifies the CPU of the status of the received pattern (normal, BPV, Al5). C.P.
In U, it is checked whether ■ and ■ are equal or not, and the result is displayed on the display device SP ■.

5VCE if normal (match), FAI if abnormal (mismatch)
It is L.

(Effect of the invention) As explained above, in the present invention, the LIU UB, B/U
, and the normal/abnormal operation of the line monitoring system can be automatically checked at power-up and periodically, simplifying the test content at the time of L1tJ shipment and detecting LIU failures early. I can do it.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the self-diagnosis method of the present invention, FIG. 2 is a state transition diagram during self-diagnosis, and FIG. 3 is a block diagram showing the configuration of a digital multiplexing device. In Figure 1, U/B is a unipolar/bipolar converter, and B/B is a unipolar/bipolar converter.
U is a bipolar/unipolar converter, PG is a pattern generator, and PD is a pattern detector.

Claims (1)

[Claims] 1. A PCM line interface that converts a multiplexed unipolar signal into a bipolar signal and sends it out, converts a received bipolar signal into a unipolar signal and sends it to a separation section, and also performs line monitoring. In the unit self-diagnosis system, the unit is equipped with a pattern generator (PG), and a return path (R
L_1, RL_2) are provided, and the return path is closed under program control when the power is turned on, etc., and the pattern generator generates various test patterns to check the output of the pattern detection section (PD). Self-diagnosis method for PCM line unit.