JPH04150327A - Order wire device - Google Patents

Abstract

PURPOSE:To attain talking with other station even when communication is established between two stations in a system by dividing usual transmission signal into three ADPCM signals for voice signal transmission and ensuring the communication for the three systems. CONSTITUTION:A voice band signal sent from a telephone set 12 is converted into a 64kbit/sec at a telephone set circuit 11 and fed to a selection circuit 14. The PCM signal is sent to any of adder circuits 16-18 by the control of a control circuit 15. The circuits 16-18 linearly add the PCM signal outputted from relevant ADPCM composite circuits 19-21 and the PCM signal from the selection circuit 14 and ADPCM coder circuits 28-30 convert the sum into ADPCM signals of 64, 16, 24kbit/sec respectively and they are fed to a multiplexer circuit 26. The circuit 26 generates a prescribed data signal of 64kbit/sec and sends it via a synchronization circuit 27. Discrimination circuits 22-24 discriminate the presence of the voice signal from the circuit 11 to control the circuit 14 via the circuit 15. Thus, communication for three systems is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an order wire device that connects a plurality of terminal devices and relay devices in tandem to transmit information.

[Conventional technology]

Order wire devices are used, for example, to communicate between terminal stations during on-site coordination test work.

FIG. 3 is a block diagram showing the configuration of a data transmission system in which a plurality of terminal devices and relay devices are connected in multiple stages.

In this system, relay devices 53 to 53 are connected between terminal stations 51 and 52.
56 are arranged.

Each terminal device 51, 52 is connected to a data transmission device 57 for transmitting data and an order wire device 58 for transmitting voice for telephone calls. For example, a facsimile machine 59 is connected to the data transmission device 57. Although not shown, a test telephone, for example, is connected to the order wire device 58. Also, the order wire device 58
Although not shown, for example, a test telephone is connected to the terminal. A data transmission device 57 to which a facsimile device 59 or the like is connected is connected to the relay devices 53 and 55, and an order wire device 58 is connected to the other relay devices 54 and 56.

In such a system, service data channels 61 to 63 are connected between terminal devices 51 and 52 and relay devices 53 to 56.
was assigned.

FIG. 4 shows the frame structure of data signals input and output from the order wire device of this conventional system. As shown in this figure, the PCM encoded data signal constitutes a multi-frame 76 in which frames 75 consisting of transmission signals 71 to 74 each having 8 bits as a unit are repeated.

One bit at the end of one frame is a synchronization bit pattern 77, which is used for frame synchronization.

[Problem to be solved by the invention]

In the conventional system described above, the service data channel for calls from the order wire device 58 is one channel, so when a call is established between two stations in the system, '' means that the line is connected between the two stations. It has been monopolized,
There was a drawback that other stations could not make calls.

SUMMARY OF THE INVENTION An object of the present invention is to provide an order wire device that allows a call to be made to another station even if a call is established between two stations within the system.

[Means to solve the problem]

The order wire device of the present invention is an order wire device that transmits information by connecting a plurality of terminal devices or relay devices in multiple stages, and in which a 64 kilobit/second transmission is transmitted as a service data channel from the terminal device or relay device. A synchronization circuit synchronizes the signals, and the output of the synchronization circuit is connected to two 24 kbit/s ADPCM signals and one
A separation circuit that separates the ADPCM signal of 6 kilobits/second, a plurality of ADPCM decoding circuits that convert the output separated by the separation circuit into PCM, and linear addition of the output of the ADPCM decoding circuit and the output of the selection circuit. a plurality of adder circuits, a plurality of ADPCM code circuits that convert the outputs of the adder circuits into ADPCM signals, and a multiplexer that multiplexes the output of the ADPCM code circuits into the 64 kilobit/second transmission signal and sends it to the synchronous circuit. a determination circuit that determines the presence or absence of an audio signal from the output of the ADPCM decoding circuit and the presence or absence of a DTMF signal assigned to the local station; and a determination circuit that is connected to a telephone and converts the audio input signal into a PCM signal and generates a call request signal. a telephone circuit that sends out a signal to a control circuit; and a control signal output from the control circuit that allocates the output of the telephone circuit to one of the inputs of the plurality of adder circuits and one of the outputs of the plurality of ADPCM decoding circuits. the selection circuit that allocates one of them to the input of the telephone circuit, and the control circuit that generates a selection control signal for controlling the selection circuit from the determination result of the determination circuit and the call request signal from the telephone circuit. It consists of

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of an order wire device showing an embodiment of the present invention.

This order wire device includes a synchronization circuit 27 that synchronizes a 64 kilobit/second transmission signal that arrives at the input/output terminal 13 from a terminal device or relay device, and a separation circuit 25 that separates this synchronization output into three ADPCM signals. , an ADPCM decoding circuit 19 that converts the three separated outputs into PCM signals.
, 20, 21, and determination circuits 22, 23, and 24 that constantly monitor the output of the ADPCM decoding circuit and determine the presence or absence of an audio signal and a DTMF signal of its own station, which are connected to the telephone 12 and convert the audio signal into a PCM signal. A telephone circuit 11 converts a PCM signal into a voice signal, a control circuit 15 receives a call request to the telephone 12 and the judgment output of the judgment circuit 22, 23, 24, and generates a control signal for the selection circuit. A.D.
A selection circuit 14 that selects one of the outputs of the PCM decoding circuits 19, 20. Adding circuits 16, 17, and 18 linearly add the signal and the output of the ADPCM decoding circuit, and an AD converting the code of the output of the adding circuit into an ADPCM signal.
It is composed of PCM code circuits 28, 29, and 30, and a multiplex circuit 26 that multiplexes the output of the ADPCM code circuit into a 64 kilobit transmission signal and sends it to the synchronization circuit.

Telephone circuit 11 is connected to telephone 12 and transmits and receives voice band signals. The voice band signal sent from the telephone 12 is converted into a PCM signal of 64 bits/second by the telephone circuit 11 and is supplied to the selection circuit 14 . This PCM signal is sent to a first addition circuit 16, a second addition circuit 17, or a third addition circuit 18 under the control of a control circuit 15, which will be described later.

In the first addition circuit 16, the first ADPCM decoding circuit 1
9 and the PCM signal supplied from the selection circuit 14 to the first addition circuit 16 are linearly added, and this is supplied to the first ADPCM code circuit 28. 1st A
The DPCM code circuit 28 converts the code into a 2-bit (16 bits/second) first ADPCM signal and supplies it to the multiplex circuit 26.

Further, in the determination circuit 22, the first ADPCM decoding circuit 1
The PCM signal outputted by the station 9 is input, and it is determined whether or not there is an audio signal therein, and whether or not there is a DTMF signal assigned to the own station, and the results are output to the control circuit 15, which will be described later.

Further, the second addition circuit 17 linearly adds the PCM signal output from the second ADPCM decoding circuit 20 and the PCM signal supplied from the selection circuit 14 to the second addition circuit 17,
This is supplied to the second ADPCM code circuit 29. Second
The ADPCM encoding circuit 29 converts this into a 3-bit (24 bits/second) second AI) PCM signal and supplies it to the multiplexing circuit 26.

Further, in the determination circuit 23, the second ADPCM decoding circuit 2
0 is input, it is determined whether or not there is an audio signal therein, and whether or not there is a DTMF signal assigned to the own station, and the results are output to a control circuit 15, which will be described later.

Similarly, the third adder circuit 18 uses the PCM signal output from the third ADPCM decoding circuit 21 and the third ADPCM signal from the selection circuit 14.
The PCM signals supplied to the adder circuit 18 are linearly added, and this is supplied to the third ADPCM code circuit 30. The third ADPCM code circuit 30 converts this into 3 bits (24
bits per second) into a third ADPCM signal;
A multiplex circuit 26 is supplied.

The determination circuit 24 inputs the PCM signal output from the third ADPCM decoding circuit 21 and determines whether or not there is an audio signal therein and whether or not there is a DTMF signal assigned to the local station. The signal is output to a control circuit 15, which will be described later.

The control circuit 15 will now be explained.

The control circuit 15 receives the call request signal output from the telephone circuit 11 and the determination circuits 22, 23 . Based on the determination results from and 24, the output of the telephone circuit 11 is added to the addition circuit 16.17.
．． and one of the inputs to 18, and
ADPCM decoding circuit 19.2 for audio signals from the other party
One of the outputs 0 and 21 is sent to the telephone circuit 11.
The selection circuit 14 is controlled to allocate the input to the input.

FIG. 2 shows the frame structure of the data signal created by the multiplexing circuit 26. As shown in FIG.

As shown in FIG. 2, this data signal constitutes a multi-frame 30 similar to the conventional data signal shown in FIG.
The first ADPCM signals 32 to 35 have a bit configuration, the second ADPCM signals 36 to 39 have a 3-bit configuration, the third ADPCM signals 40 to 42 have a 3-bit configuration, and 2 bits A
The configuration is such that the DPCM signal 43 and the synchronization bit 44 are alternately allocated. By the way, the third and final ADPC
Although the M signal 43 is originally a 3-bit signal, it becomes a 2-bit structure in the transmission path. That is, this data signal created by the multiplexing circuit 26 is supplied to the synchronization circuit 27, and the synchronization circuit 27 converts the last 32nd bit of data of one frame into the synchronization bit 44 as shown in FIG. Replace.

This data signal is then sent to the service data channel as a 64 bit/second signal.

On the other hand, the transmission signal of 64 bits/second sent from the service data channel is input to the synchronization circuit 27, where a timing signal (synchronization bit) is extracted and synchronization is performed. The synchronized signal is supplied to a separation circuit 25, where it is separated into three ADPCM signals. Of these, the first ADPCM signal is supplied to the first ADPCM decoding circuit 19, where it is decoded into a PCM signal. This decoded first PCM signal is supplied to the determination circuit 22, the selection circuit 14, and the first addition circuit 16.

The second ADPCM signal is sent to the second ADPCM decoding circuit 20.
, where it is decoded into a PCM signal. This decoded second PCM signal is supplied to the determination circuit 23, the selection circuit 14, and the second addition circuit 17. Third A
The DPCM signal is supplied to the third ADPCM decoding circuit 21, where it is decoded into a PCM signal. This decoded third PCM signal is supplied to the determination circuit 24, the selection circuit 14, and the third addition circuit 18.

One of the ADPCM decoding circuit outputs supplied to the selection circuit 14 is selected by a control signal generated by the control circuit 15 according to the judgment result of each judgment circuit, and the output is sent to the telephone circuit 11.
is connected to the telephone 12 via.

A control circuit 15 that controls the selection operation of the selection circuit 14 selects the current ADPCM signal so that when a call route is established, the call route is not cut off until the call ends. The circuit 14 is controlled. Further, when a new call request is made, the signal separated by the separation circuit 25 is monitored by the determination circuit, and control is performed so that an ADPCM signal for which a call route has not been established is selected.

This allows up to three groups to make calls.

As explained above, the conventionally used 64 kilobit/second transmission signal is converted into an ADP for audio signal transmission.
M (Adaptive Differential
Pulse CodeModulaHon) signals are divided into three to ensure three lines of communication.

〔Effect of the invention〕

As explained above, in the present invention, since the voice signal is multiplexed and transmitted using ADPCM decoding at 24 bits/second and 16 bits/second, two other stations in the system are already communicating. Even if a call is established, a new call can be made, and there is an advantage that calls are prevented from being blocked.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an order wire device showing an embodiment of the present invention, FIG. 2 is a diagram showing the frame structure of a signal output from the synchronization circuit of this order wire device, and FIG. 3 is a diagram showing a conventional order wire device. FIG. 4 is a block diagram showing the configuration of this conventional system. FIG. 4 is a diagram showing the frame structure of a signal used in this conventional system. 11...Telephone circuit, 12...Telephone, 13...
Input/output signal terminal, 14... Selection circuit, 15... Control circuit, 16... First addition circuit, 17... Second addition circuit, 18... Third addition circuit, 19 ...First ADPCM decoding circuit, 20... Second ADPCM decoding circuit, 21... Third ADPCM decoding circuit, 22...
-First judgment circuit, 23...Second judgment circuit, 24.
...Third determination circuit, 25... Separation circuit, 26...
Multiplex circuit, 27... synchronous circuit.

Claims (1)

[Claims] In an order wire device that transmits information by connecting a plurality of terminal devices or relay devices in multiple stages, a synchronization circuit synchronizes a 64 kilobit/second transmission signal transmitted as a service data channel from the terminal device or relay device. and the output of the synchronous circuit is divided into two 24-kilobyt/
seconds ADPCM signal and 16 kbit/s ADPCM
a separation circuit that separates the signal into a signal; a plurality of ADPCM decoding circuits that convert the output separated by the separation circuit into PCM;
A plurality of adder circuits perform linear addition of the output of the DPCM decoding circuit and the output of the selection circuit, and the output of the adder circuit is added to the ADPC.
A plurality of ADPCM encoding circuits that convert the code into M signals, a multiplexing circuit that multiplexes the output of the ADPCM encoding circuit into the 64 kilobit/second transmission signal and sends it to the synchronous circuit, and an audio signal from the output of the ADPCM decoding circuit. a determination circuit that determines the presence or absence of a DTMF signal assigned to the own station, a telephone circuit connected to the telephone that converts the voice input signal into a PCM signal, and sends a call request signal to the control circuit; and a control circuit. Allocates the output of the telephone circuit to one of the inputs of the plurality of adder circuits according to a control signal output from the plurality of ADPCs.
the selection circuit that allocates one of the outputs of the M decoding circuit to the input of the telephone circuit; and the selection control that controls the selection circuit based on the determination result of the determination circuit and the call request signal from the telephone circuit. An order wire device comprising: the control circuit that generates a signal.