JPS6080342A - Communication control system - Google Patents

Abstract

PURPOSE:To transmit data for both a low-speed data terminal device and a high-speed data terminal device on one line by switching the communication speed between a data terminal device and a communication control processor according to a message via a data line. CONSTITUTION:When data is switched between the low-speed data terminal device 3 and the high-speed data terminal device 4, a switch request message comprising three parts; switching request, existing speed and request speed is used. A CPU1 and a terminal device in use transmit a switch request message from one to the other via a communication control processor 2, an MODEM6, a line 7 and a switching device 5 and respond to one from the other. The switch device 5 and the communication processing unit 2 are set according to the request speed in the switching request message by the transmission/reception.

Description

DETAILED DESCRIPTION OF THE INVENTION +a) Technical Field of the Invention The present invention relates to a data communication system comprising a plurality of data terminal devices having different communication speeds.

fil) Background of the Technology Conventionally, when data terminal devices having different communication speeds are connected to a data communication system, the data line to which each data terminal device is connected uses a data line depending on the communication speed.

(C1 Prior Art and Problems Figure 1(a) shows an example of a conventional method.A data processing system consisting of a data processing device 1 and a communication control processing device 2 includes a low-speed data terminal device, a high-speed data terminal device, and a low-speed data terminal device. 4, low-speed modem 5 and low-speed data line 9
．． High speed modem 6 and high speed data line 8. Two data lines are used.

FIG. 1(bl) shows the inside of the communication control processing device 2 constituting FIG. 1(al), particularly the connection portion with the data line.

The bit-serial data from the low-speed data terminal device 3 is modulated and demodulated by the low-speed modem 5, and is input to the serial/parallel conversion circuit 10 of the communication control processing device via the low-speed data line 9, where it is input to the serial/parallel conversion circuit 10 of the communication control processing device. It is converted into an internal word form and input to the character processing control circuit 11 for processing. The data output to the low-speed data terminal device 3 is output from the character processing control circuit 11 to the serial/parallel conversion circuit 10 in the form of an internal word, converted to bit-serial data, modulated and demodulated by the low-speed modem 5, and converted into low-speed data. The data is input to the low-speed data terminal device 3 via the line 9.

Data communication is performed with the communication control processing device 2 via the data line with respect to other high-speed data terminal devices 4 through a similar route.

In the above operation, the plurality of serial-to-parallel conversion circuits 10 receive pulses of the reference frequency generated by the reference oscillator 13 according to the speed of the data terminal devices connected to each one.
desired frequency by the frequency dividing circuit 12.

Timing signals 13 and 14 converted into pulses corresponding to a plurality of two communication speeds are supplied. Low speed timing signal 1
3 is a low-speed data line, and high-speed timing signal 14 is a serial/parallel conversion circuit 10 to which the high-speed data line is connected, respectively.
However, this connection is made by wiring during system setup and is fixed. That is, the data line connection terminals of the communication control processing device 2 each correspond to a fixed communication speed. As explained above, when a low-speed data terminal device 3 and a high-speed data terminal device 4 are arranged in - number of terminal stations 7, a data line is connected to two low-speed and high-speed data lines.
In addition, the data line input terminal of the communication control processing device 2 also needs to be provided separately for two types of communication speeds: high speed and low speed.

It is possible to transmit data from the low-speed data terminal device 3 by switching and connecting the high-speed data terminal device 4 to the high-speed data line 8 by modifying the low-speed data terminal device 3. This system requires a large amount of expense and is not practical. Furthermore, using low-speed data terminal equipment without modification and providing one low-speed data line and one high-speed data line at each terminal station also poses a cost problem.

In particular, when configuring a new data communication system by adding new low-speed data terminal equipment to a system in which a large number of high-speed data terminal equipment are placed in many terminal stations, each terminal station is connected to a low-speed and high-speed data line. They were forced to choose between installing one each, or modifying all low-speed data terminal equipment to adapt it to high-speed data lines, and using a switching device to switch and connect them, both of which required a large amount of expense. do.

(dl) Purpose of the Invention In order to solve the above-mentioned problems, the present invention realizes a means for transmitting data from both a low-speed data terminal device and a high-speed data terminal device through a single line.

tel Structure of the Invention The present invention is connected to a data processing device, can be connected to a plurality of data lines, has a function of setting the communication speed with the plurality of data lines for each data line, and has a function to set the communication speed with the plurality of data lines for each data line. a communication control processing device having a communication control function for processing data input and output through a logical connection with the data processing device;

Multiple data terminal devices with different communication speeds.

A terminal station configured by connecting the plurality of data terminal devices to a switching device having a function of selectively connecting the plurality of data terminal devices to a single data line, and remotely connecting the communication control processing device and the plurality of terminal stations. In a data communication system composed of a plurality of data lines, the communication control is performed by mutually confirming the switching of the communication speed between the data terminal device and the communication control processing device using messages sent via the data lines. The processing device sets the communication speed of the line to which the data terminal device is connected to the communication speed notified by the message, and at the same time, the terminal station sets the communication speed corresponding to the communication speed notified by the message by the switching device. This is a communication control system characterized in that by selectively connecting data terminal devices, data terminal devices having different communication speeds can be selectively connected to the same data line to enable data communication.

(fl Embodiment of the invention FIG. 2 shows an embodiment of the invention in al. FIG. 2(a)
In the figure, 1 is a data processing device, 2 is a communication control processing device, 3 is a low-speed data terminal device, and 4 is a high-speed data terminal device. The two data terminal devices 3, 4 are selected by the switching device 5 and are connected to the modem 6. It is connected to the communication control processing device 2 via the data line 7. Here, the switching device 5 may be a simple device using a relay or the like. Further, the number of data terminal devices and their speed may be two or more. FIG. 2 (bl shows the inside of the communication control processing device 2. The operation 2 functions of the serial/parallel conversion circuit 10° character processing control circuit 14 are the same as those of the communication control processing device shown in FIG. are omitted. Data line 7. Input/output data is serially transmitted via modem 6.
The signals are input/output to the parallel conversion circuit 10 and converted into serial/parallel data.

The timing signal 18 used here is the speed setting circuit 1
1.

Timing signals 16, 1.7 obtained by converting the reference frequency pulses generated by the reference oscillator 13 into a plurality of desired pulses corresponding to communication speeds by the frequency dividing circuit 12 are sent in parallel to the plurality of speed setting circuits 11. The speed setting circuit 11 is supplied from the speed designation bus 15 from the character processing control circuit 14.
One of them is selected according to the speed setting command inputted to the input speed setting command, and is supplied to the serial/parallel conversion circuit 10 as a timing signal 18. This setting is performed for each line, and each line communicates with a data terminal device at a set speed. FIG. 2 fc) shows the contents of the speed setting circuit 11. The speed setting lotus 15 is
It includes a line address that designates one of the plurality of serial/parallel conversion circuits 10, and a speed setting signal 25, 26 that designates one of the plurality of timing signals. The speed setting signal is 2
There may be more than one. When a speed designation command from the character processing control circuit 14 is input to the speed setting circuit 11 through the speed setting lotus 15, its address part is input to the address detection circuit 20, and when it detects that it is its own address, it turns on the selection signal 271. Then, one of the speed setting signals 25 and 26 input from the speed setting lotus 15 is sent to the speed register 21 at the same time. The output of the speed register is outputted from either the timing signal 16 or 17 by the AND circuit 22. OR circuit 23
is selected and supplied to the serial/parallel conversion circuit 10 as a timing signal 18. As explained above, the communication control processing device 2 sets the communication speed for each line by the speed designation command from the character processing control circuit 14, and at the same time, the terminal station 8 changes the communication speed corresponding to the communication speed by the switching device 5. Select data terminal equipment and modem6. Data communication is possible by connecting to the communication control processing device 2 via the data line 7. Next, the procedure for switching the communication speed of the line is shown.

At terminal station 8, low speed data terminal equipment 3. When switching the high-speed data terminal device 4, a switching request message consisting of three parts, a switching request, a current speed, and a requested speed, shown in FIG. 2 (bl) is used.

(1) When the data processing device 1 issues a switching request, the data processing device 1 issues a switching request to the communication control processing device 2. A switching request message 7 shown at 291dl is transmitted to the terminal station 8 via the data line 7. When the terminal station 8 receives the switching request message, the low-speed data terminal device 3 or high-speed data terminal device 4 currently in use sends the data via the data line 72 and the communication control processing device 2 in response to the switching request message. The message is sent back to the processing device 1, and the switching device 5 selects a data terminal device having the communication speed indicated in the requested speed section of the switching request message, connects it to the data line, and waits for the data processing device 1 to start communication.

When the data processing device 1 receives the response from the terminal station 8, the communication control processing device 2 uses the above-mentioned means to indicate the communication speed of the corresponding line using the speed setting command in the requested speed part of the switching request message. Set the communication speed to the specified communication speed, and start communication using the normal communication procedure.

(2) When issuing a switching request from terminal station 8,
The terminal station 8 is a low-speed data terminal device 3. currently in use. Alternatively, the high-speed data terminal device 4 transmits a switching request message to the data processing device 1 via the data line 79 and the communication control processing device 2. When the data processing device 1 receives the switching request message from the terminal station 8,
The communication control processing device 2 sends a switching request message as a response.
It is sent back to the terminal station 8 via the data line 7,
By the above-mentioned means, the communication control processing device 2 sends the communication speed of the corresponding line to the switching request message 2 using the speed setting command.
The communication speed is set to the communication speed indicated in the request speed section of the message, and waits for the terminal station 8 to start communication. Upon receiving the response, the terminal station 8 uses the switching device 5 to select a data terminal device with the speed indicated in the requested speed section of the switching request message, connects it to the data line, and starts communication according to the normal communication procedure. .

As described above, a low-speed data terminal device is connected to the same data line.
Communication can be performed by switching and connecting high-speed data terminal devices.

(g) Effects of the Invention As explained above, the present invention makes it possible to switch and connect data terminal devices with different communication speeds onto a single data line. There is no need to install extra lines.

[Brief explanation of the drawing]

Figure 1 shows an example of a conventional system. FIG. 2 shows an example of a system according to the present invention. Figure 2 (
In a), 1 is a data processing device, 2 is a communication control processing device, 3 is a low-speed data terminal device, 4 is a high-speed data terminal device, 5 is a switching device, and 7 is a data line. 10 is a serial/parallel conversion circuit, 11 is a speed setting circuit, 12 is a frequency dividing circuit, 13 is a reference oscillator, 14 is a character processing control circuit, 15 is a speed setting bus, and 16, 17, and 18 are timing signals. , FIG. 2 (In C1, 20 is an address detection circuit, 21 is a speed register, and +dl in FIG. 2 is the contents of a switching request message.

Claims (1)

[Claims] It is connected to a data processing device, can be connected to multiple data lines, has a function to set the communication speed with the multiple data lines for each data line, and has the ability to input and output data via the data lines. A communication control processing device having a communication control function that performs processing through logical connection with the above data processing device, and a plurality of data terminal devices having different communication speeds, select the plurality of data terminal devices into a single data line. In a data communication system consisting of a terminal station configured by connecting to a switching device having a connection function, and a plurality of data lines remotely connecting the communication control processing device and the plurality of terminal stations. The communication speed switching between the data terminal device and the communication control processing device is performed via the data line described in section 2.
By mutual confirmation using the message, the communication control processing device sets the communication speed of the line to which the data terminal device is connected to the communication speed notified by the message, and at the same time, the terminal station uses the switching device to
By selectively connecting the data terminal device corresponding to the communication speed notified by the message, data terminal devices having different communication speeds can be selectively connected to the same data line and data communication can be performed. communication control method.