JP3305942B2 - Process control system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a process control system for connecting a computer for controlling a line for processing a material to a programmable logic controller (hereinafter, referred to as PLC) and the like.

[0002]

2. Description of the Related Art Conventionally, in a control system for controlling a line for processing a material, data associated with each material is held by a computer, and when the material reaches a predetermined position, the data is stored in the computer. Was edited by a computer and transmitted to a PLC or other computer that needed the data at that time.

[0003]

However, the conventional control system as described above has the following problems.

[0004] First, there is a problem that the load on the computer is high and the program structure is complicated because the computer program operates in synchronization with the data transmission timing.

Second, when the operation timing of the PLC is changed, the program of the computer must be changed at the same time.

Third, if the number of PLCs or other computers that receive data is large, the load on the data transmission line increases.

[0007] Fourth, when the same data is used in each PLC or another computer, the same data must be transmitted separately, which is not efficient.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an efficient process control system capable of simplifying a computer program configuration and program change and reducing a load on a data transmission line. To provide.

[0009]

In order to achieve the above object, the present invention provides a process control comprising a computer for controlling a material rolling line and a programmable logic controller connected to a data transmission line. In the system, each of the computer and the programmable logic controller has a broadcast common memory in which data for each material in the rolling line is stored in one record thereof, and the broadcast common memory includes the rolling line. A material identifier including a material identifier specifying a material name carried into each zone and material data including setting data associated with each material are stored, and the computer recognizes information on the material carried into each zone, and Calculates material setting data and stores the material stored in its own broadcast common memory. The data of each material is updated between the computer and the programmable logic controller by updating the information of the discriminator and the material data and broadcasting the updated and stored material data to another common memory. It is characterized by sharing.

According to the above configuration, the data area for storing the data for each material in one record is constructed on the broadcast common memory of the data transmission line, and the computer stores the data for each material in each record. Output to

The computer also outputs data (tracking information) indicating on which record of each material the data is stored in which record on the common memory of the data transmission line. In addition, the calculator
Update this information according to the material movement.

Each PLC or other computer can refer to the material tracking information to recognize the record in which the data of the target material is stored, and can retrieve and use the data therefrom. .

[0013]

FIG. 1 shows the configuration of an embodiment of a process control system according to the present invention.

As shown in FIG. 1, the system includes a data transmission line 1 and five stations 2, 3, 4, 5, and 6 connected to the data transmission line 1. A computer 7, a slave computer 8 at station 3, a first PLC 9 at station 4, a second PLC 10 at station 5, a station 6
Are connected to a third PLC 11, respectively.

Each of the stations 2, 3, 4, 5, 6
Have common memories 12, 13, 14, 15, 1
6 are prepared, and each station 2, 3, 4, 5,
6 is configured to hold the same data.

FIG. 2 schematically shows a rolling line to be controlled by the process control system. This rolling line is composed of zone 1, zone 2 and zone 3. In the illustrated state, material A is loaded into zone 1, material B is loaded into zone 2, and zone 3 is loaded.
Shows a state in which no material has been loaded yet.

Each of the common memories 12, 13, 14, 15, in this system for controlling such a rolling line.
16 has a tracking information area and a process data area as shown in FIG. As shown in FIG. 3A, the tracking information area includes a portion for storing a material identifier for each zone (process) of the target facility and a process data area record No. And a part for storing. The material identifier is information for specifying the name of a material in the zone, and the process data area record No. Is information for specifying the storage location of the material data in the process data area. As shown in FIG. 3B, one process data area has a plurality of record number areas. In the illustrated example, record 1 is an empty area, record 2 is a data area of material B, and record 3 is a data area of material B. This is the data area for material A.

Next, the operation of the present embodiment will be described with reference to flowcharts shown in FIGS. The flowchart of FIG. 4 shows processing on the main computer 7 side, and the flowchart of FIG.

In the rolling line shown in FIG. 2, when it is detected that the material A has been conveyed to the zone 1 (this can be detected by a signal from a material detection sensor or the like), the main computer 7 recognizes this. First, an empty record area in the process data area is secured, and the data of the material A is stored in the record (steps ST1, ST2, ST3).
In addition, the material identifier and the record No. of the process data area are set in zone 1 of the material tracking information area. Is set (step ST4). Further, when the material moves between the zones, the tracking information is moved to the moved zone in the material tracking information area (steps ST5 and ST6). When the setting data of the material is newly calculated, the data is stored in the corresponding record in the process data area. The data stored in the common memory 12 of the main computer 7 in this manner is transmitted to the other common memories 13, 14, 15,
16 so that the slave computer 8 and each PL
C9, 10, and 11 also share the same data as the main computer 7.

Next, the processing of the PLC (or the slave computer) will be described by taking the processing of the first PLC 9 as an example.

When the first PLC 9 attempts to refer to the data of the material in the zone 2 at a certain timing,
First, the location of zone 2 in the material tracking information area constructed in the common memory 14 in the own station 4 is referred to (step ST11). If there is a material identifier there (step ST12), the process data area record No. Is taken out (step ST13). Next, the retrieved process data area record No. The process data area may be accessed by using the key as a key to extract necessary data (step ST14).

As described above, according to the present embodiment, since the program of the main computer 7 operates only at the timing of data calculation, the load on the main computer 7 can be reduced. For this reason, the program structure of the main computer 7 is simplified.

Further, it is possible to change the operation timing of the PLC without changing the program of the main computer 7.

Further, when each PLC or other computer 8 uses the same data, the same data is output to only one location in the data area and the same data is transmitted by broadcast to all the system components (each PLC and other computers). Computer 8) can be shared.

Furthermore, even if the number of PLCs or computers that receive data is large, it is not necessary to transmit data separately, so that the load on the data transmission line 1 can be reduced.

[0026]

As described above, according to the present invention, the load on the computer can be reduced, and the program structure and the program change can be simplified. PLC to receive data
Even if the number of computers and the number of computers are large, the load on the data transmission line can be kept low, and efficient system operation is possible.

[Brief description of the drawings]

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

FIG. 2 is an explanatory view schematically showing a configuration of a rolling line to be controlled by a process control system according to the present invention.

FIG. 3 is an explanatory diagram showing a configuration of a common memory in the process control system according to the present invention.

FIG. 4 is a flowchart showing a processing procedure on the main computer side in the process control system according to the present invention.

FIG. 5 shows P in the process control system according to the present invention.
9 is a flowchart illustrating a processing procedure on the LC side.

[Explanation of symbols]

 Reference Signs List 1 data transmission line 2, 3, 4, 5, 6 station 7 main computer 8 slave computer 9 first PLC 10 second PLC 11 third PLC 12, 13, 14, 15, 16 common memory

Continuing on the front page (72) Inventor Ichiro Maeda 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Kawasaki Steel Corporation Chiba Works (72) Inventor Tsutomu Kiuchi 1 Toshiba-cho, Fuchu-shi, Tokyo Toshiba Corporation Fuchu Plant (56) reference Patent flat 5-304695 (JP, a) JP flat 6-44260 (JP, a) JP Akira 59-188703 (JP, a) (58 ) investigated the field (Int.Cl. ⁷ G05B 19/05 G06F 13/00 357

Claims (1)

(57) [Claims] 1. A process control system comprising a computer for controlling a rolling line of a material and a programmable logic controller connected to a data transmission line, wherein data for each material on the rolling line is stored in one record thereof. The common memory for broadcasting provided in each of the computer and the programmable logic controller, the common memory for broadcasting includes a material identifier and a material identifier for specifying a material name being carried into each zone of the rolling line. The computer stores material data including setting data associated with the material, and the computer recognizes information on the material carried into each zone, calculates the setting data of each material, and calculates its own common memory for broadcasting. Update the information of the material identifier and the material data stored in the Process control system, characterized by sharing the data for each material between the computer and the programmable logic controller by broadcasting the material data to other common memory.