JPH0620208B2 - Communication terminal adapter device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a communication terminal adapter connected to an exchange, and particularly to a communication terminal adapter which accommodates a high speed synchronous terminal and has a call control procedure for this terminal. Regarding

[Conventional technology]

Conventionally, this type of communication terminal adapter has the following 2
Kinds of things are known.

Figure 2 shows one of the CCITT (International Telegraph and Telephone Consultative Committee) V25 recommendation line control equipment (NC
The schematic block diagram of U) is shown. In this case, the terminal 11
In addition to the communication data signal interface 13 with the terminal 11, a call control signal line 14 is connected between the communication terminal adapter 12 and the communication terminal adapter 12 to perform call control with the terminal 11. A transmission path interface circuit 15 is connected to a host exchange (not shown).

FIG. 3 shows another conventional line control device. In this case, one communication connection interface 16 is provided between the terminal 11 and the terminal 11, which is configured to execute a call control procedure and data communication.

[Problems to be solved by the invention]

However, the above conventional network control device has the following problems. That is, in the case of the former line control device,
As described above, in connection with the terminal, there is a drawback that an interface connection for call control is required in addition to the data communication interface.

On the other hand, in the case of the latter line control device, call control and data communication can be performed between the terminal and the communication terminal adapter (network control device) only by connecting the data communication interface. However, when the terminal communication speed becomes high, high speed is required to support the call control procedure of the communication terminal adapter. However, generally in circuit-switched communication, when the terminal adapter completes the outgoing / incoming call control and sets up the communication path between the terminal and the network, the transmitted / received data can be handled by the software of the terminal adapter during subsequent calls. Absent. For this reason, there is a drawback or feature that it has nothing to do with communication speed and does not require high speed in software processing.

In view of such drawbacks of the conventional device, the present invention can easily accommodate a high-speed data terminal without unnecessarily increasing the speed of the constituent elements, facilitates communication port control, and further, from an asynchronous terminal to a high-speed synchronous terminal. It is an object of the present invention to provide a communication terminal adapter device capable of accommodating a wide range of terminals.

[Means for solving problems]

In order to achieve the above object, a communication terminal adapter device according to the present invention includes an interface means for communicating with a communication terminal, a means for setting terminal communication attributes such as synchronization, asynchronism, and data rate of the communication terminal, and the terminal communication attribute. It has a CPU for executing the following call control procedure and terminal communication attribute information according to the above-mentioned terminal communication attribute, and at the time of call control of call origination, call reception and disconnection with the communication terminal based on the instruction of the CPU. And a means for switching the data transmission / reception clock speed and a means for switching the data to be sent to the communication terminal at the time of call control of call origination, call termination, and disconnection and at the time of communication with the host exchange. It

According to the present invention, by providing means for setting terminal communication speed information such as synchronous, asynchronous and data speed of the communication terminal, the operation mode of the communication terminal adapter according to the communication speed condition of the connected communication terminal. Can be set.

Further, by providing means for exchanging data with the communication terminal and switching the clock speed according to the operation mode, a call path is established between the communication terminal adapter and the external exchange during call control with the communication terminal. The terminal communication speed can be switched when and when the communication terminal is busy. In other words, by using the communication terminal adapter when the terminal communication speed is faster than a certain value, the communication speed is changed to a low communication speed during call control and a high communication speed during information transfer with the host exchange. You can

〔Example〕

An embodiment of a communication terminal adapter device according to the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic circuit configuration diagram of a communication terminal adapter device showing an embodiment of the present invention.

In the figure, a communication interface 11 mediates exchange of data 12 between a terminal (not shown) and the communication terminal adapter device. Further, the transmission data clock 13 and the reception data clock 14 from the communication terminal adapter device are interrupted from the general asynchronous transmission / reception circuit 19 for synchronous / asynchronous communication and given to a terminal (not shown). The general-purpose transmitter / receiver circuit 19 for synchronous / asynchronous communication is a general-purpose commercially available product, which produces a send / receive clock signal by a built-in baud rate generator by a known technique and outputs a clock signal at a designated speed instructed by the CPU 20. Is. This communication interface 11 is a CCITTV 24 signal line interface and a V28 or V35 electrical interface circuit 16
It is composed of

The man-machine interface circuit 18 synchronizes a terminal (not shown) used by connecting to the communication terminal adapter device.
Set communication attributes such as asynchronous and data rate. This communication attribute information is sent to the general-purpose transceiver circuit 19 for synchronous asynchronous communication, and the general-purpose transceiver circuit 19 for synchronous asynchronous communication
According to this information, the operation mode is selected by the instruction of the CPU 20. A call control procedure with a terminal (not shown) is processed by a program of the CPU 20 via the general-purpose transmitting / receiving circuit 19 for synchronous asynchronous communication.

On the other hand, the call control procedure with the terminal (not shown) includes a call control signal communication processing circuit 22, a transmission line interface circuit 23,
It is converted into a procedure with a host exchange (not shown) through the host interface signal line 24 and processed. The communication data rate conversion circuit 25 uses a known technique to match the communication data rate when a terminal (not shown) communicates with a host exchange (not shown) via the transmission line interface circuit 23 after the call control procedure is established. Used. Further, the reception data selection circuit 21 receives the data to be sent to a terminal (not shown), to the side which receives the call control data from the general-purpose transceiver circuit 19 for synchronous asynchronous communication during the call control operation, and the call control is established. When the processing of the call control data becomes unnecessary via the general-purpose transmitting / receiving circuit 19 for synchronous / asynchronous communication, it is switched to the side which receives the communication data from the host exchange (not shown).

Next, the operation of this embodiment will be described.

When the data communication speed of the connected terminal (not shown) is asynchronous and is low speed (for example, 9.6 kbps), the communication terminal adapter follows the data communication speed of the terminal set by the man-machine interface circuit 18. The operation mode of the general purpose transmission / reception circuit 19 for synchronous / asynchronous communication is set by the CPU 20, and call control data is exchanged at the data rate to set the communication path.

On the other hand, the connected terminal (not shown) is a synchronous terminal, and is configured to perform slave-synchronized communication by a clock (network extraction clock 15, transmission data clock 13, reception data clock 14) synchronized with the network for digital circuit switching. If so, this terminal generally transmits and receives data in synchronization with the transmission and reception clock signals 13 and 14 sent from the communication terminal adapter. In this case, when the communication speed of the synchronous terminal set by the man-machine interface circuit 18 is faster than the communication speed fixedly predetermined by the communication terminal adapter, the CPU 20 synchronizes the call control procedure with the synchronous terminal. When executing via the general-purpose transceiver circuit 19 for asynchronous communication, the transmission / reception clock signals 13 and 14 to the synchronous terminal (not shown) are fixedly fixed by the adapter (set by the man-machine interface circuit 18). The general transmission / reception circuit 19 for synchronous / asynchronous communication is instructed to set the communication speed lower than the communication speed of the synchronous terminal, and the call control procedure is processed. Thereafter, when the mode is changed from the call control to the data communication mode, the general transmission / reception circuit 19 for synchronous / asynchronous communication is instructed to reach the original data communication speed (terminal communication speed) set by the man-machine interface circuit 18. like,
The transmission / reception clock signals 13 and 14 are switched. When the call control process ends and the call is in progress, the communication terminal adapter does not need to process the control data via the general asynchronous transmission / reception circuit 19 for synchronous / asynchronous communication. Switch to data signal reception mode. As a result, the terminal data is simply processed by hardware, that is, the communication data speed conversion circuit 2
The speed is converted by 3 and the data is transmitted / received to / from the host exchange and the other terminal. Further, when the terminal communication speed set by the man-machine interface circuit 18 is lower than the fixed fixed speed of the communication terminal adapter, call control is performed by the terminal data speed set by the man-machine interface circuit 18. The clock operation mode of the general-purpose transmitting / receiving circuit 19 for synchronous / asynchronous communication may be controlled so that it is processed as it is.

As described above, in the call control device according to the present invention, the communication speed during call control is fixed by the communication adapter according to the program processing capabilities of the general-purpose transceiver circuit 19 for synchronous asynchronous communication and the CPU 20 of the communication terminal adapter. Terminals with a wide range of data communication speeds can be accommodated by adapters with limited capacities.

The communication terminal adapter device of the present invention can be used not only in the case of controlling call setting as described above, but also in the case of switching of call control processing during communication of a communication terminal such as recovery processing due to disconnection. Also in that case, the transition to the call control procedure of the switching recovery processing is performed in the same manner as in the above case by changing the reception data selection circuit 21 from the data signal receiving mode from the higher order to the call control processing on the side of the general-purpose transceiver circuit 19 for synchronous asynchronous communication. This is executed by switching to the mode side and further switching the transmission / reception data clock to / from the communication terminal.

〔The invention's effect〕

As described above, the present invention, when supporting a call control procedure with a high-speed data terminal, reduces the communication speed with the terminal at the time of call control, thereby reducing the call control circuit and CPU of the communication terminal adapter. It is possible to easily accommodate a high-speed data terminal without unnecessarily increasing the processing speed. Further, in the communication terminal as well, there is an advantage that the call control procedure can be processed at a low speed, and the communication port control can be easily performed.

The communication terminal adapter device of the present invention has the effect of enabling accommodation of a wide range of communication terminals from asynchronous terminals to high-speed synchronous terminals.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of a communication terminal adapter device according to the present invention, and FIGS. 2 and 3 are schematic diagrams showing terminal connections of conventional communication line control devices (automatic call origination and call termination devices), respectively. It is a block diagram. 11 ... Communication interface, 18 ... Man-machine interface circuit, 19 ... General-purpose transceiver circuit for synchronous / asynchronous communication, 21 ... Received data selection circuit.

Claims (1)

[Claims] 1. An interface unit with a communication terminal, a unit for setting terminal communication attributes such as synchronization, asynchronousness, and data rate of the communication terminal, and a CPU for executing a call control procedure according to the terminal communication attribute.
And means for switching terminal clock speed of data transmission / reception during call control, call reception, and disconnection call control with the communication terminal based on the instruction of the CPU, having terminal communication attribute information according to the terminal communication attribute. A communication terminal adapter device comprising: means for switching data to be sent to the communication terminal between call control for call origination, call reception, and disconnection and communication with a host exchange.