JPH0962338A - Plant monitoring control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plant monitoring control system which can reduce the load of a CPU and a channel of a monitoring control non-machine device and also can fast display the updating of data. SOLUTION: A plant controller 2 contains a request data buffer 26 and a cycle management part 28. A data collection part 27 collects the necessary data from a memory 22 where the data are written via an application processing part 21 in response to the data request that is received by a request reception part 23 from a monitoring control man-machine device 1 and stored in the buffer 26. Then the collected data are sent to the device 1 via a data transmission part 25. At the same time, the part 28 periodically starts the part 27 to re-collect data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plant supervisory control system in which a plant controller for controlling a plant and a supervisory control man-machine device for collecting and displaying process data of the plant controller are connected by a communication path. In particular, the present invention relates to a plant monitoring control system capable of performing high-speed data update display by reducing the load on a central processing unit (hereinafter referred to as a CPU) of a communication path and a monitoring control man-machine device.

[0002]

2. Description of the Related Art FIG. 7 is a block diagram showing a conventional general plant supervisory control system in which a supervisory control man-machine device collects and displays process data of a plant controller via a communication path. In the figure, 1 is a supervisory control man-machine device for displaying process data, 2 is a plant controller for controlling a plant, and 3 is these supervisory control man-machine device 1 and plant controller 2.
It is a communication bus as a communication path for connecting with.

In the supervisory control man-machine device 11, 11 is a display for displaying the process data of the plant on a screen, 12 is screen information data, 13 is a screen switching detected, and necessary from the screen information data 12. It is a screen switching detection unit that searches for information. Reference numeral 14 is a data request unit for making a data request to the plant controller 2, 15 is a data receiving unit for receiving data returned by the plant controller 2 via the communication bus 3 in response to the data request, and 16 is the received data. And a screen drawing processing unit that performs a screen drawing process of the display 11 based on the screen information data 12. Reference numeral 17 denotes a cycle management unit that notifies the data request unit 14 to periodically request data.

Further, in the plant controller 2, 21 is an application processing unit for performing monitoring control processing of the plant, and 22 is a memory in which the application processing unit 21 writes process data. Reference numeral 23 is a request receiving unit that receives a data request sent from the monitoring control man-machine device 1, 24 is a data collecting unit that collects necessary data from the memory 22 based on the data request, and 25 is a data collecting unit. It is a data transmission unit that transmits the data to the supervisory control man-machine device 1.

Next, the operation will be described. In the supervisory control man-machine device 1, when an operator performs a screen switching operation, first, the screen switching detection unit 13 detects the screen switching operation and searches the screen information data 12 for the data of the screen to be switched. Notify the request unit 14. Further, it notifies the cycle management unit 17 of the data request cycle and activates it. The data request unit 14 transmits the data request requested by the screen switching detection unit 13 to the plant controller 2 via the communication bus 3.

The plant controller 2 receives the data request from the supervisory control man-machine device 1 in the request receiving section 23.
The request receiving unit 23 notifies the data collecting unit 24 of the received data request. The data collection unit 24 collects necessary data from the process data written in the memory 22 by the application processing unit 21, and notifies the data transmission unit 25 of the data. The data transmission unit 25 transmits the received collected data to the monitoring control man-machine device 1 via the communication bus 3.

In the supervisory control man-machine device 1, the data received from the plant controller 2 is collected by the data receiving unit 1.
5, the data receiving unit 15 notifies the screen drawing processing unit 16 of the received collected data. The screen drawing processing unit 16 performs a data update display on the display 11 based on the collected data and the screen information data 12.

Further, the cycle management unit 17 notifies the data request unit 14 of the data request restart after the request cycle time has elapsed after receiving the notification of the data request cycle from the screen switching detection unit 13. By this data request restart, the data request unit 14 again requests data to the plant controller 2 via the communication bus 3, and after the series of operations described above, the screen drawing processing unit 16 performs data update display on the display 11. After that, the cycle management unit 17
Notifies the data request unit 14 of the data request restart at every data request cycle, thereby performing a data update display on the display 11 at a constant cycle.

As a document in which a technique related to such a conventional plant monitoring control system is described, there is, for example, Japanese Patent Laid-Open No. 1-266684. In the plant supervisory control system described in Japanese Patent Laid-Open No. 1-266684, a data buffer is provided to increase the number of time-series data collected at one time, thereby reducing the number of requests.

[0010]

Since the conventional plant supervisory control system is configured as described above, a data request must be issued to the plant controller 2 every screen data update cycle of the supervisory control man-machine device. Therefore, it is necessary to transmit and receive data between the supervisory control man-machine device and the plant controller once in each data update period. Further, regardless of whether or not the data to be collected has changed, all the data is collected and the data is updated and displayed for all the data. Therefore, the load of the communication bus and the processing of the CPU of the supervisory control man-machine device for drawing are performed. There is a problem that the load becomes high and high-speed data update display cannot be performed. In addition, JP-A 1-26
In the distributed control system described in 6684, the effect cannot be exerted when the latest information is always required, and when different data are displayed on a plurality of supervisory control man-machine devices, data buffers corresponding to the number of display points are prepared. There is a need
There was a problem such as consuming a large amount of memory space.

The present invention has been made to solve the above problems, and suppresses the data request from the supervisory control man-machine device and the transmission of the collected data from the plant controller to reduce the load on the communication path and An object of the present invention is to obtain a plant monitoring control system capable of reducing the processing load of the CPU for data update display and performing high-speed data update display.

Another object of the present invention is to obtain a plant supervisory control system having a function of simultaneously displaying different data of the plant controller on a plurality of supervisory control man-machine devices.

[0013]

According to a first aspect of the present invention, there is provided a plant monitoring control system in which a plant controller is provided with a request data buffer and a cycle managing section, and the request receiving section receives the request via a communication path. The data request sent from the control man-machine device is temporarily stored in the request data buffer, and the plant monitoring control process is performed based on the data request stored in the request data buffer. The data collection unit collects the necessary data from the memory in which the process data is written by the application processing unit, and the data transmission unit transmits the collected data to the supervisory control man-machine device through the communication path. In the data collection unit, the cycle management unit periodically re-collects and activates data.

In the plant supervisory control system according to the second aspect of the present invention, the plant controller is provided with request cycle setting means, whereby the cycle requested by the supervisory control man-machine device is set in the cycle management unit. It was done.

In the plant monitoring control system according to the third aspect of the present invention, the plant controller is provided with a previous value buffer and a collected data condition check means, and the previous value buffer stores the data previously collected by the data collecting unit. Only when it is stored and the data collection unit detects that the data collected this time has changed compared to the data stored in the previous value buffer, the collected data condition check means collects the collected data. Is notified to the data transmission unit.

In the plant monitoring control system according to the fourth aspect of the present invention, the plant controller is provided with state change data extraction means, whereby the collected data state change check means collects the data currently collected by the data collecting section. When a change to the data stored in the previous value buffer is detected, extract only the changed part of the data collected this time and the data stored in the previous value buffer and notify the data transmission unit. It is the one.

According to a fifth aspect of the present invention, there is provided a plant supervisory control system, wherein a plant controller has a data request source management section, and a plurality of request data buffers, cycle management sections and previous value buffers are prepared. A request data buffer corresponding to a request source, a cycle management unit, and a previous value buffer are allocated, and an appropriate transmission destination is designated for the data transmission unit.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below. Embodiment 1. 1 is a block diagram showing a plant monitoring control system according to Embodiment 1 of the present invention. In the figure, 1 is a supervisory control man-machine device for displaying process data of a plant, 2 is a plant controller for controlling a plant, and 3 is a supervisory control man-machine device 1 and a plant controller 2 mutually. It is a communication bus as a connected communication path.

In the supervisory control man-machine device 1, reference numeral 11 is a display for displaying the process data of the plant on a screen, and for example, a CRT display device or the like is used. Reference numeral 12 is screen information data holding screen information of the screen displayed on the display 11. Reference numeral 13 denotes a screen switching detection unit that detects a screen switching operation performed by an operator and searches the screen information data 12 for corresponding screen information. A data request unit 14 makes a data request to the plant controller 2 via the communication bus 3 based on the screen information notified from the screen switching detection unit 13. Reference numeral 15 denotes the data collected and returned by the plant controller 2 in response to the data request from the data request unit 14, and the communication bus 3
It is a data receiving unit that receives via the data. Reference numeral 16 denotes a screen drawing processing unit that performs screen drawing processing of the display 11 based on the received data notified from the data receiving unit 15 and the image information data 12. In the monitoring control man-machine device 1, a cycle management unit 17 that periodically notifies the data request unit 14 to make a data request.
Is not provided.

Further, in the plant controller 2, 21 is an application processing unit for performing monitoring control processing of the plant, and 22 is a memory in which process data is written by the application processing unit 21. A request receiving unit 23 receives a data request sent from the supervisory control man-machine device 1 via the communication bus 3. Reference numeral 26 is a request data buffer for temporarily storing the data request from the supervisory control man-machine device 1 received by the request receiving unit 23. Reference numeral 27 in FIG. 7 differs from that of the conventional one indicated by reference numeral 24 in FIG. 7 in that necessary process data is collected from the memory 22 based on the data request temporarily stored in the request data buffer 26. Are different data collection units. 25
Is a data transmission unit that transmits the data collected by the data collection unit 27 from the memory 22 to the monitoring control man-machine device 1 via the communication bus 3. Reference numeral 28 denotes a cycle management unit, which is fixedly set to a predetermined cycle time, and which notifies the data collection unit 27 to perform recollection activation of data according to the fixed cycle time.

The parts in FIG. 1 designated by the same reference numerals as those in FIG. 7 are equivalent to those in the conventional plant monitoring control system.

Next, the operation will be described. In the supervisory control man-machine device 1, when a screen switching operation is performed by an operator, the screen switching detection unit 13 retrieves information of the screen which is about to be displayed from the screen information data 12 and sends it to the data request unit 14. Notice. The data request unit 14 transmits a data request via the communication bus 3 to the plant controller 2 that collects the data of the screen information based on the image information notified from the screen switching detection unit 13.

In the plant controller 2, the communication bus 3
The request receiving unit 23 receives the data request sent from the monitoring control man-machine device 1 via the. The request receiving unit 23 temporarily stores the received data request in the request data buffer 26 and also notifies the data collecting unit 27 that a data request has occurred. Upon receiving this notification, the data collection unit 27 searches the memory 22 to which the latest process data is always written by the application processing unit 21 based on the data request stored in the request data buffer 26, and the data is written. Only the necessary data is collected from the process data and notified to the data transmission unit 25. When the data transmission unit 25 receives the collected data from the data collection unit 27, the data transmission unit 25 transmits the collected data to the supervisory control man-machine device 1 as the data request source via the communication bus 3.

In the supervisory control man-machine device 1, the data receiving unit 15 receives the collected data sent from the plant controller 2 via the communication bus 3. The data receiving unit 15 notifies the screen drawing processing unit 16 of the received collected data, and the screen drawing processing unit 16 notifies the data receiving unit 15 of the received data.
The process data is updated and displayed on the display 11 based on the collected data and the screen information data 12 received.

Next, the cycle management unit 28 notifies the data collection unit 27 of data re-collection when a fixed cycle time set therein has elapsed since the first data collection was performed. Upon receiving this, the data collection unit 27 collects process data from the memory 22 again based on the data request stored in the request data buffer 26. The data collected again by the data collecting unit 27 is notified to the data transmitting unit 25, and the data transmitting unit 25 transmits the collected data to the monitoring control man-machine device 1 via the communication bus 3. After that, the plant controller 2 repeats the collection of process data from the memory 22 at fixed cycle times held by the cycle management unit 28 until a new data request is transmitted from the supervisory control man-machine apparatus 1, and the supervisory control man-machine apparatus performs the process data collection. Keep sending to 1.

As described above, in the plant monitoring control system according to the first embodiment, the monitoring control man-machine device 1 is used.
It becomes unnecessary to make a data request to the plant controller 2 via the communication bus 3 for each request cycle, and suppress data collection communication for displaying process data between the supervisory control man-machine device 1 and the plant controller 2. It is possible to obtain a plant monitoring control system capable of high-speed data update display.

In the first embodiment, the communication bus 3 is used as the communication path, but another communication path such as a local bus may be used. This also applies to the following second to fifth embodiments.

Embodiment 2 2 is a block diagram showing a plant monitoring control system according to Embodiment 2 of the present invention. In the figure, 29 is a supervisory control man-machine device 1.
The request cycle sent from the request from the request receiving section 23 is set in the cycle management section 28 for notifying the data collection section 27 to start re-collection of data. It is a request cycle setting means. The second embodiment differs from the first embodiment in that the request cycle setting means 29 is provided in the plant controller 2.

Next, the operation will be described. When transmitting the data request to the plant controller 2, the supervisory control man-machine device 1 attaches the request period to the data request and transmits the data request. In the plant controller 2, the request receiving unit 23 receives the data request accompanied by this request cycle, transfers the data request to the request data buffer 26, and transfers the request cycle to the request cycle setting means 29, respectively. The request cycle setting means 29, which has received the request cycle from the supervisory control man-machine device 1 from the request receiving section 23, sets the cycle time designated in the request cycle in the cycle management section 28.

The cycle management unit 28 uses the request cycle setting means 2
Each time the designated cycle time set by 9 elapses, the data recollection unit 27 is notified of the data recollection, and the data collection unit 27 that has received the request reissues the data request stored in the request data buffer 26. Based on this, the process data is collected again from the memory 22. The data collected again is notified to the data transmitter 25 from the data collector 27,
The data is transmitted from the data transmission unit 25 to the supervisory control man-machine device 1. After that, the plant controller 2 repeats the collection of process data from the memory 22 at every specified cycle time set in the cycle management unit 28 until a new data request with a request cycle is transmitted from the supervisory control man-machine device 1. , Keeps sending it to the supervisory control man-machine device 1.

As described above, according to the second embodiment,
The process data can be received in the cycle required by the monitoring control man-machine device 1, and the transmission and reception of the collected data more than necessary through the communication bus 3 is suppressed, and the first embodiment
It is possible to obtain a plant supervisory control system capable of data update display at a higher speed than that described in.

Embodiment 3. 3 is a block diagram showing a plant monitoring control system according to Embodiment 3 of the present invention. In the figure, 30 is a previous value buffer for storing the process data previously collected by the data collection unit 27 from the memory 22, and 31 is the process data stored in the previous value buffer 30 and the current data collection. The change is detected by comparing the process data collected by the unit 27, and only when the change is detected, the process data collected this time is notified to the data transmitting unit 25, and the new process data is used to notify the process data last time. It is a collected data state change checking means for updating the contents of the value buffer 30. The third embodiment is different from the second embodiment in that the previous value buffer 30 and the collected data state change checking means 31 are provided in the plant controller 2.

Next, the operation will be described. Each time the data collection unit 27 receives a notification of data recollection from the cycle management unit 28, it collects process data from the memory 22 based on the data request stored in the request data buffer 26. The collected data is notified from the data collecting unit 27 to the collected data condition check means 31, and the collected data condition check means 31 stores the newly collected process data in the previous value buffer 30. Compare with the data. As a result, they are the same,
If there is no change in the newly collected process data, the collected data state change checking means 31 does not notify the data transmitting unit 25 of the process data.

On the other hand, as a result of the comparison, if the two do not match, that is, if it is detected that the new process data has changed from the previous process data, the collected data state change checking means 31. Informs the data transmitter 25 of the new process data collected this time,
The data is transmitted from the data transmission unit 25 to the monitoring control man-machine device 1. Further, the collected data state change checking means 31 then updates the contents of the previous value buffer 30 with the new process data collected this time.

As described above, according to the third embodiment,
Only when a change is detected in the newly collected process data, the data transmission unit 25 is notified of the change, so that the transmission / reception of the collected data via the communication bus 3 is further suppressed, and further, the monitoring control man-machine. The data processing amount in the device 1 is also reduced, and a plant monitoring control system capable of performing data update display at a higher speed than that described in the second embodiment can be obtained.

Embodiment 4 FIG. 4 is a block diagram showing a plant monitoring control system according to Embodiment 4 of the present invention. In the figure, reference numeral 32 denotes a data transmission unit when the collected data state change checking unit 31 detects a change between the process data collected this time by the data collection unit 27 and the previous process data stored in the previous value buffer 30. The state change data extracting means that receives the data to be notified to the data processing unit 25, extracts only the changed portion of the data from the data stored in the previous value buffer 30, and notifies the data transmitting unit 25 of the extracted changed portion data. Is. The fourth embodiment differs from the third embodiment in that the state change data extraction means 32 is provided in the plant controller 2.

Next, the operation will be described. When it is detected that the process data collected this time has changed with respect to the previous process data stored in the previous value buffer 30, the collected data condition check means 31 checks the data collected this time. The data is transmitted to the data transmission unit 25 via the variable data extraction means 32. The state change data extraction means 32 compares the process data from the collected data state change check means 31 with the previous process data stored in the previous value buffer 30, and extracts the portion where the state change actually occurred. The data transmission unit 25 is notified of this. The data transmission unit 25 transmits only the data of the changed portion extracted by the state change data extraction means 32 to the monitoring control man-machine device 1 via the communication bus 3.

As described above, according to the fourth embodiment,
Regarding the data that requires the data update display processing performed by the screen drawing processing unit 16 of the supervisory control man-machine apparatus 1 by extracting only the data of the changed portion of the process data and notifying it to the data transmission unit 25. It is possible to obtain only the data, and the amount of data transmitted / received via the communication bus 3 for collecting data is further reduced, and a plant monitoring control system capable of updating data at a higher speed than that described in the third embodiment is obtained. You can

Embodiment 5 5 is a block diagram showing a plant monitoring control system according to a fifth embodiment of the present invention. In the figure, 1a, 1b, ..., 1n are a plurality of supervisory control man-machine devices connected to the same plant controller 2 via a communication bus 3 as a communication path. Further, a plurality of request data buffers 26, cycle management units 28, and previous value buffers 30 are prepared in the plant controller 2, and 33 is each request data buffer 26, each cycle management unit 28, and each previous value buffer. From the value buffer 30, the request data buffer 26, the cycle management unit 28, and the previous value buffer 30 corresponding to the requesting supervisory control man-machine devices 1a, 1b, ... Is a data request source management unit that specifies to the data transmission unit 25.

Next, the operation will be described. Here, FIG.
Is the plant controller 2 is the supervisory control man-machine device 1
a, 1b, ..., 1n, after receiving the data request from the data requesting unit 14, the data transmitting unit 25
Are requesting supervisory control man-machine devices 1a, 1b, ...
-It is a flowchart which shows the flow of operation until it transmits collected data to 1n.

First, in step ST1, the request receiving unit 23 of the plant controller 2 receives a data request from one of the supervisory control man-machine devices, for example, the supervisory control man-machine device 1a, via the communication bus 3. Request receiving unit 23
When this data request is received, the available request data buffer 26, the cycle management unit 28, and the previous value buffer 3 are sent to the data request source management unit 33 in step ST2.
Request 0. Data request source management unit 3 that received this request
In step ST3, the process 3 checks whether or not the already allocated request data buffer 26 has the same request source, that is, the data of the monitoring control man-machine device 1a. If there is the same request source data, step S
After allocating the already allocated buffer at T4, the process proceeds to step ST8. On the other hand, if there is no same request source data, an unused buffer is searched in step ST5. As a result, if there is an unused buffer, the unused buffer found first is assigned to the request source in step ST7, and then the process proceeds to step ST8. If no unused buffer is found, the data request cannot be processed, and therefore the data request is discarded as an error in step ST6.

In step ST8, the data collection unit 2
Reference numeral 7 refers to the request data buffer 26 corresponding to the request source, searches the memory 22 based on the data request stored therein, and collects necessary data. Next, in step ST9, the collected data state change checking means 31 compares the collected data with the contents of the previous value buffer 30 corresponding to the request source, and in step ST10, it is determined whether or not they are the same. If the data are different,
In step ST11, the state change data extracting means 32 extracts the state change portion of the collected data, and in step ST12, the collected data state change checking means 31 stores the changed data in the previous value buffer 30. Next, step S
In T13, the data transmitting unit 25 transmits the data of the state change portion obtained in step ST11 to the requesting supervisory control man-machine device 1a via the communication bus 3.

After that, the process proceeds to step ST14, and the cycle management unit 28 corresponding to each request source notifies the data collection unit 27 of the data recollection request when the set cycle time elapses. As a result, the process proceeds to step ST8, the data is collected and the data of the abnormal portion is extracted by using the request data buffer 26 and the previous value buffer 30 corresponding to the data request source, and then the corresponding request is made by the data transmitting unit 25. Originally, the collected data is transmitted via the communication bus 3. Also,
When it is determined that the data are the same in step ST10, the process proceeds to step ST14 without performing the processes of steps ST11 to ST13. Further, even if the request source cycle management unit 28 starts the periodic data collection in step ST15, the data recollection request is notified from the cycle management unit 28 corresponding to the request source in step ST14. Waiting for, the processing from step ST8 is executed.

As described above, according to the fifth embodiment,
Since the data request source management unit 33 can allocate the request data buffer 26, the cycle management unit 28, and the previous value buffer 30 to the data requests from the plurality of supervisory control man-machine devices 1a to 1n, the processing can be performed. At the same time, it is possible to obtain a plant monitoring control system capable of transmitting collected data in response to data requests from a plurality of monitoring control man-machine devices 1a to 1n.

In the fifth embodiment, the request source has been described as a plurality of different supervisory control man-machine devices, but the requester may be a plurality of windows in the same or different supervisory man-machine devices. Of course, the same effect as that of the fifth embodiment can be obtained.

[0046]

As described above, according to the invention of claim 1, the request data buffer and the cycle management unit are provided in the plant controller, and the data request from the supervisory control man-machine device received by the request receiving unit is received. The data is temporarily stored in the request data buffer, the necessary data is collected from the memory based on the data request, and the collected data is transmitted to the supervisory control man-machine device by the data transmission unit, and Since the management unit is configured to periodically perform the data recollection activation for the data collection unit, it is not necessary to request the data every time the monitoring control man-machine device needs the data, and Data collection communication for displaying process data performed between plant controllers is reduced, and communication paths and supervisory control man-machine devices are reduced. Because it can reduce the load on the CPU, system inexpensive to build, also it has the effect that can be obtained a plant monitoring and control system capable of performing data update display at high speed.

According to the second aspect of the present invention, the request cycle setting means is provided in the plant controller, and the cycle requested by the supervisory control man-machine device is set in the cycle management section, and the data is periodically sent according to the set cycle. Since the data recollection activation is performed for the collection unit, the process data can be received at the cycle required by the supervisory control man-machine device, and the transmission and reception of unnecessary collection data via the communication bus 3 is suppressed. Therefore, there is an effect that a faster data update display is possible.

According to the third aspect of the present invention, the previous value buffer and the collected data condition check means are provided in the plant controller, and the collected data condition check means collects the newly collected data this time. Compare with the previously collected data stored in the value buffer,
Since it is configured to notify the data transmission unit only when a change is detected in newly collected data, the amount of data sent from the plant controller to the monitoring control man-machine device can be reduced, and The amount of data processing is also reduced, which has the effect of enabling faster data update display.

According to the fourth aspect of the present invention, the state change data extracting means is provided in the plant controller, and it is confirmed that the data collected this time is different from the data stored in the previous value buffer. When the checking means detects, only the changed part of the collected data of this time and the stored data of the previous value buffer is extracted, and it is configured to notify the data transmitting part, so the screen of the monitoring control man-machine device Only the data necessary for the drawing processing unit to perform the data update display processing needs to be communicated, and the amount of data sent from the plant controller to the supervisory control man-machine device can be further reduced, and even faster data update display can be performed. There is a possible effect.

According to the fifth aspect of the invention, the data request source management unit is provided in the plant controller, and the request source is selected from the plurality of request data buffers, cycle management units and previous value buffers prepared for each. Since it is configured to allocate each one and specify the appropriate destination to the data transmission unit, the request data buffer, the cycle management unit, and the previous value buffer are assigned to the data requests from multiple request sources and processed. Therefore, it is possible to obtain a plant monitoring control system capable of transmitting collected data even if data requests are simultaneously made from a plurality of request sources.

[Brief description of drawings]

FIG. 1 is a block diagram showing a plant monitoring control system according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a plant monitoring control system according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a plant monitoring control system according to a third embodiment of the present invention.

FIG. 4 is a block diagram showing a plant monitoring control system according to a fourth embodiment of the present invention.

FIG. 5 is a block diagram showing a plant monitoring control system according to a fifth embodiment of the present invention.

FIG. 6 is a flowchart showing a flow of operations of the above embodiment.

FIG. 7 is a block diagram showing a conventional plant monitoring control system.

[Explanation of Codes] 1, 1a, 1b, ..., 1n Supervisory control man-machine device, 2 Plant controller, 3 Communication bus (communication path), 11 Display, 12 Screen information data, 1
3 screen switching detection section, 14 data request section,
15 data receiving section, 16 screen drawing processing section, 21 application processing section, 22 memory, 23 request receiving section, 25 data transmitting section, 26 request data buffer,
27 data collection section, 28 cycle management section, 29 request cycle setting means, 30 previous value buffer, 31 collected data state change checking means, 32 state change data extraction means, 33
Data request source management unit.

Claims (5)

[Claims] 1. A plant supervisory control system in which a plant controller that controls a plant and a supervisory control man-machine device that collects and displays process data of the plant controller are interconnected by a communication path. A supervisory control man-machine device detects a display on which the process data of the plant is displayed on the screen and a switching operation of the screen displayed on the display, and from the screen information data holding the screen information displayed on the display. , A screen switching detection unit for searching corresponding screen information, a data request unit for requesting data to the plant controller via the communication path, and the plant controller collecting data in response to a data request from the data request unit. , Data sent via the communication path A data receiving unit that receives a data, and a screen drawing processing unit that performs a screen drawing process of the display based on the data received by the data receiving unit, wherein the plant controller is the A request receiving unit that receives a data request sent via a communication path, a request data buffer that temporarily stores the data request received by the request receiving unit, and an application processing unit that performs monitoring control processing of the plant. A memory for storing process data of the plant; a data collecting unit for collecting necessary data from the memory based on a data request stored in the request data buffer; and a data collecting unit. A data transmission unit for transmitting the collected data to the supervisory control man-machine device via the communication path; and the data collection unit Plant monitoring control system characterized by comprising a cycle management unit for performing reacquisition start of regular data for. 2. The plant monitor according to claim 1, wherein the plant controller is provided with request cycle setting means for setting a cycle requested by the supervisory control man-machine device in the cycle management unit. Control system. 3. The previous value buffer for storing the data previously collected by the data collecting unit, the data collected this time by the data collecting unit, and the previous value buffer in the plant controller. 2. A collected data state change check means for detecting a change from the stored data and notifying the data transmitting section of the collected data only when the change is detected. Item 2. The plant monitoring control system according to Item 2. 4. When the plant controller detects a change between the data collected this time by the data collecting unit and the data stored in the previous value buffer, the collected data state change checking unit causes the data to be changed. Providing condition change data extraction means for receiving the data to be notified to the transmission unit, extracting only a changed portion between the data and the data stored in the previous value buffer, and notifying the data transmission unit of the extracted data. The plant monitoring control system according to claim 3, wherein 5. The plant controller, the request data buffer for temporarily storing a data request received by the request receiving unit, and the cycle management for periodically re-collecting and activating data for the data collecting unit. Section, and a plurality of previous value buffers for storing the data previously collected by the data collection section, respectively,
Data for assigning a request data buffer, a cycle management unit and a previous value buffer corresponding to a request source from each of the request data buffer, each cycle management unit and each previous value buffer, and designating an appropriate destination to the data transmission unit. The plant monitoring control system according to claim 4, further comprising a request source management unit.