JPS59204333A - Automatic return tester - Google Patents

Abstract

PURPOSE:To suppress the time of circuit disconnection as much as possible and to improve the reliability of a circuit by conducting a return test only when an abnormal state continues for a specific time after abnormality of a receiver is detected. CONSTITUTION:An automatic return tester 2 is set normally in a stand-by state. When the receiver 1 becomes abnromal and its detection signal is applied to a logical circuit 3, the circuit 3 drives an oscillator 4 when the detection signal is in the same state continuously for longer than the specific time. A shifter 6 generates a signal of the same frequency with a receiving signal by a signal from the side of a transmitter 5 and a signal from the oscillator 4 and sends out the signal to the receiver 1 through a BPF7 and a coupler 8. When this signal is outputted to the output terminal of the receiver 1, the circuit 3 decides that the receiver 1 is normal, and when no, it is decided that the receiver 1 is faulty. The circuit 3 does not conduct the return test when the abnromality detection signal is ceased within the specific time.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a test method in which a transmitted signal is looped back to the receiver side in order to automatically determine whether an abnormal state in the receiver of a transmitting/receiving device is due to a failure of the receiver or due to fading. This article relates to an automatic folding tester that performs

The automatic loopback tester, which loops back every time a short fading occurs even though the receiver of the transmitting/receiving device is normal, measures the frequency at which the line is disconnected for longer than the fading time. It is necessary to improve the reliability of the line by reducing it as much as possible.

Conventionally, this type of automatic loopback tester immediately performs a loopback test operation when an abnormal condition of the receiver is detected.
When short-term fading occurs, the line is disconnected for a period of time equal to the fading occurrence time and loopback test operation time. Therefore, if short-term fading occurs frequently,
Each time this happens, the line is disconnected for a period of time longer than the time at which fading occurs, reducing the reliability of the line.

An object of the present invention is to provide an automatic loopback tester that performs a loopback test operation only when the abnormal condition continues for a certain period of time after an abnormal condition of a receiver is detected, and minimizes the time during which the line is disconnected. There is a particular thing.

To achieve the above object, an automatic loopback tester according to the present invention is an automatic loopback tester that automatically determines whether an abnormal state of a receiver of a transmitting/receiving device is due to an equipment failure or another failure. a frequency oscillator, a shifter that generates the same frequency as a received signal from the oscillation frequency of the oscillator and a transmitted signal of another transmitter/receiver, and a filter that passes the same frequency as the received signal of the shifter and removes other unnecessary frequencies. When the receiver receives an abnormality detection signal in the standby state, and the abnormality detection signal continues for a certain period of time or more, the oscillator is driven and the receiver is tested using the return signal output from the filter. As a result, if the signal is returned to the output end of the receiver, it is determined to be normal, and if the signal is not returned to the output end of the receiver, it is determined that there is a failure in the receiver. It is.

According to the above configuration, deterioration in line reliability can be minimized, and the object of the present invention can be completely achieved.

Hereinafter, the present invention will be explained in more detail with reference to the drawings.

FIG. 1 is a circuit diagram showing an embodiment of an automatic folding tester according to the present invention. In the figure, 5 is a transmitter of the low transmitting/receiving device, 1 is a receiver, and 8 is a coupler. The automatic loopback tester 2 includes a logic circuit 3 that receives a detection signal from the receiver 1.
, an oscillator 4 connected to the output of the logic circuit, a shifter 6 that generates a signal with the same frequency as the received signal based on the oscillation frequency of the oscillator 4 and the transmission signal, and a shifter 6 connected to the output of the shifter 6 and having the same frequency and wave number as the received signal. Coupler 8 on receiver 1 side
It consists of a wave device 7 that supplies the Automatic loopback tester -2 is normally in standby state, and when receiver 1 becomes abnormal and its detection signal is applied to logic circuit 3, logic circuit 3 detects that the detection signal remains in the same state for a certain period of time or more. When sustained, the oscillator 4 is driven. shifter 6
Then, a signal having the same frequency as the received signal is generated by the signal sent from the transmitter 5 side, and this signal is sent to the receiver 1 via the wave transmitter 7 and the coupler 8. Here, the logic circuit 3 determines that the receiver 1 is normal when the above-mentioned signal is output to the output terminal of the receiver 1, and determines that the receiver 1 is malfunctioning when the signal is not output. . On the other hand, the logic circuit 3 controls so that the loopback test as described above is not performed when the abnormality detection signal disappears within a certain period of time.

Therefore, if short-term fading occurs, the line will be disconnected during the fading, but the line will not be disconnected due to the return test operation.

The above operation will be explained with reference to the flowchart shown in FIG. (a) The automatic loopback tester in standby state is (
b) -th receiver abnormality is detected, and if (cl) exceeds the duration of the detection signal (determined to be 0, constant time C'r), (d) repeat test operation is performed, (e ) Determine the abnormal state of the receiver, and as a result, if the receiver is malfunctioning, the receiver is stopped.If the receiver is normal, it returns to the standby state.

Also, if T is within a certain time at the time of abnormality detection, then (f
) Return to standby state. Therefore, if the duration of the abnormality detection signal is within a certain period of time, the loopback test operation is not performed.

As explained in detail above, according to the present invention, automatic loopback tests are not performed for short-term fading, and
Since line disconnections caused by this are eliminated, the reliability of the line is significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a combination of an embodiment of an automatic foldback tester according to the present invention and a transmitting/receiving device, and FIG. 2 is a flowchart for explaining the operation of FIG. 1. l...Receiver 2...Automatic loopback tester 3.
... Logic circuit 4 ... Oscillator 5 ... Transmitter 6 ... Shifter 7 ... Filter
8...Coupler Patent Applicant Nippon Tonkei Co., Ltd. Agent Patent Attorney Hisashi Inoro Figure 21

Claims (1)

[Claims] In an automatic loopback tester that automatically determines whether an abnormal state of a receiver of a transmitting/receiving device is due to an equipment failure or another failure, an oscillator of a predetermined frequency, and an oscillation frequency of the oscillator and another transmitting/receiving device are provided. A filter that generates the same frequency as the received signal from the transmitted signal of the sick, and a filter that passes the same frequency as the received signal of the sick and removes other unnecessary frequencies, and when the receiver receives an abnormality detection signal in the standby state. , When the abnormality detection signal continues for a certain period of time or more, the oscillator is driven and the receiver is tested by the return signal output from the filter, and as a result,
An automatic loopback tester consisting of a logic circuit that determines that it is normal when a loopback signal is output to the output end of the receiver, and that there is a failure in the receiver when the loopback signal is not output to the output terminal of the receiver.