JPH0118617B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a call path diagnostic device for diagnosing a call path in a PCM time-division electronic exchange.

Conventional Structure and Problems Therein Generally, a call path diagnostic device for an electronic exchange is structured as shown in FIG. In Figure 1, 1
is a PCM time division highway, which is connected between the time division highway switch circuit SW and the subscriber circuit LC. Reference numerals 2 and 3 designate a demodulator and a modulator constituting a PCM code converter (hereinafter referred to as codec) CO1 in the subscriber circuit LC, which are connected to the upstream and downstream lines of the time division highway 1, respectively.
4 is a return circuit connected to the demodulator 2 and modulator 3, 5 is a subscriber circuit control circuit, and signal repeater 8
It is connected to the central control device 9 via. Reference numeral 6 denotes a circuit block including a 2-wire/4-wire conversion circuit and a subscriber interface circuit, and is connected to the telephone set 7. 10 is a time division highway switch circuit
It is an interface circuit connected to SW,
It is used to relay control signals from the central control device 9. Reference numeral 11 denotes a time division highway switch control circuit, which controls the communication path between the calling party and the called party by controlling the control signal from the central control unit 9.
2. A PCM time division highway 13 connects the time division highway switch circuit SW and the test trunk circuit TST to each other. Reference numerals 14 and 15 denote a modulator and a demodulator, respectively, which constitute the PCM code converter CO in the test trunk circuit TST, and are connected to the upstream and downstream lines of the PCM time division highway. 1
6 and 17 are a test signal generation circuit and a test signal detection circuit connected to the modulator 14 and demodulator 15, respectively, and the output end of the test signal detection circuit 17 is connected to the central control unit 9 via a signal repeater 18. has been done.

Next, the operation of the above-mentioned conventional call path diagnosis device will be explained. In FIG. 1, the central control device 9
is connected to the subscriber circuit control circuit 5 via the signal repeater 8.
When the subscriber circuit control circuit 5 instructs codec loopback, the codec loopback is established by connecting the demodulator 2 and the modulator 3 in the loopback circuit 4, and the signal demodulated by the demodulator 2 is modulated again. The signal is input to the converter 3, modulated, and sent to the PCM highway 1. The central controller 9 also instructs the time division highway switch control circuit 11 via the interface circuit 10 to form a communication path between the subscriber circuit under test LC and the test trunk TST. Time division highway switch control section 1
1 thereby establishes a time-division communication path between communication channel a of time-division highway 1 and communication channel b of time-division highway 13. As a result of the above, a communication path is formed between the test trunk circuit TST and the subscriber circuit LC, and furthermore, loopback is established within the subscriber circuit LC. For this reason,
The test signal generated by the test signal generation circuit 16 in the test trunk circuit TST is transmitted to the modulator 14.
It is converted into a PCM code, sent to the uplink highway of the time division highway 13, relayed through the communication path memory 12 in the time division highway switch circuit SW, sent to the downlink highway of the time division highway 1, and sent to the downlink highway of the time division highway 1. Reach codec CO1. The test signal is converted back to an analog signal by the demodulator 2, then inputted to the modulator 3 by the folding circuit 4, and converted to a PCM code by the modulator 3 again. , passes through the down-bound highway of time division highway 13 and returns to the codec CO of the test trunk circuit TST. After the returned test signal is converted back into an analog signal by a demodulator 15, a test signal detection circuit 17 checks its frequency, level, etc. By doing this, it is detected whether the original test signal has returned to normal, and the detection result is sent to the central control unit 9 via the signal repeater 18.
Notify. If the detection result is normal, the central control device 9 connects the test trunk circuit TST and the subscriber circuit.
It is determined that the time-sharing communication path between LCs is normal, and
If the test signal cannot be detected, it is determined that the communication path is abnormal. Therefore, it is possible to make a certain diagnosis even with a conventional call path diagnosis device. However, in the above-mentioned conventional communication path diagnosis device, the subscriber circuit on the calling side and the test trunk circuit TST, and the subscriber circuit on the called party side and the test trunk circuit TST are only diagnosed separately and independently. However, there was a problem in that it was not possible to completely test whether the communication path used when both subscribers actually communicated was normal.

OBJECT OF THE INVENTION The present invention eliminates the above-mentioned drawbacks of the prior art, and it is possible to accurately establish a communication path between the calling party's subscriber circuit and the called party's subscriber circuit before starting a call. The purpose of the present invention is to provide an excellent communication path diagnosis device that can diagnose the situation.

Structure of the Invention In order to achieve the above object, the present invention connects the calling party's codec, the called party's codec, and the test trunk circuit to each other through a time division highway switch circuit. The test signal is sent out to the communication path connecting the users, the test signal is returned at each codec, the test signal is sent back to the test trunk, and the test signal is detected by the detection circuit in the test trunk. be. Therefore, according to the present invention, it is possible to accurately diagnose whether the communication path formed between the calling party and the called party is normal or not.

DESCRIPTION OF THE EMBODIMENTS FIG. 2 is a schematic diagram of an embodiment of the communication path diagnosis device of the present invention, and the embodiment of the present invention will be described below with reference to FIG. In the second, 20 is connected to the subscriber circuit LC-A of subscriber A.
This is a PCM highway, and 21 and 22 are a demodulator and a modulator that constitute the codec COA in the subscriber circuit LC-A. 24 is a subscriber circuit control section which controls the return circuit 23 and the communication channel of the codec COA. 25 is a circuit block including a 2-wire/4-wire conversion circuit and a subscriber line interface circuit, and is connected to subscriber A's telephone 26 through the subscriber line. The subscriber control unit 24 is configured to monitor operations such as calling and dialing on the telephone 26 of the subscriber A through the circuit block 25. 27 is a PCM highway to which the subscriber circuit LC-B of subscriber B is connected, and 28 and 29 are demodulators and modulators constituting the codec COB in the subscriber circuit LC-B. Reference numeral 31 denotes a subscriber circuit control section, which controls the return circuit 30 and the communication channel of the codec COB. 32 is a circuit block including a 2-wire/4-wire conversion circuit and a subscriber line interface circuit, and is connected to subscriber B's telephone 33 through the subscriber line. A signal relay section 34 is connected between the subscriber circuit control sections 24 and 31 and the central control device 35. 36 is an interface circuit connected to the time division highway switch circuit SW, and is for transmitting a control signal sent from the central control unit 35 to the time division highway switch circuit control section 37. Reference numeral 38 denotes a communication path memory, which forms a time-division communication link. 39 is the PCM highway to which the test trunk circuit TST is connected;
41 is the codec in the test trunk circuit TST
These are the modulator and demodulator that make up the CO. 42 is a test signal generation circuit, and 43 is a test signal detection circuit. The test signal detection circuit 43 detects the frequency, level, etc. of the test signal demodulated by the demodulator 41, and sends the detection results via the repeater 44. This is to notify the central control device 35. 45 is a typewriter control unit, and 46 is a typewriter, which prints failure messages according to instructions from the central control unit 35.

Next, the operation of the above embodiment will be explained using the operation flowchart of FIG. 4 and the communication path connection diagram of FIG. 3. When subscriber A's telephone 26 makes a call, subscriber circuit control section 2 in subscriber circuit LC-A
4 detects this and notifies the central control device 35. The central controller 35 selects an empty time slot TS-A on the PCM highway 20 and notifies the subscriber circuit controller 24 of this selection. When subscriber A's telephone 26 dials subscriber B's telephone number, subscriber A's subscriber circuit controller 24 receives and counts the dial signal, and sends it to central controller 35.
Contact. The central controller 35 splits the dialed number and finds out that the number belongs to subscriber B, and on this basis subscriber B belongs to it.
PCM Highway 27 vacant time slot TS-
B is selected and the subscriber circuit control unit 31 of subscriber B is notified. Therefore, the time slots TS-A/B used for calls between subscribers A and B are determined here, and the time-sharing call links g and h are also determined (the third
(See c in the figure). Next, the central control device 35
Call links g and h between B and codec COA,
It operates to perform two tests to test the COB. That is, the first test is
The purpose of the second test is to test the COA, COB and speech link h; the second test is intended to test the COA, COB and speech link h. Therefore, in order to carry out the first test, the central control unit 35 first informs the subscriber circuit controllers 24, 31 of the previously communicated time slot TS-
Assign A/B to each codec COA, COB,
Put the codecs COA and COB into talking mode. At the same time, it instructs the time-division highway switch circuit control section 37 to create the following three time-division call links.

Link a: A link between the upbound highway of PCM Highway 39 and the downbound highway of PCM Highway 20.

Link b: A link between the upbound highway of PCM Highway 20 and the downbound highway of PCM Highway 27.

Link c: A link between the upbound highway of PCM Highway 27 and the downbound highway of PCM Highway 39.

Therefore, the time division highway switch circuit control section 37 forms the three links in the communication path memory 38 in accordance with the above instructions. Further, the central control device 35 controls the subscriber circuit control section 2.
4 and 31 to perform a loopback operation. Therefore, the subscriber circuit controllers 24 and 31 respectively control the return circuits 23 and 30 accordingly to create a return communication path. Through the above series of operations, the test signal sent from the test trunk circuit TST to the upstream highway of the PCM highway 39 is transferred from link a to the subscriber circuit of subscriber A as shown in FIG.
LC-A→Link b→Subscriber B's subscriber circuit LC-
B→link c→test trunk circuit The signal is sent back to the test signal detection circuit 43 of TST. When the test signal returns to the test signal detection circuit 43, this
The detection result is sent to the signal repeater 4.
4 to the central controller 35. If the returned test signal is normal, the process moves to the second test, and if it is abnormal, the typewriter control unit 4
A fault message is output to the typewriter 46 through 5 and printed. Then, at the same time, another vacant time slot and another time-division call link are selected and the same test as above is performed. Continue testing until all free time slots are exhausted,
If a normal test result is not obtained, a busy tone is sent to subscriber A's telephone 26 and some troubleshooting is performed. If it is normal, we will move on to the second test, but
In this case, the codec has already been tested in the first test.
Since the return of COA and COB continues, the central controller 35 only instructs the time division highway switch circuit TDJ to switch the link connection. In the second test, the test signal is applied to the test trunk circuit as shown in Figure 3B.
TST→Subscriber B's subscriber circuit LC-B→Subscriber A
subscriber circuit LC-A → test trunk circuit TST
will be sent back via. If there is any abnormality in this test, a retest is performed by changing the time slot. If it is normal, the central controller 35 notifies the subscriber circuit controllers 24 and 31 that the test is complete;
Return circuit 23 of subscriber circuit control unit 24, 31,
Control over 30 is discontinued. In this way,
By performing the first test and the second test, the status of each codec COA, COB and each call link a, b, c, d, e, f will be known, and subscribers A, B Each codec COA and COB used for calls between each call link g = b, f
It can be easily determined whether =e is normal or not. Therefore, if these are normal, the central controller 35 will enter the normal calling operation,
A communication path between subscribers A and B is formed as shown in FIG. 3C.

Effects of the Invention As is clear from the embodiments described above, the present invention connects the codecs on the calling party side and the called party side in series with each other through a time division highway switch circuit, and connects the codecs on the calling party side and the called party side in series through the test trunk circuit. A test signal is sent to the codec on the calling party side and the codec on the called party side via the highway switch circuit, and the test signal is sent from the codec on the calling party side and the codec on the called party side via the time division highway switch circuit. The caller's codec is configured to determine whether or not the call link between the codec and the time division highway switch circuit is normal based on the test signal sent back to the test trunk circuit. Since the codec on the callee side and the codec on the called party side are connected in series to each other via a time-division highway switch circuit, it is possible to diagnose whether the communication path, communication link, and codec actually used for the call are completely normal. This has the advantage of significantly reducing the inconvenience to the calling party and the called party. Further, according to the present invention, the communication path is diagnosed each time immediately before a call, and has the advantage that the diagnosis result immediately before a call is more accurate than when diagnosis is performed periodically.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a conventional call path diagnosis device.
FIG. 2 is a schematic configuration diagram of an embodiment of the communication path diagnosis apparatus of the present invention, FIG. 3 is an operation diagram of the embodiment, and FIG. 4 is a flowchart showing the operation of the embodiment. LC-A, LC-B...Subscriber circuit, COA,
COB...PCM code converter (codec), TST
... Test trunk circuit, SW ... Time division highway switch circuit, 20, 27 ... PCM highway, 21, 28 ... Demodulator, 22, 29 ... Modulator, 23, 30 ... Return circuit, 24, 31 …
...Subscriber circuit control unit, 25, 32...Subscriber line interface circuit, 26, 33...Telephone, 3
4...Signal relay unit, 35...Central control device, 36
...Interface circuit, 37...Time division highway switch circuit control section, 38...Call path memory, 39...PCM highway, 40...Modulator,
41... Demodulator, 42... Test signal generation circuit,
43... Test signal detection circuit, 44... Signal relay section, 45... Typewriter control section, 46... Typewriter.

Claims (1)

[Claims] 1. Connect loopback circuits to the PCM code converters installed in the subscriber circuits of the calling party and the called party, respectively, and dial the telephone number of the called party's telephone using the calling party's telephone. When this happens, this is detected and the caller and called parties
The PCM code converters are connected in series to each other via the loopback circuit and the PCM time-division highway switch circuit that connects the caller and called party telephones to each other, and the
A predetermined test signal is transmitted to the PCM code converter via the PCM time division highway switch circuit and the loopback circuit, and is sent back from the PCM code converter to the test trunk circuit via the PCM time division highway switch circuit. The incoming signal is detected by the above test trunk circuit, and the above
A communication path diagnosis device for an electronic exchange configured to diagnose a communication path consisting of a PCM code converter, the PCM time-division highway switch circuit, etc.