KR100473016B1 - Private Branch Exchanger - Google Patents

Abstract

The present invention relates to a small trunk line switching system, and connects a plurality of telephones without using a conventional private switching system to detect a hook switch on / off state of the plurality of telephones. Therefore, there is an advantage that can solve the problem of the expansion or replacement of the existing exchange caused by the expansion of the trunk line and the extension and the increase in cost, and also requires a technician at the time of initial installation. Unlike in the private exchange, the user can initially easily and conveniently install it at the user level to perform the trunk line exchange function.

Description

Small Branch Exchange System {Private Branch Exchanger}

The present invention relates to a small trunk line switching device, and more particularly, to a small trunk line switching device configured to perform a circuit switching function and a call hold function by connecting a plurality of telephones without using a conventional private exchange.

Generally, in a conventional trunk line switching network that is established in a company or the like and uses two or more trunk lines, the caller's telephone call request through a specific trunk line is to be connected only to the called party connected to the specific trunk line. It connects telephones in a one-to-one relationship and performs line switching between the caller and the called party.

However, the conventional trunk line switching network which performs the circuit switching function by setting the connection relationship between the trunk line and the telephone as one-to-one, for example, whenever a corresponding callee connected to a particular trunk line 1 among a plurality of trunk lines is absent, trunk line 2 or trunk line It is inconvenient that other telephone subscribers connected to 3 get up from their seats and move to the place where the called party's telephone connected to CO line 1 is located.

In addition, the conventional trunk line exchange system using the conventional trunk line exchange network needs to additionally increase (for example, extend the extension card) or replace expensive private exchanges whenever the trunk line and extension are needed, in particular, the initial stage of such private exchange. Since installation requires a professional technician, there is a problem that the installation cost increases and the installation time takes a lot.

Accordingly, an object of the present invention is to overcome the above-described problems, and an object of the present invention is to detect a hookswitch on / off state of a plurality of telephones by connecting a plurality of telephones without using a conventional private exchange. Accordingly, the present invention provides a small trunk line switching system that performs a circuit switching function and a call hold function.

The small trunk line exchange device of the present invention for achieving the above object comprises: n trunk line loop detection circuit for detecting the use of each of the n trunk lines connected to the public telephone network (PSTN); N ring detectors for detecting a ring signal for each of the n trunk lines coming through the n trunk loop detection circuits; N trunk line loop circuits forming a trunk line loop between each of the n trunk lines and each of the m called phones; N pending sound transmission units for transmitting a call pending sound to a specific caller's telephone through n trunk line loop circuits connected to the corresponding trunk lines in a one-to-one correspondence with the n trunk lines when a pending sound transmission signal is input; M hook detection circuits for detecting a hook switch on / off state for each of the m called phones; A matrix for performing a trunk line switching function between the n trunk lines and the m called phones; And the hookswitch on / off state and the call hold of the m callees according to the result of continuously checking the hookswitch on / off states of the n trunk line detection circuits, the n ring detectors, and the m called phones. The state and ring signal input state are displayed on a status display unit. If a ring signal is detected, the matrix is controlled to form a call reception loop between the trunk line on which the ring signal is detected and the called telephone set to the hook-switched off state. If the called telephone is switched off when the signal is not input, the matrix is controlled to form a call transmission loop between the called telephone and an unused trunk line, and the hook switch of the specific called telephone is busy. Is hooked up once and then hooked off, the pending sound corresponding to the specific trunk line Sends a hold tone transmission signal to the caller to send a call hold tone to a specific trunk line that was in a call, and when the callee of the callee and other callees in the call are switched off during the hold tone call, the matrix is controlled to hold the call. It is characterized in that it consists of a micom to perform a call switching function by forming a call reception loop between the trunk line being in progress and another called phone that is newly switched off.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 and 2, in accordance with the present invention, a small trunk line exchange device 20 performing trunk line exchange function for three trunk lines and six called telephones has a public communication network for connecting a caller telephone and a called telephone. PSTN) 10 and the called telephone.

The three trunk line loop detection circuits 212, 213, and 214 detect the use of each of the three trunk lines connected to the public telephone network 10, and the three ring detection units 215, 216, and 217. A ring signal for each of the three trunk lines coming through the three trunk loop detection circuits 212, 213, and 214 is sensed.

In addition, the three trunk line loop circuits 218, 219 and 220 form a trunk line loop between each of the three trunk lines and each of the six called telephones, and three pending sound transmission circuits 221 and 222. When the pending sound transmission signal is input from the following microcomputer 211, the caller telephone is connected to the caller phone through three trunk line loop circuits 218, 219 and 220 connected to the trunk lines in one-to-one correspondence. To send a call hold tone.

In addition, the six hook detection circuits 225, 226, 227, 228, 229, and 230 detect the hookswitch on / off state for each of the six called phones, and the matrix 224 A trunk line switching function is performed between the three trunk lines and six called telephones.

In addition, the microcomputer 211 performs hook switch on / off states of the three trunk line detection circuits 212, 213, 214, three ring detectors 215, 216, 217, and six called telephones. According to the result of the check continuously, the status display unit 231 displays the hook switch on / off state, the call hold state and the ring signal input state of the six callees.

When the ring signal is detected, the microcomputer 211 controls the matrix 224 to form a call reception loop between the trunk line on which the ring signal is detected and the called telephone set to the hook-switched off state.

If the ring signal is not detected, that is, if the called telephone is switched off while the called telephone is not input, the caller telephone controls the matrix 224 to control the called telephone. A call transmission loop is formed between the trunk line and an unused trunk line.

The micom 211 is hooked off once after the hook switch of the particular called telephone phone is pressed and released by the called party once, and then hooked off again, the pending sound transmitting circuit 221 corresponding to the specific trunk line in the call (222) 223 sends a pending sound transmission signal to send a call pending sound to a specific trunk line that was in a call.

The microcomputer 211 controls the matrix 224 when the callee is off the hook-switched phone and the other called phone on the call during the holding tone transmission, and controls the matrix 224 to hold the call and the other caller who is newly hooked-off. A call reception loop is formed between phones to perform a call transfer function.

The small trunk line exchange device according to the present invention configured as described above operates as follows.

First, the operation of forming a call reception loop to receive an incoming call from the caller to the called party is as follows.

First, the microcomputer 211 includes three ring detection units 215, 216, 217, three trunk line detection circuits 212, 213, 214, and six called telephones, which correspond to three trunk lines one-to-one. The hook detection circuits 225, 226, 227, 228, 229, and 230 that constantly detect the hook switch on / off state are constantly being checked. As the ring enters the three trunk lines, When the ring detection units 215, 216 and 217 of the trunk line are set to output ring detection signals, the six hook detection circuits 225, 226, 227, 228, 229 and 230 are turned off. After checking the called phone in use, the matrix 224 serving as the trunk line switching circuit is controlled to connect the trunk line to the inactive callee phone so that the ring rings.

At this time, the number of unused called telephones may be one or more (six or less in the embodiment according to the present invention).

As described above, the microcomputer 211 continuously checks the hook detection circuits 225, 226, 227, 228, 229, and 230 corresponding to the called phone in the ringing state of the called phone. The caller picks up the handset and detects the telephone with the hook switch off. When a specific called telephone with the hook switch off is detected, the caller controls the matrix 224 to connect the caller's trunk line to the called telephone. To form.

Secondly, the operation of forming a call transmission loop for calling a caller is as follows.

When the called party makes a call and picks up the handset, hook detection circuits 225, 226, 227, 228, 229 and 230 of the called party telephone are set to detect the hook-switched off state. The microcomputer 211 recognizes the hookswitched off state of the called telephone.

At this time, the microcomputer 211 checks the trunk line loop detection circuits 212, 213, and 214 to check the trunk line which is not in use, that is, the trunk line to which a call can be connected, and then controls the matrix 224 to be inactive. The trunk line is connected with the caller's phone that wants to call the caller to form a call transmission loop.

The called party then hears a dial tone on his telephone handset and dials to speak with the caller.

In addition, the microcomputer 211 continuously checks the trunk line detection circuits 212, 213, and 214 to detect whether the call is over, and in fact, the user puts the handset on the phone after the call is terminated and thus the call transmission loop. If the corresponding CO line loop detection circuit 212 (213) (214) having formed a detects the hookswitch on state of the called telephone, the microcomputer (211) controls the matrix 224 to terminate the call and the called telephone line. Disconnect and maintain standby.

Third, the operation of changing the call reception loop by transferring the CO line to the place of another called party during the call is as follows.

The callee first presses and releases his telephone hook switch to return the trunk line to the next seat.

In this way, when the hook switch is pressed and released from the telephone connected to the trunk line to which the called party is talking, the microcomputer 211 changes the hook switch through the corresponding hook detection circuits 225, 226, 227, 228, 229, and 230. Recognizing that the CO line will be switched and applying the pending sound transmission signal to the corresponding pending sound transmission unit 221, 222, 223 and simultaneously applying the corresponding CO line loop circuits 218, 219, 220. By connecting to a CO line, music or messages of the pending sound transmitting units 221, 222, and 223 are transmitted toward the CO line in a call.

Subsequently, the microcomputer 211 examines each of the hook detection circuits 225, 226, 227, 228, 229 and 230 of the called telephones other than the called telephone which was in a call and then turned off. If a specific called telephone is found, at the same time, the trunk line loop circuits 218, 219 and 220 are removed from the pending trunk line and the matrix 224 is controlled to newly turn off the hook switch. A call on hold is connected to the caller's phone to form a new call reception loop to enable the call.

That is, this operation is to substitute the call switching function for connecting the extension in the conventional private exchange using the hook switch off state of the telephone.

As described above, the small trunk line exchange apparatus according to the present invention connects a plurality of telephones without using a conventional private exchange, and detects a hook switch on / off state of the plurality of telephones, according to a circuit switching function and call hold. Since it is designed to perform a function, it is not only advantageous to solve the problem of expansion or replacement of the existing exchange caused by the trunk line and extension, and the increase in cost, and also requires the expert in the initial installation. Unlike the private exchange in the early stage can be easily and conveniently installed at the user level can provide the effect to perform the CO line exchange function.

What has been described above is only one embodiment for implementing the small trunk line exchange device according to the present invention, the present invention is not limited to the above embodiment, but the scope of the invention as claimed in the following claims Without departing from the scope of the present invention, those skilled in the art will have the technical spirit of the present invention to the extent that various modifications can be made.

1 is a layout view of a small trunk line exchange device according to the present invention.

2 is a block diagram of a small trunk line exchange device according to the present invention.

※ Explanation of code about main part of drawing ※

10: public telephone network (PSTN) 20: small trunk line exchange device

211: Micom 212,213,214: Trunk line loop detection circuit

215, 216, 217: ring detector 218, 219, 220: trunk line loop circuit

221, 222, 223: Pending sound transmission unit 224: the matrix

225,226,227,228,229,230: Hook detection circuit 231: Status display part

Claims (1)

N trunk line loop detection circuits 212, 213, and 214 for sensing the use of each of the n trunk lines connected to the public telephone network (PSTN); N ring detectors (215) (216) (217) for detecting a ring signal for each of the n trunk lines coming through the n trunk line detection circuits (212, 213, 214); N trunk line loop circuits (218, 219, 220) forming a trunk line loop between each of the n trunk lines and each of the m called phones; N pending sounds that transmit a call holding tone to a specific caller's telephone through n trunk line loop circuits 218, 219, and 220 connected to the corresponding trunk line in response to the n trunk lines in a one-to-one correspondence with the pending sound transmission signal. Transmitting units 221, 222, and 223; M hook detection circuits (225) (226) (227) (228) (229) (230) for detecting a hookswitch on / off state for each of said m called telephones; A matrix 224 for performing a trunk line switching function between the n trunk lines and the m called phones; And On the result of continuously checking the hook switch on / off states of the n trunk line detection circuits 212, 213, 214, n ring detectors 215, 216, 217, and m called telephones. Accordingly, the hook switch on / off state, call hold state, and ring signal input state of the m callees are displayed on the state display unit 231. When a ring signal is detected, the ring signal is detected by controlling the matrix 224. A call reception loop is formed between the trunk line and the called telephone in the hook-switched off state, and the matrix 224 is controlled by controlling the matrix 224 when the called telephone is in the hook-switched off state without the ring signal being input. A call transmission loop is formed between the called telephone and the unused trunk line. When the hook switch of the called telephone is busy, the hook switch is hooked on and then hooked off again. Sends a holding tone transmission signal to a holding tone transmitting unit 221, 222, 223 corresponding to a trunk line to transmit a call holding tone to a specific trunk line that was in a call, and differs from the specific callee telephone that is in the call during the holding tone transmission. When the called phone is in the hook-switched off state, the matrix 224 controls the matrix 224 to form a call receiving loop between the call line that is on hold and the other called phone that is newly switched off to the call switch to perform a call switching function. Small trunk line exchange device, characterized in that consisting of 211).