Control apparatus for a system of monitoring and controlling a plant including simulated data mass setting and cancelling means

A control apparatus for a plant system has data input/output units for inputting measured data obtained from a plant and a control command for the plant, a data transmission unit for transmission of data between a control unit and a plant monitor unit which are coupled to each other through a network, and a stimulated data mass setting and cancelling unit for performing mass setting of data handled by the data input/output unit and/or data handled by the data transmission unit to simulated data managed in the form of a list table by means of a maintenance tool and performing mass cancelling of the stimulated data set in the list table.

BACKGROUND OF THE INVENTION

The present invention relates to a control apparatus for a system of monitoring and controlling a plant, which control apparatus is preferably applied to, for example, a power plant to monitor its operational status.

Generally, in the power plant, a system is set up in which a plant monitor unit and a computer unit such as a maintenance tool are arranged in a central control room, these units are coupled to a control unit of boiler control system and a control unit of turbine control system through a network and control equipments associated with individual sections of the plant are operated on the basis of operation commands from the plant monitor unit or control commands from the control units.

Responsive to a request made by an operator, the plant monitor unit outputs commands for individual control equipments and displays plant information on, for example, a display unit in order to offer various kinds of control information and deliver guidance. The maintenance tool is a unit adapted to carry out maintenance operation for the control unit, having functions of preparing logics for control of the plant, loading the logics on the control unit and monitoring an operation process in the control unit.

In this type of monitoring and controlling system, in order to maintain a constant output with the aim of preventing the control equipment from operating responsive to control commands from the control unit during inspection of the control equipment and in order for the result of simulation of control theory for a control unit not to affect another control unit, the function to perform mass setting and cancelling of simulated data to and from input/output data and transmission data as well can be utilized.

Information as to what kind of simulated data is set to which input/output data and to which transmission data is managed through a list table by means of the maintenance tool, permitting the maintenance tool to execute the setting and cancelling of simulated data. Pieces of information such as simulated data to be set are managed with the help of the list table and therefore, a risk of missing the cancelling can be eliminated.

An example of this type of monitoring system is described in JP-A-2002-244722.

SUMMARY OF THE INVENTION

In carrying out mass setting and cancelling of simulated data to and from the transmission data in this type of system, the number of total items of data is large, thus giving rise to two problems as below.

A first problem resides in that because of restriction imposed on the memory capacity of the control unit, blocks of a transmission isolation data management memory for managing information necessary for mass setting and cancelling of simulated data concerning the transmission data cannot be prepared by the number equal to that of all pieces of transmission data.

More specifically, one of pieces of transmission isolation data for one piece of transmission data is written in one block. Structurally, on the other hand, respective memories represented by a simulated data storage memory for the transmission data, an actual data storage memory for storing actual transmission data and a transfer switch memory for performing switchover between simulated data and actual transmission data have blocks which are prepared by the number equal to that of all pieces of transmission data. For this reason, there arises a problem that data switchover between the transmission isolation data management memory and the other type of memory cannot be executed by using the same block number.

Blocks of the input/output isolation data management memory, however, can be prepared by the number equal to the number of all pieces of input/output data and can be adapted to perform reception and transfer of data by the use of the same block number in relation to the other simulated data storage memory, actual data storage memory and transfer switch memory which are associated with input/output data, thus escaping from the problem as above.

A second problem resides in that when blocks of the transmission isolation data management memory cannot be prepared by the number adapted for the number of all pieces of transmission data, unused blocks of the memory must be searched at the time that the transmission isolation data is written to the transmission isolation data management memory, with the result that the more the number of blocks in use, the time to search the unused blocks more increases to result in a problem that the search cannot be finished within the control cycle. For example, if the blocks in use range over the first block to the 10000-th block, it is not until unused conditions of the first to 10001-th blocks have been searched that transmission isolation is written to the 10001-th block.

Accordingly, it is an object of the present invention to carry out steadily with less process and time the setting and cancelling of simulated data by the use of the control apparatus in the plant system.

The present invention can be applicable to a control apparatus for a plant monitoring and controlling system having a control unit adapted to fetch a measured value indicative of the state of a plant and deliver a control command to the plant on the basis of the measured value and/or an operation command issued by an operator, a maintenance tool for performing maintenance of the control unit and a plant monitor unit adapted to deliver a command for operation of the plant to the control unit and display the state of the plant.

Structurally, the control apparatus comprises a data input/output unit for inputting a measured value obtained from a plant and a control command for the plant as well, a data transmission unit adapted to perform transmission of data between a control unit and a plant monitor unit which are coupled through a network and a simulated data mass setting and cancelling unit for performing mass setting of data handled by the data input/output unit and/or data handled by the data transmission unit to simulated data managed in the form of a list table by means of the maintenance tool and performing mass cancelling of the simulated data set in the list table.

According to the present invention, the data handled by the data input/output unit and/or the data handled by the data transmission unit can undergo mass setting to the simulated data managed in the form of a list table by means of the maintenance tool and the set simulated data can undergo mass cancelling. Accordingly, the plant maintenance using the maintenance tool can be carried out easily and speedily. Especially, the input/output data and the transmission data can undergo mass setting to simulated data and mass cancelling therefrom through the use of the list table and therefore, significantly great effects can be obtained under a condition that setting and cancelling needs to be executed many times.

DESCRIPTION OF THE EMBODIMENTS

In the present embodiment, the invention is applied to a power plant. In the case of the power plant, a system is materialized in which a plant monitor unit and a maintenance tool such as a computer unit are arranged in a central control room, these units are coupled to control units such as a boiler control unit and a turbine control unit through a network and control equipments associated with individual sections of the plant are operated on the basis of operation command from the plant monitor unit or control commands from the control units.

Referring first toFIG. 1, a system of controlling a plant is constructed as illustrated therein. Control units10,20are provided for, for example, individual control systems. In an example ofFIG. 1, a control equipment14such as a valve and a measuring instrument15such as a temperature sensor are connected to the control unit10through the medium of metal cables3, respectively. Further control units other than control units10and20may be provided depending on the configuration of control system.

In the control unit10, a CPU (central processing unit)11representing an arithmetic operation control unit is provided and this CPU11is coupled to a control command input/output unit12and to a plant data input/output unit13through a system bus2. The control command input/output unit12is connected to the control equipment14to control the state of control equipment14(for example, make-and-break). The plant data input/output unit13is connected to the measuring instrument15to capture data indicative of the state of the plant. The CPU11of control unit10transmits data to an operation monitor unit90and also to a maintenance tool80through an established network1. Further, the CPU11also performs data transmission to another control unit in the system (such as control unit20) through the network1. For the sake of performing data transmission via the network1, the control unit10has a data transmission processing unit16,22and is coupled to the network1by way of the data transmission processing unit. The network1can be set up as a network of various types such as wired LAN, wireless LAN or the like.

Likewise, the control unit20has a CPU21representing an arithmetic operation unit which controls a similarly connected control equipment (not shown) and inputs measured data from a similarly connected measuring instrument (not shown). The control unit20also has a data transmission process unit (not shown) and is coupled to the network1by way of the data transmission process unit.

The operation monitor unit90is constructed of a computer unit, for example, and functionally, it includes an operator-operative command generator91and a plant state monitor92. Then, a command generated in the operator-operative command generator91under operation by an operator is outputted to each of the control units10,20and plant state information from each of the control units10,20is supplied to the plant state monitor92through the network1, so that various monitoring processes such as displaying data on a display can be executed. Through display executed as above, various kinds of information can be offered and guidance can be delivered to the operator.

The maintenance tool80edits logics of the individual control units10,20and besides, performs operation of maintenance for the monitor in calculation process. The maintenance tool80is also constructed of a computer unit and an operator engaging in the maintenance work has the maintenance tool in hand to couple it to the network1.

The maintenance tool80includes a control logic diagram editor81, an operation process monitor82and an isolation function unit83and transmits data to the control unit coupled through the network1.

In the control unit10, a command from the operation monitor unit90is inputted via the network1and on the basis of this command and a measured value inputted from the measuring instrument15, the CPU11operates a control command and delivers it to the control equipment14.

In the maintenance tool80, a monitor screen for monitoring, for example, a calculation process in the control unit10can be generated and displayed. Then, through the monitor screen, input/output data or transmission data to which simulated data are desired to be set are chosen and the thus selected simulated data can be registered in the list table. Now, on the basis of the registration list table, setting of simulated data and cancelling of the set simulated data can be executed collectively or in a mass fashion by commands from the maintenance tool80.

Next, by making reference toFIG. 2, an example of a process state when simulated data is set to each of the control units10,20by means of the maintenance tool80will be described.

As shown inFIG. 2, in the maintenance tool80, a monitor screen84for monitoring the results of calculation executed by the control units10,20is displayed. Displayed on the monitor screen84is a logic diagram illustrative of an operation process by the CPU as will be seen fromFIG. 2. Input/output data and transmission data having their simulated data desired to be set are selected from the monitor screen84by the operator and then the simulated data are registered in the form of a list table85in the maintenance tool80.

The data to be managed through the list table85includes, for example, a signal name, a transmission source SH (sheet) No., a transmission destination SH No. and simulated data. Since the data managed in the form of the list table85does not include addresses of input/output data and transmission data but includes the SH No. and Nos. assigned to these elements, the data is not affected by changes the addresses of the input/output data and transmission data undergo in the course of compile. The input/output data referred to herein is that interchanged between the control unit and the control equipment such as valve and between the measuring instrument and the control unit and for example, the control unit10can set simulated data in the input/output data to/from the control equipment14and the measuring instrument15. Setting of the simulated data is applied to control command input/output unit12and plant data input/output unit13which represent the data input/output unit of control unit10and an operating state corresponding to a state in question is set in a simulated fashion.

The transmission data is that interchanged through the network1and the simulated data can be set in data transmitted from the control unit10to the different control unit20, for example.

Next, an example of a memory structure associated with the setting and cancelling of simulated data to and from the input/output data will be described with reference toFIG. 3. Individual memories shown inFIG. 3are storage units provided for each of the control units10, and are coupled to the individual CPU's11,12through the internal bus2. A CPU may be provided in each of control units other than the control units10,20.

An input/output isolation data management memory101is a memory adapted to store information necessary for mass setting of data format and simulated data and for mass cancelling of the set simulated data. Blocks of the input/output isolation data management memory101are prepared by the number equal to that of pieces of input/output data.

A simulated data storage memory102is a memory for write of the simulated data stored in the input/output isolation data management memory101, an actual data storage memory103is a memory for storing actual input/output data and a transfer switch memory104is a memory used for selection of either simulated data or actual data. Prepared for the number of blocks of each of the simulated data storage memory102, actual data storage memory103and transfer switch memory104is the number of pieces of input/output data.

Thus, the number of blocks is the same for all of the memories101,102,103and104and so, inter-reference to values among the memories, for example, can be achieved by using the same block number. For example, when the maintenance tool80makes a request for setting of simulated data to input/output data corresponding to a block number1, input/output isolation data is stored at a block of block number1in the input/output isolation data management memory101and the input/output isolation data management memory101rewrites blocks of block number1of the simulated data storage memory102and transfer switch memory104, thus making it possible to output the simulated data.

Next, reference is made toFIG. 4to describe a memory structure associated with setting and cancelling of simulated data to and from transmission data. Memories for transmission data are provided for each of the control units10,20separately from or independently of the aforementioned memories101,102,103and104dedicated to input/output data.

In the present embodiment, a memory structure similar to that for input/output data is not provided for the control unit on account of restriction imposed on the memory capacity. More particularly, a simulated data storage memory112, an actual data storage memory113and a transfer switch memory114which are adapted for transmission data have the same structure as the corresponding memories102,103and104which are adapted for input/output data, having the number of blocks equal to the number of pieces of transmission data prepared.

Contrarily, a transmission isolation data management memory111has a structure in which the number of blocks does not equal to that of pieces of transmission data so as to reduce the memory capacity.

Without preparing the number of blocks equal to that of pieces of transmission data, the number of blocks of the transmission isolation data management memory111differs from that of each of the other memories112,113and114and if this condition stands intact, pieces of data cannot mutually be referred to through mutual reference of block numbers.

Accordingly, in the present embodiment, a block number corresponding to that of each of the three memories112,113and114is stored in the transmission isolation data management memory111. By making reference to the stored block number, simulated data of transmission data can be set in a mass fashion in the control unit. Thus, when consulting or making reference to the different memory, the transmission isolation data management memory111can carry out searching easily and steadily by using the block number as key.

In writing the transmission isolation data into the transmission isolation data management memory111, an unused block of the memory needs to be searched and if this stands intact, there is the possibility that search of the block number cannot be finished within the prescribed control cycle when the number of used blocks is large. Searching unused blocks is necessary because the number of blocks of the transmission isolation data management memory111does not coincide with the number of total pieces of transmission data and only information concerning transmission data for which simulated data setting is requested must be inserted sequentially in unused blocks.

Then, in the present embodiment, the list structure is adopted for the transmission isolation data management memory111so as to prepare a used list and an unused list, enabling used blocks and unused blocks to be managed. Through this, the time to search can be shortened and the search can be finished within the prescribed control cycle.

More specifically, when taking the case where the maintenance tool80requests setting of simulated data to a piece of transmission data, for instance, an unused block number is searched on the basis of the unused list of transmission isolation data management memory111and the transmission isolation data is stored. In this phase, the transmission isolation data management memory111is stored with a block number of each of the three memories112,113and114which corresponds to the transmission data for which the request for setting of simulated data is made. The transmission isolation data management memory111rewrites by using the stored block number as key values stored at blocks corresponding to block numbers in the simulated data storage memory112and transfer switch memory114, so that simulated data can be outputted in place of actual data.

Since the simulated data can be delivered in this manner, change to the simulated data can be achieved through processes which are less in number and less time consuming. Also, when the simulated data is returned to actual data, a similar process can be conducted to complete the change through processes which are less time consuming and less in number.

While theFIG. 4example has been described by way of transfer of actual data to simulated data, a similar process may proceed when simulated data is switched over to return to actual data.

In the foregoing, the process applied to the simulated data of transmission data has been described exemplarily but a similar process may be conducted when, for example, the input/output data is switched over to the simulated data and the switched simulated data is returned to the actual data as shown inFIG. 3.