KR950014623B1 - Dtmf digit sending circuit and method - Google Patents

Abstract

The method is for sending the subscriber number of a stationary line in a DTMF digit from a PABX. The method comprises the steps of; (A)detecting DTMF digit send request from a user; (B)connecting corresponding output terminal of a DTMF tone generator to a stationary line for a specific time when DTMF digit send request signal is detected in the step (A); and (C)sending DTMF digit through stationary line.

Description

DTMF digit sending circuit and sending method

1 is a block diagram of a conventional premises exchange system.

2 is a conventional DTMF digit sending flowchart.

3 is a connection diagram of the DTMF output circuit of the present invention.

4 is a flowchart of the DTMF sending method of the present invention.

In the present invention, when a subscriber of a private electronic exchange exchanges a DTMF trunk line and calls a subscriber of a local electronic exchange, the present invention restricts the number of trunk line subscribers or the congestion of trunk line outgoing calls by sending the subscriber electronic exchange subscriber number to DTMF digits. It is a method of transmitting CO line DTMF digits from a private electronic exchange which is suitable for sending DTMF digits to a local electronic exchange without receiving.

The prior art is composed of a DTMF generator for receiving and sending DTME digit data to a digit, a CODEC & FILTER for loading a DTMF digit, and a switching network and trunk line subscriber circuit, as shown in FIG.

The conventional private (premises) exchange system configured as described above operates in the order as shown in the flowchart of FIG. 2. When the subscriber of the private electronic exchange exchanges the subscriber of the local exchange by occupying the DTMF trunk line, To send a number, first make sure there is a DTMF digit sending circuit available. At this time, if there is no DTMF digit sending circuit available, it gives tone to domestic subscribers to inform the COS call calling restriction.If there is a DTMF digit sending circuit available, the sending circuit is assigned to the CO line subscriber, and the assigned DTMF sending circuit is assigned to the CO line subscriber number. The busy indicator is displayed so that other subscribers cannot use it until the digit is sent. Thereafter, the number of CO line subscribers is transmitted one digit.

In the process of sending a digit, the call path of the assigned DTMF digit sending circuit is received by the call path of the trunk line subscriber, and when the data value corresponding to the digit to be sent is input to the assigned DTMF sending circuit, the DTMF digit is sent. When the digit transmission is completed, the assigned DTMF transmission circuit is opened to the available counterpart so that other subscribers can use it.

Therefore, the conventional technique is to transmit all kinds of DTMF digits through the DTMF sending circuit allocated when the number of the CO line subscriber is transmitted.

In the prior art, since a DTMF transmission circuit must be allocated to a CO line for each CO line dial, at the same time, when many subscribers make a CO line dial, as many DTMF circuits as available can be used for CO line dialing, but the remaining subscribers hear a CO line restriction tone. do. Therefore, in order to remove this limitation, the DTMF sending circuit should be increased, which means that the capacity of the DTMF sending circuit is limited to a certain number depending on the private exchange, and in order to solve the above problem, increasing the DTMF sending circuit by the number of CO. It is uneconomical.

The present invention is to solve this problem, and as shown in FIG. In the premises exchange system consisting of a DTMF digit sending circuit connected to the DTMF digit sending circuit, the DTMF digit sending circuit is provided with a DTMF tone generator for each DTMF digit type, and each DTMF tone generator output is individually controlled by the control of the central controller. A DTMF digit sending circuit that sends DTMF digits to a CO line by connecting to a CO line subscriber circuit, and a method of sending a local electronic exchange subscriber number to DTMF digits as a method for transmitting DTMF digits to DTMF digits. DTMF tones are generated at all times, and the CO line from the subscriber This is a DTMF digit sending method that sends DTMF digits by connecting the output of the DTMF tone generator of the corresponding DTMF digits to the subscriber of the CO line for a certain time when there is a DTMF digit sending request.

The present invention thus constructed operates like the flow chart shown in FIG.

In order to send out the number of the local exchanger when the subscriber in the private electronic exchange occupies the DTMF trunk line and calls the subscriber of the local exchange, the digit of the digit is connected to the subscribers during the DTMF digit transmission duration for each digit transmission. When the transmission duration time elapses, the number of the national subscribers is transmitted by connecting during the DTMF digit transmission duration time of the CO line subscriber.

Therefore, the feature of the present invention is not a method of transmitting all kinds of DTMF digits through the assigned DTMF digit sending circuit, but a method of connecting the call path of the corresponding digits to the CO subscriber according to the DTMF digits to be sent. Is carried out. It is not at all restricted by CO. That is, one DTMF digit can be sent out to a plurality of trunk subscribers at the same time as processing various tones in a private electronic exchange.

In one embodiment, the DTMF calling dials of 424 CO subscribers are processed without restriction by one DTMF card, which is applied to a private electronic exchange. In the operation state, in order for the subscriber to occupy the CO line and transmit DTMF digits to the local electronic exchange, the subscriber's channel is blocked for the duration of the digit transmission, and the DTMF digits to be sent are transferred to the channel of the CO subscriber. DTMF digits The DTMF digits are connected during the transmission duration, and when the transmission duration has elapsed, the subscriber's channel is resumed.

By applying the present invention, DTMF digits can be transmitted to the CO line subscriber for the duration of the transmission, such as a method of receiving various types of DTMF digits sent by the private exchange. When only the circuit is prepared, it is possible to always perform CO dialing dial regardless of the number and the number of CO subscribers and the congestion of CO outgoing calls.

Claims (3)

As a method of transmitting the local electronic exchange subscriber number to DTMF digits, the DTMF tone generators for all types of DTMF digits are provided so that DTMF tones are always generated. DTMF digit sending method that sends DTMF digits by connecting the output of DTMF tone generator of the corresponding DTMF digits to the trunk line for a certain time. The DTMF digit sending method according to claim 1, wherein there are 16 types of DTMF digits, and each type includes a DTMF tone generator. A premises exchange system comprising a private electronic exchanger, a central control unit for controlling the exchanger, and a DTMF digit dispensing circuit connected to a trunk line subscriber circuit through the switching network under the instruction of the central controller, wherein the DTMF digit dispensing is performed. The circuit is composed of DTMF tone generators for each DTMF digit type, and each DTMF tone generator output is individually connected to the trunk line subscriber circuit under the control of the central control unit, and transmits DTMF digits to the trunk line. .