JPS61128663A - Signal converter - Google Patents

Abstract

PURPOSE:To prevent a forcibly cutting operation of a circuit by transmitting a response signal similar to a general call to lines T and R when the malicious call signal power source of an originating signal converter is cut. CONSTITUTION:When the malicious signal electric power source is disconnected, a grasp signal caused by a loop from an originating exchange 2 operates the A detector 15 and A function of the originating signal converter 3, and the grasp signal is transmitted from an (a)/(f)-bit output terminal 18. Afterwards, a malicious call signal is transmitted from a terminating exchange 7, and received by the originating signal converter 3. At this time, a B detector 35 detects said signal, operates a response ANS relay 31 and transmits the response signal similar to the general call. The A detector 15 of the converter 3 continues its action so as to maintain the circuit until a restoration control by loop disconnection appears. Accordingly a call can be maintained even if a malicious call trace request signal is transmitted from the terminating exchange 7.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a signal conversion device provided between a secondary telephone exchange and a PCM terminal equipment.

FIG. 3 is a block diagram of a telephone exchange system relayed by a PCM line. Now Malicious Call Registered Subscriber 8
When a call is generated from another subscriber 1 in
This is communicated to the originating exchange 2, and the originating exchange implements the recovery control method as the last party for malicious call processing.
The system switches to the recovery mode and prepares for a malicious call trace request from the called subscriber 8. When there is a malicious trace request signal from the terminating subscriber 8, the maintenance personnel of the two originating exchanges can search for the number of the other party's originating subscriber.

During such malicious call processing, the calling side signal conversion device 3 sends the malicious call registration signal and the malicious call trace signal from the terminating exchange 7 to the exchange 2 using the malicious call signal power supply provided in the conversion device. Therefore, in order to improve the security of malicious call processing, it is desired to provide a signal conversion device that includes a protection circuit against malicious call signal power cutoff.

[Conventional technology]

An example of a signal conversion device equipped with a conventional Malicious call signal power supply is shown in the circuit diagram of Fig. 4, and its normal operation is shown in Fig. 5.
This will be explained using the relay operation diagram shown in Figure (a).

In the figure, 11.12 is the T line connecting to the originating exchange 2;
In the R line, 13.14 is the 2WT line and 2WR line that connect to the PCM device 4.

The line settings from subscriber 1 to subscriber 7 in Figure 3 are as follows:
In FIG. 4, the detector 1 of the originating conversion device is
5. Software A function 16 operates, thereby:
This is done by sending the acquisition signal from the af bit 18 through the PCM line from the outgoing signal converter to the downstream device. When the terminating subscriber responds, the terminating signal converter 3 receives a malicious call registration signal from the terminating exchange 7 in the bb bit 23.

The signal operates the MC function 24 of the software circuit and the MC relay 26 of the hardware circuit, and the MC contact 2
7, the +48V pulse signal is connected to the communication path, T line 11 and R
line 12 to the originating exchange 2 in a simplex.

This signal causes the originating switch to switch to the last party recovery method for malicious call processing and to accommodate malicious call trace requests from the terminating subscriber.

When the receiving subscriber takes the telephone off-hook to indicate a response state, a response signal of -48V battery 33 on the T line 11 and earth air on the R line 12 is sent to the originating exchange 2.

The outgoing signal converter 3 receives the response signal from the called subscriber in the ab bit of the software circuit, and converts this signal into the ANS.
Function 29 and AN S 1! This is performed when the electric appliance 31 is operated.

A malicious call trace request is executed by hooking from the terminating subscriber during this call.

Due to the hooking of the subscriber 8, the terminating exchange 7 is changed from the response signal sending state to the +48V signal sending state by simplex, and this state continues until the terminating subscriber ends the call. The originating signal converter 3 sends a +48V signal to the originating exchange 2 in the same manner as the above-mentioned malicious call registration signal.

A maintenance person on the originating exchange side searches for the other subscriber by receiving this signal.

Conventionally, in the outgoing signal conversion device, disconnection protection means have not been taken into consideration with respect to the power supply provided for retransmitting the malicious call registration signal and the malicious call trace request signal to the outgoing exchange.

The operation in the event that the power supply is cut off can be determined by using the relay operation diagram shown in Figure 5(b).
explained. In this case, the +48V malicious call registration signal and malicious call trace request signal cannot be retransmitted to the T line 11 and R line 12 of the communication path, and the originating exchange cannot switch to the last party recovery control method. Therefore, the system remains the same as the originating subscriber's first recovery method. Furthermore, while the malicious call trace request signal is being sent, the MCA 19 and the MCB 2O detector, which normally receive the capture signal, become inoperable.

For this reason, the outgoing signal converter takes the same format as the recovery signal received from the outgoing exchange 2 and performs recovery control, forcing the downstream device to recover by restoring the A detector 15 and A function 16, and making a call. Disconnect the line inside.

The incoming exchange 7 has been restored, the malicious call trace request signal from the downstream side has also been restored, and the outgoing signal converter is the MC relay 2.
6 has been restored, T line 11 earth, RI*12-48V battery,
Returns to the empty state.

However, since the originating exchange 2 does not know that such recovery control has been performed from the originating signal conversion device 3, the originating subscriber 1 is off-hook, and the above-mentioned general call connection operation control does not require the original originating signal conversion. The acquisition signal will continue to be sent by the loop to device 3.

For this reason, the transmission signal conversion device 3 which has once returned to the idle state
is restarted, and the A detector 15 and A function 16 are restarted in the same way as above.
By this, the originating exchange 2 is disabled until the originating subscriber 1 controls the on-footer or forcibly disconnecting and restoring the line by monitoring the call termination time limit in the originating exchange 2.

[Problem that the invention seeks to solve]

As mentioned above, cutting off the +48V power supply for Malicious calls not only fails the original purpose of not being able to process Malicious calls, but also causes the line to be forcibly disconnected, making it impossible to make calls, and disrupting service to subscribers. There is a problem in that it causes a decrease in

[Means for solving problems]

The above-mentioned problems are such that the relay operation that sends the malicious call signal to the originating exchange via the communication path is maintained in the restored state when the power for the malicious call signal is cut off, and the response relay contact of the communication circuit to the originating exchange is The problem is solved by a signal conversion device according to the invention, which is configured to operate with malicious call signals and acquisition signals from a terminating exchange.

[Effect]

According to the present invention, when the power for the malicious call signal of the originating signal conversion device is cut off, the malicious call signal cannot be sent to the originating exchange, but the response relay contact 32 is connected to the response relay 3.
1 operation, so instead of the +48V power supply, the T line 11 sends out a response signal with a -48V battery and the R line 12 the ground air, just like a general call. The A detector of the originating signal converter continues to operate and maintains the line until recovery control is performed by disconnecting the loop from the originating exchange.

〔Example〕

The gist of the present invention will be specifically explained below with reference to the illustrated embodiments.

Figure 1 is a circuit diagram showing an example of a transmission signal conversion device.
FIG. 2 is an operational diagram of the relay.

In FIG. 1, according to the present invention, a monitoring circuit for a power supply for a malicious call signal, a +48V monitoring detector 35, a switching circuit for controlling connection operation from a malicious call to a general call, and a BB function 3 are shown.
6 is provided. In the figure, parts that are the same as those in FIG. 4 are indicated by the same numbers.

When the power supply for Malicious call signal is normal, the conventional 4th
Perform the same connection control operation as when the circuit shown in the figure is normal.

The operation when the power for the malicious signal is turned off is as follows.

A signal captured by the loop from the originating exchange 2, the A detector 15 and the AN & function 16 of the originating signal converter 3, this circuit.
operates and a capture signal is sent from the af bift 18 to the downstream device. Thereafter, a malicious call signal, that is, a malicious call registration signal and a malicious call trace request signal, are sent from the terminating exchange 7, and these are received by the MC function 24 of the originating signal converter.

At this time, the BB detector 35 detects this because the +48V power supply is cut off, and since the BB function 36 is operating, the MC24
By operating the response ANS relay 31, instead of sending a malicious call signal from the +48V power supply by simplex, the T line is connected to the 148V battery and the R line is connected to the ground. Sends out a response signal.

In such a response state, the A detector 5 of the originating signal converter continues to operate until recovery control is performed due to loop breakage from the originating exchange 2, and the line is maintained. Therefore,
Even while a malicious call trace request signal is being sent from the terminating exchange 7 under the control of the terminating subscriber 8, the communication between the subscribers can be continued as usual.

When the terminating subscriber 3 goes on-hook, the malicious call trace request signal from the terminating exchange 7 is restored, the MC function 24 and the ANS response relay 31 of the originating signal converter 3 are restored, and the T line is connected to the originating exchange 2. The R line sends out the end signal for the 148V battery.

After that, when the originating signal converter 3 receives a recovery signal due to a loop break from the originating exchange 2, the A detector 15 and the A
When the function 16 is restored, a restoration signal is sent to the downstream device to start restoration control, and the connection line between the originating subscriber 1 and the terminating subscriber 8 is opened.

〔Effect of the invention〕

According to the present invention, even if the power supply for a malicious call of the outgoing signal converter is cut off, forced line disconnection control can be prevented, and the subscriber's call can be continued even while a malicious call trace request is being made. The effect is extremely large.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing an embodiment of the transmission signal conversion device of the present invention, Fig. 2 is an operational diagram of a relay in the circuit of Fig. 1, and Fig. 3 is a block circuit diagram of a switching system having a PCM line. , FIG. 4 is a circuit diagram showing a conventional example of a transmission signal conversion device, and FIGS. 5(a) and 5(b) show operation diagrams of a relay in the circuit of FIG. 4. In the figure, 1 is the originating subscriber, 2 is the originating exchange, 3 is the originating signal converter, 4 is the originating MUX device, 5 is the terminating MLIX device, 6 is the terminating signal converter, 7 is the terminating exchange, and 8 is the terminating subscriber. , 11.12 are the T and R lines to the originating switch, 13.14 are the 2 WTI and 2WR lines to the originating MUX device, 15 is the to detector, 16 is the A function of the software circuit and the 1'N A contact, 18 is the af and throat output terminal to the transmitting MUX device, 19
．． 20 is MCASMCB detector, 21 is AA function, Mi 22 is AA function output point, 23 is bb
Bit input point, 24 is the MC function for the malicious call signal, 25 is the other contact, 26 is the MC relay for the malicious call signal, 27 is its contact, 28 is the ab bit input point from the MUX device, 29 is the AN
S function, 30 is its contact, 31 is the ANS relay, 3
2 is the relay contact 33 for the -48V power supply, 34 is the +48V power supply, 35 is the Malicious call signal power supply detector BB, and 36 is the 88V power supply.
37 is its output contact.

Claims (1)

[Claims] The relay operation that sends the malicious call signal to the originating exchange via the communication path is maintained in the restored state when the power for the malicious call signal is cut off, and the response relay contact of the communication circuit to the originating exchange is operated to transmit the malicious call signal from the terminating exchange. A signal conversion device, characterized in that it is configured to be operated by a signal and a captured signal.