JP2654024B2 - Digital key telephone equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a digital key telephone apparatus or a simple telephone exchange (hereinafter simply referred to as a digital key telephone apparatus).
More particularly, the present invention relates to a digital key telephone apparatus in which the number of extensions is expanded by connecting a plurality of main units between systems.

(Prior Art) The extension system of the digital key telephone apparatus is roughly classified into a system called a building block system and a system in which a plurality of main units are connected between systems by a small number of communication paths. The former method is a method in which an extension-dedicated module called an extension frame is stacked on a main device called a basic frame like a block to extend the number of extensions of the main device itself.

In the latter case, for example, by interconnecting a plurality of main units that are installed at a distance of about 300 meters using some of the lines, it is possible to make internal calls between the two frames and receive calls from external lines. The present invention relates to a digital key telephone apparatus suitable for the latter method, in which a simple function such as transfer can be performed.

A conventional configuration of this type of telephone main unit will be described with reference to FIG. There are two digital key telephone main units 31a, 31b installed hundreds of meters apart, their analog office line interface units 32a, 32b have analog office lines 33a, 33b, and an analog standard telephone interface unit 34a. , 34b with one or more standard telephones 35a, 3
5b is connected. Further, the two main devices 31a, 31b
Are connected by lines 36a and 36b in such a manner that one of the analog office line interface units and the local analog standard telephone interface unit are connected to each other.

The operation of the digital key telephone apparatus thus connected between the systems will be briefly described by taking as an example a case where an incoming call from a central office in the main apparatus 31a is transferred to the telephone set 35b connected to the main apparatus 31b. An incoming call from the office line 33a causes a ringtone of the telephone 35a to sound. When the handset of the telephone set 35a is raised, a communication path is formed between the office line 33a and the telephone set 35a, and a call can be made between the two. Here, when transferring the office line to another main unit 31b, the telephone 35a is hooked, for example, and a special number (for example, "7") of the partner main unit 31b is input. Then, the office line 33a is temporarily put on hold, and the telephone 35a
Is connected to the other party's main device 31b via the line 36b, and the dial tone is heard. In this state, the destination phone
Dial the extension number 35b and end the call to get the office line 3.
A communication path is formed between 3a and the transfer destination telephone 35b via the line 36b, and a call between the two can be made. In addition, the inter-extension communication between the systems can be realized by the procedure after the hooking described above.

(Problems to be Solved by the Invention) In the above-described conventional digital key telephone apparatus, voice is converted into digital data and transmitted / received through a time-division multiplexed communication path in the main apparatus. Since the external line network and telephone are for analog use, they are connected via analog interfaces 32 and 34, and connection between systems is also performed via this analog interface. Therefore, when a non-telephone type terminal (for example, a data device) is provided, it is necessary to provide a modulation / demodulation device in order to realize inter-system extension communication between the non-telephone type terminals.

In addition, since the main devices are connected to each other by the crossing method as described above, there is also a problem that the number of wirings is increased when many main devices are connected.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a digital key telephone apparatus which does not require a modem for a non-telephone system terminal and can connect a large number of main apparatuses with a small number of wires.

[Configuration of the invention]

(Means for Solving the Problems) The present invention relates to a circuit for converting digital voice data in a time-division communication path, a circuit for transmitting and receiving the voice data to and from a terminal, and a digital control data control circuit for controlling these circuits. A master main unit and a plurality of units each having a digital interface circuit for transmitting the control data and the voice data as digital codes to another main unit and receiving from the other main unit. Are connected via the digital interface circuit, and the digital interface circuit of the master main device transmits the control data and the audio data by designating the address of the slave main device of the transmission destination. And the digital interface circuit of the slave main unit is connected to the master main unit. A digital key telephone apparatus which receives the control data and the voice data only when an address of the own apparatus is specified, and performs transmission from the slave main apparatus to the master main apparatus without specifying an address. It is.

(Operation) According to the above configuration, the transmission and reception of voice and control data between the master main unit and the slave main unit are performed as digital data via the digital interface circuit. Therefore, the inter-system communication between the non-telephone terminals can be performed without the intermediary of the modem. Also, since the master main unit transmits voice and control data by designating the address of the slave main unit, and the slave main unit receives data only when its own address is specified, a plurality of units can be assigned to one master main unit. Of slave main units can be connected in a multipoint manner. Therefore, even when a large number of main devices are connected, only a small number of wires are required.

Hereinafter, the present invention will be described with reference to examples.

FIG. 2 is a connection diagram between systems in a preferred embodiment of the digital key telephone apparatus according to the present invention.

As shown in FIG. 2, a plurality of, for example, seven slave main units 2a to 2g are provided in one master device 1 and a full-duplex serial communication line including a highway 3 between downstream systems and a highway 4 between upstream systems. Multi-point connection through.

The master main unit 1 transmits downstream data to the downstream inter-system highway 3 and receives upstream data from the upstream inter-system highway 4. Conversely, slave main units 2a to 2g receive downlink data and transmit uplink data.

FIG. 1 is a block diagram showing the configuration of the main device of this embodiment. In the master main unit 1, time slot conversion of voice data of a speech highway 11, a data highway 12 for transmitting digital control data, and a speech highway 12, which is a time-division communication path of digital voice data (8-bit PCM code). Time switch 1 to exchange by
3.Transmit data to and from the slave main units 2a to 2g via the inter-system highways 3 and 4, and communicate with the other units in the main unit by the speech highway 11 and the data highway 12.
Inter-system connection interface unit 14 for transmitting and receiving data via the central processing unit for transmitting and receiving digital control data to and from other units in the main unit
15. A master sub-processor 16 for controlling transmission and reception of control data of the central processing unit 15 is provided. Further, although not shown, various interface units for connecting office lines and various terminals are also provided, and these are also connected to other units via the speech highway 11 and the data highway 12.

In the inter-system connection interface unit 14, a slave sub-processor 17, which is selected by a slave selection address from the master sub-processor 16 and transmits / receives control data to / from the master sub-processor 16, is described below. A common memory 18 for temporarily storing control data transmitted and received between the microprocessors 20 and 8 bits of audio data (8-bit PCM code) on a specified time slot of the speech highway 11 under the control of the microprocessor 20. A time switch 19 for transmitting to the data bus and receiving the voice data from the time switch 19, reading out the control data in the common memory 18 and constructing it in the format shown in FIG. And send it serially to the inter-system highway, and vice versa. Microprocessor 20 is provided to perform. The microprocessor 20
Input the frame synchronization signal on speech highway 11 to its interrupt terminal INT,
The timing of reading the audio data from the speech highway 11 via 19 is synchronized with the time slot position of the speech highway 11.

The configuration of the slave main units 2a to 2g is the same as that of the master main unit 1 described above. However, since the format of data transmitted and received between the systems is slightly different from that of the master main unit as described later, the programs of the microprocessor 30 of the inter-system connection interface unit 24 and the like are different accordingly.

FIG. 3 shows a format of data transmitted on the highways 3 and 4 between the systems.

The system of data transmission between the systems is a full-duplex serial transmission system and an asynchronous system in which each data (8 bits) is transmitted in 11-bit burst units. In this transmission method, the length of one frame is 125 μsec, which is the same as one frame of time-division multiplex transmission of audio data in the main unit, so that data is not lost or transmitted twice.
Transmission speed is 64Kb / s (= 8kHz) for audio data (8bit)
× 8 bits), and two channels are provided for audio data and one channel for control data (however,
In the case of downlink data, as will be described later, since control data can be transmitted at the same time as address designation at the time of transmission of each audio data, the control data is substantially three channels.)

Each burst has a start bit F (1 bit), data (8 bits), an address /
It is composed of a total of 11 bits of a data select bit A / D (1 bit) and a stop bit S (1 bit). The address / data select bits A / D identify whether the burst transmits audio data B (hereinafter referred to as audio data burst) or transmits the selected address A of the slave main unit (hereinafter referred to as address burst). Is a bit to be done. In the case of the audio data burst, all 8 bits of the data are allocated to the audio data B. On the other hand, in the case of an address burst, FIG. 3 (a) (in this figure, a start bit, an address / data select bit,
The stop bit is omitted in the figure).
Only some of the bits are assigned to address A, and the remaining bits are assigned to control data D.
In this embodiment, three bits in the first stage are assigned to addresses A of the seven slave main units, and the remaining five bits are assigned to the control data D.
Assigned to. Note that this address burst configuration is applied only to downlink data from the master main unit to the slave main unit. In the case of data from the slave main unit to the master main unit, the transmission destination is determined to be the master main unit and the address is determined. Since there is no need to specify, 3 in FIG. 3 (b)
As in the third burst (the start bit and the like are not shown), the data in the burst is composed of only the control data D.

When the microprocessor 20 of the master main unit 1 outputs data to the downstream inter-system highway 3, the operation is performed after addressing the slave main unit which is the transmission destination.
That is, as shown in FIG. 3A, when transmitting voice data, an address burst is transmitted first, and then a voice data burst is transmitted. When transmitting control data, only the address burst is output because the control data D is incorporated in the address burst as described above.

The microprocessor 30 of each of the slave main units 2a to 2g receives the burst sent from the master main unit 1 and identifies whether the burst is an address burst or a voice data burst from the address / data select bits A / D. .
If it is an address burst, the preceding stage 3 of the data
The address A of the bit is read and compared with the address of its own device, which is registered in advance as operation / maintenance data at the time of installation. As a result, only the slave main unit having the matching address receives the subsequent 5-bit control data D, and
If the subsequently transmitted burst is a voice data burst, the voice data B is received, and the upstream data is transmitted to the master main unit 1 as shown in FIG. 3 (b). On the other hand, the other slave main units whose addresses do not match are in a standby state, and do not receive or transmit until the reception of the next address burst.

Next, the operation of the digital key telephone apparatus according to the present invention configured as described above will be described in the case where an extension intercommunication is performed between a terminal connected to the extension of the master main apparatus and a terminal connected to the extension of the slave main apparatus. Will be described as an example.

FIG. 4 is a sequence chart of the audio data in such a case, and shows how the audio data is transmitted between the main units. Since the procedure for transmitting voice data from the terminal to the downstream speech highway via the upstream speech highway and the time switch in the main device is well known, the description thereof is omitted here.

Audio data B ₁ (on one time slot) carried on speech highway (down) 11 in master main unit 1
Is read out to the data bus by the time switch 19 and received by the microprocessor 20. Reading by the microprocessor 20 is performed by designating a highway number and a time slot address from the microprocessor 20 to the time switch 19. The timing of this reading is determined by inputting the frame synchronization signal on the speech highway 11 to the interrupt terminal INT of the microprocessor 20 as described above, and every time this frame synchronization signal is input, the microprocessor 20 Read audio data. Thus reading the audio data B _1, microprocessor 20 sends the address burst that indicates the first destination in the downstream system between highway 3, followed by sending a burst of the audio data B _1.

Destination serving slave main device (here, a slave main device 2a) Because operating in its own frame synchronization timing different from the master main unit 1, the microprocessor 30 completes receiving the audio data B ₁ after, in synchronism with the interrupt signal from the speech highway 21, and transmits the audio data B ₁ via the time switch 29 to time slot which is determined on the speech highway 21. Audio data B ₁ which is placed on the speech highway 21 thus is transmitted to the terminal specified are replaced by the time switch 23.

On the other hand, as for the control data, when a special number for selecting the slave main unit 2a is input from a terminal connected to the master main unit 1, and then the extension selection number of the slave main unit 2a is input, the master main unit 1 The central processing unit 15 decodes the data and outputs control data D indicating the incoming call from the master sub-processor 16 to the slave sub-processor 17 via the data highway 12. This control data D is written into the common memory 18 and is
20 reads from the common memory 18 and puts the address of the selected slave main unit 2a into the three bits preceding the data 8 bits, puts the control data D into the remaining 5 bits, and sends it out to the downstream inter-system highway 3.

The microprocessor 30 of the slave main unit 2a receives the control data D with the address of the slave main unit 2a and writes the control data D into the common memory 28. This is read by the slave sub-processor 27 and sent to the central processing unit 25 via the data highway 22 and the master sub-processor 26. This is decoded by the central processing unit 25 and an incoming call operation to the selected terminal is performed.

Conversely, the procedure for transmitting audio data and control data from the slave main unit to the master main unit is also substantially the same as described above, and a description thereof will be omitted.

〔The invention's effect〕

As described above, according to the present invention, since voice and control data are transmitted and received between systems via the digital interface circuit, communication between systems of non-telephone terminals can be easily performed without using a modem. Can be realized. Furthermore, since the systems can be connected at a multipoint via the interface, there is an advantage that the number of wirings can be reduced even when a plurality of main devices are connected.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a digital key telephone apparatus according to the present invention, FIG. 2 is a connection diagram between systems of the embodiment of FIG. 1, and FIG. 3 is a system in the embodiment of FIG. FIG. 4 is a sequence diagram of data transmission in the embodiment of FIG. 1, and FIG. 5 is a connection diagram between systems of a conventional digital key telephone apparatus. 1 Master master device 2 Slave master device 3,4 Highway between systems 11,21 Speech highway 12,22 Data highway 13,23,19,29
Time switch, 14,24 ... Inter-system connection interface unit, 15,25 ... Central processing unit, 16,26 ... Master sub-processor, 17,27 ... Slave sub-processor, 18,28 ... Common memory , 20,30 …… Microprocessor.

 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-56-87970 (JP, A) JP-A-62-78993 (JP, A) JP-A-62-122354 (JP, A)

Claims (1)

(57) [Claims] A circuit for exchanging digital voice data in a time-division communication path; a circuit for transmitting and receiving said voice data to and from a terminal; a circuit for controlling these circuits based on digital control data; A master interface and a plurality of slave interfaces each provided with a digital interface circuit for transmitting the voice data as a digital code to another main unit and receiving from the other main unit. A digital interface circuit of the master main unit transmits the control data and the audio data by designating an address of a slave main unit of a transmission destination, and a digital interface circuit of the slave main unit. The circuit has its own address specified by the master main unit. The control data and performs reception of the voice data, transmitted from the slave main device to the master main unit digital key telephone system for performing without addressing only if.