JPH03268694A - Private branch exchange - Google Patents

Abstract

PURPOSE:To obtain a non-ringing function with a simple operation by applying polarity inversion control to a caller subscriber circuit and a called subscriber circuit. CONSTITUTION:In the case of a non-ringing incoming call, when a polarity inversion signal is sent to a called subscriber B, a terminal side network control unit 4 reaches a half-conduction state and a subscriber circuit 32 does not detect a reply. A central control unit 35 sends a polarity inversion signal to the subscriber B and sends the polarity inversion signal to the caller subscriber A as a pseudo reply signal. A central side network control unit 2 sends a terminal selection signal and the control unit 4 sends a terminal reply signal. Thus, the control unit 2 requests the collection of a metering data to the central unit 1 and data communication is implemented between the unit 1 and the terminal equipment 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for non-ringing connections in private telephone exchanges.

[Conventional technology]

A private branch exchange with a traditional non-ringing connection is
As described in Japanese Patent Application Laid-Open No. 61-4394, a first special trunk and a second special trunk are provided in the exchange, and non-ringing connection processing is performed by dialing a specific number to indicate a non-ringing connection. Ta.

[Problems to be Solved by the Invention] The above-mentioned conventional technology requires a specific dial to identify a non-ringing connection, which complicates operation, and requires a first trunk for controlling a non-ringing connection. It also requires a second trunk, which is disadvantageous in terms of size and economy.

The present invention does not require the above-mentioned specific dial, the above-mentioned first trunk, and the above-mentioned second trunk, and with a simple operation,
The objective is to provide an economical non-ringing function.

[Means to solve the problem]

The present invention provides a private telephone exchange equipped with a call path switch that selectively connects a large number of subscriber lines, which does not have a dedicated trunk or the like, and which uses only polarity reversal control of the calling subscriber circuit and the called subscriber circuit. , is characterized in that the calling connection of the called subscriber's line is performed without sending out a calling signal current.

[Effect]

The private branch telephone exchange of the present invention does not require equipment such as dedicated trunks for non-ringing connections, and can realize the non-ringing function by specific control of subscriber circuits provided in general private branch telephone exchanges. .

〔Example〕

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

FIG. 1 is a block diagram of a private telephone exchange and a device for collecting data such as meter readings connected to the exchange, showing an embodiment of the present invention.

The solid device 1 is connected to the medium practical network control device 2 . The medium-utility network control device 2 is connected to the exchange 3 through a transmission line 101. In addition, the solid device 1 and the medium practical network control device 2 are as follows.
Configure the central device.

The exchange 3 has a subscriber circuit (LIF) 31 . A subscriber circuit (LIF) 32 connected to the terminal network control device 4. A communication path switch (SN) 33 that connects the above subscriber circuits, a central control unit (CC) 35 that performs switching processing, and a tone trunk (TNT)
It is composed of 34 pieces.

The exchange 3 connects the terminal network control device 4 through the transmission path 102.
connected to. A terminal network control device 4 is connected to a telephone 5 and a terminal device 6. Note that the terminal network control device 4, the telephone 5, and the terminal device 6 constitute a terminal side device.

The solid device 1 controls the medium-sized practical network control device 2 and processes collected data such as meter reading. The medium-utility network control device 2 transmits dial information, transmits and receives various control signals for non-ringing connections, and modulates and demodulates data communications.

The hardware configuration of the subscriber circuit 31 connected to the utility network control device 2 of the exchange 3 and the subscriber circuit 32 connected to the terminal network control device 4 is a normal subscriber circuit with a built-in polarity inversion circuit. is the same as The subscriber circuit 31 becomes the calling side, and the subscriber circuit 32 becomes the called side and performs a non-ringing connection.

The medium-sized practical network control device 2 has functions of automatic dialing and automatic transmission based on commands from the solid-state device 1, and the terminal network control device 4 has a function of automatically responding to non-ringing incoming calls.

Next, the characteristics of the operation of the private branch exchange according to the embodiment of the present invention will be explained.

FIG. 2 is an explanatory diagram showing the operation of the private branch exchange according to the embodiment of the present invention, and FIG. 3 is a signal sequence diagram of this operation.

In FIG. 2, subscriber A represents a central device, and subscriber B represents a terminal device.

In the state shown in FIG. 2(1), subscriber A and subscriber B are both on-hook, that is, in an idle state.

In the state shown in FIG. 2(2), subscriber A is off-hook, and the central controller 35 detects the call made by subscriber A.

When the solid equipment 1 starts meter reading (subscriber A makes a call), it activates the medium practical network control device 2, and from this point on, the medium practical network control device 2 forms a DC loop with the subscriber circuit 31 of the exchange 3. , the subscriber circuit 32 detects the DC loop and connects the medium utility network control device 2 and the tone rung 34;
400Hzl 20 INT for medium utility network control equipment
The dial tone DT is sent.

The state shown in FIG. 2(3) is a state in which subscriber A dials subscriber B's telephone number and is calling subscriber B.

In this case, ring bag tone RBT is sent to subscriber A.
(400Hz/16Hz, 1 second connection, 2 seconds disconnection), and a calling signal REV is being sent to the subscriber. At this time, the calling signal for the subscriber is generated by inverting the polarity from the subscriber circuit 32 without sending out a 16 Hz calling signal current.

In the present invention, as a calling signal for subscriber B, 1
The connection class of the calling subscriber A determines whether a 6 Hz ringing signal current is sent or whether only polarity reversal, ie non-ringing, is received. Normally, subscriber A is registered as a non-ringing connection class in the central control unit 35 as subscriber data, so that when subscriber A makes a call, the call is received as a non-ringing call to all called parties. It is set. When a call is made from someone other than subscriber A,
A call arrives at the called party with a 16 Hz ringing signal current.

In the case of a non-ringing incoming call, when a ringing signal, that is, a polarity inversion signal is sent to the called subscriber B, the terminal-side network control device 4 enters a semi-conducting state (DC resistance 4 is Ω or more), and in the semi-conducting state, , subscriber circuit 32 detects no response. Since the central control unit 35 cannot identify the response of the called subscriber B, the central control unit 35 sends the polarity inversion signal to the calling subscriber A as a pseudo-response signal at a timing of approximately 1 second after sending the polarity inversion signal to the subscriber B. Sends out an inverted signal REV2. This state is shown in FIG. 2 (4).

In the state shown in FIG. 2 (4), a polarity inversion signal (pseudo response signal) REV2 is sent to subscriber A, a polarity inversion signal (calling signal) REVI is sent to subscriber A, and subscriber A and subscriber B is closed by the communication path switch 33, indicating that communication is in progress.

Upon receiving the polarity inversion signal REV2, the central network control device 2 outputs the terminal selection signal NR3 (PB double signal "O" to "9").
Upon receiving the above-mentioned NR3, the terminal side network control device 4 sends out a terminal response signal ANS (PB double signal #'').

By receiving the terminal response signal ANS, the central network control device 2 learns that the terminal device has responded, requests the solid device 1 to collect meter reading data, and communicates between the solid device 1 and the terminal. Data communication is performed using the device 5.

In the state shown in FIG. 2 (5), when the meter reading is completed, the intermediate utility network control device disconnects the DC loop, disconnects the polarity reversal signals REVI and REV2 of the subscriber circuits 31 and 32, and thereby disconnects the communication path switch 33. , indicating that it is empty again.

The state shown in Fig. 2 (6) changes from the data communication raw state shown in Fig. 2 (4) to the central side because the telephone 5 of the terminal side device detects ○FFH○OKL and the subscriber circuit 32 detects a DC loop. The communication path between the device and the terminal side device is cut off, and the middle practical network control device 2 is listening to a busy tone (BT) and the telephone 5 of the terminal side device is listening to a dial tone.

That is, if the telephone is set to FFHOOK on the terminal side during meter reading, the meter reading is immediately interrupted and telephone calls are prioritized, and the present invention also has the above-mentioned function that has been used in the past.

[Effects of the Invention] According to the present invention, the non-ringing connection can be achieved simply by controlling the polarity reversal of the subscriber circuit provided in a general private branch telephone exchange, without the need for special equipment such as a special trunk for non-ringing connection. can. Therefore, it has the effect of realizing an automatic meter reading service at a lower cost.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a private branch telephone exchange according to an embodiment of the present invention and a device connected to the private branch telephone exchange for collecting data such as meter reading. FIG. 2 is an explanatory diagram showing the operation. FIG. 3 is a signal sequence diagram. 1...Solid equipment 2...Medium practical network control device 3...Private telephone exchange 4...Terminal network control device 5...Telephone 6...Terminal device 31... Calling subscriber circuit 32...Called subscriber circuit 33...Call path switch 35...Central control unit

Claims (1)

[Claims] 1. In a private telephone exchange equipped with a call path switch that selectively connects a large number of subscriber lines, it does not have a dedicated trunk, etc., and only controls the polarity reversal of the calling subscriber circuit and the called subscriber circuit. A private telephone exchange characterized in that a calling subscriber line is connected to a calling subscriber line without sending out a calling signal current.