JPS6361354A - Data transmission system - Google Patents

Abstract

PURPOSE:To attain the transmitted mode transmission by applying bit string adding conversion to data on one side transmission system, transmitting as the data even on the other side transmission system and obtaining the necessary data by reverse conversion at a receiving side. CONSTITUTION:At the time of the data transmission between a host 1 transmitting by a non-transmitted mode and a host 2 transmitting by a transmitted mode, a procedure converting device 3 is provided between hosts 1 and 2. the data from the host 2 are first received by the device 3 and by 3 byte 4 byte conversion, the transmitted mode data are converted to the data of the non- transmitted mode. Further, by the procedure in which the transmitted mode transmission is not supported, the transmission is transmitted to the host 1, the received data are converted from 4 byte/3 byte at the host 1, converted to original transmitted data, and by the conversion reverse to the time of receiving, the data are transmitted to the host 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a data communication system, and particularly to code conversion optimal for transparent mode transmission.

[Conventional technology]

When connecting systems with different transmission methods,
Previously, the program for either system was modified to process data using a transmission method suited to the other system. In addition, related to this type of transmission method, for example, Japanese Patent Application Laid-open No. 5
9-216351, 58-185014, and the like.

[Problem that the invention seeks to solve]

The above-mentioned conventional technology has a problem in that it requires modification of existing programs when connecting systems with different transmission methods, resulting in a large amount of development work.

An object of the present invention is to provide a means for transmitting data between systems having different transmission methods by simple code conversion processing without modifying existing programs when connecting systems having different transmission methods.

[Means for solving problems]

The above purpose is to convert data of one transmission method into data that can be received by the other transmission method, that is, data and control codes can be correctly distinguished, and then send it. This is accomplished by converting it back to data.

[Effect]

Since the data after code conversion does not match the control code of the transmission system on the receiving side, the data and control code can be distinguished even by a program that does not change them, making it possible to send and receive data between different transmission systems.

〔Example〕

The present invention will be explained in detail below.

FIG. 1 shows an example of application of the present invention. In this example, host 1 can only perform transmission in non-transparent mode. This host transmits data between it and the terminal or host 2 that performs transmission in transparent mode.

Transparent mode is a transmission block that starts with LE/STX and ends with DLE-ETX, and the data in between is transmitted as is without being detected as a control code even if the same pit pattern as the transmission control code appears. This is a data transmission method that allows any combination of pits. In this example, when receiving data from the terminal side, a procedure conversion device 3 is provided, and here first, by converting from 3 bytes to 4 bytes, transparent mode data is converted into non-transparent mode data, that is, a pit pattern different from the control code. data and transmit it to the host using a procedure that does not support transparent mode transmission. The host converts the received data from 4 bytes to 3 bytes and converts it into the original transparent data. When sending data to a terminal, the reverse conversion is performed as when receiving data.

Figure 2 shows a 3-byte → 4-byte conversion method.

In this example, the code system on the non-transparent mode side will be explained as a JIS code. The data before conversion is 3n bytes (n=1, 2
), the first K is added every 6 bits of data before conversion.
Code conversion is performed by adding 01 and 02 bits. By adding the "01" and "02" bits, the converted data does not match the transmission control code. For the last 2 bytes when the pre-conversion data is 3n+2, see (
Perform the conversion shown in 11). That is, 0010 is added to the last byte. Data before conversion is 3n+1
Regarding the last 1 byte at the time of , the conversion as shown in (liD in FIG. 2) is performed.

That is, 001100 is added to the last byte.

FIG. 3 shows a 4-byte → 3-byte conversion method.

When the pre-conversion data is 4n (n=1.2...), code conversion is performed by deleting the first two bits of the transparent data in units of bytes. For the last 2 bytes when the pre-conversion data is 4n+2, code conversion as shown in (11) in FIG. 3 is performed. For the last 3 bytes when the pre-conversion data is 4n+3, code conversion as shown in (11D) in FIG. 3 is performed.

Figure 4 shows 3 bytes → 4 when the data length before conversion is l bytes.
A schematic flow of byte conversion processing is shown.

Figure 5 shows 4 bytes → 3 when the data length before conversion is l bytes.
A schematic flow of byte conversion processing is shown. The above flow is executed by the procedure conversion device 3 and the conversion mechanism program added to the host.

First, FIG. 4 will be explained. Read the message length (1) in the control information at the beginning of the transmitted message, and calculate the number of conversions m
and the number of fractional bytes n is calculated (101). If m is 1 or more, the process in FIG. 2 (1) is repeated m times (102). Next, determine the value of n, and if n is 2, the second
The process shown in Figure (11) is applied (103), and if n is 1, the process shown in Figure 2 (1++) is applied to the last 1 byte (104).
), if n is O, nothing is done and the process moves to step 105. In the next step, the converted data will be explained with reference to FIG.

As in step 101, the number of conversions m゛ and the number of fractional bytes n
seek. If m is 1 or more (200), then Fig. 3 (1
) is executed m times (202). Next, the value of n is determined (207), and if n is 2, the process in Figure 3 (11) is performed (203), and if n is 3, the process in Figure 3 (illll) is performed (204). Similar to step 105, the converted data length and converted data are passed to other processing functions (205).

〔Effect of the invention〕

According to the present invention, transparent mode transmission is enabled by code conversion of transmitted and received data on a host computer that does not support the transparent mode transmission method. This has the effect of eliminating the need for development.

[Brief explanation of the drawing]

Figure 1 shows an overview of the present invention, Figure 2 shows 3 bytes → 4 bytes.
FIG. 3 is a schematic flowchart of a 4-byte to 4-byte conversion method, and FIG. 5 is a schematic flow of a 4-byte to 3-byte conversion method. Representative Patent Attorney Katsuo Ogawa - Figure 1 Figure 2 (1) Telegram Lf3yta'cla>3
la force bin (7t, -12-) 3 bytes single note 1; review the above meeting's processing. (i'+1)li length fJ*+Inc! ! cJL end 1 by htr 1, t > Kudzu 4-Figure 5

Claims (1)

[Claims] When interconnecting systems that use different data transmission methods, the data on one transmission method is converted by adding a certain pit string, and the data is transmitted as data that can be handled as data in the other transmission method, and the data on the receiving side is A data transmission method characterized by obtaining the required data by inversely converting the data.