JPS584863B2 - Communication path test method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a test method for confirming the normality of a space-division communication path using a semiconductor switching element having a self-holding function using a communication current.

In addition to electromagnetic-mechanical communication paths using mechanical switches, communication paths in exchanges include electronic communication paths using semiconductor switching elements (for example, thyristors) that have a self-holding function using communication current.

This electronic communication path has superior advantages over the former electromagnetic communication path, such as light weight, small size, and high speed.

On the other hand, the electronic communication path uses a self-holding function based on the communication current of the switch element, so the holding current (
In general, the communication route is open when the current is less than several tens of μA to several mA), so special measures are required when testing with minute currents.In addition, in terms of maintenance and operation, they have lower withstand voltage and lower current than mechanical switches. It is expected that the failure rate will be high due to the capacity, so it is desirable for maintenance and operation to have a configuration that allows all communication paths to be tested constantly or periodically in a short period of time.

Conventionally, there have been methods shown in FIGS. 1 and 2 as testing methods for electromagnetic communication channels.

FIG. 1 shows an example of a communication path test method for a crossbar exchange. In the figure, SUB is a subscriber telephone, LC is a subscriber circuit, L is a relay for detecting that a subscriber has made a call, co is the contact point of relay CO (not shown in the figure) for disconnecting the subscriber circuit, LLN and TLN are the communication path network,
a1 to a4, b1 to b4, c1 to c4 are contacts of the communication path switch, A and B are a pair of communication lines, C is a control line paired with the communication line, TRK is a trunk circuit, and b is a ground to the control line C. Contact points of relay B (not shown in the diagram) placed in the trunk circuit to send air, W, X, Y, Z, CONA, CONB
1 is a current detection relay for a communication path test, t is a contact point of a relay T (not shown) for switching control during a communication path test, and B and E are DC power supplies.

The method shown in FIG. 1 is as follows.

Communication path switch contacts a1 to a4, b1 to b4, C1 to
After driving C4, normally contact b is connected from trunk circuit TRK.
The ground air sent to the control line C via the current detection relay w,
By detecting x, y, and z, it is confirmed that the contacts c1 to c4 are closed.

Here, the contacts a1 to a4 and b1 to b4 each operate, for example, since the contacts a1 and b1 operate by driving the same coil of the crossbar switch as the contact c1, the contacts c1 to
By confirming that c4 is closed normally, contact a1
~a4, b1~b4 are also considered to have operated normally, and the communication path test includes communication lines A and B.

On the other hand, the trunk circuit TRK is connected to the communication path network TLN.
If it is accommodated in a specific terminal, in addition to confirming the closure of the control line C, a relay for switching control is operated, and the communication lines A and B are detected by the contact t of the relays CONA and CO.
Directly drawn into NB, current flows through contact points a1 to a4 and b1 to b4 of the communication path by direct current power supplies B and E to either the loop or capacitor of the subscriber telephone SUB or the subscriber circuit LC, and CONA and CONB operate. By confirming that this is the case, a communication path test including communication lines A and B is conducted.

In the method shown in FIG. 1, normally only the control line C is tested, and the communication lines A and B are also considered to be good, and the test is not performed reliably.

In addition, in order to remedy this, we have created a communication channel network TL.
Even if communication lines A and B are tested only when connected to specific terminals of N, a4) b
The contact located at 4 cannot be tested.

In addition, in the test method for the communication lines A and B shown in FIG. 1, since the test circuit includes the subscriber line and the subscriber telephone SUB, if the test result is defective, it does not necessarily mean that the contact points a1 to It cannot be said that it is only a4, b1-b4 disorder.

There were drawbacks such as. FIG. 2 shows an example of a conventional communication path test for an electronic exchange.

In the figure, S is the control relay S in the trunk circuit TRK.
The contact AO (not shown) is a relay for loop current detection, and the other symbols are the same as those used in FIG. 1.

In this example, contacts a1 to a4, b1 to
After driving b4, the DC power supply E in the trunk circuit TRK passes through the relay AO in the trunk circuit TRK, contacts S, contacts a1 to a4 of the communication path, and the subscriber line to the subscriber telephone SUB, and connects the subscriber line to the subscriber telephone SUB. , contacts b1 to b4, contact S,
A communication path test is performed by confirming that a current flows through the loop returning to the earth via the relay AO and that the loop current detection relay AO in the trunk circuit TRK operates.

Compared to the testing method for communication lines A and B shown in Figure 1, the method shown in Figure 2 has the advantage that communication lines A and B are directly tested and all communication path contacts can be tested. Although this has been improved, it has the same drawbacks as in Figure 11 in that the test circuit includes the subscriber line and the subscriber telephone SUB, and since the condition on the subscriber side is only a loop, when an incoming call is connected, If there is no loop of the subscriber telephone SUB, as in the case of the above, there is a drawback that a call path test cannot be performed.

In addition, all of the above explanations are communication path test methods for exchanges in which mechanical contacts such as crossbar switches, which operate slowly and are kept closed mechanically, are used as communication path switch contacts. This is done only during call path setting operations associated with call processing when calls are made or received at the exchange.

Next, a case where a semiconductor switch element having a self-holding function using a communication current is used in the communication path network will be explained using FIG. 3.

In the figure, the order of forming the test route is to first close the route from the trunk circuit TRK to the subscriber telephone SUB as the route to be tested, and then close the route between a5, b5 and a8, b8 leading to the detection circuit DET. Closed and 3
connection.

After that, switch the subscriber telephone SUB using switches a9 and b9.
It is necessary to control the separation of the

In another method, a9b9 is kept in an open state, and routes a4, b4...a1, b1-a5, b5...a8, from the trunk circuit TRK to the detection circuit DET,
It is necessary to drive and close b8 at the same time.

The former method has drawbacks such as the need for ag and bg switches and the need to supply current to the subscriber line for testing the communication path networks LLN and TLN.

In addition, in the latter method, self-maintenance by communication current cannot be achieved unless the two loop-connected routes are driven at the same time, so special measures such as providing two independent switch drive devices are required. There is.

As explained above, in the configuration shown in Fig. 3, the test method for the electromagnetic communication path shown in Figs. 1 and 2 cannot be directly applied, and further, the communication current Since the property of semiconductor switches with self-holding function is used to maintain the communication route, it is necessary to form a closed circuit with a minute current less than the holding current (several 10 μA to several mA) used in subscriber line insulation tests. There are problems such as restrictions that require special measures depending on the case.

The present invention has been made in view of these points, and
This provides an effective communication path testing method, and includes a test switch network that can be selectively connected to all incoming and outgoing lines on each of the ingress and egress sides of the communication path network. In the case of a subscriber line test, connect the two test switch networks with a bypass link to form a test path that can be closed even with a minute current, and in the case of a communication line test, connect any communication line. The test switch is connected to the standard power supply through one of the test switch networks and into the detection circuit through the other test switch network, and the test switch is used for subscriber line testing by detecting the presence or absence of current flowing through the communication path switch. This is a shared communication path test, which eliminates the above-mentioned drawbacks and directly tests the normality of the communication path switch for all communication paths.
Additionally, confirmation is possible regardless of the status of subscriber lines, subscriber telephones, and call processing control operations.

A detailed explanation will be given below according to examples.

FIG. 4 is a connection diagram showing the configuration of an embodiment of the present invention.

In FIG. 4, SUB1 to SUBm are a plurality of subscriber telephones, TSW1 and TSW2 are first and second test switch networks, respectively, and ta1 to tam and tb1 to tbn are first and second test switches. Network TSW1,T
SW2 test switch contact, e is a protection resistor r, standard power supply consisting of DC power supply E, LLN, TLN are communication path networks, a11 to a41, b11 to b41, a1m
~a4m, b1m~b4m are the contacts of the communication path switch, D
ET is a current detection circuit DETA, D for each line of the communication line.
A detection circuit consisting of ETB, DC power supplies E1, E2, etc.
A1, B1~An, Bn are multiple call lines TRK1~TR
Kn is a plurality of trunk circuits, s is a contact of a control relay S (not shown in the figure) in the trunk circuit TRK, la and lb are bypass links, ch1 and ch2 are switching contacts, and in normal cases, the switching contacts ch1, By leaving ch2 in the state shown in the diagram, bypass links la and lb can be used for the purpose of subscriber line testing, and switching contacts ch1 and ch
2 to disconnect the bypass links la and lb, connect the subscriber side to the standard power supply e, and connect the trunk side to the detection circuit DE.
Connect to T.

Next, the communication path test system configured as described above will be explained using FIG. 4.

In the case of subscriber line testing, select test switch networks TSW1 and TSW2 that are composed of switch elements (e.g. relay contacts, electronic switches with memory circuits) that can conduct a minute current to any subscriber line under test. drive to close a test route from the test trunk (for example, TRK1) via the bypass link.

After this, various tests are performed between the subscriber line and the test trunk.

Next, the case of a communication path test will be explained.

Assume that a test is performed using a communication path connecting subscriber telephone SUB1 and trunk circuit TRK1 as a communication path to be tested.

First, contact points a11, a21, a31, a of the communication path switch
41 and bll, b21, b31, b41,
After that, the contacts ta1 and tb1 of the test switch are driven.

Here, test switch networks TSW1, TSW
2 is the contact point ta1~tam, tb1~ of the test switch
By opening and closing tbn and operating changeover switches ch1 and ch2, the bypass link is disconnected, and the standard power supply e is selectively connected to each subscriber line, and the detection circuit DET is selectively connected to each trunk circuit TRK1 to TRKn. be.

Therefore, if the normally closed contact S of the control relay in the trunk circuit TRK1 is controlled to open in this state, for the communication line A1, the DC power supply E - the protection resistor r - the contact ta1 of the test switch - the communication line switch Contact points all, a
21, a31, a41 - Test switch contact tb1 - Current detection circuit DETA - The presence or absence of a current flowing in the path of the DC power supply E1 is determined by the current detection circuit DETA. The test will be considered defective.

Similarly, regarding the communication line B1, between the DC power supply E2 and the earth, there is a connection between the earth air, the test switch contact tal, the communication path switch contacts b11, b21, b31, b41, the test switch contact tb1, and the path of the DC power supply E2. The presence or absence of a current flowing is determined by a current detection circuit DETB, and if a current flows, the test is determined to be good, and if no current flows, the test is determined to be a failure.

Although the test for the communication path connecting the subscriber telephone SUB1 and the trunk circuit TRK1 has been described above, it is possible to test other communication paths in a similar manner.

In addition, in Fig. 4, the values of the DC power supply E as the standard power supply e and the protective resistance r are made equivalent to the subscriber circuit, and the polarity of the DC power supplies El and E2 on the detection circuit DET side is set as shown in Fig. 4. If the subscriber telephone SUB1 is in a loop, it can be detected by the current flowing between the ground air and the DC power supply E1 for the communication line A, and between the ground air and the DC power supply E2 for the communication line B. When the telephone line circuit is connected, the same operation as in the case of the above-mentioned test of the communication lines A1 and B1 is performed.

As explained above, in the embodiment shown in FIG. 4, all communication lines can be drawn through the test switch networks TSW1 and TSW2, so all communication path contacts can be directly tested.

Also, the voltage, protection, and resistance r value of the DC power supply E as the standard power supply e, and the DC power supplies E1 and E2 on the detection circuit DET side.
By setting the voltage to an appropriate value, there is an advantage that the communication path networks LLN and TLN can be tested regardless of the states of the subscriber telephones SUB1 to SUBm and the subscriber circuits.

In addition, if electronic contacts are used as the test switch contacts, their high speed can be used to quickly test all communication paths connecting vacant trunk circuits and vacant subscribers, independent of call processing control operations. There is an advantage that it can be done within a certain amount of time.

As described in detail above, according to the present invention, the normality of the call path switch of the exchange can be checked for all connection paths without being affected by the state of subscriber telephones or subscriber lines, and call processing control operations can be performed. It can be tested independently and without any acquisition.

In addition, by sharing the switch network for subscriber line testing and the network for communication path testing, it is possible to eliminate complicated control and special disconnection switches in communication paths using semiconductor switches that have a self-holding function using communication current. This makes it possible to perform detailed tests, and it is also applicable when electronic contacts with high operating times are used in test switches, or to relatively small communication line networks such as the communication lines of remote concentrators. If this is done, excellent effects can be expected, such as particularly large effects.

[Brief explanation of the drawing]

FIGS. 1, 2, and 3 are block diagrams of conventional communication path systems, and FIG. 4 is a block diagram showing an embodiment of the communication path test system according to the present invention. SUB, SUB1 to SUBm; subscriber telephone, LC; subscriber circuit, LLN, TLN; call path network, a1
~a9, b1~b9, c1~c4, a11~a41, b
11-b41, a1m-a4m, b1m-b4m; Communication path switch, A, A1, An, B, B1, Bn; Communication line, C; Control line, W, X, Y, Z, CONA, CONB;
Current detection relay, TRK, TRK1 to TRKn; Trunk circuit, E, E1, E2; DC power supply, t: Switching relay contact, CO, b, s; Control relay contact, L: Call detection relay, AO: Loop Relay for current detection, TSW1,
TSW2; Test switch network, ta1 to ta
m, tb1 to tbn: test switch contacts, DET: detection circuit, DETA, DETB: current detection circuit, e: standard power supply, ch: switching contact, r: protection resistor, la, lb: bypass link.

Claims (1)

[Claims] 1. In testing a communication path in a space-division exchange using semiconductor switching elements with a self-holding function using communication current, bypass links for subscriber testing are connected to all incoming and outgoing lines of the communication path network. The first and second test switch networks are connected to the subscriber test bypass link so as to be selectively connectable to the subscriber test bypass link. A first and second changeover switch is inserted so that it can be connected to a second test switch network, and by controlling both test switch networks and both changeover switches, during subscriber line testing. A test route is formed from the outgoing line of the communication path network to the incoming line of the communication path network via the bypass link for subscriber testing, and when testing the communication path, a test route is formed from the outgoing line of the communication path network to the incoming line of the communication path network under test. A communication path test method that is characterized by connecting a standard power supply and a detection circuit to form a test route for detecting the flowing current, and using the test switch network for testing subscriber lines and communication paths.