JP7708352B2 - Monitoring and Control Systems - Google Patents

Description

The present invention relates to a monitoring and control system used to monitor and control the operation of various types of plant equipment, etc.

In plant facilities such as factories, power generation facilities, waste incineration facilities, and water treatment facilities, supervisory control systems known as distributed control systems are widely used to centrally control a large number of different types of field devices (see Non-Patent Document 1, etc.).

As described in Patent Documents 1 and 2, such monitoring and control systems are composed mainly of control devices including an I/O unit that communicates with various sensors and controlled objects installed at the plant site, a communication interface unit that communicates with an operator terminal (which is actually a personal computer: PC) where an operator operates the plant, and a control unit that performs predetermined arithmetic processing on input data. For example, in the distributed control system described in Non-Patent Document 1, the control station corresponds to the control device.

The control unit generates control data by performing calculations according to a pre-created control program at predetermined calculation intervals for data input via the I/O unit and communication interface unit, and monitors and controls the plant equipment by sending this control data to various control targets via the I/O unit.

The control program is created using a maintenance tool (software) implemented on an operator terminal or an engineering terminal operated by a specialized engineer. As described in Patent Documents 1 to 3, in a typical monitoring and control system, a control program can be created by arranging symbols corresponding to various cells, such as input/output cells and calculation cells, on the screen of the maintenance tool according to the calculation order and connecting them, in other words, creating an instrumentation diagram showing the process flow. When the control program created in this way is executed in a control unit, the control unit executes calculation processing based on the input data connected to the calculation cells and the calculation parameters (calculation coefficients) set in the calculation cells, and the results of the calculation processing are expanded into output data connected to the calculation cells.

The maintenance tool also has a monitoring function that displays the status of the control device, i.e., the output data values of each input cell and calculation cell, in real time on the instrumentation drawing when the monitoring and control system is actually operating (when the plant is running).

JP 2005-148802 A JP 2007-109022 A Japanese Patent Application Publication No. 10-124115

"Distributed Control System (DCS): Hardware", [Online], [Retrieved January 11, 2022], Shimadzu System Solutions Co., Ltd., Internet <URL: https://www.shimadzu.co.jp/sss/products/syn/ms-one.html>

In an actual system, there may be anomalies in the data input to the control device, or anomalies caused by hardware or software in various cells such as calculation cells and input/output cells. There may also be cases where an operator is in the middle of performing some operation, or performs an operation such as intentionally changing input data. Naturally, in a monitoring and control system, operators are required to quickly recognize such abnormal situations and take appropriate action if necessary.

However, in conventional maintenance tools for monitoring and control systems, such abnormal conditions are not taken into account in the instrumentation drawings used to create control programs. As a result, it is not possible to monitor abnormal conditions in the actual system on such instrumentation drawings, making it difficult to understand what abnormality has occurred and where. Furthermore, in order to properly monitor such abnormal conditions, it is necessary to create a control program for abnormality occurrences in addition to the normal control program, which is extremely troublesome and costly for users.

The present invention was made to solve these problems, and one of its objectives is to provide a monitoring and control system that can easily create control programs, including cases where various cells themselves, such as calculation cells, or input data, etc., are in an abnormal state.

One aspect of the monitoring and control system according to the present invention, which has been made to solve the above problems, is a monitoring and control system having a control device that collects data from a monitored and controlled object in accordance with a preset control program, executes a predetermined arithmetic processing to generate control data, and transmits the control data to the monitored and controlled object, and a terminal that is connected to the control device via a communication line and has a program creation support function for creating the control program, wherein the terminal:
a cell information storage unit in which various cells, which are elements of processing including input, output, and calculation in the control program, are registered, at least a part of which is provided with an area for handling signal status information indicating the state of a signal being transferred;
a drawing creation unit that creates an instrumentation drawing showing the flow of processing in the control device while displaying, on a display screen, symbols corresponding to the cells stored in the cell information storage unit and connection elements showing the flow of data and signal status between a plurality of cells in response to an operation by a person in charge;
An individual cell information setting unit that sets a correspondence to a calculation parameter and/or a signal status for a cell used in the instrumentation drawing according to a type of the cell in response to an operation by a person in charge;
a programming unit that converts the instrumentation drawing in which the individual information of each cell has been set by the individual cell information setting unit into a program that can be executed by the control device;
It is equipped with the following.

According to the above-mentioned aspect of the monitoring and control system of the present invention, the person in charge can easily create a control program that includes cases where the various cells themselves, such as calculation cells, or input data, are in an abnormal state by performing tasks similar to conventional procedures, such as appropriately arranging symbols corresponding to various cells on the display screen of the terminal and connecting the cells. This eliminates the need to create a separate control program that corresponds to an abnormal state, reducing the number of work steps related to system operation, shortening construction time, and reducing costs.

1 is a schematic configuration diagram of a distributed control system according to an embodiment of the present invention; FIG. 2 is a functional block diagram of an engineering terminal in the distributed control system of the present embodiment. FIG. 4 is a conceptual diagram showing the data contents of operation cells used when creating a control program in the distributed control system of the present embodiment. FIG. 2 is a diagram showing an example of a simple instrumentation diagram created in the distributed control system of the present embodiment. FIG. 5 is a diagram showing a specific example of each cell and their interrelationships in the instrumentation diagram shown in FIG. 4 . FIG. 2 is a schematic diagram showing an example of an instrumentation diagram during operation status monitoring in the distributed control system of the present embodiment.

Hereinafter, a distributed control system, which is one embodiment of a monitoring and control system according to the present invention, will be described with reference to the accompanying drawings.
Fig. 1 is a schematic diagram of a distributed control system according to the present embodiment, and Fig. 2 is a functional block diagram of an engineering terminal in Fig. 1.

This system monitors and controls plant equipment to ensure smooth operation of the plant equipment, and as shown in FIG. 1, includes a control device 1 connected to a field device 5 including field devices (various sensors, switches, etc.) for collecting data included in the plant equipment and the field devices to be controlled, an operator terminal 2 connected to the control device 1 via a control network 4, and an engineering terminal 3. In this example, a PLC (programmable logic controller) 7 is connected to the control device 1 via a local network 6, but these elements are not required.

Both the operator terminal 2 and the engineering terminal 3 are actually PCs. The operator terminal 2 is usually operated by an operator who operates the plant equipment. On the other hand, the engineering terminal 3 is a terminal that is operated only by personnel with specific authority, such as engineers from the instrumentation manufacturer that provides this system or system administrators. However, it is also possible to use the same terminal as both the operator terminal 2 and the engineering terminal 3, in which case the functions that can be used can be restricted according to the authority.

As shown in FIG. 2, the engineering terminal 3 includes, as functional blocks, a control program creation support unit 30, a cell information storage unit 31, an instrumentation drawing data storage unit 32, an operation status monitoring unit 33, and a signal simulation execution unit 34.

The control device 1 includes an I/O unit 12 that exchanges data (including both analog and digital signals) with the field device 5, a communication unit 10 that exchanges data with the operator terminal 2 and the engineering terminal 3 via the control network 4, and a control unit 11 that mainly executes arithmetic processing. Although not shown, the control unit 11 has an arithmetic unit such as a computer and/or digital signal processor for executing arithmetic processing, and a memory in which a control program that operates the arithmetic unit is stored. The memory has an area in which a basic program that operates the arithmetic unit is stored, and an area in which cells that hold information on the arithmetic operations, etc., executed by the basic program are stored.

In the example shown in FIG. 1, there is one operator terminal 2, but multiple operator terminals 2 may be provided. Similarly, multiple control devices 1 may be provided.

FIG. 3 is a conceptual diagram showing the data contents of the operation cells stored in the cell information storage unit 31 in the engineering terminal 3. As shown in FIG.
As shown in Fig. 3, each operation cell 8 is registered with operation type information 80 indicating the type of operation executed by the operation cell, one or more parameters (operation parameters) 82 used in the operation, connection relationship information 81 indicating which cell's output is passed to which input of which cell, and signal status correspondence information 83, which will be described in detail later. Of these, the operation type information 80 is fixed information for each operation cell (i.e., it is unchanging), but the rest are information that is determined when a control program is created in the engineering terminal 3. The types of operations include simple arithmetic operations such as addition, subtraction, multiplication, and division, various functions, first-order lag, and PID (Proportional-Integral-Differential) control. Note that the information other than the signal status correspondence information 83 is also prepared in conventional distributed control systems.

Here, the signal status correspondence information 83 contained in the calculation cell will be described.
In this specification, "signal status" refers to the state of data exchanged between various cells including input cells, output cells, and arithmetic cells, and more specifically, anomalies caused by hardware, software, and human-caused anomalies (different from normal states) caused by some operation by an operator or signal simulation. Therefore, the signal status attached to data input from a certain cell to another certain cell indicates the reliability or soundness of the data. However, an anomaly here does not necessarily mean a malfunction such as a breakdown.

In the monitoring and control system of this embodiment, in a normal control program, both the data value and the signal status are sent and received for each input/output data exchanged between cells. This signal status is sent and received in a format that can manage different types of abnormalities. Specifically, as an example, tags are used to transmit the signal status, which can identify three types of abnormalities: abnormalities caused by hardware, abnormalities caused by software, and abnormalities caused by signal simulation, etc.

One form of signal status response information in each cell is information indicating what processing should be performed in response to the signal status indicated by the above-mentioned tag being input ("check response processing information" in Figure 3). For example, if the input data is tagged with an anomaly due to hardware or software, processing such as changing the value of a calculation parameter or setting the output data to a predetermined value can be performed.

One form of signal status correspondence information in an input cell is information indicating the content of a process that checks the level of the input data value and adds a tag according to that level ("signal check information" in Figure 3). Specifically, for example, it can be determined whether the input data value is within a normal range determined by upper and lower limits, and if it is not within that range, a tag indicating that the abnormality is caused by hardware is added.

One form of signal status response information in a calculation cell is information indicating the content of a process in which the level of the input data value is checked before calculation, or the level of the output data is checked after calculation, and warning (alarm) data is generated according to the level ("alarm generation information" in FIG. 3). This warning data can be used, for example, to generate a visual warning by display or an auditory warning by a buzzer or the like.

The signal status correspondence information in a calculation cell can also include information that determines whether or not to assign an abnormal tag to the output of a cell when the same tag indicating an abnormality is input to the cell. In other words, the signal status indicating an abnormality may be passed only between two cells and not passed on to subsequent cells, or it may be passed on to cells that receive data directly and indirectly from a certain cell. This is because, for example, even if a tag indicating an abnormality is attached to the input data in a certain calculation cell, if the value of the output data in that calculation cell can be fixed to a certain value and subsequent calculations can be performed without problems, there is no need to pass on the signal status indicating an abnormality.

Next, we will explain the operation when creating a control program on the engineering terminal 3 in the distributed control system of this embodiment.

The person in charge logs into the engineering terminal 3, starts the maintenance tool, and selects to execute the control program creation process. This activates the control program creation support unit 30. Under this control program creation support unit 30, the person in charge creates an instrumentation drawing for implementing the monitoring and control of the target plant, using various cells registered in the cell information storage unit 31. Figure 4 is an example of a drawing screen 100 for constructing a control program. In the drawing screen 100 shown in Figure 4, a drawing area 101 is arranged on the left, and a cell selection area 102 for selecting an available cell is arranged on the right. Figure 5 is a diagram showing a specific example of each cell in the instrumentation drawing shown in Figure 4 and their interrelationships.

The person in charge selects the appropriate input cell, calculation cell, output cell, etc. from the cell selection area 102 of the drawing screen 100 by clicking or other operations, and pastes them in the appropriate position in the drawing area 101. Then, the person in charge draws connections in the drawing area 101 that show the relationships between the multiple cells, that is, the input/output relationships. The calculation type and other information set for each cell in this way and the mutual connection relationship information are temporarily saved in the instrumentation drawing data storage unit 32.

Then, the person in charge continues by setting and registering the calculation parameter values and signal status correspondence information for each cell that has been set. For example, when the person in charge clicks on any cell on the drawing screen 100, a calculation parameter and signal status correspondence information setting screen in a specified format is displayed. Then, on that screen, the person in charge inputs the calculation parameter value for each cell as necessary, for example, for a multiplication cell, a constant value by which the input data is multiplied, and for a first-order lag cell, a delay time value, either numerically or by selecting from the given options.

The person in charge also sets and registers the signal status correspondence information as described above by selecting from the given options or by inputting appropriate values, as necessary.

When all drawing is completed, the values of the calculation parameters and the signal status correspondence information for each cell used are set, and the person in charge performs the specified operations on the engineering terminal 3, all of this information is saved in the instrumentation drawing data storage unit 32. The control program creation support unit 30 also creates a control program in a specified format by compiling the data that makes up the created instrumentation drawing. The program is then transferred to the control device 1 via the control network 4 and stored in the memory provided in the control unit 11. This enables the control device 1 to execute monitoring and control operations in accordance with the control program.

When operating plant equipment using the distributed control system of this embodiment, the control unit 11 performs data collection, calculation processing, and data output processing according to the control program stored in memory. When performing operations according to the control program, processing is performed by sending and receiving data between each cell as shown in Figure 5, and signal status is also sent and received along with the sending and receiving of the data. Each cell performs processing according to the input data value and signal status correspondence information. The following describes the operation status monitoring operations that can be performed by the engineering terminal 3 while the plant is in operation.

Figure 6 is a schematic diagram showing an example of an instrumentation drawing displayed during operation status monitoring. The person in charge logs into the engineering terminal 3, starts the maintenance tool, and selects the monitoring function. This activates the operation status monitoring unit 33. The operation status monitoring unit 33 reads out the instrumentation drawing data corresponding to the control program currently being executed in the control device 1 from the instrumentation drawing data storage unit 32, and displays the instrumentation drawing on the screen of the display unit. In addition, the operation status monitoring unit 33 collects in real time the values of input/output data and signal statuses being transmitted and received between cells from the control device 1 via the control network 4. This information changes from moment to moment depending on the operation status.

As shown in FIG. 6, the operation status monitoring unit 33 displays the values of the input/output data collected as described above as numerical values superimposed on or near the connections between cells on the instrumentation drawing. On the other hand, if the signal status is normal, it is not reflected in the display, but if there is an abnormality, the type of abnormality is displayed on the instrumentation drawing using characters, figures (appropriate marks or symbols, or changes in line thickness or line type, etc.), color changes, etc.

In the example of FIG. 6, the signal level of input cell B is checked and found to be outside the normal range, so a tag indicating an abnormality caused by hardware in input cell B is added to the output data. As a result, the operation status monitoring unit 33 changes the display color of the outer frame of input cell B to a color different from that of normal (however, since it is not possible to express the difference in color here, the outer frame is shown in bold). In addition, the connection line between input cell B and the next calculation cell D is changed from a solid line to a dotted line, and the color of the line is also changed to a color different from that of normal (however, the connection line is also shown in bold here). In addition, the type of abnormality (in this example, "SER" indicates an abnormality caused by hardware) is indicated by displaying the tag characters indicating the signal status (XXX_XX.SER in this example) near input cell B along with a symbol indicating that an abnormality has been detected.

Calculation cell D is set to inherit the signal status tag attached to the input data. Therefore, the output data of calculation cell D is also tagged with a tag indicating an abnormality caused by hardware. As a result, the operation status monitoring unit 33 changes the connection between calculation cell D and the next calculation cell E from a solid line to a dotted line, and also changes the color of the line from normal. On the other hand, calculation cell E is set not to inherit the signal status tag attached to the input data. Therefore, although the input data of calculation cell E is tagged with an abnormality, the connection between calculation cell E and output cell F is the same as in normal times.

As described above, the display on the instrumentation drawing during operation status monitoring changes according to the value of the collected data and the signal status. For example, when the level of the input signal to input cell B returns to the normal range over time and the tag indicating a hardware-related abnormality in input cell B is resolved, all displays on the instrumentation drawing transition to a normal state. In this way, the person in charge can easily visually grasp the location where an abnormality may be occurring on the instrumentation drawing displayed during operation status monitoring. In addition, it is easy to guess what factors are causing the abnormality. As a result, even if an abnormality occurs, for example, if the abnormality does not significantly impede plant operation, it can be dealt with while continuing operation.

The above-mentioned manner in which the display is changed when the signal status indicates an abnormality is merely an example, and can be changed as appropriate. For example, when an abnormality occurs, the manner in which the display is changed can be changed depending on the importance of the abnormality.

In addition, in the distributed control system of this embodiment, in order to verify or modify the control program, some operations may be switched to simulated operations while the plant is running. In such cases, the signal simulation function installed in the maintenance tool of the engineering terminal 3 can be used.

In this case, in the engineering terminal 3, while an instrumentation drawing corresponding to a control program as shown in FIG. 6 is displayed, the signal simulation execution unit 34 replaces, for example, one of the input cells with a simulated signal generation cell in response to an instruction from a person in charge. The simulated signal generation cell is a cell that generates and outputs a set simulated signal instead of the signal input from the field device 5. The data output from such a simulated signal generation cell is tagged with a signal status indicating that it is a simulated signal. In this case, the operation status monitoring unit 33 displays the connection lines through which the simulated signal data is sent and received in a manner that makes it possible to distinguish between a normal state and an abnormal state as described above. This allows the person in charge to easily visually grasp the connection lines and cells through which the simulated signal flows on the displayed instrumentation drawing.

In the distributed control system of the above embodiment, the engineering terminal 3 is provided with an operational status monitoring function, but this function may also be installed in the operator terminal 2.

Furthermore, the above embodiment is merely one example of the present invention, and it goes without saying that any appropriate changes, modifications, or additions made within the spirit of the present invention will be included within the scope of the claims of this application.

[Various aspects]
It will be appreciated by those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

(1) One aspect of the monitoring and control system according to the present invention is a monitoring and control system having a control device that collects data from a monitored and controlled object in accordance with a preset control program, executes a predetermined arithmetic process to generate control data, and transmits the control data to the monitored and controlled object, and a terminal that is connected to the control device via a communication line and has a program creation support function for creating the control program, wherein the terminal:
a cell information storage unit in which various cells, which are elements of processing including input, output, and calculation in the control program, are registered, at least a part of which is provided with an area for handling signal status information indicating the state of a signal being transferred;
a drawing creation unit that creates an instrumentation drawing showing the flow of processing in the control device while displaying, on a display screen, symbols corresponding to the cells stored in the cell information storage unit and connection elements showing the flow of data and signal status between a plurality of cells in response to an operation by a person in charge;
An individual cell information setting unit that sets a correspondence to a calculation parameter and/or a signal status for a cell used in the instrumentation drawing according to a type of the cell in response to an operation by a person in charge;
a programming unit that converts the instrumentation drawing in which the individual information of each cell has been set by the individual cell information setting unit into a program that can be executed by the control device;
Equipped with.

In the monitoring and control system described in paragraph 1, the terminal is actually a personal computer, and the computer can be configured to execute the functions of each of the above-mentioned parts by executing software (programs) installed on the computer.

According to the monitoring and control system described in paragraph 1, a person in charge can easily create a control program that includes cases where various cells themselves, such as calculation cells, or input data, are in an abnormal state by performing tasks similar to conventional procedures, such as appropriately arranging symbols corresponding to various cells on the terminal display screen and connecting the cells. This eliminates the need to create separate control programs for abnormal states, making it possible to reduce the number of work steps related to system operation, shorten construction time, and reduce costs.

(2) In the monitoring and control system described in 1, the control device can be configured to execute, under a control program, arithmetic processing for data and signal status input to a cell based on the correspondence between the arithmetic parameters and signal status set in the cell, and to output output data and signal status that are the results of the arithmetic processing.

According to the monitoring and control system described in paragraph 2, the control device executes arithmetic processing that reflects not only the data value but also the signal status. As a result, for example, if the input data value is outside the normal range and a signal status indicating an abnormality is attached, instead of normal arithmetic processing, arithmetic processing can be performed in which the possibly abnormal input value is replaced with a predetermined value, or processing can be performed in which the output value itself is replaced with a predetermined value. In other words, by switching the arithmetic processing depending on the reliability and soundness of the input data value, it is possible to prevent unintended abnormal values from being output, maintain plant operation, and avoid a chain reaction of malfunctions in the plant equipment itself.

(Clause 3) In the monitoring and control system described in paragraphs 1 and 2, the terminal may further include an operating status monitoring unit that monitors the values of data and signal status transmitted and received between each cell in a series of arithmetic processes executed by the control device when the system is in operation, and reflects at least a portion of the monitored information in an instrumentation drawing on the display screen.

(4) In the monitoring and control system described in 3, the operation status monitoring unit may change the manner in which the corresponding location on the instrumentation drawing is displayed depending on the monitored signal status.

The monitoring and control system described in paragraph 4 allows engineers and operators to quickly determine whether or not there are any abnormalities during plant operation or test runs, making it easier to identify the location and cause of the abnormality.

LIST OF SYMBOLS 1...Control device 10...Communication unit 11...Control unit 12...I/O unit 2...Operator terminal 3...Engineering terminal 30...Control program creation support section 31...Cell information storage section 32...Instrumentation drawing data storage section 33...Operation status monitoring section 34...Signal simulation execution section 4...Control network 5...Field device 6...Local network 7...Programmable logic controller 8...Calculation cell 80...Calculation type information 81...Connection relationship information 82...Calculation parameters 83...Signal status correspondence information 100...Drawing screen 101...Drawing area 102...Cell selection area

Claims (4)

A monitoring and control system comprising: a control device that collects data from a monitored and controlled object according to a preset control program, executes a predetermined arithmetic process to generate control data, and transmits the control data to the monitored and controlled object; and a terminal that is connected to the control device via a communication line and has a program creation support function for creating the control program, wherein the terminal comprises:
a cell information storage unit in which various cells, which are elements of processing including input, output, and calculation in the control program, are registered, at least a part of which is provided with an area for handling signal status information indicating the state of a signal being transferred;
a drawing creation unit that creates an instrumentation drawing showing the flow of processing in the control device while displaying, on a display screen, symbols corresponding to the cells stored in the cell information storage unit and connection elements showing the flow of data and signal status between a plurality of cells in response to an operation by a person in charge;
An individual cell information setting unit that sets a correspondence to a calculation parameter and/or a signal status for a cell used in the instrumentation drawing according to a type of the cell in response to an operation by a person in charge;
a programming unit that converts the instrumentation drawing in which the individual information of each cell has been set by the individual cell information setting unit into a program that can be executed by the control device;
A monitoring and control system comprising: The monitoring and control system of claim 1, wherein the control device is configured to execute, under a control program, arithmetic processing for data and signal status input to a cell based on the correspondence between the arithmetic parameters and signal status set in the cell, and to output output data and signal status that are the results of the arithmetic processing. The monitoring and control system according to claim 1 or 2, further comprising an operating status monitoring unit that monitors the values of data and signal statuses transmitted and received between each cell in a series of arithmetic processes executed by the control device during operation of the system, and reflects at least a part of the monitored information in an instrumentation drawing on a display screen. The monitoring and control system according to claim 3, wherein the operation status monitoring unit changes the display mode of the corresponding part on the instrumentation drawing according to the monitored signal status.