JPS6097757A - Remote test system of data modulator-demodulator - Google Patents

Abstract

PURPOSE:To attain simplicity and efficiency of maintenance by starting a test device of a station to be tested by an indication from a test station so as to start the test, transferring a test signal to the test station, stopping temporarily the transfer at detection of fault and discriminating the propriety from the number of times of stop and the time. CONSTITUTION:The test device 53 of the test station 5 transmits a test start signal to a 2-wire line 7 via a modulator 51. The signal is demodulated 62 via an analog signal controller 64 of the station 6 to be tested and when the test device 63 detects the test start signal, a test code is generated after fixed time. The test code is transferred to the test station 5 via a modulator 61 and a communication line 7 and reflected to a demodulator 62. An output signal of the demodulator 62 is inputted to the test device 63. The test device 63 stops the transmission of the test code to the test station 5 every time an error is detected from the state of the own station reflecting of the station 6 to be tested. The test station 5 decides the propriety of the station to be tested from the number of times of stop and the length of stop time. Thus, the remote test is attained with a simple 2-wire line.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides data modulation and demodulation devices (hereinafter referred to as data modems) that are distributed and installed in various locations.

This invention relates to a remote testing method for data modulation and demodulation equipment in which the quality of data modulation and demodulation equipment is determined centrally at a computer center or the like from a remote location via a communication line.

An example of the configuration of a conventional remote testing method for a data modem is shown in FIG. FIG. 1 shows an example in which a test station data modem 1 and a station under test data modem 3 are connected via a four-wire communication line 2. In FIG. 1, a loopback circuit 3 is connected from the output side of the demodulator 32 of the station data modem 3 under test to the input side of the modulator 31.
3 to return to the 4-wire communication line side. The return operation of the return circuit 33 is performed either automatically by detecting the return signal sent from the test station data modem 1 by the station data modem 3 under test, or by a switch operation by the terminal operator. There are cases where you are forced to do it, but either is fine.

Under the above conditions, the test equipment 13 of the test station data modem l
When the test code is sent to the four-wire data communication line 2 via the digital modulator 11, it is transmitted to the demodulator 32. of the station data modem 3 under test. It passes through the loopback circuit 33 and the modulator 31, and again through the 4-wire communication line 2, and reaches the test equipment 13 via the demodulator 12 (i:) of the test station data modem 1. Therefore, if this signal is determined, , it is possible to determine the quality of the station data modem 3 under test, including the quality of the four-wire communication line 2.

The test code sent by the test device 13 is (2N-1
) Pseudo-random patterns (N is a positive integer) are often used, and the bit error rate and the like are used to determine pass/fail.

However, if the communication line is a two-wire type and the required transmitting and receiving frequency bands of the test station data modem 3 and the test station data modem l are the same, it is not possible to transmit and receive at the same time, and the data modem Remote testing was not possible.

Therefore, an object of the present invention is to connect a test station data modulation/demodulation device and a station data modulation/demodulation device under test through a two-wire communication line, and to make sure that the transmitting/receiving frequency bands of the test station data modulation/demodulation device and the station data modulation/demodulation device under test are the same. An object of the present invention is to provide a remote testing method for data modulation/demodulation equipment applicable to various cases.

In the remote testing method of the data modulation/demodulation device of the present invention, in the test station data modulation/demodulation device, the test start signal and the test termination signal generated for a certain period of time in the first test device are sent to the 2# type line via the first modulator. In the station data modulation/demodulation device under test, the output of the analog signal controller connected to the two-wire communication line is inputted to a second demodulator, the output is inputted to a second test device, and this In the second test device, when the test start signal is detected, the test code is input to the second modulator after a certain period of time, and the output of the second modulator is folded into the input terminal of the second demodulator. At the same time, the analog signal controller is input to the two-wire communication line.

input to the first test device via the first demodulator;
The second test device counts data errors in the second demodulator, controls the analog signal controller, and stops transmission of test codes to the two-wire communication line for a certain period of time every time a data error occurs. At the same time, when the transmission stop time of the test code continuously exceeds a predetermined time, when data errors are counted up to a certain number, or when the test termination signal is received from the tenth test device. In this case, the first test device stops generating the test code, and the first test device monitors the test code sent by the second test device, and also monitors the timing of sending the test end signal. It is characterized by determining the quality of the station data modulation/demodulation device under test.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. FIG. 2 shows an embodiment of a remote testing method for a data modulation/demodulation device according to the present invention. In the test station data modem 5 of FIG. 2, the test device 53 generates a test start ia@ for a certain period of time. This test start signal is sent to the two-wire communication line 7 via the modulator 51, inputted to the station under test data modem 6, passed through the analog signal controller 64, demodulated by the demodulator 62, and sent to the test equipment 63.
Detected by When the test equipment 63 detects the test start signal, after a certain period of time (this time is selected so that there is no call collision between one opposing data modem), the test code generator in the test equipment 63 A test code is generated by This test code is sent out to the two-wire communication line 7 through the modulator 61't of the station data modem 6 under test and transmitted to the test station data modem 5. The signal is returned to the demodulator 62. The output signal of this demodulator 62 is input to a test device 63.

That is, the remote test state is set. The test device 63 counts data errors in the self-return state of the station data modem 6 under test, controls the analog signal controller 64 every time a data error is detected, and controls the 2m communication line of the test code for a certain period of time. All transmissions to will be stopped.

Each time a data error is detected, the transmission of the test code from the analog signal controller 64 to the two-wire communication line is stopped for a certain period of time. When visually displaying using one LED 54 or the like, for example, about 100 m5 is selected.

In the test device 63, when the count value of data errors reaches a certain value, and when the analog signal controller 64 is controlled, the continuous transmission of the test code to the two-wire communication line is stopped for a predetermined time. If it exceeds the above, the generation of the test code is intentionally stopped and the remote test state is canceled.

Further, in the test station data modem 5, the above-mentioned test code sent from the station under test data modem 6 is sent to a demodulator 52.
The quality of the data modem 6 of the station under test is determined by demodulating the data modem 6 and monitoring the test code and its stop using the test device 53. Furthermore, the test device 53 has the station under test data.
If the modem 6 stops transmitting the test code every time an error is counted and exceeds a predetermined period of nine hours, the end of the remote test is automatically determined. If the data modem 6 of the station under test is in good condition, in order to prevent the test from continuing permanently, the test device 53 sends a test termination code, and similarly to the test start signal described above, the data modem under test Φ The test is completed by the test device 63 of No. 6. The test termination signal may be a code that intentionally generates an error in the data modem of the station under test during the return test, so if two opposing data modems have the same transmitting and receiving frequency band and their data spectrum, All that is required is to transmit the normal modulated output of the test station data modem 5 to the station data modem under test 6, superimpose it on the test code, and transmit it continuously during the period when the above-mentioned fixed value error occurs. It's obvious.

As explained above, according to the present invention, remote testing is possible even when the data modem is connected to a T-2 communication line with the same transmitting and receiving frequency band, which greatly simplifies maintenance of the data modem. This has the effect of streamlining and streamlining.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a conventional example, and FIG. 2 is a block diagram showing an embodiment of the present invention. 1.5... Test station data modem, 2...
...4-wire communication line, 3.6...Test station data modem, 4...Data terminal device, 7...
...2-wire communication line, 11.31, 51.61...
... Modulator, 12,32°52.62 ... Demodulator, 13 ... Test equipment, 33 ... Folding circuit, 53 ... Test Device, 63...
-Test equipment, 64...Analog signal controller.

Claims (1)

[Scope of Claims] In a test station data modulation/demodulation device, a test start signal and a test end signal generated for a certain period of time in a first test device are outputted to a two-wire system via a first modulator, and In the station data modulation/demodulation device, the output of the analog signal controller connected to the two-wire communication line is input to a second demodulator, the output is input to a second test device, and the second test device When the test start signal is detected, the test code is input to the second modulator after a certain period of time, and the output of the second modulator is returned to the input terminal of the second demodulator, and the analog signal is input to the controller, said two-wire communication line; input to the first test device via the first demodulator;
the second test device counts data errors of the second demodulator and controls the analog signal controller, and if the transmission time of the test code to the two-wire communication line is exceeded;
When the number of data errors is counted up to a certain number, or when the test end signal from the first test device is received, the first test device stops generating the test code, and the first test device 2. A remote testing method for a data modulation/demodulation device, characterized in that the quality of the data modulation/demodulation device of the station under test is determined.