JPS5821274B2 - data terminal equipment - Google Patents

Description

Detailed Description of the Invention (1) Field of Application of the Invention The present invention relates to data displayed on a display device or output data printed on a printer, and screen control data of the display device or paper of the printer from a central control device. The present invention relates to a data terminal device that receives control data and the like through the same data communication line.

It is particularly suitable when the communication speed of the data communication line is relatively high.

(2) Prior Art A cathode ray tube display device, etc. that receives conventional output data uses control data for controlling screen erasure, character insertion, etc., and display data for character display, as shown in the example in Figure 1. The data is mixed in a series of data strings (hereinafter, a transmission unit made up of a series of data strings as shown in Figure 1 is called a transmission block), the data is identified character by character in the order in which it is received, and then stored in the display storage device. The methods used have been to store the data or to perform predetermined control as control data.

On the other hand, a series of transmitted display data is stored in an arbitrarily specified location in the display storage device and displayed, and a arbitrarily specified portion of the data stored in the display storage device is predetermined. A block transmission method in which the data is divided into data strings with a block length of
No. 380.

(3) Problems with the prior art The conventional method of transmitting control data and display data in a mixed manner in the same transmission block has been designed to prevent predetermined control using control data from being carried out in one block as the communication speed of data communication lines increases.
Since it is difficult to complete the process within the reception time for characters, one redundant character that does not involve processing is added following the control data to ensure reception time sufficient for performing the specified control using the control data. It became necessary to send more than 100 lines of data, which caused a decrease in the efficiency of line usage.

On the other hand, the block transmission method that transmits only display data is
Although proposals have been made as typified by the above patent, an effective method for transmitting control data has not yet been completed.

(4) Purpose of the Invention Accordingly, the purpose of the present invention is to provide a data terminal device that receives control data and display data from a central control unit through the same data communication line without reducing the efficiency of use of the line. .

Another object of the present invention is to provide a data terminal device that receives control data without affecting the transmission of display data in a block transmission system that transmits only display data.

(5) Summary of the Invention The present invention provides, for example, in a cathode ray tube display device having a display storage device connected to a central control device via a data communication line, by separating display data and control data transmission blocks, Display data blocks are directly stored in the display storage device, control data blocks are temporarily stored in the control storage device, and then the control data is sequentially retrieved from the control storage device and predetermined control is executed. Even though data and display data are transmitted over the same data communication line, there is no need to transmit redundant characters to secure time for executing control data, thereby improving the efficiency of line usage. It is characterized by

More specifically, display data and control data are transmitted and received by the same processing circuit, each character is determined whether it is display data or control data, and if it is display data, it is stored in the display storage device, and if it is control data, it is stored in a predetermined storage device. In conventional methods for controlling display data, the transmission speed of display data is generally limited by the writing and reading speed of the display storage device, so it is necessary to increase the communication speed when transmitting only display data. However, on the other hand, predetermined control using control data, such as erasing the screen or inserting or deleting lines, requires execution time, so it is necessary to ensure sufficient execution time for the control data. However, in the present invention, the processing circuits for display data and control data are separate, and the control data is temporarily stored in the control storage device. However, by sequentially fetching and executing the characters from the control storage device, redundant characters are no longer necessary, and the efficiency of using the data communication line is further improved.

Note that, as is clear from the above, in the present invention, it is not important to separate transmission blocks for display data and control data.

In other words, even when both types coexist in a transmission block, the object of the present invention can be achieved by separating each processing circuit and storing data in a corresponding storage device.

Furthermore, the present invention provides a method for communication, since the transmission speed of display data or control data is mainly limited by the writing/reading speed of the display storage device or the control storage device. It has the characteristic of being able to improve speed.

(6) Embodiment of the Invention The details of the present invention will be explained below according to an embodiment shown in FIGS. 2 and 3.

FIG. 2 shows the format of messages sent from the central control unit. Format 1 is used to transmit control data, and format 2 is used to transmit display data.

In FIG. 2, command 1 and command 2 indicate whether the message includes display data or control data.

FIG. 2 shows a block diagram of one embodiment of the invention.

) 1 is the central control unit.

2 is a communication line. 3 is a receiving circuit which performs a parity check on the message received from the central control device 1, and the like.

4 is a display storage device which stores display data received from the central control device 1;

A control storage device 5 stores control data received from the central control device 1.

Reference numeral 6 denotes a control circuit that sequentially retrieves control data stored in the control storage device 5 and performs predetermined control.

Reference numeral 7 denotes a data transfer address register, which indicates a write address when display data is written to the display storage device 4.

8 is a data transfer counter, which indicates the number of characters written when display data is written to the display storage device 4.

Reference numeral 9 denotes an arithmetic circuit that increases, decreases, or updates the contents of the data transfer address register 7 and the data transfer counter 8 when writing display data to the display storage device 4.

10 is a determination circuit that determines whether the data received through the receiving circuit 3 is display data or control data, and if it is display data, it is stored in the display storage device 4; if it is control data, it is stored in the control storage device. Accumulate to 5.

Control data from the central controller 1 is transmitted in format 1 shown in FIG.

A format 1 message transmitted from the central control unit 1 via the communication line 2 is subjected to control such as a parity check by the receiving circuit 3, and then enters the determination circuit 10.

The determination circuit 10 determines the command part of the message, and if it is determined to be command 1 indicating format 1, the following message is stored in the control storage device 5.

The control data stored in the control storage device 5 is sequentially retrieved by the control circuit 6 and predetermined control is executed.

On the other hand, display data from the central control device 1 is transmitted in format 2 shown in FIG.

A format 2 message transmitted from the central control device 1 via the communication line 2 is subjected to control such as a integrity check by the receiving circuit 3, and then enters the determination circuit 10.

The determination circuit 10 determines the command part of the message, and when it determines that it is command 2 shown in format 2, the following message is stored in the display storage device 4.

At this time, the display data i is written to the address indicated in the data transfer address register 7 of the display storage device 4, and the data transfer address register 1 is increased or decreased by the arithmetic circuit 9 every time one character of display data is written.

Furthermore, each time one character of display data is written, the value of the data transfer counter 8 is decremented by 1 by the arithmetic circuit 9, and when the content of the data transfer counter 8 indicates zero, the arithmetic circuit 9 transfers the value to the display storage device 4. Finish writing the display data.

Although the method of setting the contents of the data transfer address register 7 and the data transfer counter 8 described above is essentially unrelated to the present invention, for example, the data transfer address register 7 is set as one of the control data from the central control unit 1. Alternatively, this can be realized by transmitting and setting the value to be set in the transfer counter 8.

Note that, as is clear from the above description, there are no restrictions on the order and combination of the transmission blocks of Format 1 and Format 2 in FIG.

(7) As described in detail, the present invention provides the ability to perform predetermined control using control data regardless of the transmission of display data by providing both a display storage device and a control storage device; Since the transmission of control data and the execution of control using control data can be separated, there is no need to transmit redundant characters following side split data, and the transmission speed of display data and control data is mainly dependent on the display storage device and control data. This is an effective method for transmitting data to terminal devices such as cathode ray tube displays and for displaying data, as it is limited by the writing and reading speed of the storage device used, but it is effective for transmitting data to terminal devices such as cathode ray tube displays, and is particularly effective over high-speed communication lines. If used,
The benefits include improved line efficiency.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of a message in a conventional method, FIG. 2 is a diagram showing an example of a message in a data transmission method of the present invention, and FIG. 3 is a block diagram showing an embodiment of the present invention. In Fig. 3, total...receiving circuit, 4...
・Display storage device, 5... Control storage device, 6
... Control circuit, 10 ... Judgment circuit.

Claims (1)

[Claims] 1. In a data terminal device that receives output data and control data from a central control unit through the same communication line, a storage device is provided to separately store output data and control data, and the output data and control data are received independently. A data terminal device characterized by: