JPH02149154A - Automatic test system for transmission quality - Google Patents

Abstract

PURPOSE:To judge the transmission quality of each relay section with one time of execution of a test by setting the duration of a loop back test proper to each repeater longer at every passage of a relay stage. CONSTITUTION:Synchronism is taken at a synchronous circuit 5 in the repeater from a test pattern string generated by a test pattern generation circuit 1, and the loop back test is recognized, and the input signal of an IN2 is folded to an OUT2 at a folding circuit 7 only for time length proper to the repeater set at a time constant circuit 6, and the similar operation is performed at the repeater at following stages. Here, a time constant is set longer sequentially as passing the next and after stages. At the reception part of test equipment, the synchronism is taken at a synchronization circuit 2 and the error of the test pattern is detected from reception data at an error detecting circuit 3, and the transmission quality of each relay section is decided from the duration of the loop back test proper to each repeater and error information from the error detecting circuit 3 at a decision circuit 4. In such a way, it is possible to automatically test and decide the transmission quality between adjacent repeaters.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to multi-stage relay transmission that transmits signals over long distances while compensating for losses caused by the transmission line using repeaters placed at intervals along the transmission line. This invention relates to an automatic test method for determining the transmission quality of each relay section in a system.

(Prior art) In the conventional test method for determining the transmission quality of each relay section in a multi-stage relay transmission system, a unique address is assigned to each relay device, and the corresponding relay is The device was performing loopback.

(Problem to be Solved by the Invention) In the conventional test method described above, in order to determine a fault section, in the case of an n-stage relay, it is necessary to change the address from the tester at most once and execute the test. There were drawbacks.

(Means for Solving the Problems) Means provided by the present invention to solve the above-mentioned problems are as follows:
In a multi-stage relay transmission system in which a plurality of repeating devices are placed at intervals along a transmission line and signals are transmitted over long distances by compensating for deterioration in signal quality on the transmission line with the repeating devices, adjacent repeating devices are used. A method for automatically testing the transmission quality of the transmission line between the transmission lines by connecting a tester to the transmission line, the method comprising: a test pattern generation circuit that sends a test pattern sequence to the transmission line; and the relay device. a first synchronization circuit that generates a synchronization signal when detecting the test pattern sequence looped back by the relay device; a circuit for detecting an error in a pattern string; and a circuit for determining the transmission quality from the duration of the test pattern string sent back by the relay device and the error detected by the error detection circuit. a second synchronization circuit provided in the tester and generating a synchronization signal when detecting the test pattern train sent from the test pattern generation circuit; a time constant circuit that outputs a return signal for a predetermined return duration time for each relay device; and a time constant circuit that outputs a loopback signal for a predetermined loopback duration time for each relay device; Each of the repeating devices is provided with a circuit for folding back toward the destination.

(Example) Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a tester used in an embodiment of the present invention, and FIG. 2 is a block diagram showing the configuration of a relay device used in the embodiment. INl and 0UT1 are the input and output of the tester, IN2 and 0UT2 are the input and output of the tester in the relay device, 1N3 and OUT3
are the inputs and outputs of the next-stage relay device in the relay device. 1 is a test pattern generation circuit, 2 is a synchronization circuit, 3 is an error detection circuit that detects errors in the test pattern from received data, and 4 is a test pattern generation circuit for each relay based on the return test duration time of each relay device and error information from error detection circuit 3. A determination circuit for determining the transmission quality of the section, 5 is a synchronization circuit, and 6 is a loopback test Ill! specific to the relay device. A time constant circuit 7 for setting the duration is a folding circuit that enters a folding state for the test duration set by the time constant circuit 6. When the folding circuit 7 enters the folding state, the signal line 10 is connected to the signal line 11,
At other times, the signal line 11 is connected to the signal line 12.

Next, the operation of this embodiment will be explained. First, the synchronization circuit 5 of the relay device synchronizes the test pattern sequence generated by the test pattern generation circuit 1, recognizes the loopback test state, and loops back for a time length specific to the relay device, which is certified by the time constant 16. In circuit 7, input signal of IN2 is set to 0UT.
Turn back to 2.

The same operation is performed at the next stage and subsequent relay devices.Here,
It is assumed that the time constants are made sequentially longer from the next stage onward. In the receiving section of the tester, a synchronization circuit 2 synchronizes, an error detection circuit 3 detects an error in the test pattern from the received data, and a judgment circuit 4 detects the loopback test duration specific to each relay device and the error detection circuit 3. The transmission quality of each relay section is determined from the error information from.

(Effects of the Invention) As explained above, according to the method of the present invention, by setting the loopback test duration specific to each relay device to be longer for each relay stage from the tester, the transmission of each relay section is Quality can be determined with a single test run.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a tester in a repair example of the present invention, and FIG. 2 is a block diagram showing the configuration of a relay device in the embodiment. 1... Test 11 pattern generation circuit, 2... Synchronous circuit,
3...Error detection circuit, 4...Judgment circuit, 5...Synchronization circuit, 6...Time constant circuit, 7...Return circuit.

Claims (1)

[Claims] Multi-stage relay transmission that transmits signals over long distances by arranging a plurality of repeaters at intervals along a transmission line and compensating for deterioration in signal quality on the transmission line with the repeaters. In the system, the transmission quality of the transmission line between the adjacent repeating devices is automatically tested by connecting a tester to the transmission line, the method comprising: generating a test pattern to send a test pattern sequence to the transmission line; a first synchronization circuit that generates a synchronization signal when the repeating test pattern sequence is detected by the relay device; A circuit for detecting errors in the test pattern string returned by the relay device, a duration of the test pattern string sent back by the relay device, and the error detected by the error detection circuit to determine the transmission quality. a second synchronization circuit that generates a synchronization signal when detecting the test pattern sequence sent from the test pattern generation circuit; and a second synchronization circuit that generates the synchronization signal from the second synchronization circuit. a time constant circuit that outputs a loopback signal for a loopback duration predetermined for each relay device from the time when the loopback signal is received; and the test pattern that is sent from the test pattern generation circuit only during the period when the loopback signal is received. An automatic transmission quality testing method, characterized in that each of the repeating devices is provided with a circuit for turning back a column toward the tester.