JPS61111035A - Data communication system - Google Patents

Abstract

PURPOSE:To allow an information processor at the transmission side to check the propriety of an error check processing for a reception data by including information corresponding to an error check code generated from the reception data from an error check means of an information processor at the reception side into a frame. CONSTITUTION:Response frames 10, 20 consist of a field 11 for synchronizing character string, a field 12 for ACK character and a field 13 to which the result of error check operation obtained from a parallel transmission line 6 is given. Then a field 21 for error check code is added to the response frame 20 especially in order to improve further the reliability. The basic information of error check, that is, the result of error check operation generated from the reception data and the information corresponding to the error check code at the transmission side are included in the response frame in this way. Thus, even a fault not detected by the information processor at the reception side is detected by the information processor at the transmission side.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a data communication system comprising a plurality of information processing devices. In particular, the present invention relates to a data communication system in which a transmission control procedure is processed in a part that cannot be recognized by a control program of an information processing device, and a failure that cannot be detected by a receiving information processing device can be detected by a sending information processing device.

[Conventional technology]

In a conventional data communication system, a plurality of information processing devices are connected through a single serial data transmission path, and data transmission and reception between the information processing devices is performed based on a predetermined procedure. These procedures use various procedures such as basic data transmission control procedures and high-level data link control procedures specified in JIS, and in these types of procedures, when transmitting data, the information processing device on the sending side Delivery of the transmitted data is confirmed based on a response from the information processing device on the receiving side.

On the other hand, due to the recent development of integrated circuits and the decentralization of processing within information processing equipment, the control of the above procedures is performed separately from the control program of the information processing equipment, and is required to be controlled by large-scale integrated circuits or devices that apply integrated circuits and installed therein. This is now done by a microprogram. In this way, as the data transmission control procedure between information processing devices in the data communication method is performed in a part that cannot be recognized by the control program of each information processing device, errors in transmitted information are occurring more frequently than in the conventional procedure. In addition, in the conventional procedure, error checking is performed only by the information processing device on the receiving side, and an ACK code (Acknowledgment) is sent to the information processing device on the transmitting side.
edge code, confirmation code), etc., and if error checking is no longer performed due to a failure of a large-scale integrated circuit that performs procedural control, even if data with an error is received, it will be processed as normal. Unfortunately, a response such as ACK was made, and the failure could not be detected in either of the information processing devices on the transmitting side or the receiving side.

FIG. 3 is a block diagram of a serial data receiving section of a conventional data communication type information processing apparatus.

In FIG. 3, serial reception data sent via a serial data transmission line 1 is supplied to a serial/parallel conversion circuit 7 and an error check calculation circuit 2.

The serial/parallel conversion circuit 7 converts the serially received data into character data according to the transmission unit. For this output, a circuit not shown in the figure detects synchronized characters, and the character data after synchronization is sent via a parallel data line 8 to an information processing device not shown in the figure or to a control unit that controls the transmission procedure. It will be done.

The error check calculation circuit 2 detects the synchronization character and receives the following text, and also performs calculations for error checking, such as a cyclic redundancy check (CRC cyclic redundancy check).
dundancy check) is started and continues until the end of text reception.

When the reception of the text is completed, the content of the memory circuit 3 in which the expected value of the error check calculation result is stored is compared with the content of the error check calculation circuit 2 in the comparison circuit 4, and the comparison result is displayed on the status display line 5. The above control unit is notified via.

In this control section, when the reception of the text is completed and the error check result is displayed as OK on the status display line 5, a response frame 10 shown in FIG. 4 is returned to the transmitting side information processing device. FIG. 4 is a configuration diagram of a response frame in a conventional data communication system.

In FIG. 4, field 11 is a synchronization character string, and field 12 is an ACK character determined in advance in the transmission procedure.

[Problem that the invention seeks to solve]

However, in a data communication system with such a configuration, the error check calculation circuit 2, memory circuit 3, and comparison circuit 4 shown in FIG.
If a failure occurs in the status display line 5, etc., and the error check results are always good, the error in the received data cannot be recognized by the control unit, and furthermore, since the code in the response frame is predetermined, the transmitter Even in the information processing apparatus, the processing proceeds as if the transmission had been completed normally, and there was a drawback that failure could not be detected in either the information processing apparatus on the transmitting side or the receiving side.

The present invention solves the above-mentioned drawbacks, and aims to provide a data communication system that can check the validity of error checking processing of received data in a receiving side information processing device.

[Means for solving problems]

The present invention provides a data communication method that includes a communication means for performing data communication between a plurality of information processing apparatuses, and includes an error check calculation means for performing error check calculations on received data. The present invention is characterized by comprising means for including information corresponding to an error check code generated from the received data from the check calculation means in the response frame sent back to the side device.

[For production]

The present invention enables a receiving information processing device to transmit information by including information corresponding to an error check code generated from received data from an error checking means of the receiving information processing device in a response frame sent back to the sending information processing device. The validity of the error checking process of the received data can be checked by the transmitting side information processing device.

〔Example〕

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block configuration diagram of an error checking section of an information processing apparatus using a data communication method according to the present invention. In FIG. 1, data is transmitted from a transmitting side information processing device (not shown) to serial data transmission path 1.
The error check calculation circuit 2 performs calculations for error checking until the end of text reception.

The calculation result from the error check calculation circuit 2 and the contents of the memory circuit 3 in which the expected value of the error check result is stored are connected to the comparison circuit 4. The comparison result is sent from the comparison circuit 4 to the information processing device via the status display line 5 or to the control section 30 that controls the transmission procedure.The feature of the present invention is that the parallel transmission line surrounded by the dashed line It is 6. That is,
Information corresponding to the error check code generated from the received data from the error check calculation circuit 2 is added to the response frame via the parallel transmission path 6 and sent back to the source information processing device.

The operation of the data communication system configured in this way will be explained.

In FIG. 1, a serial data transmission line 1, an error check calculation circuit 2, a memory circuit 3, a comparison circuit 4, a status display '41A5
correspond to the transmission line, circuit j and signal line shown in FIG. 3, respectively, and a parallel transmission line 6 which is not shown in FIG. 3 and which transmits the calculation results of the error check calculation circuit 2 is added.

FIG. 2 is a configuration diagram of a response frame of the data communication system of the present invention, and the response frame 10.20 is obtained from the synchronization character string field 11, the ACK character field 12, and the parallel transmission line 6 shown in FIG. In particular, in the response frame 20, a field 21 for an error check code is added to further increase credibility.

As described above, the present invention provides a response frame in addition to the conventional method in which the error check result of received data sent from the transmitting information processing device is returned from the receiving information processing device to the transmitting information processing device as a response. By also including basic error check information, that is, information corresponding to the error check calculation result generated from the received data and the error check code on the transmitting side.

Failures that cannot be detected by the receiving information processing device can also be detected by the transmitting information processing device.

〔Effect of the invention〕

As explained above, the present invention includes information corresponding to an error check code in a response frame from the receiving information processing device and returns it to the transmitting information processing device, so that the receiving information processing device detects the error. This has the excellent effect that even failures that cannot be detected can be detected by the transmitting information processing device. Therefore, it is possible to prevent malfunctions such as data containing errors being processed normally due to a failure, so a highly reliable data communication system can be obtained. Furthermore, there is an advantage that the receiving side information processing apparatus can be diagnosed by transmitting data containing failure errors from the transmitting side, and the failure location can also be detected.

[Brief explanation of the drawing]

FIG. 1 is a block configuration diagram of an inspection section of an information processing apparatus using a data communication method according to the present invention. FIG. 2 is a configuration diagram of a response frame of the data communication system of the present invention. FIG. 3 is a block diagram of a serial data receiving section of an information processing apparatus using a conventional data communication system. FIG. 4 is a configuration diagram of a response frame in a conventional data communication system. DESCRIPTION OF SYMBOLS 1... Serial data transmission line, 2... Error check calculation circuit, 3... Memory circuit, 4... Comparison circuit, 5... Status display line, 6... Parallel transmission line, 7... ...Serial to parallel conversion circuit, 8...Parallel data line, 10.20...Response frame, 11...Synchronization character string field, 12...
ACK character field, 13...Error check calculation result field, 21...Error check code field,
30...A control unit that controls the information processing device or the transmission procedure. Patent Applicant: NEC Corporation -1 Agent: Patent Attorney Takaki Ide, 1 Kuchuni 3 Figure

Claims (1)

[Claims] (1) In a data communication system that includes a communication means for performing data communication between a plurality of information processing devices and includes an error check calculation means for performing error check calculations on received data, the receiving side device of the communication means has a transmitting side. A data communication system comprising means for including information corresponding to an error check code generated from data received from the check calculation means in a response frame sent back to the apparatus.