JPH05257852A - Process data processing system and processing method - Google Patents

Abstract

PURPOSE:To provide the process data processing system which is improved in control capacity by simplifying the response wait time control of a computer and shortening the processing time of the computer. CONSTITUTION:The rationality of address data and direction data as parameters is checked and when the result is O.K., a response as a normal end is sent back at the stage; and then the setting of address data in an address memory 44 and the setting of direction data in a direction memory 45 which require a long time are performed. If the address data and/or direction data as the parameter is abnormal, a response as parameter abnormality is sent back and the process ends. Consequently, the time between a command and the response becomes constant irrelevantly to whether the data to be processed are long or short, so the time control of the computer can be simplified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process data processing system, and more particularly to a process data processing system in which a plurality of communication control devices are connected by a transmission line and a cyclic communication system is adopted for data exchange between the communication control devices. The present invention relates to a system in which command data and response data to the command data are provided in a cyclic communication data frame, a process I / O device is remotely controlled by a command, and a response is efficiently returned.

[0002]

2. Description of the Related Art In a conventional cyclic communication system, a transmission side communication control device transmits information in a memory at regular time intervals, and each reception side communication control device receives the information with a constant delay time. Was becoming. In the computer connected to each receiving side communication control device, the received data is updated in the memory at fixed time intervals, so it can be used freely when needed and the data sent by the sending side communication control device can be used. Can be received by all the other communication control devices on the receiving side, so the computer connected to the communication control device on the transmitting side does not need to send data to each receiving station one by one, There is an advantage that the processing of the computer can be reduced.

Data to be subjected to cyclic communication is
JP-A-62-258534 and JP-A-57-20692
As can be seen in No. 4 etc., it is process data for process control, for example.

In Japanese Patent Laid-Open No. 258534/1987, a computer employs a cyclic communication system in which process data is transmitted or received at a constant cycle. The process data is collected by a computer connected to each communication control device in the network.

On the other hand, in JP-A-57-206924,
Install a dedicated controller for each process monitoring and control target,
A configuration is adopted in which those control devices are connected by a communication network and the load is distributed. The process control target is connected to the communication network via a plurality of process input / output devices, and each control device fetches necessary process control data from the subordinate process input / output devices to perform arithmetic processing, but is not under its own control. When the data of the process input / output device is needed, the data communication is executed with the control device that controls the process input / output device to obtain the necessary data.

Further, when sending a command instructing the transmission of a plurality of frames between a computer which constitutes one station and a communication control device, a method of shortening the waiting time of the computer is disclosed in, for example, Japanese Patent Laid-Open No. 1-2232852. Have been proposed to. In this method, an interface table storing a pointer during transmission processing and a latest pointer is provided between the computer and the communication control device to enable interruption by a command indicated by the latest pointer.

[0007]

In a conventional process control system using cyclic communication, a computer connected to a communication control device that constitutes a network inputs and outputs data to and from a process input / output device. If the process input / output device is far away, it is necessary to interpose another computer for data input / output with the process input / output device, which has a drawback of high cost.

An object of the present invention is to provide an inexpensive process data processing system which does not require a dedicated computer for data input / output to / from variously arranged controlled objects.

On the other hand, in the conventional distributed processing type process control device, each control device is configured to hold only the data of the process input / output device under its own control, so that the data held by other control devices are required. In such a case, it is necessary to perform data communication with the computer that holds the data at the required timing. During this data communication process,
There was a problem that the responsiveness of the system deteriorates and the control performance is impaired.

Another object of the present invention is to provide a high responsiveness, a flexible operation mode and a system constructability without causing a failure such as a non-mounting error on the control unit side even when the process input / output unit or the like is updated. And a process data processing system having

Further, in the conventional process control system,
When the process I / O device was changed, such as removing it, the control device was directly inputting / outputting data, so processing such as removing the process I / O device indicates that the process I / O device is not installed. Inviting mounting errors,
There is a problem that it becomes a fatal obstacle for the computer of the control device.

Another object of the present invention is to provide flexibility in the operation form of the process control system, and to perform maintenance work or the like.
It is to provide a process data processing system that does not affect the overall operation even if the process input / output device is removed.

An interface table for storing a pointer in the process of transmission and the latest pointer is provided between the computer and the communication control device, and in the method of interrupting by the command indicated by the latest pointer, the emergency transmission in the station is performed. Although the processing of required commands and data was rationalized, no improvement was seen between the other device, for example, the process input / output device.

That is, in a process control system having a command interface between a computer and a process input / output device, the computer often manages the time until a response arrives and determines the response wait timeout. If the response wait timeout time is different for each command, the computer must manage the response wait time for each command.
There is a problem that the number of types of time to be managed increases and the processing on the computer side becomes complicated.

Furthermore, for a command whose processing time is long and does not end within a fixed time, not only the time management from command issuance to response arrival cannot be unified, but also the processing becomes complicated and the processing time becomes long. There was a problem.

The most important object of the present invention is to reduce the types of time to be managed by the computer, simplify the processing on the computer side and reduce the load thereof as much as possible, and shorten the time for returning a response to a command of the process input / output device. In addition, it is to provide a process data processing system in which the processing time of the computer is shortened and the control capability of the system is improved.

[0017]

In order to achieve the above object, the present invention connects a plurality of communication control devices, each of which is connected with a control computer or a process control device, to a transmission line, and at least one communication control device. In the process data processing system including the data transmission means for cyclically transmitting the process data from the communication control device other than the transmission side communication control device, the computer transmits the control command in the cyclic frame data. Rationale of the control command included in the received frame data between the process input / output unit and the communication control unit connected to the process input / output unit, the process control unit including means for inserting and transmitting control data. And a normal end response in the frame data immediately after the check is completed. Process data with means for sending and returning as a parameter abnormal response, and means for executing control contents based on the control command and control data only when returning a normal end response and sending and sending the control result as a response in the frame data It proposes a processing system.

The process control device may include means for ignoring the control command when the control command identification number included in the received frame data is the same as the previous one.

In order to achieve the above object, the present invention cyclically transmits process data from at least one station among a plurality of stations connected to a transmission path at a predetermined cycle, and the process data other than the station on the transmission side is transmitted. In the process data processing method adopting a data transmission method in which a station receives the process data, a transmitting station puts a control command and control data in cyclic frame data to transmit, and a receiving station side receives the received frame data. Check the rationality of the control command included in, and immediately after the check is completed, it is returned as a normal end response or parameter abnormal response in the frame data, and only when the normal end response is returned, control is performed based on the control command and control data. Run the contents It proposes a process data processing method of transmitting placed as a response to your results in the frame data.

Also in this process data processing method,
When the control command identification number included in the received frame data is the same as the previous one, the control command can be ignored.

[0021]

In the present invention, since each computer has all the data to be controlled by the process input / output device, the necessary data can be obtained by referring to its own memory. Therefore, inter-computer data communication for data acquisition is not required, and system responsiveness and control performance are improved.

The response transmitting means sets the mounting information of the process input / output device by a command from the computer, and changes the mounting information when the process input / output device is changed. If you reissue the command there, no unimplemented error will occur. Since the computer takes in the data sent by the response sending means via its own communication control device and process data memory, no unimplemented error occurs on the computer side.

When acquiring data from a process control target, the computer simultaneously accesses the address on the process input / output control device of the data to be acquired and the address on the memory for storing the data in sequence, and performs cycle access at a predetermined cycle. Send to click. If the cycle is sufficiently shorter than the rate of change of the process, the latest data can be acquired with the required accuracy.

Since the computer is not directly connected to the process control device but is indirectly connected via the process data memory, the system constructability is improved and the process control device can be disconnected for maintenance. The property is also good.

In the present invention, particularly, the rationality of the control command included in the received frame data is checked, and regardless of the length of the data to be processed, the normal end response or the parameter abnormality is immediately recorded in the frame data immediately after the check is completed. Send and return as a response. And
Only when the normal end response is returned, the control contents are executed based on the control command and the control data, and the control result is put in the frame data as a response and transmitted. Therefore, regardless of the length of the data to be processed, the computer reads the response data from the process I / O device after a certain period of time has elapsed since the command was issued, and determines whether the issued command ended normally or abnormally. Good. Therefore, it is not necessary to constantly monitor the arrival of responses, and the load on the computer is reduced. Further, even if the response data is read after the elapse of a certain time, if the response does not arrive, it is possible to immediately determine that the response has timed out, so that special timer management is unnecessary.

The original processing of the command and data after returning the response is executed by using the idle time of the command processing after the next command. Since the command-to-command interval is fixed, it is always possible to secure a free time.

Since all commands are completed within a fixed time, it is not necessary for the computer to set the response waiting time in consideration of the processing contents of the command, and the response waiting time for the command can be managed uniformly.
This also reduces the burden.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the process control system according to the present invention will be described below with reference to FIGS. Figure 1
FIG. 1 is a block diagram showing an overall configuration of an embodiment of a process control system according to the present invention. The process control system includes a plurality of computers 1 and 2 for controlling the processes of a process control target 60 in a distributed manner, and communication control devices 30, 31, 32, 33 connected in a ring shape by a communication path 70, for example.
And the process data memories 10 and 11 respectively connected between the computers 1 and 2 and the communication control devices 30 and 31.
And the memory control devices 20 and 21 for managing the input / output of the process data memories 10 and 11 and the cycle of cyclic communication, respectively.

The process control system also includes process input / output devices 50 and 51 provided between the communication control devices 32 and 33 and the controlled object 60, and a scanning device for scanning the process input / output devices 50 and 51, respectively. 40,
41, each scanning device 40, 41, and communication control device 3
Process data memories 12 and 13 and process data memories 12 and 13 respectively connected between
And memory control devices 22 and 23 which respectively manage the input / output and cyclic communication cycles.

FIG. 2 is a block diagram showing in more detail the relationship among the computer, process data memory, memory controller and communication controller of the embodiment of FIG. The computer 1 includes a central processing unit (CPU) 80, a data memory 81, a program memory 82, and an address bus 8 connecting these.
3 and a data bus 84. The address bus 83 and the data bus 84 are used as the process data memory 10
And a memory controller 20. The process data memory 10 and the memory control device 20 are connected to the communication control device 30 by another set of address bus and data bus, respectively.

Computer 2, process data memory 1
1, the configuration of the communication control device 31 is the same as that of the computer 1, the process data memory 10, and the communication control device 30.

The CPU 80 executes a necessary calculation using the process data of the controlled object 60 stored in the data memory 81 according to the program stored in the program memory 82, and executes the process via the communication control device 30. The process of the controlled object 60 is controlled. In order to realize this control, it is necessary to determine the transmission area and the reception area in the process data memory 10 and the transfer cycle.

As shown in FIG. 4, the CPU 80 divides the process data memory 10 into areas according to the program stored in the program memory 82. Uppercase letters such as A and E shown in the process data memory 10 represent transmission areas, and lowercase letters such as b, c, and d represent reception areas. This notation method using uppercase and lowercase letters is the same for the other process data memories 11, 12, and 13, and the uppercase letters represent the transmission area and the lowercase letters represent the reception area. The CPU 80 writes the control data for dividing the area and the transfer cycle in the memory control device 20.

The communication controller 30 is the memory controller 20.
The data is retrieved from the process data memory 10 and transmitted according to the setting information written in. Also, communication path 7
Capture the data in the received frame sent with 0,
This data is written in the process data memory 10.

Therefore, the computer 1 can transmit / receive process data and control the process control target 60 by writing data in the process data memory 10 or reading data from the process data memory 10 at a predetermined timing.

FIG. 3 is a block diagram showing the connections of the processor input / output device 50, the scanning device 40, the process data memory 12, the memory control device 22 and the communication control device 32 in more detail. In the scanning device 40, the processing device 42, the program data memory 43, the address memory 44, and the direction memory 45 are connected by the address bus 83 and the data bus 84. The address bus 83 and the data bus 84 are connected to the external process data memory 12
And the memory controller 22. The external process data memory 12 and the memory control device 22 are connected to the transfer control device 47. The transfer control device 47 is
Further, it is connected to a counter 46 for knowing the transmission timing. The transfer control device 47 controls reading and writing of data between the process data memory 12 and the process input / output device 50.

When the power is turned on, the scanning device 40 separates the transmission area and the reception area as indicated by a, b, c and d shown in FIG. 4 at 12, for example, the area a is the computer 1. The area for receiving a command from c and the area for sending a command are determined in advance as an area for sending a response to a command.
The other areas e, f, g, and h are not yet classified when the power is turned on because they are classified by the command. The division information of the command response area is set in the memory control device 22 connected to the scanning device 40 so that the command from the computer 1 can be received.

FIG. 5 is a diagram showing an embodiment of the structure of command data according to the present invention. In this embodiment, in the command format, the partner device number A1, the command A2,
It has a command identification number A3 and data A4, and transmits a command issuing partner A1, command processing contents A2 and A3, and data A4 associated with the command.

FIG. 6 is a flow chart showing the processing procedure of command acquisition and command execution of the scanning device of the embodiment of FIG. On the scanning device 40 side, the command format is referred to and the command is processed in the procedure shown in FIG. The scanning device 40 determines whether the command is addressed to itself, and if the command is addressed to itself, determines whether the command identification number is different from the previous command identification number. This process prevents processing the same command multiple times. If the command identification number is different from the previous one, the command is processed, and the processing result is written in area G in FIG. 4 as a response. The content to be written is information such as whether command processing has been completed normally, there is an error, or there is an error in the command parameter.

The control contents by the command will be described below. First, data is set in the address memory 44 and the direction memory 45. Data for associating the X address of the process data memory 12 with the Y address of the process input / output device 50 is set in the address memory 44. Further, the direction data indicating whether the access direction is from address X to address Y or address Y to address X is set in the direction memory 45. Next, the separate data of the e, f, G, and h areas and the transfer cycle are set by another command. In response to the command, the scanning device 40 writes, in the memory control device 22, data that determines the transmission / reception division and cycle of the e, f, G, and h areas. The communication control device 32 starts the operation of transmitting and receiving the areas e, f, G, and h from this point based on the written data of the division and the cycle. Finally, for the scanning device 40,
Issue a command instructing the start of data transfer between the process data memory 12 and the process input / output device 50,
The process data of the process control target 60 is exchanged between the process data memory 12 and the process input / output device 50.

When the above processing is carried out for all of the computers 1, 2 and the scanning devices 40, 41, the process data memories 10, 11, 12, 13 are divided as shown in FIG. In addition, each scanning device 40 and 41
Can execute data transfer between the process control target 60 and the process data memories 12 and 13, respectively.

In this state, for example, if the computer 1 sets data in the transmission area E, each of the scanning devices 40, 41
Transfers the data set in the transmission area E. Therefore, the transfer control device 4 in each scanning device 40, 41
7 transfers a control signal to the process control target 60 via the process input / output devices 50 and 51.

For transfer in the reverse direction, the transfer control device 4
7 writes the process data of the process control target 60 in the respective transmission areas G and H of the process data memories 12 and 13 and transmits it to the areas g and h of the computers 1 and 2, so that the process data can be freely set on the computer side. Can be used. When the process data memories 10, 11, 12, and 13 are set as shown in FIG. 4, each computer 1 and 2 holds all process data, and data communication between the computers is unnecessary.
The processing load on the computer is reduced.

FIG. 7 shows an address data setting process which is one of the "processes according to the command" in FIG. 6, that is, a data setting process procedure unique to the present invention to the address memory 44 and the direction memory 45, and a subsequent response returning process. It is a flowchart which shows the procedure together. When a large amount of data is set, it takes a long time in the conventional apparatus to check the rationality of the address information as a parameter and set the data in the address memory 44 and the direction memory 45.

On the other hand, in the present embodiment, the rationality of the address data and the direction data as parameters is checked, and if OK, a response of normal termination is returned at that stage, and after that, an address that takes time is taken. A method of executing setting of address data in the memory 44 and setting of direction data in the direction memory 45 is adopted. On the other hand, if there is an abnormality in the address data and / or the direction data as a parameter, a response indicating that the parameter is abnormal is returned and the process ends.

Therefore, according to the present embodiment, the reasonableness of the address data and the direction data as parameters is checked, and if OK, a response of normal end is returned, that is, the length of the data to be processed is short. However, before the command processing is completed, the response is returned at a nearly constant time from the command reception, and the time management processing of the computer can be centralized and simplified, reducing the processing time of the computer and controlling the system. Can be increased.

[0047]

According to the present invention, the time between the command and the response is constant regardless of the length of the data to be processed, so that the time management processing of the computer can be unified and simplified. The processing time can be shortened and the controllability of the system can be improved.

Since the address to be scanned can be set by the command, the system can be easily constructed, and the process input / output device and the computer can be easily separated by changing the setting of the address to be scanned, and the maintenance work can be executed.

Since each computer has all data to be controlled by the process input / output device, necessary data can be acquired by referring to its own memory. Therefore, inter-computer data communication for data acquisition is not required, and system responsiveness and control performance are improved.

The acquisition of data from the process control target is
The address of the data to be acquired on the process input / output control device and the address on the memory for storing the data are simultaneously accessed in order, and transmitted at a predetermined cycle by cyclic communication. If the cycle is sufficiently shorter than the rate of change of the process, the latest data can be acquired with the required accuracy.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of an embodiment of a process control system according to the present invention.

2 is a block diagram showing the relationship among a computer, a process data memory, a memory controller, and a communication controller of the embodiment of FIG. 1 in more detail.

FIG. 3 is a block diagram showing a detailed configuration of a scanning device according to the embodiment of FIG.

FIG. 4 is a diagram illustrating a method of transferring a command of cyclic communication and a method of transferring process data.

FIG. 5 is a diagram showing an embodiment of the structure of command data according to the present invention.

FIG. 6 is a flowchart showing a processing procedure of command acquisition and command execution of the scanning apparatus of the embodiment of FIG.

7 is an address data setting, that is, an address memory 44, which is one of the "processing according to the command" in FIG.
9 is a flowchart showing a data setting processing procedure unique to the present invention to the direction memory 45 and a response returning processing procedure that follows.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 computer 2 computer 10 process data memory 11 process data memory 12 process data memory 13 process data memory 20 memory control device 21 memory control device 22 memory control device 23 memory control device 30 communication control device 31 communication control device 32 communication control device 33 communication Control device 40 Scan device 41 Scan device 42 Processing device 43 Program data memory 44 Address memory 45 Directional memory 46 Counter 47 Transfer control device 50 Process input / output device 51 Process input / output device 60 Process control target 70 Communication path 83 Address bus 84 Data bus

Claims (4)

[Claims] 1. A plurality of communication control devices, each of which is connected with a control computer or a process control device, are connected to a transmission line, and process data is cyclically transmitted from at least one of the communication control devices, and the transmission side communication control is performed. In a process data processing system provided with a data transmission means for communication control device other than the device to receive the process data, the computer comprises means for putting and transmitting a control command and control data in cyclic frame data, The process control device, between the process input / output means and the communication control device connected to the process input / output means,
A means for checking the rationality of the control command included in the received frame data, a means for returning and returning a normal end response or a parameter abnormal response in the frame data immediately after the completion of the check, and a case where the normal end response is returned A process data processing system comprising: means for executing a control content based on the control command and the control data, and inserting a control result in the frame data as a response for transmission. 2. A plurality of communication control devices, each of which is connected with a control computer or a process control device, are connected to a transmission line, and process data is cyclically transmitted from at least one of the communication control devices, and the transmission side communication control is performed. In a process data processing system provided with a data transmission means for communication control device other than the device to receive the process data, the computer comprises means for putting and transmitting a control command and control data in cyclic frame data, The process control device, between the process input / output means and the communication control device connected to the process input / output means,
Means for ignoring the control command when the control command identification number included in the received frame data is the same as the previous time, and means for checking the rationality of the control command included in the received frame data that has not been ignored. , A means for inserting and returning a normal end response or a parameter abnormal response in the frame data immediately after the completion of the check, and when the normal end response is returned, executes the control contents based on the control command and the control data, and displays the control result. A process data processing system, characterized in that the process data processing system further comprises means for inserting and transmitting as a response in the frame data. 3. A data transmission method in which process data is cyclically transmitted from at least one station among a plurality of stations connected to a transmission path at a predetermined cycle, and stations other than the transmission side station receive the process data. In the process data processing method employing the above, the transmitting side station puts the control command and the control data in the cyclic frame data and transmits the cyclic frame data, and the receiving station side executes the rationalization of the control command included in the received frame data. Check the data, and immediately after the completion of the check, put it back in the frame data as a normal end response or a parameter abnormal response, and send it back.
A process data processing method characterized in that, when the normal termination response is returned, the control content is executed based on the control command and the control data, and the control result is put in the frame data as a response and transmitted. 4. A data transmission system in which process data is cyclically transmitted from at least one station among a plurality of stations connected to a transmission path at a predetermined cycle, and stations other than the transmission side station receive the process data. In the process data processing method employing the above, the transmitting side station puts the control command and the control data in the cyclic frame data and transmits, and the receiving station side, the control command identification number included in the received frame data is If it is the same as the previous time, the control command is ignored, the rationality of the control command included in the received frame data that was not ignored is checked, and immediately after the check is completed, a normal end response or parameter abnormality is included in the frame data. Put in as a response Feed to the process data processing method and transmitting putting execution control results control content on the basis the said control commands when returns a normal end response to said control data as a response to the frame data.