JPH11125650A - Multiple circuit wiring-testing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely test conduction, short circuit, wrong wiring by a smaller count of tests, by feeding signals outputted in parallel to lines of a multiple circuit to be measured and carrying out a simultaneous wiring test. SOLUTION: Signals are read out in parallel from stages of an n-stage pseudo random bit sequence PRBS generation part 10 and supplied to drivers 31-3n and one end of a comparator 50. Output signals from the drivers 31-3n are applied via a connector 51 to one terminal of a multiple circuit 90 to be measured, and also fed to the other end of the comparator 50 via another connector 52 of the multiple circuit 90. Moreover, when the applied signal does not agree with a signal to be tested at the comparator 50, an error display of wrong wiring or a disconnection is displayed by an error display means 60. When the drivers 31-31n are, for instance, line drivers of an open collector, a short circuit in the wiring of the lines can be detected as an error. More specifically, test signals are fed simultaneously in parallel to lines of the multiple circuit at random at all times and are random signals in time sequence in one cycle, and therefore, wrong wiring or short circuit between other wiriness can be tested surely simultaneously with a condition test by a minimum count of tests.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pseudo random bit sequence (PRBS).
e) The present invention relates to a multi-circuit wiring test apparatus using the signal of e).

[0002]

2. Description of the Related Art An example of the prior art will be described with reference to FIGS. As shown in FIG. 5, the conventional multi-line wiring test apparatus includes scanners 93 and 94, a digital multimeter 95, and a controller 96. Then, the wiring of the multi-circuit under test 90 is tested.

As shown in FIG. 4, an example of a multi-circuit under test 90 is composed of a connector 91, a connector 92, and four stages of latching relays S1, S2, S3, and S4. The wiring between the n outputs can be freely connected.
As a specific example of use, there is a switch module for switching wiring between a telephone exchange and various simulator devices on a telephone line.

Next, a conventional test method will be described. In accordance with the internal wiring of the multi-circuit under test 90, cable wiring on the test apparatus side is performed in advance so that the order of the connectors 51 and the connectors 52 is one-to-one. And
To test only the continuity of each line of the multi-line, use the scanner 9
3 and the scanner 94 are sequentially scanned from the 1st to the nth, and are tested by a digital multimeter. Here, the scanner 93, the scanner 94, and the digital multimeter are program-controlled by a controller.

[0005] Next, when a short circuit between multiple lines is to be tested, for example, the scanner 93 is scanned from the first to the nth in a state where the scanner 94 is connected first, and conduction is performed to other than the first. If there is, it is understood that the wiring is short-circuited. Similarly, with the scanner 94 connected to the nth position, the scanner 93 is scanned from the 1st to the nth position. Recognize.

In this method, if the number of lines is n, the number of tests is n × n, and the number of times the contacts of the scanner to be tested are turned on / off is very large. For example, in the case of 511 lines, it is necessary to perform 2611221 tests. Therefore, it is necessary that the reliability of the device itself to be tested is also high.

By using a digital multimeter,
Conducting a continuity test on multiple wires one by one is easy when the number of lines is small, but when the number of lines is large, the number of test steps increases, and short-circuits with other wires and incorrect wiring can be checked. Have difficulty.

[0008]

As described above, in the conventional test method, when there are many lines to be tested, when the test including the short circuit between the wirings is performed, the number of tests is increased, and the test apparatus itself is increased. There was a problem with reliability, a long test time, and a large-scale apparatus, which was inconvenient for practical use. Therefore, the present invention has been made in view of such a problem, and an object of the present invention is to provide a simple circuit configuration, conduct a reliable test with a small number of test times for a multi-line wiring test, and to perform a test for short-circuiting between wires and erroneous wiring. It is an object of the present invention to provide a multi-circuit wiring test apparatus that can perform the test.

[0009]

That is, a first aspect of the present invention, which has been made to achieve the above object, is to transmit a parallel output signal from each stage of the PRBS pattern generating means to each of the multi-circuits to be measured. The gist of the present invention is to provide a multi-circuit wiring test apparatus characterized in that wiring tests are performed simultaneously.

A second aspect of the present invention, which has been made to achieve the above object, is to provide a shift register and an adder to use a PRBS.
PBRS pattern generating means for generating the pattern of the above, a line driver receiving the parallel output of each stage of the shift register to drive the lines of the multi-measuring line, and a line receiver receiving the line outputs of the multi-measuring line respectively And receiving the output of the line receiver at one end,
The other end of the shift register receives the parallel output of the shift register and performs a logical comparison of signals, and an error display unit that receives an error signal from the comparator and displays an error to test multi-line wiring. The gist is a multi-circuit wiring test apparatus characterized by the above.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described in the following examples.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the multi-line wiring test apparatus of the present invention includes a PRBS generator 10 and a line driver 3.
1-3n, the line receivers 41-4n, and the comparator 50
, Connectors 51 and 52 wired with cables, and error display means 60. Then, the wiring of the multi-circuit under test 90 is tested.

First, an M-sequence pattern generator will be described as a PRBS pattern generator. For example, as shown in FIG. 3, an M-sequence generator using a seven-stage shift register can store 127 random states except for an all-zero state. Is always shifted to one of the 127 states. Therefore, no matter what the initial state of the register is all states other than 0, a maximum of 12
If the register is shifted seven times, the contents of the register must return to the initial state by then. And 12
Seven clocks constitute one cycle, after which the same series of data is repeatedly output. Therefore, the maximum period of the M sequence that can be realized by the seven-stage shift register is 127, and the maximum period of the M sequence that can be realized by the n-stage shift register 11 is 2
^n- 1.

Hereinafter, each component and operation will be described. As shown in FIG. 1, signals are read out in parallel from each stage of the n-stage PRBS generator 10 and supplied to the line drivers 31 to 3n and one end of the comparator 50, respectively.

The output signals of the line drivers 31 to 3n are applied to one of the multi-circuits to be measured 90 via a cable-connected connector 51. Also, the other cable-wired connector 52 of the multi-line under test 90
To the other end of the comparator 50.

If the applied signal and the signal under test do not match in the comparator 50, an error is displayed on the error display means 60 as an error. If, for example, an open collector line driver is used as the line drivers 31 to 3n, a short circuit between line wirings can be detected as an error.

An example of the error display means 60 is shown in FIG.
As shown in the figure, each output signal of the comparator 50 is
1 and an output is applied to the D terminal of the D flip-flop 61, and its Q output is connected to the other end of the OR gate 71 to maintain an error state. The LED is turned on by the inverted Q output of the D flip-flop 61 to indicate that an error has occurred.

In the method of the present invention, if the M-sequence generator uses a seven-stage shift register, the random sequence is 127 clocks. A circuit can be tested at once for 127 clocks, and erroneous wiring and short circuit between wirings can be tested. Also, if the M-sequence generator uses a nine-stage shift register, if the number of registers is similarly increased to 511, even if the 511 line is 511 clocks at one time, conduction and erroneous wiring and wiring Can test short.

That is, since each test signal applied simultaneously to each of the multiple lines in parallel is always random, and one cycle is also a random test signal in time series, erroneous wiring or other wiring is performed simultaneously with the continuity test. Short tests can be executed reliably, and the number of tests is minimized.

When the internal connection of the multi-circuit under test 90 is changed, one of the input and output to be tested is:
The same can be implemented by preparing only necessary types of connectors wired with cables corresponding to signal connections.

[0021]

The present invention is embodied in the form described above and has the following effects. That is,
The test signal applied to multiple lines at the same time is random and is a random test signal in chronological order, so that a continuity test and a test for erroneous wiring or a short circuit between other wirings can be reliably executed, and the minimum The effect is great because only the number of tests is required. In addition, since a scanner or a controller that requires a switch is not required, a low-cost and highly reliable multi-line wiring test apparatus can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram of a multi-line wiring test apparatus of the present invention and a multi-line to be measured.

FIG. 2 is a circuit diagram example of an error display means.

FIG. 3 is a circuit example of PRBS generation using a seven-stage shift register.

FIG. 4 is a circuit diagram example of a multi-line to be measured.

FIG. 5 is a block diagram of a conventional multi-line wiring test apparatus and a multi-line to be measured.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 PRBS generation part 11 Shift register 20, 21 EXOR 31-3n Driver 41-4n Receiver 50 Comparator 51, 52 Connector 60 Error display means 90 Multi-line to be measured

Claims (2)

[Claims] 1. The PRBS pattern generating means includes:
A multi-circuit wiring test apparatus characterized in that a signal of a parallel output is given to each of the multi-circuits to be measured, and a wiring test is performed simultaneously. 2. A PBRS pattern generating means for generating a PRBS pattern by a shift register and an adder, a line driver receiving parallel outputs of respective stages of the shift register and driving respective multi-measurement lines, A line receiver that receives the line output of the multi-line under test, a comparator that receives the output of the line receiver at one end, and receives the parallel output of the shift register at the other end and compares the logic of each signal; An error display means for receiving an error signal and displaying an error, and testing a multi-line wiring, comprising: