JP2537659B2 - Communication speed transmission method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a start-stop data terminal device having various communication speeds such as a personal computer and a data line terminating device such as a telephone with a built-in modem having various communication speeds. Then, the present invention relates to a transmission method of the determined communication speed.

[Conventional technology]

Start-stop data terminal device capable of operating at a plurality of communication speeds,
For example, when a data line termination device that can operate at multiple communication speeds, such as a personal computer, such as a telephone with a built-in modem, is connected to each other by the 100 series interconnection circuit of CCITT Recommendation V.24 and communicates with each other, It is necessary to match the speed in advance. In addition to the method of manually setting each individually, the published patent publication Sho 60-30239
As described in, the special data predetermined for communication speed identification is sent via the interconnection circuit circuit number 103 (transmission data) or circuit number 104 (reception data), and the special data is identified on the receiving side. Therefore, there is a method of determining and setting the communication speed. This method will be described with reference to FIG. Personal computer 1 and telephone with built-in modem 2
This is effective when the database 5 is accessed via the subscriber telephone network 3 via. Here, the database 5 is connected to the subscriber telephone network via the telephone 4 with a built-in modem. 7,
8 indicates a line. The personal computer 1 and the telephone 2 with a built-in modem are connected to each other via an interconnection circuit 6 of V.24 standard. 6a is a transmission data line (SD) 6b is a reception data line (RD) 6c is another interconnection. It is a circuit line. If the operator of the personal computer 1 who accesses the database 5 sets the communication speed of the personal computer 1 in advance so as to match the communication speed of the database 5, the telephone with a built-in modem 2 sends predetermined special data to the transmission data line 6a. Thus, the communication speed can be identified and matched with that of the personal computer 1. After that, data communication with the database 5 side is started. In this system, an identification circuit for identifying the communication speed is required on the side of the telephone with built-in modem 2 based on predetermined special data transmitted from the personal computer 1 via the transmission data line 6a. In the above example, it is necessary that the communication speed on the database 5 side is known in advance. On the contrary, if the communication speed on the database 5 side is unknown, the following must be done. First, when the line is connected to the database 5 side in the subscriber telephone network 3,
A carrier signal is transmitted from the telephone 4 with a built-in modem on the database 5 side. Before setting its own communication speed, the telephone 2 with built-in modem on the terminal side discriminates the communication speed of the modem from the carrier signal sent from the telephone 4 with built-in modem on the database 5 side, and matches its communication speed with it. After that, special data that is predetermined to the personal computer 1 side is sent via the reception data line 6b,
As a result, the personal computer 1 has the database 5
It is necessary to identify the communication speed on the side and match your communication speed with the communication speed. However, generally, the personal computer 1 does not have a function of identifying the communication speed from the special data because communication is not the main purpose.

[Problems to be Solved by the Invention]

In the above-mentioned conventional example, as a means for transmitting the determined communication speed from the data line terminal (DCE) side such as a telephone with a built-in modem to the data terminal equipment (DTE) side such as a personal computer via the V.24 interface, Received data line (RD) of circuit number 115 before starting data communication
The predetermined special data is sent to the above, and the personal computer side needs the identification function to identify the communication speed thereby, but the present invention does not require the identification function or the like on the personal computer side, It is an object of the present invention to provide a means for transmitting a determined communication speed from the DCE side to the DTE side via the V.24 interface, which can be easily realized by a personal computer.

[Means for solving the problem]

The above purpose is to use the transmission signal element timing signal (S + 2) line of the circuit number 114, which is not used in the normal start-stop data communication in the V.24 interface signal, for the communication speed determined from the DCE side to the DTE side or an integral multiple thereof. It is achieved by sending a timing signal and using this as an external timing signal of the serial interface unit for data communication on the DTE side.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an outline of the present invention, and FIG. 2 is an explanatory diagram of feasibility on the DTE side. In FIG. 1, reference numeral 1 is a start-up type data terminal device such as a personal computer which can operate at a plurality of communication speeds, 2 is a start-up type data line terminal device such as a telephone with a built-in modem which can operate at a plurality of communication speeds, 6 Is an interconnection circuit compliant with the V.24 interface standard, 6a is a transmission data line, 6b is a reception data line,
6d is a transmission signal element timing signal which is not normally used in start-stop data communication, and 6c is another interconnection circuit line. The present invention is to transmit the communication speed determined on the data line terminal 2 side to the data terminal device 1 side by using the transmission signal element timing signal 6d. That is, it is supplied to the data terminal device 1 side via the transmission signal element timing signal line 6d as a clock signal having a frequency of the defined communication speed itself or a clock signal 16 times or 64 times the frequency thereof. Although the data terminal device 1 side determines the communication speed from the frequency of the clock signal, a normal start-stop type data terminal, for example, a personal computer, can be easily realized without requiring any special function. This will be described with reference to FIG. This figure is a functional block diagram of a portion corresponding to a V.24 interface in a general personal computer. 1'is generally LS
It is controlled by the I / O start / reception circuit (UART) via a bus interface 5 with a microprocessor or the like. This serial output 7a becomes transmission data 6a via the level conversion circuit 4a. Similarly, the reception data 6b of the interconnection circuit 6
Is input to the serial input 7b of the UART via the level conversion circuit 4b. The transmission timing element signal 6d relating to the invention of the interconnection circuit 6 likewise passes through the level conversion circuit 4c and the switch 2 ', and the transmission timing input 7e of the UART,
Input to the reception timing input 7f. An internal timing generator 3 uses signals from the internal timing generator 3 as a transmission timing input 7e and a reception timing input 7f of an ordinary personal computer UART. The signal can also be set to be available. When the internal timing generator 3 is used, it is necessary to preset the timing frequency to a value suitable for the communication speed from the microprocessor or the like via the bus interface 5 to the timing generator 3, but from the outside. When the timing signal is used, it is not necessary to control the timing generator 3 on the personal computer side, and if the timing frequency input from the transmission element timing signal 6d has a value suitable for the communication speed, the personal computer can be used. The computer does not need to be aware of the communication speed. Generally, the transmission timing input 7e and the reception timing input 7f of this UART are 1 times the communication speed,
Or 16 times and 64 times can be used by setting UART.

〔The invention's effect〕

As described above, according to the present invention, the V.24 interface section of an ordinary personal computer does not require a special function for identifying the communication speed from the special data input from the data line terminating device side on the reception data line. , It is possible to receive the transmission of the determined communication speed from the data line terminal device side.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of a communication speed transmission system of the present invention, and FIG.
FIG. 3 is a diagram showing a general V.24 interface unit on the data terminal side for explaining the feasibility of the present invention, and FIG. 3 is a diagram showing a conventional communication speed transmission system. 1 ... Data terminal equipment (DTE), 1 '... Start-stop transceiver circuit (UART) 2 ... Data line terminating equipment (DCE), 2' ... Switcher 3 ... Timing generator 4a, 4b, 4c ... … Level conversion circuit 6 …… Interconnection circuit

Claims (1)

(57) [Claims] 1. A start-up type data terminal device capable of operating at a plurality of communication speeds, and a data line terminating device having a modem function, and the interconnection of these devices is CCITT Recommendation V.24-1.
In the communication speed transmission method consisting of interconnection circuits defined in the 00 series, the data line terminal device whose communication speed is fixed, and the interworking data terminal device whose communication speed is not fixed are The transmission signal element / timing signal line of the connection circuit (“interconnection circuit number 114” in the above regulation) is provided with means for transmitting a timing signal at a communication speed or an integral multiple thereof, and the timing data is provided to the start-stop data terminal device. A communication speed transmission method comprising means for setting a communication speed based on a signal.