JPH01276841A - Data transferring method - Google Patents

Abstract

PURPOSE:To shorten the time necessary to detect a data error at a receiving side by adding a prescribed code to the peak side of data to be transmitted, transmitting it from a transmitting side, decoding a prescribed received code and detecting the transmission error of the transmission data by the result. CONSTITUTION:A prescribed code 1b is added and transmitted to the peak side of data 1a to be transmitted and at the receiving side, the prescribed received code 1b is decoded. Thus, since it is obvious whether or not an error occurs at the data received at a receiving part, when an error detecting code is received, the re-transmission can be immediately executed at the time point without awaiting the receiving completion of all data and the processing time necessary to the re-transmission at the time of generating an error is shortened.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for transferring data, especially digital data, and more specifically, to a method for detecting errors that occur during data transfer and for detecting errors in data when an error is detected. This invention relates to a data transfer method that facilitates recovery.

[Conventional technology]

When transmitting and receiving digital data, preventing data errors from occurring and recovering from them are important issues. FIG. 3 is a schematic diagram showing an example of the configuration of a device used in the conventional data transfer method disclosed in, for example, Japanese Patent Application Laid-Open No. 59-81940.

In the figure, 1a is data to be transmitted (hereinafter referred to as transmission data), 9 is data that is actually transmitted (hereinafter referred to as transfer data), and transfer data 9 has a thumb check value 9a at the end of transmission data la. is added.

In addition, 1 is a transmission data area storing transmission data la, and 2 is a transmission data area that generates a thumb check value 9a of transmission data 1a, adds this to transmission data la to create transfer data 9, and transmits it via data line 5. 3 is a receiving section that receives the transfer data 9 transmitted via the data line 5; 4 is a receiving section that stores only the transmission data 1a portion of the received transfer data 9 as reception data 4a. This is the receive data area.

Further, 8 is a data collation unit, which generates a sum check value of the portion corresponding to the transmission data 1a of the transfer data 9 received by the reception unit 3, and combines this with the sum check value added to the end of the transfer data 9. 9a, and if they match, it is assumed that there was no data error, and the portion of the transmitted data 1 of the transferred data 9 is given from the receiving unit 3 to the received data area 4 for storage, and if they do not match, it is assumed that there is no data error. If so, it is determined that there is a data error and a transfer contact code is transmitted to the control line 6.

Reference numeral 7 denotes a transfer contact code receiving section which receives a transfer contact code from the control line 6, and if this is a signal indicating the occurrence of a data error, causes the transmitter 2 to retransmit the data.

In such conventional data transfer methods, data is transferred in the following manner to avoid data errors.

The transmission data la stored in the transmission data area 1 is sequentially taken out by the transmission section 2, and a sum check value 9a is generated by adding all the bytes. This sum check value 9a is added to the end of the transmission data 1a that should originally be transmitted, is temporarily stored in the transmission section 2 as transfer data 9, and is then transmitted to the reception section 3 via the data line 5.

The receiving section 3 temporarily stores the transfer data 9, and the transmission data Ia portion of the transfer data 9 is taken out by the data collation section 8. The data collation unit 8 generates a sum check value for the transmission data 1a portion of the transfer data 9, and compares and verifies this with the sum check value 9a added to the end of the transfer data 9 stored in the reception unit 3. do.

As a result, if both sum check values match, the data collation section 8 transmits a transfer communication code with no data error to the transfer communication code reception section 7, and the transfer data 9 stored in the reception section 3 is Samchie 7 value 9a is removed and only the part corresponding to transmission data 1a is received data 4
stored in a. - On the other hand, if the two sum check values do not match, the data matching section 8 transmits a transfer communication code indicating that a data error has occurred to the transfer communication code receiving section 7. Upon receiving this, the transfer contact code receiving section 7 immediately retransmits the data.

[Problem to be solved by the invention]

In the conventional data transfer method as described above, the transfer data 9
Since the sum check value cannot be generated until all of the data have been received, it is not possible to determine whether or not there is an error in the transferred data 9, and the correctness of the data is determined only by the sum check value. Therefore, there is a problem of poor reliability.

The present invention was made in view of these circumstances, and
The present invention aims to shorten the time required for detecting data errors on the receiving side and to provide a data transfer method with higher reliability.

[Means to solve the problem]

In the data transfer method of the present invention, a predetermined code is added to the beginning of the data to be transmitted, and the receiving side decodes the received predetermined code.

[Effect]

In the data transfer method of the present invention, by decoding a predetermined code received on the receiving side, the presence or absence of a data error during data transfer is detected before all data is received.

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on drawings showing embodiments thereof.

FIG. 1 is a block diagram showing the configuration of a device used to implement the data transfer method of the present invention. Note that the same reference numerals are given to the same or corresponding parts as in the explanatory diagram of the conventional data transfer method shown in FIG. 3 described above.

In FIG. 1, 1a is data to be transmitted (hereinafter referred to as transmission data), and 9 is data to be actually transmitted (hereinafter referred to as transmission data).
The transfer data 9 (hereinafter referred to as transfer data) is the transmission data la with a predetermined code (hereinafter referred to as an error detection code) added to the beginning and a thumb check value 9a added to the end.

Further, 1 is a transmission data area storing transmission data 1a, and 2 is a transmission data area in which an error detection code 1b and a thumb check value 9a are added to the transmission data la to create transfer data 9, and this is transmitted via a data line 5. A transmitter 3 receives transfer data 9 transmitted via the data line 5; 4 a receive data area that stores only the transmit data 1a portion of the received transfer data 9 as received data 4a; It is.

Further, 8 is a data verification unit, which decodes the error detection code 1b in the transfer data 9 received by the reception unit 3, and detects based on the result whether or not the data has been received normally. If the data has not been received normally, the data matching section 8 immediately transmits a transfer communication code indicating that fact to the transfer communication code receiving section 7 via the control line 6. Furthermore, if the error detection code lb has been received normally, a sum check value of the part corresponding to the transmission data 1a is created, and this and the sum check value 9 added to the end of the transfer data 9 are added.
If they match, it is assumed that no data error has occurred during data transfer, and the transmission data la portion of the transfer data 9 is transferred from the receiving section 3 to the reception data area 4, and once again. If not, it is assumed that there is a data error and a transfer contact code is transmitted to the control line 6.

Reference numeral 7 denotes a transfer contact code receiving section, which, when receiving a transfer contact code from the control line 6, assumes that an error has occurred in the transmitted data and causes the transmitter 2 to retransmit the data.

The data transfer method of the present invention performed by such a device configuration is as follows. Note that FIG. 2 is a flowchart showing the procedure.

The transmission data 1a stored in the transmission data area 1 is sequentially taken out by the transmission section 2, where an error detection code lb is added to the head thereof, and a sum check value 9a is generated by adding all the bytes.

This thumb check value 9a is added to the end of the transmission data la that should originally be transmitted and sent to the transmitter 2 as transfer data 9.
After being temporarily stored in the data line 5, the data is transmitted to the receiving section 3 via the data line 5.

The receiving section 3 temporarily stores the transfer data 9, but when the error detection code 1b is received, the data collating section 8 decodes it, and based on this result, it is detected whether or not the data has been received normally. If it is not normal, a transfer contact code indicating that fact is transmitted to the transfer contact code receiving section 7. Thereby, the transfer contact code receiving section 7 causes the transmitting section 2 to retransmit the same transmission data la.

When the error detection code 1b is normally received, the data collation section 8 checks the transmission data la part of the transfer data 9 after all the sum check values 9a are received and stored in the reception section 3. Take out, create a thumb check value of the transmission data la part of the transfer data 9, and combine this with the reception section 3.
The sum check value 9a added to the end of the transfer data 9 stored in the transfer data 9 is compared and verified.

As a result, if both sum check values match, the data matching section 8 transmits a transfer communication code with no data error to the transfer communication code receiving section 7 via the control line 6, and
A portion of the transfer data 9 stored in the receiving section 3 corresponding to the transmission data la from which the error detection code 1b and sum check value 9a have been removed is stored in the reception data area 4. On the other hand, if the two thumb check values do not match,
A transfer contact code indicating that a data error has occurred is transmitted from the data matching section 8 to the transfer contact code receiving section 7, and the transfer contact code receiving section 7 immediately retransmits the data.

〔Effect of the invention〕

As described above, according to the data transfer method of the present invention, whether or not an error has occurred in the data received by the receiving section can be determined at the time when the error detection code is received. It becomes possible to perform retransmission immediately at that point without waiting for completion, and the processing time required for retransmission when an error occurs is shortened.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of equipment used to carry out the data transmission method of the present invention, FIG. 2 is a flowchart showing the procedure of the method of the present invention, and FIG. 3 is an explanatory diagram of the conventional data transfer method. . 1a...Transmission data 1b...Error detection code 4a...Reception data 9...Transfer data 9a
...Thumb check value Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] 1. Data characterized by adding a predetermined code to the beginning of data to be transmitted, transmitting it from the transmitting side, decoding the received predetermined code, and detecting a transmission error in the transmitted data based on the result. Transfer method.