JPS62232243A - Fault detection device for subscriber line - Google Patents

Abstract

PURPOSE:To attain a frequent test even if there are large number of subscriber lines and to relieve the trouble of a maintenance personnel by applying a high frequency signal of an oscillator at the exchange side to a subscriber line in a prescribed period and a consecutive time. CONSTITUTION:The oscillator 12 at the exchange side generates continuously a high frequency signal, which is turned on/off by a relay 19 of a timing circuit 13 at the exchange side and a receiver 20 at the exchange side starts the reception at the same time. If subscriber lines 2A,2B are normal, the output of the receiver 23 at the telephone set side goes to an H level, an output of the oscillator 31 at the telephone set side is turned on/off by a relay 30 of a telephone set side timing circuit 24 and the receiver 20 goes to an H level. If a fault such as an open line takes place in a subscriber line 2A or 2B or the both, the output of the receiver 20 goes to an L level. Then a counter 41 starts counting and if the counter 41 coutns'4' before a counter 36 counts '8', an output terminal A2 goes to an H level, the count of the counters 36,41 is stopped and an alarm lamp 44 is lighted.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a device for detecting an abnormality in a subscriber line in an automatic exchange.

(Prior art) Conventional technologies in this field include those described in Nippon Telegraph and Telephone Public Corporation line 1-D 10 type automatic exchanger Part 6 Ancillary equipment and power supply equipment J (P72-78) be.

FIG. 2 shows the connection between a subscriber and a subscriber line automatic testing device in a conventional automatic exchange. In the figure, 1 is a subscriber (telephone 1fl), 2 is a subscriber line, 3 is a network (NW), 4 is an additional device for accommodating a subsequent device in network 3, and 5 is an abnormality detected in the subscriber line. Automatic subscriber line testing equipment (ALTIN,
6 is a central control unit (CC), and 7 is a typewriter device.

In J3 of the above configuration, when the maintenance person types in the telephone number of the subscriber group to be tested and the number of lines per line and the test start time from the typewriter device 7, the central control device 6 activates the relay drive device (not shown) at that time. The additional device 4 is controlled via the additional device 4, and the automatic subscriber line testing device 5 is activated by the activation signal from the additional device 4.

The automatic subscriber line testing device 5 automatically checks the insulation resistance and capacitance for each subscriber between both lines of the subscriber line, between one line and the ground, and between the other line and the ground. Do the test.

The test results are output to a scanning device (not shown), and the central control device 6 reads the scan results and compares the normal pattern with the test results. If a faulty line is found as a result of the comparison, the subscriber telephone number of that line and the judgment results of each test item are typed out using a typewriter (not shown) or the like.

Note that for lines determined to be defective by the automatic subscriber line testing device 5, a more detailed test is separately performed by a line testing device.

(Problems to be Solved by the Invention) As described above, the conventional subscriber line automatic testing device
Since only one device is installed per unit, if the number of subscriber lines increases, it will take a considerable amount of time to test all subscriber lines, and even if you limit the number of subscriber lines to important subscribers, you will only be able to test them a few times a day. This is not possible, and the time between exams becomes longer. Therefore, even if an abnormality occurs in the subscriber's line during this period, it cannot be detected, and even if an emergency call is attempted in the event of an accident or disaster, the connection will be cut off and there is a problem in that it will not be possible to take immediate action. In addition, a maintenance person is required to type in the subscriber's phone number, test time, etc.
There has been a problem in that the time required for the operation increases as the number of subscribers increases.

It is an object of the present invention to provide a subscriber line abnormality detection device that eliminates the above-mentioned conventional problems, allows frequent testing even when there are a large number of subscriber lines, and can reduce the work burden on maintenance personnel. purpose.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention includes an exchange side oscillator that generates a predetermined high frequency signal, and a high frequency signal of the exchange side oscillator that is connected with a predetermined period and duration. a timing circuit on the exchange side that is added to the telephone line; a receiver on the telephone side that outputs a determination signal indicating that reception is in progress (or not in progress) when receiving the high frequency signal from the exchange oscillator; When a discrimination signal is output from a telephone transmitter that generates a high frequency signal and a telephone receiver,
A timing circuit on the telephone side adds a high frequency signal from the telephone side oscillator to the subscriber line at a predetermined period and duration, and when the high frequency signal from the telephone side oscillator is received, a signal indicating that the high frequency signal from the telephone side oscillator is being received (or is being received) is provided. The system is comprised of a receiver on the exchange side that outputs a discrimination signal indicating that the switch is not present, and a monitoring circuit that monitors the discrimination signal of the receiver on the exchange side and issues an alarm when the signal is abnormal.

(Function) According to the present invention, when the subscriber's line is normal, a high-frequency signal from the exchange side oscillator is sent to the subscriber's line with a predetermined period and duration by the timing circuit, and the telephone receiver receives the high-frequency signal from the exchange side oscillator. The timing circuit on the telephone side sends out a high-frequency signal from the oscillator on the telephone side to the subscriber's line at a predetermined period and time based on the discrimination signal, and then sends out a high-frequency signal from the telephone side oscillator to the subscriber line. The side receiver receives this and similarly outputs a discrimination signal indicating that it is receiving, and the monitoring circuit detects from the discrimination signal that the subscriber line is normal.On the other hand, when the subscriber line is abnormal, In this case, the receiver on the telephone side cannot receive the high frequency signal output from the oscillator on the exchange side, and the timing circuit on the telephone side does not operate normally, so the receiver on the exchange side cannot receive the high frequency signal from the oscillator on the telephone side. If the signal is not received or receives a signal with a period or duration different from the original one, the monitoring circuit detects an abnormality and issues an alarm.

(Embodiment) FIG. 1 is a block diagram of an apparatus showing an embodiment of the present invention, and FIG. 3 is a diagram showing its operating waveforms. In FIG. 1, the same components as those in the conventional example are represented by the same reference numerals, i.e., 1
is subscriber (telephone), 2A.

2B is a subscriber line, and 3 is a network.

The subscriber lines 2A and 2B are provided with low-pass filters 9 and 10 on the subscriber 1 side (telephone side) and the network 3 side (exchange side), respectively. is connected to subscriber 1 or network 3, and the high frequency signal used by this device is connected to subscriber 1 or network 3.
etc., so as not to affect the The subscriber circuit 11 is for detecting a normal outgoing call from the subscriber 1.

The exchange side oscillator 12 continuously generates a high frequency signal having a constant output level, in this case a 16 KHz signal.

The timing circuit 13 on the exchange side is connected to the start switch 14
The operation starts by operating the low frequency oscillation circuit 1.
5 continuously generates a rectangular wave signal of a predetermined period with a predetermined delay time, and outputs a waveform 8 shown in FIG.
Turn it on and off as shown at 19.

The exchange side oscillator 12 and the exchange side receiver 20, which will be described later, are connected to the subscriber line 2A via the contact 19a of the relay 19 and the capacitor 21 for DC blocking, and similarly via the contact 19b and the capacitor 22 on the exchange side. Subscriber line 2B
and when relay 19 is off, contact 19a
, 19b are placed on the oscillator 12 side, and placed on the receiver 20 side when turned on.

The waveform 812 shown in FIG.
9a or 19b shows on/off characteristics.

The telephone side receiver 23 is turned on by the timing circuit 13 on the telephone side, as will be described later.

The release that was turned off [! The waveform 32 shown in FIG.
3, and the subscriber lines 2A and 2B are normal and output an H level logic signal while they are on or off.

When the low frequency oscillation circuit 25 receives the H level signal via the AND gate 26, the telephone side timing circuit 24 receives the H level signal.
Oscillation starts with a predetermined delay time, and the low frequency oscillation circuit 1
Continuously generates a rectangular wave signal with the same period as NAN
Through the D gates 27 and 28 and two transistors, the relay 30 is turned on and off as shown in the waveform S30 shown in FIG.

The telephone oscillator 31 has the same configuration as the oscillator 12, and continuously generates a 16 KHz signal. Receiver 2
3 and the oscillator 31 are connected to the subscriber line 2A via the contact 30a of the relay 3o and the DC blocking capacitor 32, and similarly to the subscriber line 2B via the contact 30b and the capacitor 33 on the telephone side. When the relay 30 is off, the contacts 30a and 30b are placed on the receiver 23 side, and when the relay 30 is on, the contacts 30a and 30b are placed on the oscillator 31 side. The J waveform S31 shown in FIG. 3 shows the on/off characteristics of the signal of the oscillator 31 due to the contact point 30a or 30b. Then, during each off period, the receiver 23 receives the signal from the oscillator 12 as described above.

The exchange side receiver 20 converts the signal of the oscillator 31 turned on and off by the timing circuit 24 into a waveform 20 shown in FIG.
When received as shown in 1, the subscriber lines 2Δ and 2B are normal, and while they are on or off, an H level logic signal is output.

The monitoring circuit 34 receives the logic signal from the receiver 20, and
The system monitors whether or not this is a normal signal based on the timing circuit 24, and generates an alarm in the event of an abnormality.

The contact 19c turns on and off according to the operation of the relay 19 of the timing circuit 13, and turns on the flip-flop 35.
Turn it off. The counter 36 receives the ON/OFF signal at its clock terminal CPB via an AND gate 37, counts the signal, and calculates the signal as shown in waveform S36 in FIG.
The output terminals 80 to B3 are successively carried up in accordance with the count and output an H level signal.

In this case, the output terminal 83 is used and the contact 19C is "8".
'' times, a level signal is applied to the connection point N1, and the counter 36 is set via the connection point N2 and the NAND gate 38 and the AND gate 39. Ru.

The spark quencher 40 is made up of a resistor and a capacitor, and is used to eliminate noise caused by sparks when the contact 19G turns on and off.
This is to prevent the downstream circuit from malfunctioning due to contact ringing of the contact 19C.

The counter 41 is reset by receiving a torque signal at the reset terminal RA at the same time as the counter 36. N
The AND gate 42 receives the output of the receiver 20 and the output of the AND gate 37, and when the receiver 20 receives a signal based on the period of the timing circuit 24 and outputs a torque signal, the NAN[) gate The output of the receiver 42 becomes the low level, and the clock terminal CPA of the counter 41 does not receive the clock and does not count. However, when the output of the receiver 20 becomes the low level, it counts together with the counter 36 and starts counting.
As shown in the waveform S41 in the figure, the I'' level signal is output from the output terminals AO to A3 by being carried up sequentially according to the count.

In this case, output terminal A2 is used and contact 19C is "4".
'' times, a torque signal is applied to the connection point N3, the output of the tNAND gate 43 becomes L level through the connection point N4, the alarm lamp 44 lights up, and at the same time the AND gate 3
The counting of the counters 36 and 41 is stopped at gate II of 7. That is, in this case, during the eight operations of the relay 19,
``4'' The criterion for determining an abnormality is when the recovery operation period is exceeded. When the reset switch 45 is operated, the counters 36 and 41 are reset so that their counting is restarted. In addition, +5 in Figure 1
V and +12V indicate each power supply voltage.

Next, the operation of the device will be explained.

When the start switch 14 is operated, the exchanger side oscillator 1
The output of 2 is the relay 19 of the timing circuit 13 on the exchange side.
At the same time, the exchange side receiver 20 starts receiving.

When the subscriber lines 2A and 2B are normal, the output of the telephone side receiver 23 becomes H level, and the output of the telephone side oscillator 31 is turned on and off by the relay 30 of the telephone side timing circuit 24. Receiver 20 receives the on/off signal from oscillator 31 and becomes H level.

On the other hand, the counter 36 of the monitoring circuit 34 counts each time the relay 19 is turned on, and when the count reaches "8", the output B3
becomes H level and is reset, and this operation is repeated.

The counter 41 does not count because the receiver 20 is at the H level.

Next, when an abnormality such as disconnection occurs in subscriber line 2A or 2B or both, the output of receiver 23 becomes L level, relay 30 does not operate, and oscillator 31
The signal is subscriber line 2A.

Not sent to 2B. Therefore, the output of the receiver 20 is at the lowest level. As a result, the car counter 41 starts counting, and when the counter 36 counts "4" before counting "8", the output terminal A2 goes to H level, the counting of these counters 36 and 41 is stopped, and the alarm lamp 4
4 lights up.

By lighting the warning lamp 44, the maintenance person recognizes that an abnormality has occurred in the subscriber line 2A or 2B.

Here, when the return switch 45 is operated, the counter 36
．． 41 is reset and the operations described above are resumed.

If the above abnormality is detected, for that subscriber line,
Various tests will be conducted as necessary.

Although FIG. 1 shows the line of one subscriber, if these devices are installed for each subscriber and operated in sequence, the presence or absence of an abnormality in each subscriber's line can be detected based on the presence or absence of an alarm.

It should be noted that abnormalities in the subscriber line can be detected not only when the line is disconnected, but also when lines are crossed or when one subscriber line falls into the ground.

(Effects of the Invention) As explained above, according to the present invention, a high frequency signal is sent from the exchange side to the telephone side via the subscriber line, and only when the subscriber line is normal, the exchange A high-frequency signal is similarly sent to the exchange, and the exchange side checks this and generates an alarm in the event of an abnormality, allowing maintenance personnel to detect whether there is an abnormality by simply monitoring the alarm. can reduce the work burden of
In addition, since the test can be executed for each line at any period,
It has the advantage that even if the number of subscriber lines increases, abnormalities can be quickly detected.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the subscriber line abnormality detection device of the present invention, FIG. 2 is a diagram showing how a conventional test device is connected, and FIG. 3 is a diagram showing each part of the device shown in FIG. 1. FIG. 2 is a waveform diagram for explaining the operation of FIG. DESCRIPTION OF SYMBOLS 1... Subscriber (telephone), 2A, 2B... Subscriber line, 12... Exchange side oscillator, 13... Exchange side timing circuit, 20... Exchange side receiver, 23...
Telephone side receiver, 24...Telephone side timing circuit,
31...Telephone side oscillator, 34...Monitoring circuit. Patent applicant Oki Electric Industry Co., Ltd. Nippon Telegraph and Telephone Corporation

Claims (1)

[Scope of Claims] An exchange-side oscillator that generates a predetermined high-frequency signal, an exchange-side timing circuit that applies the high-frequency signal of the exchange-side oscillator to a subscriber line with a predetermined period and duration, and an exchange-side oscillator. a telephone-side receiver that outputs a determination signal indicating that the high-frequency signal is being received (or not being received) when the high-frequency signal is received; a telephone-side transmitter that generates a predetermined high-frequency signal; a timing circuit on the telephone side that applies a high-frequency signal from the telephone-side oscillator to the subscriber's line with a predetermined period and duration when the telephone-side oscillator outputs the telephone-side oscillator; , a receiver on the exchange side that outputs a discrimination signal indicating that the receiver is receiving (or that the receiver is not receiving); and a monitoring circuit that monitors the discrimination signal of the receiver on the exchange side and generates an alarm when the signal is abnormal. A subscriber line abnormality detection device consisting of: