JPH03270426A - Signal transmission examining system and signal transmission system - Google Patents

Abstract

PURPOSE:To prevent the reliability of signal transmission from being lowered by dividing reception data in the same group form as transmission data when transmission error is present on the received data, and correcting the erroneous data for every group according to a normal character word and an error examination word. CONSTITUTION:In the case of transmitting/receiving data between signal devices 10 and 12, character word groups W1-W4 constituting the transmission data are respectively divided into plural groups for each word, and based on the data of the respective groups, error examination words PW1-PW2 are generated at every group and transmitted while adding these error examination words PW1 and PW2 to the character word groups W1-W4. On the other hand, on the reception side receiving the transmission data, when the transmission error is present on the reception data, the reception data is divided with the same group from as the transmission data, and the erroneous data is corrected for every group according to the normal character words of the respective groups and the error examination words PW1-PW2 of the respective groups. Thus, the transmission error over plural character words can be corrected and the reliability can be prevented from being lowered.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a signal transmission verification method and a signal transmission system, and in particular, to a method for transmitting and receiving data between a plurality of signal transmission devices using lines such as power distribution lines. The present invention relates to a signal transmission verification method and signal transmission system suitable for.

[Conventional technology]

When exchanging data between multiple signal transmission devices,
Traditionally, transmission data is composed of multiple character words,
An error check word is added to a character word group in units of information transmission. For example, if each character word is composed of 6 bits, each character word is defined by a constant mark code of C1 (1/I I of the 6 bits).
3 I's and 3 '0''s), and generate a parity word that matches this constant mark code.
When representing numerical values of kind in character words, bit O is represented by it 1 n, bit 1 is represented by 2'', bit 2 is represented by (1
4#, construct character words based on the promise that bit 3 is 7''', bit 4 is ``parity'', and bit 5 is ``fixed bit (1)'', and add a parity word to these character words. and transmit it.

However, when a parity word is generated based on a group of character words, the parity word may not be a fixed mark code depending on the state of the character word. That is, if a parity bit is formed for each bit of each character word and a parity word is constructed from these parity bits, the parity word is (1171It I
II 11011110”, “1”, and “1” data may be generated.

Therefore, the parity word is divided into the first half and the second half according to the order of data composition, and the first parity word "11°001" is generated from the data "110" in the first half and the data rooIJ obtained by inverting this data. A method has been proposed for generating the second parity word ro11100J from data ro11J in the latter half and data rloOJ obtained by inverting this data. By using this method, the parity word can always be a constant mark code regardless of the content of the parity word.

Furthermore, as related to this type of technology, Japanese Patent Application Laid-open No. 1983
-26133 publication is mentioned.

[Problems to be Solved by the Invention] In the above-mentioned prior art, sufficient consideration is not given to the case where a transmission error occurs across two words, and in order to correct such error data, a group of character words is Divide into odd numbered words (first word, third word...) and even numbered words (second word, fourth word...), and provide a first parity word and a second parity word for each group. Must be. Therefore, in such a case, if the transmitted data is short, the proportion of the error test word in the total data will increase, and there is a risk that the reliability of data transmission will decrease.

SUMMARY OF THE INVENTION An object of the present invention is to provide a signal transmission verification method and a signal transmission system that can correct transmission errors ranging from a minimum error verification word to a plurality of character words.

[Means to solve the problem]

In order to achieve the above object, the present invention, as a first method, adds an error check word to a character word group made up of a data group in an information transmission unit, and when transmitting and receiving data, each character word is Divide each word into multiple groups, generate error test words for each group based on the data of each group, add the generated error test words of each group to the character word group, and transmit. The data receiving side performs a character word error check based on the received data, and if there is a transmission error in the character word, the received data is divided into the same group form as the transmitted data, and the normal character words of each group and the normal character words of each group are divided. This method employs a signal transmission verification method in which error data is corrected for each group based on the error verification word.

As a second method, when sending and receiving data by adding an error check word to a character word group consisting of a data group in an information transmission unit, the data group of each character word is divided into the first half and the second half according to the order of data composition. Based on the data of each group, the error test words for the first half and the error test words for the second half are generated in the same form as the character words, and each error test word is added to the character word group. The data receiving side performs a character word error check on the received data.

When a character word has a transmission error, each received data is divided into the same group format as the transmitted data, and the error data is corrected for each group from the normal character words of each group and the error check word of each group. This method was adopted.

The first system is a system that sends and receives data between multiple signal transmission devices, in which multiple character words are divided word by word and divided into multiple groups, and errors are made for each group based on the data of each group. An error test word generation means for generating a test word, and a transmission means for adding each error test word generated by the error test word generation means to a character word group in an information transmission unit and transmitting the result to at least one signal transmission device. a receiving means for receiving the transmission data from the transmitting means; an error testing means for testing the error of a character word from the data received by the receiving means; , data correction means for dividing each received data in the same group form as the transmitted data and correcting error data for each group from normal character words of each group and error check words of each group; This configuration constitutes a signal transmission system provided in

As a second system, in a system that sends and receives data between multiple signal transmission devices, the data group of multiple character words is divided into two groups, the first half and the second half, according to the data composition order, and the data of each group is An error test word generating means for generating an error test word for the first half and an error test word for the second half in the same form as the character word based on the above.

At least one signal transmission device is provided with a transmitting means for adding each error test word generated by the error test word generating means to a character word group in an information transmission unit and transmitting the same, and receiving transmission data from the transmitting means. a receiving means for
Error checking means performs an error check on character words from data received by the receiving means; A signal transmission system is constructed in which at least the other signal transmission device is provided with data correction means for correcting error data for each group from the normal character words of the above and the error check words of each group.

[Effect]

When transmitting and receiving data between signal devices, the character words that make up the transmitted data are divided into multiple groups, and an error test word is generated for each group based on the data of each group. , this error test word is added to the character word group and transmitted. On the other hand, on the receiving side that has received the transmitted data, if there is a transmission error in the received data, the received data is divided into the same group form as the transmitted data, and the normal character words of each group and the error test word of each group are divided into groups. Since the error data is corrected for each character word, it is only necessary to have the same number of error test words as there are groups, and it is possible to correct transmission errors that span multiple character words even with the minimum number of error test words. .

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

In FIG. 1, a signal transmission device 10 and a signal transmission device 12 are shown.
and are connected via a signal transmission path 14 such as a power distribution line. Each signal transmission device 10.12 is provided with a transmitter as a transmission means, a receiver as a reception means, and a controller that constitutes an error verification word generation means, an error verification means, and a data correction means. . Based on commands from each controller, data is exchanged between the signal transmission device 10 and the signal transmission device 12 via the signal transmission path 14.

Here, when the signal transmission device 10 is the transmitting side and the signal transmitting device 12 is the receiving side, the signal transmission device 10 generates transmission data. A character word as transmission data is composed of a plurality of character words to form one information transmission unit. When each character word is composed of 6 bits, each character word is generated according to the &C3 constant mark code, for example. When generating an error test word from each character word, each character word is divided according to the order of data composition, with the upper 3 bits as the first half 16 and the lower 3 bits as the first half 16, as shown in FIG.
Pi1- is divided into two groups as data of the second half 18.

After dividing each character word into two groups, as shown in FIG. Character word W4~4th
The XOR (exclusive OR) of each bit at the same bit position of the character word W4 is performed to generate a temporary parity word PWO.

Next, the temporary parity word PWO is divided into the first half and the second half, and the parity word PWO for the first half is
Generate WI. Further, a parity word PWI for the second half of the temporary parity word PWO is generated from data rllOJ of the second half and data "OOl" obtained by inverting the data. That is, in order to make the temporary parity word PWO the same form as each character word, the temporary parity word PWO is divided into the first half and the second half, and these data are
Parity word PWI for the first half that matches the constant mark code
and is generated as the parity word PWI for the second half.

When transmitting data from the signal transmission device 10,
1st character word W1 to 4th character word W4
The parity word PWI for the first half and the parity word PW2 for the second half are added to and transmitted.

When the signal transmission device 12 receives the transmission data from the signal transmission device 10, each received data is transferred to the controller, and the character words are checked for errors. When performing this error test, the error test for each character word, that is, the test using parity bits,
Fixed mark sign test and fixed bit test are performed,
A parity test is performed on the entire character word, and a character word in which a transmission error has occurred is identified.

Data as shown in FIG. 4(A) is transmitted from the signal transmission device 10, and data as shown in FIG. 4(B) is received by the signal transmission device 12. If a transmission error occurs in the second half of the first character word W1 and the first half of the second character word W2, the controller of the signal transmission device 12 assumes that the transmission error has occurred over two consecutive character words. The received data is divided into groups.

That is, each received data is grouped into first half and second half data in the same group form as the data transmitted by the signal transmission device 10. In this case, since a transmission error has occurred in the second character word W2 in the first half group, the first character word W1, the third character word W3, the fourth character word The data in the first half of the character word W4 and the data in the first half of the parity word PWI for the first half are used. Furthermore, since a transmission error has occurred in the second half of the first character word W1, the data in the second half of the second character word W2, the third character word W3, and the fourth character word W4 and the parity for the second half are The data in the first half of word PW2 is used as the second group of normal data. Then, XOR (exclusive OR) is performed on the data at the same bit position for each group, and the data rl11J in the first half of the second character word W2 is corrected to rloOJ, and the data in the second half of the first character word Wl is data r111” rllOJ
Correct. Thereafter, various processes are performed in the signal transmission device 12 based on the corrected data.

In this way, in this embodiment, by simply adding two parity words PW1 and PW2 as parity words to a character word group, even if a transmission error spanning two character words occurs, normal character words and each Since error data can be corrected from the parity word, it is possible to suppress the proportion of the parity word from increasing even when the transmission data is short, and it is possible to prevent the reliability of signal transmission from decreasing. This can contribute to reducing the number of retransmission processes due to transmission errors.

In the embodiment described above, a correction process for a transmission error spanning two character words has been described, but the embodiment can also be applied to a case where a transmission error occurs in only one character word.

Further, in the above embodiment, 1. Error correction using the C1 code has been described, but in the case of a 6-bit configuration, even if an error occurs in 4 consecutive bits, this error can be corrected. When correcting such continuous transmission errors, the number of bits in one word is determined by how many bits of continuous errors are to be corrected.

For example, even if a transmission error occurs in 5 consecutive bits,
To correct this, one character word should consist of 8 bits. In other words, it is sufficient to adopt a bit configuration that satisfies the following equation.

1-word code structure = (number of consecutive error data - 1)
2 [Effects of the Invention] As explained above, according to the present invention, a character word group is divided into a plurality of groups for each word, and error test words of each group are generated based on the data of each group. An error test word is added to a group of character words for transmission, and if there is a transmission error in the received data, the received data is divided into the same group form as the transmitted data, and the error data is extracted for each group from normal character words and error test words. This makes it possible to correct erroneous data even for transmission errors that span multiple character words, which can prevent deterioration in signal transmission reliability and contribute to reducing the number of retransmission processes. can.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a block diagram of a character word, Fig. 3 is an explanatory diagram for generating a parity word from a character word, and Fig. 4 is a diagram showing transmission data and reception. FIG. 5, which is an explanatory diagram of the data structure, is a diagram for explaining a method of correcting erroneous data. 10.12...Signal transmission device, 14...Signal transmission path, 16...First half, 18...
Second half, Wl...first character word, W2...
2nd character word, W3...3rd character word, W4...4th character word, PWO...lower parity word, PWI...parity word for first half, PW2...second half Departmental parity word.

Claims (1)

[Scope of Claims] 1. When transmitting and receiving data by adding an error check word to a character word group composed of a data group in an information transmission unit, each character word is divided word by word into a plurality of groups. An error test word is generated for each group based on the data of each group, the generated error test word for each group is added to the character word group and transmitted, and the data receiving side generates a character word based on the received data. Word error checking is performed, and if there is a transmission error in the character word, the received data is divided into the same group form as the transmitted data, and the error data is extracted for each group from the normal character words of each group and the error check word of each group. Signal transmission verification method to correct. 2. When transmitting and receiving data by adding an error check word in the information transmission unit to a character word group consisting of a data group, the data group of each character word is divided into two groups, the first half and the second half, according to the data composition order. divided into
Based on the data of each group, an error test word for the first half and an error test word for the second half are generated in the same format as the character word, each error test word is added to the character word group and transmitted, and the data is received on the data receiving side. Error checking of character words is performed from the data, and if there is a transmission error in the character word, each received data is divided into the same group form as the transmitted data, and the normal character words of each group and the error check word of each group are combined into groups. A signal transmission verification method that corrects erroneous data every time. 3. In a system that exchanges data between multiple signal transmission devices, multiple character words are divided word by word into multiple groups, and error test words are generated for each group based on the data of each group. At least one of the signal transmission devices is provided with an error test word generating means for generating the error test word, and a transmitting means for adding each error test word generated by the error test word generating means to a character word group in an information transmission unit and transmitting the result. a receiving means for receiving transmission data from the receiving means; an error checking means for performing an error check on a character word from the received data of the receiving means; at least the other signal transmission device is provided with data correction means for dividing the data into the same group form as the transmission data and correcting the error data for each group from the normal character words of each group and the error check word of each group. Signal transmission system. 4. In a system that exchanges data between multiple signal transmission devices, the data group of multiple character words is divided into two groups, the first half and the second half, according to the data composition order, and the first half is divided based on the data of each group. An error test word generation means for generating a first half error test word and a second half error test word in the same form as character words, and each error test word generated by the error test word generation means is converted into a character word group in an information transmission unit. At least one of the signal transmission devices is provided with a transmitting means for additionally transmitting data, a receiving means for receiving transmission data from the transmitting means, an error checking means for performing an error check on character words from the received data of the receiving means, When a test result indicating that there is a transmission error is generated by the test means, the received data is divided into the same group form as the transmitted data, and error data is extracted for each group from the normal character words of each group and the error test word of each group. A signal transmission system, wherein at least another signal transmission device is provided with data modification means for modifying the data.