JP2014089540A - Plant control system, plant analysis device, plant analysis method and plant analysis program - Google Patents

Abstract

Provided are a plant control system, a plant monitoring apparatus 103, a plant analysis method, and a plant analysis program, which have an interlock analysis function while ensuring security and improve the maintainability and convenience of plant facilities.
A plant analysis apparatus 104 receives a control command for a plant device 106 and state information of the plant device 106 from a control network 105, and predicts an expected processing result for the control command. And if it detects that the result different from the said prediction produced | generated from the received status information, it will analyze where the conditions of the interlock concerning the plant apparatus 106 were not satisfied. If the cause can be identified as a result of the analysis, the analysis result is displayed on the operation terminal 116 through the monitoring network 115.
[Selection] Figure 1

Description

  The present invention relates to a plant control system for controlling plant equipment, a plant analysis apparatus, a plant analysis method, and a plant analysis program used therefor.

  In many plant facilities, when a certain plant device in the plant facility is started, a strict interlock is often applied to the plant device for safety. The programmable controller installed in the plant equipment has a built-in logic library that records information related to the interlock for each plant device so that the plant device can be activated only after clearing various predetermined conditions. Yes. A programmable controller checks an interlock with respect to the apparatus used as the object of the starting request | requirement transmitted from the plant monitoring apparatus, and starts the said plant apparatus, only when conditions are satisfy | filled. Otherwise, it is determined that the activation conditions are not satisfied, and status information indicating that the plant equipment has not been activated is returned to the plant monitoring apparatus.

  Prior art documents considered to be related to the present invention are shown in Patent Document 1. Patent Document 1 discloses a function for creating and executing a unified control program for diagnosing an interlock condition, a function for displaying a ladder circuit composed only of a plurality of factor signals when a plant device cannot be activated, and a plant device. A plant control system having a function of displaying a ladder circuit composed of only a plurality of factor signals and their trigger signals when an abnormal stop occurs.

JP 2006-24015 A

If the plant equipment operator tried to start up and the desired equipment did not start up, the operator would investigate the cause that did not satisfy the interlock condition and remove the cause in order to start up the equipment correctly. Must. For this purpose, it is necessary to analyze the interlock.
The logic library used for the interlock treats the plant facility design drawing data as a programming language, and extracts logic conditions using a predetermined compiler. Analyzing the interlock is an operation of tracing design drawing data of the plant equipment. This task is complicated and very laborious.

In order to analyze the interlock, there is a maintenance terminal having a logic monitor function. This maintenance terminal is used by connecting to a control network connecting the programmable controller and the plant monitoring device. However, the maintenance terminal has a function that can modify the arithmetic processing function of the programmable controller. For this reason, it is stipulated by law that maintenance terminals must not be connected to the network at all times in order to ensure security.
An operation terminal for monitoring the state of the plant equipment is always connected to a monitoring network that is physically separated from the control network in order to ensure security. A programmable controller is not connected to this monitoring network. However, since instructions for starting and stopping the device are issued from the operation terminal, it is convenient if the plant equipment is configured so that interlock analysis can also be performed from the operation terminal.

  The present invention solves such problems, has a security analysis, has an interlock analysis function, and improves the maintainability and convenience of plant equipment, a plant control system, a plant analysis device, a plant analysis method, and a plant analysis program The purpose is to provide.

In order to solve the above problems, a plant analysis apparatus of the present invention is connected to a control network and has a control command for a plant device transmitted from a plant monitoring device, and status information regarding the plant device transmitted from a programmable controller, And an input / output memory for storing the status information corresponding to the control command, and a predictive comparison processing unit for detecting an event in which the plant device subject to the control command did not achieve an expected operation result. To do.
In addition, in response to the detection of the event, the prediction comparison processing unit analyzes the cause of the event and generates information on the cause, and the operation connected to the monitoring network for the information on the cause An analysis result display processing unit to be transmitted to the terminal.

According to the present invention, it is possible to provide a plant control system, a plant analysis apparatus, a plant analysis method, and a plant analysis program that have an interlock analysis function and improve the maintainability and convenience of plant facilities while ensuring security. .
Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

It is a block diagram which shows the outline of the plant control system which is one Embodiment of this invention. It is a block diagram which shows the structure of the hardware of a plant analyzer. It is a processing flow figure of a plant control system. It is a processing flow figure of a plant control system. It is the schematic explaining the search pattern currently recorded on the search pattern library. It is a figure which shows the display screen of an operating terminal.

[overall structure]
FIG. 1 is a block diagram showing an outline of a plant control system 101 according to an embodiment of the present invention.
A programmable controller 102, a plant monitoring device 103, and a plant analysis device 104 that constitute the plant control system 101 are connected to a control network 105.
The programmable controller 102 has an interlock check function, controls the plant equipment 106 based on a control command received from the plant monitoring apparatus 103 through the control network 105, and collects state information of the plant equipment 106 to monitor the plant. To the device 103. For example, valve 107 open / close control and pump 108 start / stop control are performed, and the valve 107 open / close state, pump 108 start / stop state, and measurement values obtained from various sensors such as the pressure gauge 109 are collected.

A control command transmitted from the plant monitoring apparatus 103 through the control network 105 is temporarily stored in the input / output memory 110 of the programmable controller 102. The control command is input to the calculation unit 111. The calculation unit 111 refers to the logic library 112 and the input / output memory 110 to determine whether or not the plant device 106 that is the target of the control command satisfies the interlock condition stored in the logic library 112. It confirms from the status information of the current plant equipment stored in 110. If it can be confirmed that the interlock condition is satisfied, the calculation unit 111 passes the control command to the control information output unit 113. The control information output unit 113 transmits a control signal based on the control command to the device to be controlled.
The control signal may be an analog signal depending on the target plant device 106.

On the other hand, the state information acquisition unit 114 of the programmable controller 102 periodically collects state signals from all the plant devices 106 connected to the programmable controller 102 and delivers them to the calculation unit 111. The calculation unit 111 performs engineering value conversion and data quality check on the status signal of each device received from the status information acquisition unit 114 and transfers it to the input / output memory 110. Then, the calculation unit 111 transmits the state information generated from the state signal collected by the state information acquisition unit 114 to the plant monitoring device 103 and the plant analysis device 104 through the control network 105.
The state signal may be an analog signal depending on the target plant device 106.

The plant monitoring apparatus 103 is operated from operation terminals 116a and 116b (hereinafter referred to as operation terminals 116 when collectively referred to without any particular specification) connected to a monitoring network 115 provided separately from the control network 105. Various control commands are received and transmitted to the programmable controller 102 through the control network 105. And the status information of a plant installation is received from the programmable controller 102, and it displays on GUI (Graphical User Interface) which the operation terminal 116 provides.
Although the control network 105 is a network dedicated to plant control, the monitoring network 115 is a LAN using a well-known TCP / IP, and includes a plant monitoring device 103, an operation terminal 116, and a plant analysis device 104 described later. All devices connected to the monitoring network 115 are assigned a fixed private address.

A control command for the plant equipment 106 transmitted from the operation terminal 116 through the monitoring network 115 is received by the control information acquisition unit 117 of the plant monitoring apparatus 103 and temporarily stored in the input / output memory 118. Then, the control command is transmitted to the programmable controller 102.
Further, the state information transmitted from the programmable controller 102 through the control network 105 is temporarily stored in the input / output memory 118 of the plant monitoring apparatus 103. Then, the status information is input to the monitoring information output unit 119. The monitoring information output unit 119 refers to the terminal management table 120 to display the current plant equipment state on the GUI of the operation terminal 116 for all the operation terminals 116 connected to the monitoring network 115, and periodically. Update to

The plant analysis device 104 is a device newly provided in the plant control system 101 of this embodiment for the analysis of the failure of the interlock.
Similar to the plant monitoring apparatus 103, the plant analysis apparatus 104 is connected to both the control network 105 and the monitoring network 115. And the apparatus control command transmitted from the plant monitoring apparatus 103 and the state information of the plant equipment transmitted from the programmable controller 102 are received, and interlock non-establishment is monitored. If it is determined that the interlock has not been established, the interlock is analyzed, and if the cause can be identified, information on the cause can be identified, and if the cause cannot be identified, the logic sheet at the location where it can no longer be identified can be manipulated. It is displayed on the terminal 116.

  A control command transmitted from the plant monitoring apparatus 103 through the control network 105 and state information transmitted from the programmable controller 102 through the control network 105 are temporarily stored in the input / output memory 121 of the plant analysis apparatus 104. Then, the prediction comparison processing unit 123 reads information on the result of normal operation corresponding to the control instruction included in the input / output memory 121 from the instruction state library 122 and monitors the contents of the input / output memory 121. For example, the information is “the pump 108 starts within 10 seconds from the start command of the pump 108”. In this case, if a timer (not shown) is started from the start command of the pump 108 and it can be confirmed that the status information indicating that the pump 108 has been started can be received from the programmable controller 102 within 10 seconds, it is determined that the pump 108 has operated normally. it can.

When the prediction comparison processing unit 123 detects that the state information of the plant device 106 corresponding to the control command indicates abnormality, the prediction comparison processing unit 123 copies and captures the entire contents of the input / output memory 121 at that time. Hereinafter, the entire contents of the captured input / output memory 121 are referred to as a snapshot. Then, the prediction comparison processing unit 123 activates the analysis processing unit 124.
The analysis processing unit 124 refers to the logic sheet library 125 and the search pattern library 126 based on the snapshot held by the prediction comparison processing unit 123, and investigates the cause of the plant device 106 indicating abnormal termination.

  The snapshot is the entire contents of the input / output memory 121 when the result of the control command for the plant device 106 is abnormal. In the logic sheet library 125, design drawing data of the plant equipment that is the basis of the logic library 112 in the programmable controller 102 is recorded. In the search pattern library 126, a pattern of determination processing at a branch when tracing an interlock described later is recorded. When the analysis processing unit 124 reads the logic sheet related to the plant device 106 in which an abnormality has occurred from the logic sheet library 125 and finds a branch existing in the logic sheet, the analysis processing unit 124 reads the content of the branch from the snapshot and reads the branch. Whether or not to trace back is read from the search pattern library 126, and finally it is determined whether or not the cause of the failure of interlock can be identified.

If the cause of the interlock failure is identified, the analysis processing unit 124 displays information on the cause on the GUI of the operation terminal 116 through the analysis result display processing unit 127 with an appropriate explanatory text.
If the cause of the failure of the interlock cannot be identified, the analysis processing unit 124 finally provides information on the location in the plant facility where the cause of the failure of the interlock could not be identified, with an appropriate explanation. The result is displayed on the GUI of the operation terminal 116 through the analysis result display processing unit 127. At this point, the emulation processing unit 128 can be activated from the operation terminal 116.
When the emulation processing unit 128 receives an activation command from the operation terminal 116, the emulation processing unit 128 reads the logic sheet library 125 based on the snapshot held by the prediction comparison processing unit 123. Then, the design drawing data relating to the location in the plant equipment where the cause of the failure of the interlock could not be finally identified is displayed on the GUI of the operation terminal 116 through the analysis result display processing unit 127 with the snapshot value. To do.

FIG. 2 is a block diagram illustrating a hardware configuration of the plant analysis apparatus 104.
The plant analysis apparatus 104 is a known microcomputer, and a CPU 201, a ROM 202, a RAM 203, and a nonvolatile storage 204 are connected to a bus 205.
Further, an input / output memory 121 connected to the control network 105 and a NIC (Network Interface Card) 206 connected to the monitoring network 115 are also connected to the bus 205.
A nonvolatile storage 204 composed of a hard disk device or the like stores a program for operating a microcomputer as the plant analysis device 104, an instruction state library 122, a logic sheet library 125, and a search pattern library 126.

3 and 4 are process flow diagrams of the plant control system 101. FIG.
First, the processing flow will be described with reference to FIG.
The operator operates the operation terminal 116 to transmit a start request for a desired plant device 106 to the plant monitoring apparatus 103 (S301). The “start request for the plant device 106” generated from the operation terminal 116 is input to the control information acquisition unit 117 of the plant monitoring apparatus 103 through the monitoring network 115. The control information acquisition unit 117 writes the “start request for the plant device 106” in the input / output memory 118 and transmits it to the programmable controller 102 and the plant analysis device 104 through the control network 105 (S302).

  When the plant analysis apparatus 104 receives the “start request for the plant device 106” transmitted from the plant monitoring apparatus 103 (S303), the plant analysis apparatus 104 records it in the input / output memory 121. Then, the prediction comparison processing unit 123 predicts the result of normal operation of the plant device 106 (S304).

  When the programmable controller 102 receives the “start-up request for the plant device 106” transmitted from the plant monitoring apparatus 103 (S305), it records it in the input / output memory 110. Then, the calculation unit 111 calculates an interlock condition by referring to the logic library 112 as to whether or not the plant device 106 can be normally started (S306). As a result, the calculation unit 111 detects that the interlock condition is not satisfied, and writes the “state information of the plant device 106” in the input / output memory 110 to the effect that the plant device 106 has not been started normally. It transmits to the plant analysis apparatus 104 and the plant monitoring apparatus 103 (S307).

  When receiving the “state information of the plant device 106” transmitted from the programmable controller 102 (S308), the plant analysis device 104 records it in the input / output memory 121. Then, the prediction comparison processing unit 123 compares the result of the normal operation predicted in step S304 with the received “state information of the plant device 106” (S309), and confirms that the plant device 106 has not started up normally. recognize. Then, the entire contents of the input / output memory 121 at this time, that is, the state of the plant equipment is recorded as a snapshot (S310).

When receiving the “state information of the plant device 106” transmitted from the programmable controller 102, the plant monitoring apparatus 103 records this in the input / output memory 121. Then, the monitoring information output unit 119 transfers “state information of the plant device 106” to be displayed on the GUI of the operation terminal 116 (S311).
The operation terminal 116 receives “state information of the plant device 106” from the plant monitoring apparatus 103 and displays it on a display unit (not shown) (S312).

With reference to FIG. 4, the description of the process flow diagram of the plant control system 101 will be continued.
In step S310, after the prediction comparison processing unit 123 of the plant analysis device 104 records the state of the plant equipment as a snapshot, the analysis processing unit 124 analyzes the cause of the failure of the interlock condition (S413). If it is determined as a result of the analysis that the cause of the failure of the condition can be identified (YES in S414), the analysis processing unit 124 passes the analysis result to the analysis result display processing unit 127.
The analysis result display processing unit 127 converts the analysis result into a format that can be displayed on the GUI of the operation terminal 116, and transmits it to the operation terminal 116 through the monitoring network 115 (S415). The operation terminal 116 receives the analysis result and displays it on a display unit (not shown) (S416).

In step S414, if it is determined that the cause of the failure of the interlock condition as a result of the analysis cannot be specified (NO in S414), the analysis processing unit 124 finally determines that the interlock condition is satisfied. The analysis result of the part that could not be specified is transferred to the analysis result display processing unit 127.
The analysis result display processing unit 127 converts the analysis result into a format that can be displayed on the GUI of the operation terminal 116, and transmits the result to the operation terminal 116 through the monitoring network 115 (S417). The operation terminal 116 receives the analysis result and displays it on a display unit (not shown) (S418).
Further, when the operator manually requests display of a snapshot in order to specify the cause of the failure of the interlock condition (S419), the emulation processing unit 128 snaps to the logic sheet library 125 each time. The design drawing data and a part of the snapshot are read with reference to the shot. And it transmits to the operation terminal 116 through the analysis result display process part 127 (S420). Thereafter, the operation terminal 116 displays the received logic sheet (S421).

[Search pattern]
5A, 5B, and 5C are schematic diagrams illustrating search patterns recorded in the search pattern library 126. FIG. The search pattern library 126 contains hundreds of search pattern records, but only a part thereof is disclosed in FIG.
In the design drawing data, as shown in FIG. 6C described later, plant equipment 106 and an operator symbol indicating a condition are illustrated. The operator receives a plurality of assumed inputs and outputs an expected output.

FIG. 5A is a table showing a search for a symbol of a logical product operator, an assumed input and an expected output, and an interlock condition failure condition factor.
When a plant device 106 is activated with an expected output of logical product, if the expected output is logic true, the plurality of assumed inputs are all the only true combination of logic. On the other hand, if the output is a false logic, for example, if there are three assumed inputs, seven combinations of inputs are assumed as shown in FIG. 5A.
When only one of the three assumed inputs is false in logic, it is possible to search for an interlock condition failure factor for the operator or plant equipment 106 ahead of the input. However, if there are two or more logic false among the three assumed inputs, it cannot be specified which is the true cause of failure of the interlock condition. Therefore, at this time, the search for the cause of the failure to establish the interlock condition is terminated.

FIG. 5B is a table showing whether or not to search for a symbol of an OR operator, an assumed input and an expected output, and an interlock condition failure factor.
When a certain plant device 106 is activated by an expected output of logical product, if the expected output is logical true, a plurality of assumed inputs are seven combinations in which one or more of the logical inputs are true of logic. On the other hand, if the output is logic false, the assumed input is the only combination where all inputs are logic false. If only one of the three assumed inputs is false in logic, it is possible to search for an interlock condition failure factor for the operator or plant device 106 ahead of the input. However, it is not possible to identify which of the three assumed inputs is a true interlock condition failure factor. Therefore, at this time, the search for the cause of the failure to establish the interlock condition is terminated.

FIG. 5C is a table showing whether or not to search for a symbol of a logical negation operator, an assumed input and an expected output, and an interlock condition failure condition factor.
If a plant device 106 is activated with an expected output of logic negation, if the expected output is logic true, the assumed input is single and logic false. On the other hand, if the output is logic false, the assumed input is single and logic true. Therefore, the search for the cause of the failure to establish the interlock condition is continued.

[Display screen]
6A, 6B and 6C are diagrams showing display screens of the operation terminal 116. FIG.
FIG. 6A is an analysis result display screen when the interlock condition failure factor can be identified. This corresponds to step S416 in FIG.
The analysis result display processing unit 127 displays an analysis result of “low pump 108 inlet pressure” in a part of the plant equipment diagram displayed on the display screen of the operation terminal 116 by the monitoring information output unit 119 of the plant monitoring apparatus 103. Displayed as message 601.
FIG. 6B is a display screen of the analysis result when the interlock condition failure factor cannot be identified. This corresponds to step S418 in FIG.
The analysis result display processing unit 127 can finally specify the interlock condition in a part of the plant equipment diagram displayed on the display screen of the operation terminal 116 by the monitoring information output unit 119 of the plant monitoring apparatus 103. “AND condition not established” regarding the missing part is displayed as an analysis result message 602.
FIG. 6C is a display screen of a logic sheet when an interlock condition failure factor cannot be identified. This corresponds to step S421 in FIG.
When the analysis result message 602 of the analysis result “AND condition not satisfied” in FIG. 6B is clicked with a pointing device such as a mouse, a diagram of the plant equipment based on the design drawing data of the location where the interlock condition could not be finally specified is displayed. Are displayed on the screen of the operation terminal 116 with the snapshot value.

In the present embodiment, the following application examples are possible.
There are various means for the analysis result display processing unit 127 to provide a GUI to the operation terminal 116. For example, the analysis result display processing unit 127 serves as a web server, and the operation terminal 116 operates a web browser to display an analysis result and a snapshot. In addition, a client-server system using a general client application program, a virtual desktop environment such as the well-known VNC (Virtual Network Computing) and RDP (Remote Desktop Protocol), a multi-user environment such as a POSIX OS and an X Window System, etc. Various means are available.

In the present embodiment, the plant control system 101 has been disclosed.
A plant analysis system 104 is newly provided in the plant control system 101. The plant analysis apparatus 104 receives a control command for the plant device 106 and state information of the plant device 106 from the control network 105, and predicts an expected processing result for the control command. Then, when it is detected from the received state information that a result different from the prediction has occurred (an event that has not resulted in the expected operation result), it is analyzed where the interlock condition relating to the plant device 106 is not satisfied. To do. If the cause can be identified as a result of the analysis, the analysis result is displayed on the operation terminal 116 through the monitoring network 115.

  If the cause cannot be identified as a result of the analysis, the analysis result of the location where the interlock condition could not be identified finally is displayed on the operation terminal 116 through the monitoring network 115. In addition, a snapshot screen that realizes tracing of the relevant part of the plant equipment is displayed on the operation terminal 116 in accordance with the operation of the operator. By providing the above functions by the plant analysis device 104, it is possible to provide an interlock analysis function from the operation terminal 116 while ensuring the security of the security of the control network 105. Thereby, the plant control system, the plant monitoring apparatus 103, the plant analysis method, and the plant analysis program which can improve the maintainability and convenience of the plant facilities can be provided.

The embodiment of the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and other modifications may be made without departing from the gist of the present invention described in the claims. Includes application examples.
For example, the above-described exemplary embodiments are detailed and specific descriptions of the configuration of the apparatus and system in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described. . Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Moreover, it is also possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

Each of the above-described configurations, functions, processing units, and the like may be realized by hardware by designing a part or all of them with, for example, an integrated circuit. Further, each of the above-described configurations, functions, and the like may be realized by software for interpreting and executing a program that realizes each function by the processor. Information such as programs, tables, and files for realizing each function is stored in a memory, a hard disk, a volatile or non-volatile storage such as an SSD (Solid State Drive), or a recording medium such as an IC card or an optical disk. be able to.
In addition, the control lines and information lines are those that are considered necessary for the explanation, and not all the control lines and information lines on the product are necessarily shown. Actually, it may be considered that almost all the components are connected to each other.

  DESCRIPTION OF SYMBOLS 101 ... Plant control system, 102 ... Programmable controller, 103 ... Plant monitoring apparatus, 104 ... Plant analysis apparatus, 105 ... Control network, 106 ... Plant equipment, 115 ... Monitoring network

Claims (7)

An operation terminal;
A monitoring network to which the operation terminal is connected;
A control instruction for a plurality of plant devices, a control network through which the state information of the plant devices flows,
Connected to the control network, receives the control command from the control network, gives an operation control signal based on the control command to a plurality of plant devices, and obtains a status signal from the plurality of plant devices. A programmable controller for transmitting the state information to the control network;
Plant monitoring connected to the monitoring network and the control network and transmitting the control command received from the operation terminal to the programmable controller and receiving the state information from the programmable controller and transmitting to the operation terminal Equipment,
An event that is connected to the monitoring network and the control network, receives the control command and the state information from the control network, and the plant equipment corresponding to the control command does not achieve an expected operation result A plant control system comprising: a plant analysis device that detects information from the state information and transmits information related to the cause of the event to the operation terminal.   When the cause of the event can be identified, the plant analysis device transmits information on the cause to the operation terminal, and when the cause of the event cannot be identified, the determination of the cause in the plant equipment branches. The plant control system of Claim 1 which transmits the information regarding the location to do to the said operating terminal. An input / output memory that is connected to the control network and stores a control instruction for the plant equipment transmitted from the plant monitoring device, and status information about the plant equipment transmitted from the programmable controller;
A prediction comparison processing unit that monitors the state information corresponding to the control command and detects an event in which the plant equipment that is the target of the control command does not reach an expected operation result;
In response to the prediction comparison processing unit detecting the event, the cause of the event is analyzed, and an analysis processing unit that generates information on the cause;
A plant analysis apparatus comprising: an analysis result display processing unit that transmits information on the cause to an operation terminal connected to a monitoring network. Furthermore,
The plant analysis apparatus according to claim 3, further comprising: an emulation processing unit that transmits information regarding a location where the determination of the cause in the plant equipment branches when the cause of the event cannot be specified. A control command receiving procedure for receiving a control command for the plant equipment transmitted from the plant monitoring device;
Status information reception procedure for receiving status information corresponding to the control command;
A predictive comparison procedure for detecting an event in which the plant equipment subject to the control command did not reach an expected operation result;
An analysis processing procedure for analyzing the cause of the event in response to detecting the event in the prediction comparison procedure and transmitting information on the cause to an operation terminal connected to the monitoring network. Plant analysis method. Furthermore,
The plant analysis according to claim 5, further comprising: an emulation processing procedure for transmitting, to the operation terminal, information on a location where the determination of the cause in the plant facility branches when the cause of the event cannot be specified in the analysis processing procedure. Method. On the computer,
A control command receiving procedure for receiving a control command for the plant equipment transmitted from the plant monitoring device;
Status information reception procedure for receiving status information corresponding to the control command;
A predictive comparison procedure for detecting an event in which the plant equipment subject to the control command did not reach an expected operation result;
In response to detecting the event in the predictive comparison procedure, an analysis processing procedure is performed for analyzing the cause of the event and transmitting information on the cause to an operation terminal connected to the monitoring network. A plant analysis program.