JP3137092B2 - Data transmission method and transmission / reception device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data transmission technique, and more particularly to an error correction technique in data transmission for detecting and correcting an error in transmitted data. 2. Description of the Related Art In recent years, a transmitting apparatus and a receiving apparatus are connected by a single transmission path, and a plurality of data are periodically transmitted from the transmitting apparatus to the receiving apparatus via the transmission path in order of addresses. Data transmission schemes have been proposed. In this cyclic data transmission method, in order to prevent erroneous data from being received due to noise mixed in the transmission path,
An error test code such as a parity bit determined by the content of data included in one frame is added to the frame and transmitted. Then, the receiving apparatus detects the presence or absence of a data error in the frame according to the error test code, and if there is an error, performs a process of discarding all data in the frame. However, in the conventional cyclic data transmission system, when erroneous data is received, all the data is discarded, so that it is difficult to receive normal data of the word. In addition, it was necessary to wait at least one cyclic. Therefore, the transmission efficiency when an error is detected is very poor. [0004] Therefore, an object of the present invention is to solve the above-mentioned problems, and to correct the error of received data and to reliably receive normal data in one cyclic cycle even if there is an error in the data. It is to provide technology that can do it. [0005] An object of the present invention is a data transmission method for transmitting data at a predetermined transmission rate, comprising the steps of transmitting data at a predetermined transmission rate; Transmitting inverted data at the predetermined transmission rate; and transmitting the data as error correction data at a transmission rate of の of the predetermined transmission rate;
Receiving the data and the inverted data, and detecting an error, and, if an error is detected, correcting the error using data having a large logic among the data, the inverted data, and the error correction data. And a data transmission method. Incidentally, as a data transmission method, not only a cyclic data transmission method but also a non-procedural transmission method can be used. An object of the present invention is a data transmitting and receiving apparatus for transmitting and receiving data at a predetermined transmission rate,
Means for generating first transmission data and second transmission data obtained by inverting the first transmission data; means for generating the same error correction data as the first transmission data; Means for transmitting the transmission data and the second transmission data at a predetermined transmission rate, means for transmitting the error correction data at a transmission rate of 1/2 of the predetermined transmission rate, and the first transmission Means for receiving data and the second transmission data, means for receiving the error correction data, and error detection of the transmission data using the first transmission data and the second transmission data. Means for correcting an error in the transmission data using data having a large logic among the first transmission data, the second transmission data, and the error correction data when an error is detected by the detection means. Having means It is achieved by the data transmitting and receiving apparatus according to claim and. The transmission method is not limited to the cyclic data transmission method, but may be a non-procedural transmission method. An embodiment of the present invention will be described. In the present embodiment, transmission of cyclic data will be described as an example. The transmission rate of the cyclic data is 1200 bps, and the transmission rate of the error correction data is の of the transmission rate of the cyclic data, ie, 6
00 bps. Further, the inverted continuous transmission unit data refers to data obtained by inverting the initial transmission unit data in bit units. FIG. 1 is a timing chart of the cyclic data and the error correction data in the case described above. The number in each slot indicates the bit number, and the number in parentheses of the error correction data indicates the corresponding bit of the cyclic data.
P indicates a parity bit. The transmitting side creates data (initial sending part data + inverted continuous sending part data) in accordance with the transmission format shown in FIG.
Transmit repeatedly in ps. When the transmission data is created, the parity bit for the initial transmission unit data (address + data), the inverted continuous transmission unit data, and the inverted continuous transmission unit data for the error test on the receiving side. Add a parity bit.
Here, the parity bit determines whether the parity is odd or even depending on the transmission protocol. On the other hand, the error correction data is created based on the initial transmission unit data, and is transmitted at a transmission rate of the error correction data of 600 bps. When an error is detected in the cyclic data, the receiving side corrects the error by referring to the data received by the error correcting data transmission line. More specifically, the initial transmission section of the cyclic data (when the bit is 1 to 2)
The data of 2) is "11111111111000000"
000111 ", the data of the inverting serial transmission section (bits 23 to 44) of the cyclic data is data obtained by inverting the data of the initial transmission section, that is," 000000000001 ".
11111111100 ". Further, since the data for error correction uses only the data of the first transmission part of the cyclic data," 111111111100000000000 "is used.
11 ". The cyclic data is transmitted at a transmission rate of 1200 bps and the error correction data is transmitted at 600 bps from each transmission line. Next, as a receiving operation, first, a cyclic operation is performed from a 1200 bps transmission line. Data is received, and an error test such as a parity test and a reverse matching test is performed on the received cyclic data, where the parity test is data including parity bits (this time, the first transmission unit, Parity bit is created and added so that the number of 1s is always an odd number (or even number), and
This is a verification method in which it is confirmed that the number is odd (or even), but if it is even (or odd), it is regarded as error data. For example, D0 to D7
Is "01010101" and the parity is odd,
Since the number of 1s of D0 to D7 is 4, P = 1 is added to make it an odd number. In addition, the inversion collation test means that a test is performed on a bit-by-bit basis to determine whether or not the inverted continuous transmission unit data is inverted data of the initial transmission unit data. If an error is detected as a result of the parity test and the reverse collation test, the error correction data, cyclic data initial transmission data and inverted continuous transmission data received through the communication line of 600 bps are used. Error correction is performed by adopting the logic of the larger number. Explaining in a specific example, the data of the initial transmission part of the received cyclic data is “101111111100000000000011”.
And the inversion data of the inversion connection part of the received cyclic data is "1101111111000000000000".
010 ", an error is detected in the second and third bits. Here, the received error correction data is" 1 ".
11111111100000000011 ", and if the logic of the larger of the error correction data, the initial transmission data of the cyclic data and the inverted continuous transmission data is adopted, the data of the second bit is" 1 "and the third bit is" 1 ". Is "1", so that the data is error-corrected and "1111111111000000000000"
Next, a specific apparatus for achieving the above-described method will be described. FIG. 2 is a block diagram of a specific apparatus for achieving the above-described method. In FIG. This transmission data generation circuit 1 is a circuit for generating cyclic data (initial transmission section and reverse continuous transmission section) and error correction data, and 2 is an error test / correction circuit. The error test / correction circuit 2 is a circuit for performing error test and error correction of cyclic data.3 is a 1200 bps communication circuit.The 1200 bps communication circuit 3 has a transmission rate of 1200 bps and cyclic data. 4 is a 600 bps communication circuit.
The 600 bps communication circuit 3 has a transmission rate of 600 bp.
s is a circuit for transmitting and receiving error correction data. The 1200 bps communication circuits 3 and 60
The 0 bps communication circuit 4 includes transmission circuits 301 and 401 and reception circuits 302 and 402. Next, the operation of the above-described device will be described. In the transmission operation, the transmission data creation circuit 1 creates cyclic data (initial transmission section and inverted continuous transmission section) and error correction data (initial transmission section of cyclic data) shown in FIG. 120
Transmitted by the transmission circuit 301 of the 0 bps communication circuit 3,
The error correction data is transmitted by the transmission circuit 401 of the 600 bps communication circuit 4. Next, as a receiving operation, first, 1200 bp
The cyclic data received by the receiving circuit 302 of the communication circuit 3 is subjected to an inversion verification test and a parity test by the error test / correction circuit 2. Therefore, when an error is detected, the logic of the larger of the error correction data, the initial transmission data of the cyclic data, and the inverted continuous transmission data received by the reception circuit 402 of the 600 bps communication line 4 is adopted. Make corrections. In the above example, the transmission rate is 12
Although 00 bps and 600 bps were used, it is clear that the transmission rates are not limited to these.
Although the basic configuration of another embodiment of the present invention is as described above, the transmission method is not limited to the cyclic data transmission method, but may be a non-procedural transmission method such as a start-stop synchronization method as shown in FIG. Can also be adopted. The first effect is that when an error is detected, the error can be corrected. The reason is that the transmission side adds error correction data and transmits the data. The second effect is that the address can be extended within a range in which the transmission cycle (= 1 cyclic transmission time) is acceptable. Conventionally, when an error is detected, the data is discarded without retransmission, but by correcting the error, normal data can be reliably received in one cyclic cycle.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a timing chart of cyclic data and error correction data. FIG. 2 is a block diagram of a transmission / reception device. FIG. 3 is a diagram for explaining another embodiment of the present invention. [Description of Code] 1 Transmission data creation circuit 2 Error test / correction circuit 3 1200 bps communication circuit 4 600 bps communication circuit

Claims (1)

(57) Claims 1. A data transmission method for transmitting data at a predetermined transmission rate, comprising: transmitting data at a predetermined transmission rate; Transmitting the data at a transmission rate of で of the predetermined transmission rate as error correction data, receiving the data and the inverted data, and detecting an error. And (c) when an error is detected, correcting the error using data having a large number of logics among the data, the inverted data, and the error correction data. 2. The data transmission method according to claim 1, wherein the data transmission method is a cyclic data transmission method. 3. The data transmission method according to claim 1, wherein the data transmission method is a non-procedural transmission method. 4. A data transmitting and receiving apparatus for transmitting and receiving data at a predetermined transmission rate, comprising: means for generating first transmission data and second transmission data obtained by inverting the first transmission data; Means for generating the same error correction data as the first transmission data; means for transmitting the first transmission data and the second transmission data at a predetermined transmission rate; Means for transmitting at a transmission rate of 前 記 of the predetermined transmission rate; means for receiving the first transmission data and the second transmission data; means for receiving the error correction data; Means for detecting an error in the transmission data using the first transmission data and the second transmission data; and when the detection means detects an error, the first transmission data and the second transmission Data and said error Data transmitting and receiving apparatus characterized by having a means for correcting errors in transmission data by using the logical-rich data of correction data. 5. The data transmission / reception device according to claim 4, wherein the transmission system is a cyclic data transmission system. 6. The data transmission / reception device according to claim 4, wherein the transmission system is a non-procedural transmission system.