JPS58187038A - Automatic folding tester - Google Patents

Abstract

PURPOSE:To minimize the frequency of line interruption, by stopping the folding test for a prescribed time, after a failure in a reception signal is detected and the folding test is executed once. CONSTITUTION:When a receiver 1 is failed and its detection signal is applied to a logical circuit 7, an oscillator 3 is driven and a shifter 5 generates the same frequency as that of the reception signal with a transmission signal from a transmitter 4 and a signal of the oscillator 3. The generated signal is transmitted to the receiver 1 via a filter 6 and a coupler 8. When this signal is outputted to an output terminal of the receiver 1, the circuit 7 discriminates that the receiver 1 is normal, and when the signal is not outputted, the circuit 7 discriminates it as in failure. The circuit 7 stops the folding test for a prescribed time when the receiver 1 is normal. If fading takes place frequently in a short time, since the failure is detected because of the 1st fading, the folding test is stopped for a prescribed time and no folding test is exercised even if the fading takes place during the time.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention automatically detects whether an abnormal state in a receiver of a transmitting/receiving device is due to a failure of the receiver or due to fading. The present invention relates to an automatic loopback tester that performs a confirmation test by loopbacking a transmitted signal from a transmitter of a device to a target receiver.

Conventionally, this type of automatic loopback tester has performed a loopback test operation every time an abnormal state of a received signal is detected. Therefore, even though the receiver of the transmitting/receiving device is normal, there is a drawback that the line is disconnected every time fading occurs due to frequent occurrence of processing.

The purpose of the present invention is to provide an automatic loopback tester that minimizes the frequency of line disconnections by stopping the loopback test operation for a certain period of time after the loopback test operation is performed once an abnormal state of the received signal occurs. I have a lot to offer.

To achieve the above object, the automatic loopback tester according to the present invention automatically detects an abnormal state of a transmitting/receiving receiver. A shifter that generates the same frequency as the received signal from the transmitted signal of the transmitter/receiver, a filter that passes the same frequency as the received signal of the shifter and removes other unnecessary frequencies, and receives a receiver abnormality detection signal in a standby state. In 9 cases, the oscillator is driven and the receiver is tested using the return signal output from the filter, and as a result, when the return signal is output to the output end of the receiver, the return test is stopped for a certain period of time. However, it also includes a logic circuit that determines that there is a failure in the receiver when the folded signal is not output to the output end of the receiver.

Hereinafter, the present invention will be described in 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, 4 is a transmitter of another transmitting/receiving device;
1 is a receiver, and 8 is a coupler. The automatic loopback tester 2 includes a logic circuit 7 that receives the detection signal from the receiver 1, an excavator 31 connected to the output of the logic circuit, and a signal having the same frequency as the received signal based on the oscillation frequency of the oscillator 3 and the transmission signal. The output of the shifter 5 is connected to the output of the shifter 5 to supply the same frequency as the received signal to the coupler 8 on the side of the receiver 1. Automatic folding tester 2
is normally in a standby state, and when the receiver 1 becomes abnormal and its detection signal is applied to the logic circuit 7, the logic circuit 7 drives the oscillator 3.

In the shifter 5, a signal having the same frequency as the received signal is generated by the transmitting signal as described above, and the signal is sent to the receiver IK via the pm signal transmitter 6 and the coupler 8. Here, the logic circuit 7 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. . If the receiver l is normal, the logic circuit 7 stops the loopback test for a certain period of time. If fading occurs frequently in a short period of time, an abnormality will be emitted due to the first fading, so the loopback tester 2 discriminates the abnormal condition of receiver L as described above. After that, the loopback test is stopped for a certain period of time, during which time fading occurs and the loopback test is not performed.

The above operation will be explained with reference to flowchart 1 in FIG.

(a) The automatic loopback tester in standby state is f
b) Detect an abnormality in the -th receiver, drive the (C) oscillator with the detection signal, perform a test operation for one section, and (
d) Determine whether the receiver is in an abnormal state, and (e) if the receiver is normal, stop loop test operation for a certain period of time. (fl) After a certain period of time has passed, it automatically returns to the standby state of (al). Therefore, even if fading occurs in state (e), a return operation test is not performed.

As explained in detail above, according to the present invention, even if hourly fading occurs frequently, there is no line disconnection caused by the automatic loopback tester.

[Brief explanation of drawings]

FIG. 1 is a diagram showing 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 return tester 3...
・Oscillator 4...Transmitter 5...Shifter 6...Filter 7...Logic circuit 8...Coupler Patent applicant NEC Corporation Representative Patent attorney Hisashi Inoro 2 Figure

Claims (1)

[Claims] An automatic loopback tester that automatically detects abnormal conditions in the receiver of a transmitting/receiving device uses an oscillator with a predetermined frequency and a frequency equal to that of the received signal from the oscillating frequency of the oscillator and the transmitting signal of other transmitting/receiving devices. a filter that passes the same frequency as the received signal of the shifter and removes other unnecessary frequencies; and a filter that drives the oscillator when receiving a receiver abnormality detection signal in a standby state IC; The receiver is tested using the return signal output from the filter, and when the return signal is output to the output end of the receiver, the return test is stopped for a certain period of time, and the return signal is returned to the output end of the receiver. An automatic loopback tester consisting of a logic circuit that determines that there is a failure in the receiver when no signal is output.