JPS59255A - Modem testing system - Google Patents

Abstract

PURPOSE:To search efficiently a fault of an MODEM, by detecting an error of a test pattern sent from a slave station, in a main station MODEM and testing all slave station MODEMs by an operation of once from the main station MODEM. CONSTITUTION:In a main station MODEM 1, a modulating signal of a test pattern from slave station MODEMs 2, 3 and 4 is demodulated by a demodulating circuit 13, and thereafter, is inputted to a bit error detecting circuit 9, and a bit error of the test pattern is detected. Also, as for the demodulating signal, the test pattern end is detected 8, and by its output, the MODEM 1 sends an address signal which adds ''1'' to the previous address, to a slave station, and sends out the test pattern from the slave station. As a result, the MODEM 1 receives successively up to the test pattern designated by the maximum setting signal from the slave station, and detects a bit error. Also, by controlling the circuit 7, the MODEM 1 repeats the slave station MODEM of an address 1 through 4, designates it many times and can detect the bit error.

Description

[Detailed description of the invention] The present invention relates to a test method for a modem device.

Conventionally, the method of remotely testing modem equipment (abbreviated as DM) is to send a control signal from the main station modem to the slave station modem, and the slave station modem detects this signal. After forming a loop pack, a test pattern was sent from the master modem, and errors in the test pattern returned by the slave modem were detected.

Furthermore, the addresses of the slave modems were manually set each time using a switch on the master modem.

However, in the conventional method, the test is performed after forming a loopback with the slave station modem, so in a multi-point configuration line, the master station modem must manually switch the address of the slave station modem for each station. Therefore, it took a long time to test all stations. In addition, since a loopback is formed, it is difficult to conduct tests in a manner different from the modem's actual use, and there is a drawback that fault finding is not efficient.

The object of the present invention is to eliminate the above-mentioned drawbacks and to automatically switch all the slave modems of a multi-point Indian line without looping back the modems, in a manner consistent with the actual usage, and in a single operation. An object of the present invention is to provide a modem test method for testing.

According to the present invention, a test control signal indicating the start or end of a test and first address information for specifying the address of a slave station modem are sent from a master station modem, and in the first slave station modem, , when detecting the test control signal and address information indicating the start of the test, sends a test pattern to the main station modem, detects an error in this test butter / in the main station modem, and further changes the address information. This is a modulation/demodulation device testing method that can automatically test all of the slave station modulation/demodulation devices by sending the address information to another slave station modulation/demodulation device.

Next, a test method for a modem according to the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention, in which 1 is a main station modem, 2 to 4 are slave station modems, 5 is a sequence control circuit, 6 is a test control signal generation circuit, 7 is an address signal generation circuit, 8 is a test pattern end detection circuit, 9 is a bit error detection circuit, 10 is a gate circuit, 11 is a selection circuit, 12 is a modulation circuit, 13 is a demodulation circuit, 14 is a modulation circuit, and 15 is a demodulation circuit. Circuit 16 is a selection circuit, 17 is a test pattern generation circuit, 18 is a test control signal detection circuit, 1
9 is an address signal detection circuit, 20 is a gate circuit 0
In particular, a is a transmission data input signal to the main station modem 1, b is a slave station address maximum value setting signal, C is a control signal for starting and ending the test, d is an error detection signal, and e is a main station modem Received data output signal from 1, if, i3, 14
is the received data output signal from slave station modem 2゜3.4・u
2. H3, u4 are the local station address setting signals V2.4 of slave station modems 2, 3.4. V3. V4 is slave station modem 2, 3.4
This is the data input signal to be sent to. Normally, the data input signal a input to the main station 1 is modulated by the modulation circuit 12, sent to the slave station modems 2, 3.4, and demodulated by the slave station modems to obtain the received output signal "2+13t t4." Slave modem 2,
3 and 4, the data input signal v2. v3゜v4
The modulation circuit 14 modulates the signal, the signal is sent to the main station modem, and the main station modem demodulates it in the demodulation circuit 13 to obtain a received data output signal e, thereby performing data transmission over a multipoint line.

In the above configuration, the test is initiated from the main station modem l. Activation is performed by turning on the control signal C after specifying the maximum number N of slave station modems using the maximum value setting signal of the slave station address. This activates the sequence control circuit 5, which switches the signal input to the selection circuit 11 to the test control signal generation circuit 6 using the control signal j, and at the same time controls the gate circuit 10 to output the received data output signal e. Set to OFF state. Furthermore, the control signal f instructs the test control signal generation circuit 6 to generate a test start signal.

As the test start signal, for example, a random pattern frequently generated by a scrambler can be used.

Next, the sequence control circuit 5 receives the control signal f after a certain period of time.
is turned OFF, the test start signal is stopped, and the control signal g is used to send the address 1 to the address signal generation circuit 7.
Instructs to generate an address signal meaning . As the address signal, for example, an information exchange code according to JIS C6220 can be used. The test start signal and address signal are passed through the selection circuit 11 to the modulation circuit 12.
and sent out to transmission path m.

On the other hand, in the slave station modem, the signal from the master station modem is demodulated by the demodulation circuit 15 and the test control signal detection circuit 18
, address signal detection circuit 19 is input to gate circuit 20.

When the test control signal detection circuit 18 detects the test start signal from the main station modem, the gate circuit 20f is activated by the control signal 0:
control to set the received data output signal (t2°13, 14) to OFF. Furthermore, the control signal 0 mainly controls the selection circuit 16 and transmits the input data input signal (v21) to the modulation circuit.
V31V4) to the output of the test pattern generation circuit 17. Furthermore, the address signal detection circuit 19
The address signal following the test start signal is detected, and if the address matches the local station address setting signal (■2+v3+v4), the test pattern generation circuit 1 is activated by the control signal p.
7 is instructed to generate a test pattern. As a result, the test pattern is input to the modulation circuit 14, and a modulated signal of the test pattern is sent to the main station modem.

Further, the address signal detection circuit 19 instructs the test pattern generation circuit 17 to stop transmitting the test pattern after a certain period of time. Note that the address from the main station modem is the local station address setting signal (v
2+v3+Va), the control signal p does not become active and no test pattern is sent.

On the other hand, in the main station modem, the test pattern modulation signal from the slave station modem is demodulated by the demodulation circuit 13 and then input to the bit error detection circuit 9 to detect bit errors in the test pattern. Further, when the test pattern end detection circuit 8 detects the end of the input of the demodulated signal, it notifies the sequence control circuit 5 of this by means of a control signal. Accordingly, the sequence control circuit 5 outputs the control signal g and instructs the address signal generation circuit 7 to generate an address signal that is +1 higher than the previously generated address.

As a result, an address signal specifying address 2 is sent from the master modem 1 to the slave modem, and the slave modem 3
If is set to address 2, the modem sends a test pattern to the master station modem 1 in the same way as described above for the slave station modem 2. In this way, the main station modem 1 sequentially sends out address signals up to the address (N) specified by the maximum value setting signal of the slave station address, receives the test pattern from the corresponding slave station modem, and detects error bits. can be done.

Furthermore, if the sequence control circuit 5 controls the address signal generation circuit to generate address 1 after address N, bit errors can be measured by specifying that the slave station modem from address 1 to address N be visited repeatedly. becomes possible.

Next, this test can be stopped by turning off the control signal C'f of the main station modem 1.

That is, in the sequence control circuit 5, the control signal C is OFF.
Now, the control signal f instructs the test control signal generation circuit 6 to generate all test end signals. As a result, a test end signal is transmitted to all slave station modems. As the test end signal, it is possible to use, for example, a random turn with the polarity of the test start signal reversed.

Furthermore, the sequence control circuit 5 outputs the control signal j after a certain period of time.
) The selection circuit 11 is instructed to switch its input to the transmission data input signal a, and the gate circuit 10 is controlled to output the output of the demodulation circuit 13 as the reception data output signal e. This restores the main station modem 1 to the state before the start of the test.

On the other hand, the slave station modem detects the test end signal from the master station modem in the test control signal detection circuit 18 and transmits the input of the modulation circuit 14 to the selection circuit 16 as the data input signal (V2+V
3+v4) and also controls the gate circuit 20 so that the output of the demodulation circuit becomes the received data output signal (j2+ta+
t4). This allows all slave station modems to be restored to the state they were in before the test started.

As explained above, according to the present invention, a modem can be tested in the same manner as when it is actually used without looping back the slave modem, and all tests can be performed in one operation from the master modem. Since the slave station modem can be tested, it has the effect of greatly increasing the efficiency of finding faults in the modem.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention. 1...Main station modem, 2,3.4...Slave station modem, 5...Sequence 7 control circuit, 6...Test control signal generation circuit, 7...Address signal Generation circuit, 8...Test pattern end detection circuit, 9...
... Bit error υ detection circuit, 10 ... Gate circuit, 11 ... Selection circuit, 12 ... Modulation circuit,
13...Decoder circuit, 14...Modulation circuit,
15... Demodulation circuit, 16...- Selection circuit, 17... Test pattern generation circuit, 18...
... Test control signal detection circuit, 19 ... Address signal detection circuit, 20 ... Gate circuit.

Claims (1)

[Claims] In a system that uses a modem to transmit data in a multi-point line configuration, the main station modem,
A means for generating test control signals indicating the start and end of the test and address information for specifying the address of the slave station modem device, receiving a test pattern from the slave station modem device, and detecting an error p in the test pattern. and means for changing the address information upon completion of reception of the test pattern, and means for detecting the test control signal and address information from the master station modem and demodulator in the slave station modem, and generating the test pattern. and means for transmitting data to the main station modem/demodulator.