JPH07146827A - Data transfer method in network - Google Patents

Abstract

PURPOSE:To increase the processing speed of an information data transfer method between data processing stations arranging frame inspection sequence for right/wrong discrimination of reception information starting from flag sequence at the end of an information main body part and setting a message frame ending by completion flag sequence in transfer unit via a network. CONSTITUTION:A position information part 35 consisting of a memory position code, a data number code, and leading part inspection sequence is arranged between the header 31 of the message frame 3 and the information main body part 32, and when a part up to the position information part 35 of the frame message 3 is received by the data processing station 1, the header position 31 and the right/wrong reception of the position information part 35 are inspected by the leading part inspection sequence 353 of the position information part 35, and when it is confirmed that they are received correctly, the data in the information main body part 32 is directly written in the reception data area of the main memory 13 of the data processing station 1 designated by the header part 31 decided by the memory position code and the data number code.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network system such as a distributed control system in which information data is transferred and processed through a network, and a data processing station such as a controller connected to the network processes each data via the network. The present invention relates to a data transfer method when updating and replacing.

[0002]

2. Description of the Related Art FIG. 2 (a) shows a block configuration centering on a communication control unit of a data processing station for transmitting / receiving information data via a network to exchange / update data by a conventional method. The structure of the message frame 3 as an information data transfer unit in the system is shown in FIG. 2 (b), and the prior art will be described below with reference to FIGS. 2 (a) and 2 (b).

In FIG. 2 (b) showing the structure of the message frame 3, 311 and 34 are start and end flag sequences which also function as an identifier for notifying the start and end of one unit of information data and a synchronizing signal in transmission. , 312 is an address part indicating the destination or the source of the message frame to be transmitted, 313 is a control part indicating the operation command to the transmission destination station, or the response of the reception source station to the command, and the above start flag The sequence 311, the address part 312, and the control part 313 form the header 31. The data body to be transmitted is stored in the information body section 32, and at the end of the information body section 32, a key (Key) for confirming whether the contents of the header 31 and the information body section 32 have been correctly transferred. A frame check sequence (hereinafter abbreviated as FCS) that functions as a), and the above-mentioned termination flag sequence 34 is arranged at the end to terminate the message frame 3.

In FIG. 2A showing the block configuration of the data processing station 1 for receiving the message frame 3 having the above-mentioned configuration, 11 is a main CPU which controls the execution of the basic functions of the data processing station 1, and 12 Is a main memory in which information data relating to the operation of the main CPU is stored. Reference numeral 2 denotes a communication control unit for controlling reception and storage of received information in the data processing station 1. The receiver 21 has a demodulation function, the reception control unit 22,
It is composed of a communication control CPU 23 and a reception buffer 24.

When a modulated serial signal containing the message frame 3 in the arrangement of FIG. 2B is transmitted from another or higher-order data processing station and placed on the network, communication control of the data processing station 1 is performed. The receiver 21 of the unit 2 demodulates this signal and inputs the contents of the message frame 3 as serial data to the reception control unit 22.

The reception control unit 22 converts the input serial data into parallel data and temporarily stores it in the reception buffer 24, and at the same time monitors the received message frame 3 passing through the reception control unit 22 and receives the FCS. At this time, the presence or absence of a reception error in the message frame 3 received by this FCS is checked, and the result is notified to the communication control CPU 23.

When the communication control CPU 23 receives from the reception control unit 22 a notification that the reception inspection result of the message frame 3 is positive, the contents described in the address section 312 of the header 31 of the message frame 3 stored in the reception buffer 24. Is read to determine whether or not there is an instruction to fetch the data of the information body 32 of the message frame 3 into the data processing station. If fetching is required, the contents of the address section 312 and the control section 313 are read. The address of the reception data storage area in the main memory 12 of the data processing station is generated by the information main body section 32 of the message frame 3 stored in the reception buffer 24 in the address area.
Transfer data.

On the other hand, when the communication control CPU 23 determines that the fetching of the message frame 3 into the data processing station 1 is unnecessary, and when the communication control CPU 23 receives the report that the FCS inspection result is invalid, the communication control CPU 23 receives the message. A process of discarding the message frame 3 stored in is performed.

[0009]

In the above conventional network data transfer method, the message frame 3
Once all the messages that compose the message are stored in the reception buffer 24 of the data processing station 1, the reception control result of the frame data in the reception control section 22 is confirmed, and then the data of the information main body section 32 in the message frame 3 is rechecked. Since the transfer processing to the main memory 12 of the reception data processing station 1 is performed, the transfer processing operation is performed twice when receiving one message frame 3. For this reason,
It takes a long time from the reception of one message frame to the transition to the reception operation of the next message frame. Further, the address of the main memory storage area of the new data received by each data processing station of the data processing station is based on the contents described in the header 31 of the message frame 3 based on a predetermined rule.
Communication control CPU 23 of each data processing station
Therefore, when various types of data are received, there is a problem that management / registration of the storage address becomes complicated and the processing time becomes long.

The present invention solves the problems of the above-mentioned conventional data transfer method in a network, provides means for shortening the cycle of a message frame reception cycle, and provides a distributed control system and the like constructed on this network. The purpose is to increase the processing speed of the network system and enhance the system function.

[0011]

[Means for Solving the Problems] To achieve the above object,
In the method of the present invention, a frame inspection sequence for determining whether the received information is correct or not is arranged at the end of the information main body having a header beginning with a flag sequence at the beginning, and a message frame ending with the end flag sequence is transmitted through the network. In a data transfer method in which information data is transferred between data processing stations, a position information section consisting of a memory position code, a data number code, and a head inspection sequence is arranged between the header of a message frame and the information body section. I have decided. Then, at the data processing station, when the position information part of the message frame is received, the header section and the position information part are inspected for correctness by the head part inspection sequence of the position information part, and it is confirmed that they have been correctly received. In this case, the data of the information body of the message frame is directly written into the received data storage area of the main memory of the data processing station specified by the header, which is determined by the memory position code and the data number code of the position information section, and the frame inspection is performed. When the inspection result of the received data by the sequence is judged to be incorrect,
Access to the data written in the received data storage area of the main memory is prohibited.

[0012]

When the message frame having the above configuration is placed on the network, when the data processing station connected to the network receives up to the position information section of the message frame, the header and the position information section of the position information section are checked by the address check sequence of the position information section. When the message is checked for correctness and it is confirmed that the message was received correctly, the contents of the header are analyzed and the message is stored in the received data storage area of the main memory specified by the position information section of the data processing station specified by the header. When the data of the information body of the frame is stored and the frame inspection sequence is received, it is inspected whether the data stored by this sequence is received correctly and it is determined that it is not received correctly. Sometimes written to receive data storage area Access of the data is prohibited.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A block configuration centering on a communication control unit of a data processing station for receiving and refreshing data according to the method of the present invention is shown in FIG. The structure of the loaded message frame is shown in FIG. 1B, and the present invention will be described below with reference to this figure.

In the structure of the message frame shown in FIG. 1B, the header 31, the frame check sequence 33, and the termination flag sequence 34 as well as the information body 32, which is the information data body, are formed by the conventional method. It is a constituent element of a message frame having a content function equivalent to that of the corresponding portion to which the same reference numeral is assigned in the constitution of the message frame shown in 2 (b).

On the other hand, the position information part 35 is a part inserted and arranged between the header 31 and the information part 32 according to the present invention.
It is composed of a memory position code 351, a data number code 352, and a head inspection sequence 353, which are codes representing the information of the contents described in 1) to 3) below. 1) Memory position code; divided in the received data storage area in the main memory 13 of the data processing station 1 for storing the data of the information section 32 which is the information data body of the received message frame, corresponding to each transmission source data processing station Information related to generation of a data storage area such as the start address of the created block.

2) Data number code: Information such as the number of data bytes indicating the length of the data placed in the information section 32. 3) Leading part inspection sequence; header 31 and position information part 35
A check sequence consisting of a cyclic code method (CRC) or an inverted information method for checking whether or not the contents specified in 1 are correctly received in the data processing station 1.

In the data processing station having the block structure shown in FIG. 1A for receiving the message frame to which the position information section is added, reference numeral 11 denotes a main CPU which executes the basic functions of the data processing station 1. , 13 are main memories in which information data relating to the operation of the main CPU 11 is stored. This main memory 13
Is a redundant memory 13 with the same address assigned.
a and 13b, and memories 13a and 13b
Is divided into blocks corresponding to each data processing station of the transmission source. Which of the memories 13a and 13b is selected is determined by the switch 14 for each block.
Reference numeral 2 is a communication control unit that controls the reception and storage of the reception information in the data processing station 1, and includes a receiver 21 having a demodulation function, a reception control unit 22, and a communication control CPU.
28 and a memory position information buffer 25 and an output lock unit 26 provided by the present invention.

In the data processing station having the above-mentioned configuration, the elements denoted by the same reference numerals as those in FIG. 2A function similarly to those in FIG. When a modulated serial signal containing the message frame of the arrangement of FIG. 1B is transmitted from another or higher order data processing station, the receiver 21 of the communication control unit 2 of the data processing station 1 receives the received signal. Reception control unit 22 by demodulating the
To enter.

The reception control unit 22 converts the input serial data into parallel data, stores the data up to the header 31 of the message frame 3 and the position information unit 35 in the head information buffer 25, and controls the reception control unit 22. The frame data passing through is monitored, and when the leading portion or the frame inspection sequence is received, it is inspected by the inspection sequence whether or not the data arranged before the inspection sequence is correctly received, and the inspection result is sent to the communication control CPU 28.
To notify.

When the data processing station of the network system according to the present invention in which the message frame 3 has the structure shown in FIG. 1 (b), the first inspection sequence detected is the leading inspection sequence.
353, and if the inspection result by this inspection sequence is determined to be positive, the communication control CPU 28 reads the contents described in the address part 312 of the header 31 stored in the head information buffer 25, and reads the message frame information body. Department
If it is necessary to import 32 data to the data processing station, the output lock unit is judged.
Memory position code 351 and data number code 35 with 27 open
Control is performed so that the data of the information main body 32 of the message frame 3 is directly written in the received data storage area of the main memory 13 determined by 2. For example, it is assumed here that the data is written to the memory 13a side by the switch 14. At this time,
The main CPU 11 uses the information in the memory 13b by the switch 14.

Then, the frame check sequence (FCS) 33 at the end of the message frame is received, and this FC
When the inspection result of the reception control unit 22 of the reception data by S is determined to be positive, the switcher 14 causes the communication control CPU 28
The main CPU 11 receives the switching notification from the memory 13a.
Information can be used and the next received data can be stored in the memory 13b. On the other hand, when the inspection result is determined to be incorrect, the switching notification is not sent from the communication control CPU 28 to the switch 14, so the main CPU 11 uses the information in the memory 13b as before. At this time, the reception data stored in the memory 13a is held until the next reception data is stored.

On the other hand, when the address part of the header does not specify the data processing station and when the inspection result by the position inspection sequence 353 is determined to be incorrect, the communication control CPU 28 closes the output lock part 27 and the message frame. The data stored in the information section 32 is prevented from being written in the main memory 13.

[0023]

When data is transferred through the network according to the method of the present invention, the data in the information body of the message frame is transferred directly to the main memory of the data processing station designated to receive the data. The effect that is improved is obtained.

On the other hand, a method of directly writing data in the main memory of the data processing station is used. However, after confirming that the header and the position information section of the message frame 3 have been correctly received by the data processing station, the information of the message frame is displayed. The data of the main body is written as the data for updating the old data written in the area defined by the memory position code 351 and the data number code 352 of the position information part 35 of the message frame of the main memory of the data processing station specified by the header. So,
Data of a type that does not belong to the division of the received data storage area is erroneously written in the reception data storage area of the main memory that is divided corresponding to the division of the information data, and the original stored data is destroyed. There is no end. The head information buffer required for the reception inspection of the header portion and the position information portion does not need to hold the information of the entire message frame 3, so that it is possible to prepare a small-capacity storage area. To be

[Brief description of drawings]

FIG. 1 is a diagram showing a block configuration of a data processing station for performing data transfer by the method of the present invention and a configuration of a message frame as a transfer unit.

FIG. 2 is a diagram showing a block configuration of a data processing station for performing data transfer according to the related art and a configuration of a message frame according to the related art.

[Explanation of symbols]

 1 data processing station 2 communication control unit 3 message frame 11 main CPU 12, 13 main memory 14 switcher 21 receiver 22 reception control unit 23, 28 communication control CPU 24 reception buffer 25 start information buffer 27 output lock unit 31 header 32 information body Part 33 Frame inspection sequence 34 End flag sequence 35 Position information part 311 Start flag sequence 312 Address part 313 Control part 351 Memory position information part 352 Data length information part 353 Start part inspection sequence

Claims (1)

[Claims] 1. A network frame is provided with a frame check sequence for determining whether the received information is correct or not at the end of an information main body having a header beginning with a flag sequence at the beginning through a network, and a message frame ending with a termination flag sequence as a transmission unit. In a data transfer method for transferring information data between data processing stations, a position information section consisting of a memory position code, a data number code, and a head inspection sequence is arranged between a header of a message frame and an information body section, When the data processing station receives the header of the message frame and the position information part, it checks the reception correctness of the header and the position information part by the head part inspection sequence of the position information part, and when it is confirmed that they are received correctly. , The data specified by the header The data of the information body of the message frame is directly written to the received data storage area of the main memory of the processing station, which is determined by the memory position code of the position information section and the data number code, and the check result of the received data by the frame check sequence is incorrect. When it is determined that the data is written, the access to the data written in the received data storage area of the main memory is prohibited.