JPH09153944A - Subscriber line testing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain a diagnostic test in a short time by providing a discharge means discharging rapidly a capacitive component between both subscriber lines R, T and using a control means to execute each measurement after the charges in the capacitance are discharged by the discharge means. SOLUTION: At first an exchange station 1 is disconnected from a communication line 23 by a changeover switch SW7 and a terminator 10 is connected to a subscriber line test equipment 22. In order to discharge a charging voltage VC 12 across a capacitive component C24 in a charging state in a short time, a discharge resistor RS13 is connected to the line by a changeover switch SW8. Then the changeover switch SW8 is restored and a voltage of the subscriber line 4 through high impedance elements RB20, RC21 is measured. In the case of starting the measurement of an insulation resistor with respect to ground, charges might be stored in the terminator 10 as time elapses, then the charged voltage VC is discharged in a short time through a low impedance discharge resistor RS13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a subscriber line tester for diagnosing quality of subscriber lines, which are individual telephone lines wired from a telephone exchange of a telephone exchange in telecommunications.

[0002]

2. Description of the Related Art A subscriber line tester is a tester having a built-in multimeter function having a voltage measuring function, an impedance measuring function and the like for checking a subscriber line and a terminating device. As shown in FIG. 2, the connection configuration with the subscriber line tester 22 according to the conventional technique is as follows: the subscriber line 4 in which the terminating device 10 is connected to one end of the T line 5 and the R line 6 and the telephone exchange 1. The switchboard SW7, which is a channel panel 3 for switching the subscriber line 4 to the subscriber line tester 22 side or the communication line 23 side in response to a control command from the telephone exchange 2, and the subscriber line tester 22.

The terminal device 10 may be a telephone or an NT1 (Ne
There are twork Terminals 1) and they are in normal condition, the insulation between subscriber line 4 and ground is maintained, and the diagnostic test for insulation between subscriber line 4 and commercial power source etc. It was taking a long time.

Although details of the measuring circuit of the subscriber line tester 22 are omitted, the measurement items for the test for diagnosing the quality of the subscriber line 4 are the DC / AC voltage test between the T line 5 and the ground. DC / AC voltage test between R line 6 and ground,
Insulation resistance between T wire 5 and ground, insulation resistance between R wire 6 and ground, insulation resistance between T wire 5 and R wire 6, impedance, ringer circuit check, etc.

Particularly, in the subscriber line tester 22 of the prior art, the following test means required a long time. That is, for example, an analog telephone, which is one of the terminating devices 10, has a ringer circuit, and its equivalent circuit has a resistance component RA shown in the figure.
11 and a capacitance component C24. It has a resonance near 24 Hz. Also, since the frequency is low, the resistance component R
The time constant formed by the charge voltage VC12 by A11 and the capacitance component C24 becomes large. That is, since the capacitive component C24 exists, it takes a time on the order of seconds to charge up there. As a result, it took about 2.0 seconds to measure one of the above-mentioned measurement items with desired accuracy, and about 20 seconds to measure 10 items.

Further, in measuring the insulation resistance between the T line 5 and R line 6 of the subscriber line 4 and the ground, the T line 5 is used so that an unnecessary current flowing through the terminating device 10 is not generated.
And the measurement voltages VA16 and VB of the same value simultaneously on the R line 6
17 is applied and the measurement currents IA14 and IB15 are obtained by the measuring unit 25. And again the DC voltage V between the ground
Since the DC 18 exists, the polarity of the applied voltage is changed and the measurement is performed to cancel the influence of the DC voltage between the ground.

Conventionally, the diagnostic test of the subscriber line 4 has been carried out after receiving a defect report of the terminal device 10. For this reason, it was not necessary to carry out the diagnostic test in a short time.

However, ISDN (Integrated Service)
The main trunk line that has deteriorated due to the progress of the Digital Network) is laid from the metallic line to the optical fiber line, and in order to guarantee the quality of the metallic line on the terminal equipment side, the telephone exchange 1 side regularly or Diagnostic tests of all subscriber lines 4 have come to be voluntarily performed. However, the execution of a diagnosis in which the subscriber line 4 is temporarily interrupted has a drawback that it hinders the use of the subscriber line 4 during this interruption, and the execution of a diagnosis that takes a long time is a practical difficulty.

[0009]

Therefore, the problem to be solved by the present invention is to provide a means for rapidly discharging the capacitive component C24 for a diagnostic test to greatly reduce the measurement waiting time and shorten the diagnostic test. The purpose is to enable.

[0010]

In order to solve the above problems, in the structure of the present invention, the T line 5 and the R line 6 of the subscriber line 4 are used.
Discharge means for rapidly discharging the capacitance component C24 between both wirings is provided, and control means for carrying out each measurement after discharging by the discharge means is provided. As a result, a short-term diagnostic test is realized in the subscriber line tester 22 for diagnosing the subscriber line 4 wired from the telephone exchange 2.

More specifically, the discharge resistor RS13 for rapidly discharging the capacitance component C24 between the T line 5 and the R line 6 of the subscriber line 4, the discharge resistor RS13, and the subscriber line tester 22 are measured. There is a configuration means for providing a changeover switch SW8 for switching between the system and a control means for controlling the changeover switch SW8 to rapidly discharge the capacitance component C24 between both wirings and then performing each measurement.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below in detail with examples.

[0013]

【Example】

(1) FIG. 1 is a connection configuration diagram of a subscriber line tester 22 according to an embodiment of the present invention. As shown in FIG. 1, the continuous configuration of the present invention has a configuration in which a changeover switch SW8 and a discharging resistor RS13 are added to the conventional configuration.

(2) Normally, in addition to the terminating equipment 10, power is supplied from the telephone exchange 2 or the like in the telephone exchange 1 via the subscriber line 4 by the power supply voltage VX9. Electric charges are accumulated in a certain capacitance component C24 by a power supply voltage of VX9, and a charge voltage VC12 is generated. This discharge procedure is provided for the test. The test procedure according to the invention is described below. First, it is disconnected from the communication line 23 by SW7 and the connection is switched to the subscriber line tester 22 side. In order to discharge the charge voltage VC12 across the capacitive component C24 in the charged state in a short time, RS13
Are connected by the changeover switch SW8. Then, the changeover switch SW8 is returned to the original state and the voltage of the high impedance RB20 or RC21 of the subscriber line 4 is measured.

(3) Further, when starting the measurement of the insulation resistance between the earth and ground, some electric charge may be accumulated in the terminating device 10 with the lapse of time, so that in this case as well, discharge of low impedance is performed. Charge voltage VC
12 can be discharged in a short time.

(4) By carrying out as described above,
The diagnostic test of the quality of the subscriber line 4 is now possible at high speed.

(5) Although not shown, the subscriber line 4
Has a large number of lines, and SW7 of the channel board 3 is sequentially switched to carry out a test of all lines.

[0018]

Since the present invention is configured as described above, it has the following effects. (1) By adding the quick discharge means to the connection structure of the subscriber line tester of the present invention, various tests of the subscriber line can be carried out at high speed.
It can be shortened to 1/10. (2) According to the present invention, the subscriber line test can be performed at high speed in a short time and with high accuracy, so that the interruption time of the subscriber line 4 is shortened, the trouble to the user is minimized, and the periodical execution is easy. It became possible.

[Brief description of the drawings]

FIG. 1 is a connection configuration diagram of a subscriber line tester according to an embodiment of the present invention.

FIG. 2 is a connection configuration diagram of a subscriber line tester according to a conventional technique.

[Explanation of symbols]

 1 Telephone exchange station 2 Telephone exchange 3 Channel board 4 Subscriber line 5 T line 6 R line SW7, SW8 Changeover switch VX9 Power supply voltage 10 Termination device RA11 Resistance component VC12 Charge voltage RS13 Discharge resistance IA14, IB15 Measuring current VA16, VB17 measurement Voltage VDC18 DC voltage component RB20, RC21 High impedance 22 Subscriber line tester 23 Communication line C24 Capacitance component 25 Measuring unit

Claims (2)

[Claims] 1. A subscriber line tester (22) for diagnosing a subscriber line (4) wired from a telephone exchange (2), wherein a T line (5) and an R line ( 6) A subscriber is provided with a discharge means for rapidly discharging the capacitance component (C24) between both wirings, and a control means for carrying out each measurement after discharging by the discharge means, comprising the above configuration. Line tester. 2. A subscriber line tester (22) for diagnosing a subscriber line (4) wired from a telephone exchange (2), wherein a T line (5) and an R line ( 6) A discharge resistor (RS1) that rapidly discharges the capacitance component (C24) between both wirings.
3), a switch (SW8) for switching between the discharge resistor (RS13) and the subscriber line tester (22) measurement system
And a control means for controlling the change-over switch (SW8) to rapidly discharge the capacitance component (C24) between the two wirings and then performing each measurement. The subscriber is provided with the above configuration. Line tester.