JP3644984B2 - Process control device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a process control apparatus in which an operator console and a calculation control apparatus are connected by communication means such as a communication LAN.
[0002]
[Prior art]
Conventionally, as shown in FIG. 1, an operator console 6 having an input device 1, a CPU 2, a RAM 3, a CRT device 4, and a communication device 5, and a plurality of units connected by a communication LAN 7 via the communication device 5 of the operator console 6. the arithmetic and control unit _{28-1, 8-2,} ..., there is a process control system consisting of 8 _-n. In this type of process control device, communication between the operator console 6 and the arithmetic control devices 8 ₋₁ , 8 ₋₂ ,..., 8 _-n includes broadcast communication for communicating between the devices at regular intervals, and operator Asynchronous event communication such as a parameter change command from the console 6 to the arithmetic control devices 8 ₋₁ , 8 _{−2 ,.}
[0003]
[Problems to be solved by the invention]
In the process control system, an asynchronous communications, replies the arithmetic and control unit _28-1 corresponding to the command, _8-2, ..., back to the operator console 6 from 8 _-n. This response includes the result of communication (success, failure). When sending asynchronous communication commands continuously in time, the next command is sent until a certain command is sent and the result is received. Cannot be sent. This is because, when a plurality of commands are sent at a time, when receiving a response to them, it may not be possible to identify which command is the response.
[0004]
The present invention has been made paying attention to the above problems, and even if commands are continuously sent from the operator console, if there is a response from the arithmetic and control unit, it is possible to identify which command is the response. The object is to provide a process control device.
[0005]
[Means and Actions for Solving the Problems]
The process control device of the present invention is a process control device comprising a program storage means loaded with one or more application programs and an operator console including a communication device, and one or more arithmetic control devices connected via the communication device. A first identification number assigning means for assigning a unique identification number unique to each command to a communication command from the application program, and when sending the communication command from the communication device to the arithmetic and control unit, A second identification number giving means for giving a unique identification number unique to the command, a first identification signal as a response between the application and the communication device, and a response between the communication device and the arithmetic control device The second identification signal is used.
[0006]
According to this process control device, when receiving a communication command with a first identification signal from the application program of the operator console, the communication device stores the communication command and the first identification signal, and stores them in the arithmetic control device. A communication command is transmitted with a second identification signal corresponding to the arithmetic and control unit, and the second identification signal is stored. When there is a response from the arithmetic and control unit, it is possible to know whether the response is from the arithmetic and control unit by referring to the second identification signal, and to which application by referring to the first identification signal You can know if it is a response to the program.
[0007]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples.
The hardware configuration of the embodiment process control apparatus is basically the same as that shown in FIG. The characteristic part of the process control apparatus of this embodiment is conceptually shown as shown in FIG. 2, and the communication apparatus 5 is operated by the arithmetic control apparatus 8 in response to communication commands from the application programs 9 _{−1 ,. -1} ,..., 8 _-n are given communication commands, a response is obtained, and they are returned to the application programs 9 _{-1 ,.} Each of the communication responses between the application programs 9 ₋₁ ,..., 9 _-n and the communication device 5 and the communication responses between the communication devices 5 and the arithmetic control devices 8 _{−1 ,.} A number is provided.
[0008]
In this process control apparatus, when a communication command is sent from the application programs 9 _-1 ,..., 9 _-n to the communication apparatus 5, the application program sends out a first identification number. The communication device 5 stores the combination of the received communication command and the first identification number in its own transmission waiting buffer. Further, the communication command is sent out to the appropriate arithmetic control device 8- _i with the second identification number newly determined by the communication device 5, and stored in the response waiting buffer. Further, the communication command received from the application program 9 ₋₁ ,..., 9 _-n is associated with the second identification number. The arithmetic control devices 8 ₋₁ ,..., 8 _-n receive a command and perform a predetermined process according to the command. Thereafter, the response is returned with the second identification number attached to the command. Based on the received response and the second identification number, the communication device 5 searches for the original communication command received from the application program 9- _i from its own response waiting buffer. Based on this, the application to be returned and the first identification number are recognized, a response to the application program 9 _-1 ,..., 9 _-n is created, and the application program 9 _-1 is attached with the first identification number. Return to 9- _n . The application programs 9 ₋₁ ,..., 9 _-n can recognize which command is the response based on the response and the first identification number.
[0009]
FIG. 3 is a conceptual model block diagram showing still another embodiment. This embodiment is a simple process control device composed of two application programs 9 _-1 and 9 _-2 and one arithmetic control device 8. The application program _9-1 is an application that displays a screen on the CRT device 4 of the operator console 6 and accepts a driver's operation on the operator console 6. The application program 9 _-2 is an application that does not display a screen on the CRT device 4 of the operator console 6 and does not perform a driver's operation on the operator console 6. The application program _9-1 and the application program _9-2 transmit a communication command to the same arithmetic control device 8 via the communication device 5 and receive a response via the communication device 5.
[0010]
Further, the application program _9-1 transmits M communication commands to the arithmetic and control unit 8 and receives M responses according to the operation of the driver. For example, a control parameter change command from the operator console 6 to the arithmetic and control unit 8 corresponds to this. The application program _9-2 transmits N communication commands to the arithmetic and control unit 8 at regular intervals and receives N responses regardless of the operation of the driver. For example, this corresponds to the case where the control parameter is instructed to change at a fixed time.
[0011]
In the process control apparatus of this embodiment, the operation proceeds in the following flow. First, when a communication command is sent from the application programs 9 ₋₁ ,..., 9 _−n to the communication device 5, the identification number (first) is added and sent. In the communication device 5, as shown in FIG. In the determination NO (step ST1), there is a communication command from the application program or waiting (step ST2). When the communication command is entered, the set of the communication command and the identification number is copied to its own transmission waiting buffer. (Step ST3). Then, it is determined whether there is a next communication command (step ST4). If there is, the set of the communication command and the identification number is copied again to the next empty area of the transmission waiting buffer. If there is a command, this process is repeated as long as the transmission waiting buffer capacity permits.
[0012]
In a state where no communication command is sent, it is determined whether there is a command stocked in the transmission waiting buffer (step ST5). If there is a command, the command is taken out from the transmission waiting buffer (step ST6), and is sent to a frame for transmission. Conversion is performed (step ST7). In this case, an identification number for frame identification is stored in the frame. Then, the frame is transmitted to the communication LAN 7 (step ST8). At this time, the communication device 5 stores the application identification information, the message identification number given by the application, the frame identification number (second) given by the communication device, and related information such as the message content in the response waiting buffer ( Step ST9).
[0013]
The arithmetic and control unit 8 receives the command and performs a predetermined process according to the command. A response such as the calculation result is returned with the identification number attached to the communication command.
On the other hand, after transmitting the frame, the communication device 5 further determines whether there is a waiting command in the transmission waiting buffer (step ST10), and if there is, returns to step ST6, extracts the command from the transmission waiting buffer, and step ST7. Processes -ST9 are performed, and new transmission data is transmitted to the communication LAN 7.
[0014]
If there is no standby command in the transmission waiting buffer, the determination in step ST10 is NO, and then it is determined whether a response is received (step ST11). If there is a response received, the identification number (second) is extracted from the response frame (step ST12), and the identification number of the extracted frame is compared with the identification number stored in the response waiting buffer to determine whether or not they match. (Step ST13).
[0015]
If there is a match, the application identification information and the message identification number given by the application are extracted from the information (ST14), converted into a message to be returned to the application program _9-1 , ..., 9- _n (step ST15), and the application The given message identification number is added and transmitted to the application programs _9-1 , ..., 9- _n (step ST16). Thereafter, it is determined whether there is a reply waiting command (step ST17). If there is no other command in the place where there is a response waiting command in ST1, the process returns to ST11 through ST4, ST5, ST17, and the same processing is performed.
[0016]
The application programs 9 _-1 ,..., 9 _-n can recognize which command the response is based on the response and the identification number.
[0017]
【The invention's effect】
According to this invention, the first identification number giving means for assigning a unique identification number unique to each command to the communication command from the application program to the communication device, and the communication device to the arithmetic control device. A second identification number giving means for giving a unique identification number unique to each command when sending the communication command, and a first identification signal in a response between the application and the communication device, Since the second identification signal is used for the response between the communication device and the arithmetic control device, the communication command and response between the application program and the communication device, the communication device and the arithmetic control device can be uniquely identified, The command can be sent to the next without waiting for a response to the command. As a result, asynchronous communication that fully utilizes the bandwidth of the communication LAN can be performed, so that the processing time of the application program of the operator console can be shortened.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a hardware configuration of a process control apparatus employing a communication LAN.
FIG. 2 is a block diagram showing a schematic model configuration of an example process control apparatus.
FIG. 3 is a block diagram showing a schematic model configuration of a process control apparatus according to another embodiment.
FIG. 4 is a flowchart for explaining the operation of the communication apparatus of the embodiment process control apparatus.
[Explanation of symbols]
5 Communication device 6 Operator console 7 Communication LAN
8 ₋₁ ,..., 8- _n arithmetic control device 9 _{−1 ,.}

Claims (1)

In a process control device comprising an operator console including a program storage means and a communication device loaded with one or more application programs, and one or more arithmetic control devices connected via the communication device,
The application program comprises means for giving a unique first identification number to a communication command comprising a message, information for identifying the commanded application, etc., and sending it to the communication device,
The communication device converts the message into a transmission frame, adds the unique second identification number newly determined by the communication device to the transmission frame, and sends the frame to the arithmetic and control unit. Means for storing the related identification number, message, and related information of the second identification number,
The arithmetic and control unit comprises means for returning a reply to the received message with a second identification number attached thereto,
Further, the communication device searches for the related information from the response waiting buffer based on the received second identification number, recognizes the application to be returned, and returns the created response with the first identification number. A process control apparatus comprising:

Images