JPS5837757B2 - Dial pulse control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dial pulse control system when automatically calling 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 toll control function controls the dial pulse according to the service class of the extension subscriber when an automatic private branch exchange's extension makes an automatic call to a central office line, thereby blocking the call.

FIG. 1 shows a relay system diagram when an extension of a general automatic private branch exchange makes an automatic call.

In FIG. 1, EXT indicates an extension subscriber, LP a link frame, COT a central office trunk, and OR an originating register.

When an extension subscriber (EXT) goes off-hook, the EXT is connected to an originating register (OR) via a link frame (LF).

Next, when the extension subscriber dials a dial for automatic dialing of the central office line, for example, "0", the originating register (OR) receives and identifies this "O" dial, and as a result, the connection path is transferred to the extension subscriber (EXT). Change the connection to the central office trunk (COT).

In exchanges that have a toll control function, the central office line transformer (C
By combining both the monitoring of the number of digits of the dial pulse sent to the central office line (OT) and the monitoring of the first digit dial pulse, calls from long distances, etc. are blocked.

FIG. 2 shows an example of a circuit that controls dial pulses by counting the number of digits and regulates outgoing calls, and the counting circuit is installed in 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 C IJ relay is a relay that operates while receiving a dial pulse for each digit, the PA-PD is a counting relay, and the A relay is a relay that is not shown in the diagram, but is a relay that operates when a dial pulse is received for each digit. Each receiving relay is shown.

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

The caller's dialing signal is operated by a CIJ-ray every digit, and the intermittent operation of the CIJ-ray causes the PA-
The PE counting relay starts counting operation.

In this conventional example, the number of digits is set to 11, and when the caller dials the 11th digit, as shown in the time chart in Figure 4, when the 11th digit is received, PA relay operation, PB relay operation, and PC
The states of relay recovery, PD relay recovery, and PE relay operation are formed and extracted as the toll control information shown in FIG.

The toll control information is the central office trunk (COT) shown in Figure 5.
When the 11th digit is received, the circuit is closed and earth air is supplied to the A line.

Therefore, the current path of the ground air - b make contact - Pe make contact - Pd break contact - Pc break contact - Pa make contact - A line RL relay ■ winding - rll break contact one relay - one battery is formed, and the As a result, the RLIJ relay operates.

The RLIJ relay is a disconnection relay for the central office line trunk that connects the winding and
If both windings are energized, it will not work, but if only one winding is energized, it will work.

(The trunk is disconnected using one-line information during long-distance control from the OR.) However, according to this conventional method, when performing long-distance control by monitoring the number of digits, at least one dial pulse is sent to the central office line. I end up.

This is because the number of digits is counted after receiving the dial pulse from the extension subscriber, and then adding up the digits to determine whether the number of digits has reached the number of digits that should be controlled.

The purpose of the present invention is to eliminate the above-mentioned drawbacks, and to transmit data from a central office trunk (COT) to a later point at the end of the 1 digit (10 digits) before the arbitrary number of digits (11 digits) to be controlled. The present invention provides a new and economical out-of-town control method that does not affect downstream devices by blocking the pulse sending circuit.

In order to achieve the above object, the present invention provides a common control type automatic private branch telephone exchange with a circuit for counting the number of dialed digits for each central office line trunk, and forcibly disconnects the central office line trunk when a dial of a specific digit or more arrives. The system is characterized in that some relay contacts of the dial digit number counting circuit are connected in parallel with the dial pulse sending circuit of the office line trunk to prevent dial pulses from being sent beyond a specific digit.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 6 is an embodiment of the dial pulse control system according to the present invention, and shows a communication path portion of a central office trunk (COT).

The main office line trunk (COT) has the same digit counting circuit as shown in Figure 2, and if the number of digits is set to 11, as shown in Figure 4, PA relay operation, PB relay operation, PC relay recovery, PD relay Under the conditions of recovery and PE relay operation, toll control information is retrieved, and A, B, C, RL!
jray works.

The main office line trunk (COT) is disconnected by relay operation.

The explanation up to this point is exactly the same as that of the conventional central office trunk (COT) having a digit counting circuit.

The present invention is characterized in that a contact point for the digit number counting circuit is added in parallel with the a contact point on the communication line that sends dial pulses to the rear end.

As can be seen from the operation table in Figure 4, the added contacts Pe, Pd, and Pb are in the state of the counting circuit at the end of 10 digits, that is, at the end of 10 digits, the pulse sending circuit is closed regardless of the a contact. Put it away.

Even when the first digit is dialed, the pulse sending circuit remains closed and detects toll control, disconnects the central office line trunk and eventually opens the central office line loop.

(Refer to Figure 4, Office Line Loop B) In this way, by using the contacts of the digit counting circuit to stop sending dial pulses for digits exceeding the set number of digits to the office line, the switching equipment at the office side can be disabled. can be prevented.

As explained above, according to the present invention, in an automatic private branch exchange having a toll control function based on digit counting, a single pulse is not sent to the central office line side, and therefore the invalid connection of the train is held. No problem.

The negative effect of the pulse at the 11th digit, which was given as an example in this example, is that if the pulse is at the 11th digit, the transmission register (OR) on the central office line side
, ORT, etc.) are separated and there is no problem, but if the central office line side is reacquired by hooking etc., and the actual pulse to the central office line is at the 9th or 10th digit, even though it is at the 11th digit, the transmission register will start both 4E devices and complete the desired connection.

The connected train detects that the caller is in a recovery state and then recovers.

That is, according to the present invention, it is possible to completely prevent the invalid activation of the exchange equipment on the central office side, which is highly effective.

[Brief explanation of drawings]

Figure 1 is a relay system diagram when an extension telephone of a private branch exchange makes an automatic central line call, Figure 2 is a circuit example of a conventional long-distance control system using digit counting, and Figures 3 and 4 are Figure 2. FIG. 5 is an example of a central office line trunk having a toll control function by counting the number of digits, and FIG. 6 shows a dial of a central office line trunk having a toll control function by counting the number of digits according to the present invention. The pulse control method is shown. LF: Link frame, EXT: Extension telephone, COTr
Office line trunk, A: Dial pulse reception relay, B:B
Position relay C: c position relay, PA-P
D: Counting relay, RL: Forced disconnection relay.

Claims (1)

[Claims] 1. In a common control type automatic private branch telephone exchange, a circuit for counting the number of dialed digits is provided for each central office line trunk, and when a dial of a certain digit or more arrives, the central office line trunk is forcibly disconnected, and the circuit for counting the number of dialed digits is installed. A dial pulse control system characterized in that a relay contact of a part of the circuit is connected in parallel with the dial pulse sending circuit of the central office line trunk to prevent dial pulses from being sent for a specific digit or more.