JPS60229454A - Subscriber circuit test system - Google Patents

Abstract

PURPOSE:To attain earlier troubleshooting and repair by adding a prescribed current to a subsriber circuit from a subscriber idle/busy supervisory circuit of a common controller at the trasmission connection of a subsriber in a common control exchange and applying reverse bias to a line C diode in a main link to make the nonconductive. CONSTITUTION:A common controller MKR in the subscriber circuit test controls a main link LINK and conducts the test when a trunk TRK and a subscriber circuit LC are connected. First, a TST relay in the common controller MKR is actuated and its contact tst connects a current source I to a subscriber idle/ busy supervisory lead. The contact tst of the TST relay cuts off temporarily the restoring circuit of the common controller MKR at the same time. When a potential across the coil of the L relay is +48V or over, a -48V potential of the L relay power supply is cancelled and the line C potential is a positive potential. When the line C potential reaches a positive potential, the line C diode DO of the main link LINK is brought into a reverse bias state. Thus, the subscriber circuit LC is separated electrically from the main link LINK to discriminate line contact or line open.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for testing subscriber circuit crosstalk and disconnection in a common control exchange.

The conventional subscriber circuit testing method is automatic central testing equipment CAC.
T-5UEIJTE) and subscriber frequency meter testing equipment (SUB
METTST) etc. In these conventional methods, a maintenance person sets the subscriber number to be tested in advance, makes an incoming call connection using the set number, and performs a test by connecting to the subscriber circuit via the main link. In addition, a method is adopted in which the test is conducted periodically by maintenance personnel over a certain period of time. For this reason, problems such as crosstalk and disconnections in subscriber circuits that occur until periodic tests are left unattended for a certain period of time. Furthermore, there is a possibility that temporary failures due to poor contact, etc., cannot be detected and become latent. Furthermore, the subscriber circuit is connected to the subscriber via the distribution board.
There are many opportunities for wiring changes due to service orders, resulting in crosstalk.

There are many factors that cause wire breakage, and if there is crosstalk or wire breakage in the subscriber circuit, normal call monitoring will not be possible. This causes problems for subscribers regarding telephone services.

In addition, in the conventional method, there are operational problems such as the maintenance person having to set all subscriber numbers to be tested one by one, or even if the number has been set, the test cannot be performed if the subscriber to be tested is busy.

The purpose of the present invention is to solve the problems of the conventional subscriber circuit testing method described above, and to solve the problems of the existing conversion equipment. The purpose of the present invention is to provide a method that makes it possible to test subscriber circuits on a local basis.

At the same time, a constant current is applied to the subscriber idle monitoring circuit of the common control device and the subscriber circuit. The added current raises the potential of the subscriber circuit to a positive potential.

The C-line diode in the live link is reverse biased to be non-conducting. As a result, since the C line of the subscriber circuit is electrically disconnected from the main link and the circuit is tested, it is possible to detect and repair wiring crosstalk and disconnection problems in the subscriber circuit at an early stage. This makes it possible to prevent subscriber troubles related to the telephone service. Another advantage is that maintenance personnel operations are not required for testing.

The present invention will be fully explained below with reference to the drawings. Figure 9 shows an embodiment of the present invention. SUB is a subscriber, LINE is a subscriber line, LC is a subscriber circuit, MDF is a distribution board, NET is a frequency meter, and C is a Relay, lc is relay contact, leg is common control device, TST Fi subscriber circuit test section, I is current source, LI
NIT'' is the king link, DO is the raw link C line diode, HM retaining electromagnet, TRK is the trunk, C is the capacitor, Dl is the diode, R is the resistor, h, m are the relay contacts, -4sV, +5oV are the power supply shows.

First, the outgoing connection operation will be explained. When the subscriber SUB picks up the handset, the L relay of the subscriber circuit LC is activated (the operating circuit is omitted in Figure C) and the common control device MKR is activated in a generally known manner. The common controller side controls the main link LINK 2 and connects the subscriber circuit LCy2 with one transmitting register OR (not shown). When the connection is completed, the side of the control device will be restored.9 Outgoing register CAR is subscriber 5
IIE translation and output route selection is performed, and the corresponding free trunk TRK @selected and acquired 0. Next, the common control device Q controls the raw link LIM and connects the selected and acquired trunk TRK to the subscriber circuit LC. In parallel with this, the transmission register 0Rt-is opened on the side of the common control device. When these controls are completed, the common control device side performs a subscriber circuit test in three or more outgoing connection operations in which the common control device side recovers.

The subscriber circuit test is conducted by the common control device W-Gun LIN.
K? : First, when the trunk TRK and subscriber circuit LC are connected, the TS in the common control device lIMKR is
A T-relay (not shown) is activated.

A current source I is connected to the monitoring lead during one unoccupied subscriber call at the contact point O.
Connect. TST at the same time! The recovery circuit of the common control device MAR is temporarily disconnected by the J relay contact txt. Current source I
With the current supplied from , the potential across the coil of L relay becomes +
When it becomes 48V or more, about -a8V% of the L relay power supply is canceled out, and the C line potential becomes a positive potential. When the C line potential becomes positive, the main link LINK no C? The IM diode becomes reverse biased. As a result, the subscriber circuit LC becomes a state πb which is completely separated from the main link LIIVK. In this state, the subscriber circuit LC is tested in the subscriber circuit testing section TST, and all cross-wire and disconnection judgments are carried out.The testing method in the subscriber circuit testing section TST is to measure the voltage or current and make a judgment. Although it is possible, it will be omitted in this explanation.

Since tests can be performed, early detection and repair of failures becomes possible. This makes it possible to prevent subscriber troubles related to Shimi-Sei-Sei.

[Brief explanation of drawings]

The figure shows an embodiment of the subscriber circuit testing method according to the present invention. W...Subscriber circuit m...Common control device LINK,
...Main link TRK...Trunk TST...Subscriber circuit test section I...Current source m,, c-line diode SUB...
・Subscriber MDF...Distribution board NET...Degree meter attorney's attorney ±1) 7t prayer to 4t

Claims (1)

[Claims] In a common control exchange, with the subscriber terminal and trunk connected via the main link, a constant current is applied from the common control device to the C# of the relevant subscriber circuit, making the Cf1A diode in the raw link non-conductive. A subscriber circuit testing method characterized by fully confirming the normality of the 114Kl and cH.