JPS5826239B2 - out-of-town control system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a long-distance connection control method for automatically making a call to a central office line from an extension telephone housed in an automatic private branch exchange.

A toll control function is provided as a supplementary service to automatic private branch exchanges.

This function prevents long-distance calls, etc., depending on the service class of the extension subscriber, when an automatic private branch exchange's extension makes an automatic call to the central office line.

Figure 1 is a diagram of the relay system when an extension makes an automatic call.
XT indicates an extension subscriber, LF indicates a link frame, and COT indicates a central office trunk.

When an extension subscriber (EXT) makes an automatic call to the central office line, the corresponding E
XT is a central office line trunk (CO) via a link frame (LF).
It is connected to the central office line trunk (Ca2) to monitor the number of digits of the dial pulse sent to the central office line and monitor the first digit dial pulse in combination.

FIG. 2 shows an example of a circuit for a conventional toll control system using digit counting, and the counting circuit is mounted on a central office trunk (COT).

In Figure 2, the B relay is a relay that operates while acquiring a central office line trunk (COT), the CIJ relay operates while receiving a dial pulse for each digit, the PA-PD is a counting relay, and the A relay (not shown in the diagram) is a dial reception relay. Each is shown below.

Next, the operation of this conventional example will be explained with reference to FIG.

The caller's dial signal is activated by a CIJ relay for each digit, and when the CIJ relay intermittent operation is restored, the counting relay of the PA-PE starts counting operation.

In this example, the number of digits is set to 11, and when 11 digits are received, P
A relay operation, PB relay operation, PC relay recovery, P
The status of DIJ data and PEIJ data is created and retrieved as out-of-town control information.

However, according to this conventional circuit, when performing long-distance control by monitoring the number of digits, if the extension dials an additional dial while the normal office line and extension line are in a talking state, the preset number of digits is exceeded. This has the disadvantage that the number of digits exceeds the number of digits, resulting in a problem with out-of-town control.

In order to prevent this kind of situation, a commonly considered countermeasure is to use an EAIJ relay relay (the EA relay has a response memo IJ relay and once the station When the line subscriber answers, the operation continues until the end of the call), and by inserting the break contact of the EA relay into the CIJ relay operation circuit, which is a step relay of the counting circuit, and stopping the CIJ relay operation, the call can be terminated. Prevent external control from occurring.

However, with such a measure, when the extension subscriber disconnects only the central line side and makes a re-transmission due to an operation such as hooking by an extension subscriber, the counting circuit does not advance and the central line can be freely transmitted, which is undesirable.

As another countermeasure, as shown in FIG. 6, the EA relay, which is an EIJ relay auxiliary relay, is set to a slow recovery so that it does not recover even during dialing (the E relay recovers during dialing).

As can be seen in the figure, when the EAIJ relay is activated, the C'J relay operation, which is the input to the counting circuit, is stopped, the progress of the counting circuit is stopped, and out-of-town control is prevented.

However, this method requires a delay circuit (1 second or more) to ensure that EAIJ relay redialing is in progress, which is uneconomical.

An object of the present invention is to eliminate the above-mentioned drawbacks. When a normal office line and an extension line are in a communication state, even if the calling party and the called party perform dialing, hooking, etc. The present invention provides a new and economical toll control method that does not affect the counting circuit for toll control provided in the trunk.

In order to achieve the above object, the present invention adds a contact point of a called party response information receiving relay to the counting circuit in a common control type private branch exchange that performs long-distance control by counting the number of digits of a dial number. The counting state is forcibly returned to the past state, and the counting state is not allowed to advance after a certain counting state.

The present invention will be explained in detail below with reference to the drawings.

FIG. 4 shows a specific example of a counting circuit provided in a central office line trunk of the toll control system according to the present invention, and FIG. 5 shows an operational diagram of FIG. 4.

The difference between FIG. 4 of the embodiment of the present invention and FIG. 2 of the conventional example is P.
This is where the make contact of the e-relay is inserted into the D IJ operation circuit.

Although not shown in the figure, the E relay is a relay that operates in response to a response from a subscriber on the central line side, in which the polarity of the communication line is reversed.

An extension subscriber makes an automatic call to the central office line, and the number of digits dialed is 1.
If it ends with 0 digit and the state is in progress with the central office line, E IJ
The PDIJ is operated by the earth contact, the e contact, and the PDIJ by the battery.

As is clear from FIG. 5, this state is exactly the same as the state of 8 digits.

Therefore, even if the extension subscriber dials once in this state, E/IJ will be restored during dialing, but toll control will not be regulated.

When the dial is completed, the counting circuit shown in FIG. 4 is in the state of the 9th digit, but since the E IJ function is activated again, the P D IJ function is activated in addition to the 9th digit.

If you dial again, it will be the 10th digit, but E
IJWare - returns to the 8th digit state to operate again.

Even if you dial after that, the state of the 8th and 10th digits will only be repeated.

By using this method of resetting the number of digits, it is possible to provide services on the central office line side through additional dialing during a call and to prevent the central office line from being opened due to erroneous operation.

As explained above, according to the present invention, a complete out-of-town control (regulation) system using a digit counting system can be realized with an extremely simple circuit.

[Brief explanation of drawings]

Figure 1 is a relay system diagram when an extension telephone of a private branch exchange makes an automatic call to the central office line, Figure 2 is a circuit example of a conventional long-distance control system using digit counting, and Figure 3 is the operation of Figure 2. Figure, 4th
The figure shows an example of a circuit for a long-distance control system using digit counting according to the present invention, FIG. 5 shows an operation diagram of FIG. 4, and FIG. 6 shows a known over-dial prevention circuit. LF...Link frame, EXT...
Extension telephone, COT... Central office trunk, B...
...B position relay, C...C position relay, PA-PD...counting relay, EA
...Auxiliary relay for E relay.

Claims (1)

[Claims] 1. In a common control type automatic private branch exchange that performs long-distance control by counting the number of digits in a dialed number, a contact for a called party response information reception relay is added to the counting circuit, and the counting state of the counting circuit is forcibly changed at the time of response. An out-of-town control method that is characterized by returning to the past state and not allowing progress after a certain count state.