JP7675607B2 - Plant Control Device - Google Patents

Description

An embodiment of the present invention relates to a plant control device.

Conventionally, in industrial plant control systems, etc., a plant control device is used that includes multiple I/O (Input/Output) and transmission modules that input and output various data between various devices such as sensors, and an interface module that executes the process of reading and writing the input and output data of the multiple I/O and transmission modules. The appropriate access period for the I/O and transmission modules used in such plant control devices varies depending on the type.

JP 2016-81390 A

However, in conventional technology, the interface module accessed multiple I/O and transmission modules at the same cycle to obtain data.

The plant control device of the embodiment includes a plurality of input modules that receive data input from external devices, and an interface module that connects to the plurality of input modules. The interface module includes a register and a control circuit. The register stores an access period for each module type. The control circuit acquires the module type of each of the plurality of input modules from the plurality of input modules, identifies the access period of each of the plurality of input modules by referring to the acquired module type and the access period stored in the register, and accesses the plurality of input modules for each access period of the identified plurality of input modules to acquire data.

FIG. 1 is a diagram illustrating an example of a control system including a plurality of plant control devices according to an embodiment. FIG. 2 is a block diagram illustrating an example of a configuration of a plant control device according to the embodiment. FIG. 3 is a diagram illustrating an example of an access period table according to the embodiment. FIG. 4 is a diagram illustrating an example of an input data table according to the embodiment. FIG. 5 is a diagram showing an example of the data update period of the input data stored in the memories of the two input modules according to the embodiment and the data acquisition timing by the control circuit of the interface module. FIG. 6 is a flowchart showing an example of the flow of an initial setting process executed by the control circuit of the interface module according to the embodiment. FIG. 7 is a flowchart showing an example of the flow of an access process to an input module executed by a control circuit of an interface module according to the embodiment.

(First embodiment)
In this embodiment, a plant control device used mainly for controlling an industrial plant (hereinafter, simply referred to as a plant) will be described. Generally, as a technology for controlling a plant, it is known to connect a plurality of plant control devices to configure a control system.

Figure 1 shows an example of a control system S including multiple plant control devices 1 and 2 according to this embodiment.

The plant control devices 1 and 2 are each configured by combining multiple modules with a basic base 10 or 20. The basic base 10 or 20 is provided with multiple slots, and each module is inserted into one of the slots.

The plant control device 1 includes a basic base 10, an interface module 110, a plurality of input modules 120a to 120k, and a power supply module 130.

The power supply module 130 obtains power from a power cable (not shown) and supplies the obtained power to the interface module 110 and the multiple input modules 120a to 120k.

The multiple input modules 120a to 120k receive data input from various external devices. The various external devices are, for example, sensors, control devices, PCs (Personal Computers), and servers. The multiple input modules 120a to 120k have I/O ports to which cables can be attached to connect to various external devices. The multiple input modules 120a to 120k each support a different communication standard. The communication standard may be, for example, an existing standard such as Ethernet (registered trademark), or a unique standard for the control system S. Hereinafter, when there is no need to distinguish between the individual input modules 120a to 120k, they will simply be referred to as input modules 120. Note that the input module 120 may be an input/output module that has the function of not only inputting data but also outputting data to external devices.

The interface module 110 acquires input data acquired by the multiple input modules 120a to 120k from various devices, and stores the acquired input data in memory within the interface module 110. The memory within the interface module 110 is called a shared memory because it can be read by the interface module 210 of the plant control device 2 described below. The shared memory is illustrated in FIG. 2 described below. The input data is data input to the input modules 120a to 120k from various devices. In this embodiment, when the word "data" is used simply, it refers to the input data.

The interface module 110 also has multiple interface ports 111a, 111b to which the cable 3 can be connected. In the example shown in FIG. 1, one end of the cable 3 is inserted into the interface port 111a. The other end of the cable 3 is inserted into the interface port 211a of the interface module 210 of the plant control device 2. In this case, the interface module 110 is connected to the interface module 210 of the plant control device 2 via the cable 3. Note that the interface module 110 may also be connected to a plant control device other than the plant control device 2 via the interface ports 111a, 111b.

The plant control device 2 includes a basic base 20, an interface module 210, a plurality of I/O/transmission modules 220a to 220i, a power supply module 230, and a controller 240.

The plant control device 2 is, for example, a higher-level device of the plant control device 1. For example, although there is a limit to the number of I/O and transmission modules 220a to 220i that can be inserted into the plant control device 2, there are cases where the user wishes to add further I/O and transmission modules to the control system S. In such a case, by connecting the plant control device 1 to the plant control device 2, multiple input modules 120a to 120k can be added. Note that the input modules 120a to 120k may be I/O and transmission modules with output functions.

The multiple I/O/transmission modules 220a to 220i of the plant control device 2 input and output data and transmit information between various external devices.

The power supply module 230 of the plant control device 2 acquires power from a power supply cable (not shown) and supplies the acquired power to the interface module 210, the multiple I/O/transmission modules 220a to 220i, and the controller 240.

The controller 240 of the plant control device 2 includes a CPU (Central Processing Unit) and memory, and executes programs stored in the memory to input and output data to and from the I/O and transmission modules 220a to 220i. The controller 240 also controls the interface module 210 to read input data stored in the shared memory of the interface module 110 of the plant control device 1.

The interface module 210 of the plant control device 2 has multiple interface ports 211a to 211d to which the cable 3 can be connected. In the example shown in FIG. 1, one end of the cable 3 is inserted into the interface port 211a, and the interface module 210 is connected to the interface module 110 of the plant control device 1 via the cable 3. Note that there are no particular limitations on the standards to which the cable 3 and the interface ports 111a, 111b, 211a to 211d conform, and a general serial communication standard may be adopted, or a unique standard for the control system S may be used.

Under the control of the controller 240, the interface module 210 of the plant control device 2 reads input data from the shared memory of the interface module 110 of the plant control device 1 and stores the read input data in the memory of the controller 240. The interface module 210 is an example of another interface device in this embodiment.

Next, the configuration of the plant control device 1 according to this embodiment will be described in more detail.

Figure 2 is a block diagram showing an example of the configuration of the plant control device 1 according to this embodiment. As shown in Figure 2, the interface module 110, the multiple input modules 120a to 120k, and the power supply module 130 of the plant control device 1 are inserted into the slots 11a to 11m of the basic base 10, respectively. Hereinafter, when there is no need to distinguish between the individual slots 11a to 11m, they will simply be referred to as slots 11.

The basic base 10 includes an interface module 110, a number of input modules 120a to 120k, and a power supply cable 91 and bus 90 that connect the power supply module 130.

The interface module 110, the multiple input modules 120a-120k, and the power supply module 130 are equipped with connectors 112a-112k. The connectors 112a-112k connect to the power supply cable 91 and the bus 90 of the basic base 10.

The power supply module 130 supplies power via a power supply cable 91 to the interface module 110 inserted into the slots 11b to 11m and to the multiple input modules 120a to 120k.

The interface module 110 includes a control circuit 400, a shared memory 410, and interface ports 111a and 111b.

As described in FIG. 1, interface ports 111a and 111b are ports into which cable 3 can be inserted.

The control circuit 400 is a programmable integrated circuit, for example an FPGA (Field-Programmable Gate Array). In the control circuit 400, various processes are defined by a hardware description language. The control circuit 400 includes a register 41. The control circuit 400 acquires input data 61a to 61k from a plurality of input modules 120a to 120k according to the access cycle for each type of input module 120 registered in an access cycle table 51. The control circuit 400 stores the acquired input data 61a to 61k in an input data table 52a. Hereinafter, when the input data 61a to 61k are not particularly distinguished from each other, they are simply referred to as input data 61.

The control circuit 400 also transfers the input data table 52a stored in the register 41 to the shared memory 410. For example, the transfer means copying the input data table 52a from the register 41 to the shared memory 410.

Register 41 stores access period table 51 and input data table 52a.

The access period table 51 is a table in which the access period for each type of input module 120 is registered. The access period table 51 is stored in advance in the register 41 before the plant control device 1 is shipped. An example of the configuration of the access period table 51 will be described later with reference to FIG. 3. Hereinafter, the type of input module 120 is referred to as a "module type." In this embodiment, the access period of each module type is the data update period for each module type. The data update period is the period in which each input module 120 acquires input data from an external device. The input data 61a to 61k stored in the memories 600a to 600k of each input module 120a to 120k is updated at each data update period.

The input data table 52a is a table in which the slot numbers of the slots 11c to 11m into which the multiple input modules 120a to 120k are inserted, the module types of the multiple input modules 120a to 120k, and the input data 61a to 61k acquired from the memories 600a to 600k of the multiple input modules 120a to 120k are associated. The input data table 52a is generated by the control circuit 400 when the interface module 110 is started for the first time. An example of the configuration of the input data table 52a will be described later with reference to FIG. 4.

The shared memory 410 is a readable and writable storage device such as a static random access memory (SRAM). The shared memory 410 stores the input data table transferred from the register 41 by the control circuit 400. In FIG. 2, the input data table in the register 41 is described as "input data table 52a", and the input data table transferred from the register 41 to the shared memory 410 is described as "input data table 52b". The input data tables 52a and 52b have the same item configuration. The input data tables 52a and 52b are collectively referred to as "input data table 52".

The register 41 cannot be accessed from the interface module 210 of the plant control device 2, but the shared memory 410 can be accessed from the interface module 210. The control circuit 400 copies the input data table 52a of the register 41 to the shared memory 410, so that the interface module 210 of the plant control device 2 can read the input data stored in the input data table 52b of the shared memory 410. The interface module 210 of the plant control device 2 accesses the shared memory 410 of the plant control device 1 at a timing determined by, for example, the controller 240. Since the interface module 110 of the plant control device 1 acquires input data from the multiple input modules 120a to 120k according to their respective data update periods, the plant control device 2 can acquire the input data of each of the input modules 120a to 120k from the shared memory 410 without adjusting the access timing to the data update period of the multiple input modules 120a to 120k.

The input modules 120a to 120k each include a memory 600a to 600k, a control circuit 610a to 610k, and an I/O port 121a to 121k. Note that while FIG. 2 illustrates a configuration common to the input modules 120a to 120k, each input module 120a to 120k may also include its own unique configuration. Hereinafter, when there is no need to distinguish between the individual control circuits 610a to 610k, they will simply be referred to as control circuits 610. When there is no need to distinguish between the individual memories 600a to 600k, they will simply be referred to as memories 600. When there is no need to distinguish between the individual I/O ports 121a to 121k, they will simply be referred to as I/O ports 121.

In the example shown in FIG. 2, sensors 6a to 6k are connected to I/O ports 121a to 121k. Sensors 6a to 6k are examples of external devices that input data to input modules 120a to 120k. Note that external devices connected to I/O port 121 are not limited to sensors. Hereinafter, when there is no need to distinguish between sensors 6a to 6k, they will simply be referred to as sensor 6.

Memories 600a to 600k store input data 61a to 61k, module types 62a to 62k, and control circuits 610a to 610k. Memories 600a to 600k are, for example, storage devices such as readable and writable SRAMs.

Alternatively, the input modules 120a to 120k may have both read-only memory and read/write memory. In this case, a read-only memory such as a ROM (Read Only Memory) stores the module types 62a to 62k, and a read/write memory such as a RAM (Random Access Memory) stores the input data 61a to 61k. Hereinafter, when there is no need to distinguish between the individual module types 62a to 62k, they will simply be referred to as module type 62.

The functions of the input module 120 will be explained below using the input module 120a as an example. The I/O port 121a of the input module 120a is connected to, for example, the sensor 6a.

The control circuit 610a controls the input and output of data via the I/O port 121a. For example, the control circuit 610a stores the input data 61a acquired by the I/O port 121a from the sensor 6a at a specified data update period in the memory 600a. The time length per data update period of the input data 61a depends on the module type of the input module 120a.

The memory 600a also stores the module type 62a of the input module 120a. The module type 62a is stored in the memory 600a in advance before the input module 120a is shipped.

Input modules 120b to 120k have the same configuration as input module 120a.

Next, we will explain the configuration of the access period table 51 stored in the register 41 of the interface module 110.

Figure 3 is a diagram showing an example of an access period table 51 according to this embodiment. As shown in Figure 3, a module type and an access period are stored in association with each other at each address of the register 41. Among the addresses in the storage area of the register 41, the addresses that are not used as the access period table 51 are assumed to be predetermined.

The module type is, for example, a code representing the model of the input module 120. The control circuits 610 of the input modules 120 of the same module type update the input data 61 of the memory 600 at the same data update period. For example, the data update period of the input module 120 of the module type "GEN610nnn" is 50 microseconds. In this case, the access period "50 microseconds" is associated with the module type "GEN610nnn" and registered in the access period table 51. The data update period of the input module 120 of the module type "GSN620nnn" is 100 microseconds, and the data update period of the input modules 120 of the module type "GPI630nnn" and the module type "GDI650nnn" is 10 microseconds. In this case, in the access period table 51, the module type "GSN620nnn" is registered with an access period of "100 microseconds", and the module types "GPI630nnn" and "GDI650nnn" are registered with an access period of "10 microseconds".

The module types of the input modules 120 that may be attached to the basic base 10 are determined in advance, so the module types and access periods of the input modules 120 that may be attached to the basic base 10 are preregistered in the access period table 51.

Next, we will explain the configuration of the input data table 52a stored in the register 41 of the interface module 110.

Figure 4 is a diagram showing an example of an input data table 52a according to this embodiment. As shown in Figure 4, a slot number, a module type, and input data are stored in association with each other at each address in the register 41. Among the addresses in the storage area of the register 41, addresses that are not used as the input data table 52a are assumed to be predetermined.

The slot number is identification information that identifies the slot 11c to 11m in which the input module 120a to 120k is inserted. In the plant control device 1, one input module 120 is inserted per slot 11, so one input module 120 can be identified by the slot number.

As an example, slot number "1" indicates slot 11c, slot number "2" indicates slot 11d, slot number "3" indicates slot 11e, and slot number "11" indicates slot 11m.

The input data stored in the input data table 52a is the input data 61a to 61k obtained from the memories 600a to 600k of the input modules 120a to 120k by the control circuit 400 of the interface module 110.

Next, we will explain the relationship between the update period of the input data 61a to 61k in the memories 600a to 600k of the input modules 120a to 120k and the acquisition timing of the input data 61a to 61k by the control circuit 400 of the interface module 110.

Figure 5 shows an example of the data update period of the input data 61a, 61c stored in the memories 600a, 600c of the two input modules 120a, 120c according to this embodiment, and the timing of access for data acquisition by the control circuit 400 of the interface module 110.

Figure 5 shows the values of input data 61a and 61c that change over time from left to right. Also, arrows 70a to 70j, 71a, and 71b in Figure 5 show the timing of data acquisition by the control circuit 400 of the interface module 110.

For example, as shown in FIG. 2, input module 120c is inserted into slot 11e. As described above, slot 11e has the slot number "3". As shown in FIG. 4, the module type of input module 120c inserted into slot 11e with slot number "3" is "GPI630nnn". And, as shown in FIG. 3, the data update period corresponding to module type "GPI630nnn" is 10 microseconds.

In other words, the input module 120c updates the input data 61c stored in the memory 600c every 10 microseconds. In the example shown in FIG. 5, the value of the input data 61c stored in the memory 600c changes every 10 microseconds in the following order: "XXXX", "XXXA", "XXXB", "XXXC", "XXXD", "XXXE", "XXXF", "XXXG", "XXXH", and "XXXI".

In this case, the control circuit 400 of the interface module 110 accesses the input module 120c at an access period corresponding to the data update period of the input module 120c and acquires the input data 61c from the memory 600c. More specifically, the control circuit 400 reads the input data 61c once per data update period of the input module 120c. For example, the control circuit 400 acquires the data a second time at the timing indicated by the arrow 70b 10 microseconds after acquiring the data a first time at the timing indicated by the arrow 70a. This allows the control circuit 400 to acquire the input data 61c every time the input data 61c changes. In addition, since the input data 61c does not change even if data is acquired multiple times in one data update period, acquiring data once per data update period can reduce the control circuit 400 from accessing the memory 600c more than necessary.

In addition, as shown in FIG. 2, input module 120a is inserted into slot 11c. As described above, slot 11c has the slot number "1". As shown in FIG. 4, the module type of input module 120a inserted into slot 11c with slot number "1" is "GEN610nnn". And, as shown in FIG. 3, the access period corresponding to module type "GEN610nnn" is 50 microseconds.

In other words, the input module 120a updates the input data 61a stored in the memory 600a every 50 microseconds.

In this case, the control circuit 400 of the interface module 110 accesses the input module 120a once per data update period of 50 microseconds to read the input data 61a.

If the control circuit 400 reads the input data 61a and the input data 61c at a timing that matches the data update period of the input module 120a, the frequency of reading will be lower than the frequency of updating the input data 61c. Alternatively, if the control circuit 400 reads the input data 61a and the input data 61c at a timing that matches the data update period of the input module 120c, multiple read processes will occur before the input data 61a is updated. The control circuit 400 of this embodiment can obtain the input data 61a and 61c at an appropriate timing that matches each input module 120a and 120c by obtaining the input data 61a and 61c from the memories 600a and 600c according to the data update period of the input modules 120a and 120c.

Note that while FIG. 5 illustrates input data 61a and 61c stored in memories 600a and 600c, the control circuit 400 similarly acquires input data 61b, 61d to 61k stored in other memories 600b, 600d to 600k from memories 600b, 600d to 600k according to the data update period of each input module 120b, 120d to 120k.

Next, we will explain the process flow for acquiring and saving the input data 61a to 61k, which is executed by the control circuit 400 of the interface module 110 configured as described above.

Figure 6 is a flowchart showing an example of the flow of the initial setting process executed by the control circuit 400 of the interface module 110 according to this embodiment. The process of this flowchart is executed when the plant control device 1 is started up. In addition, as a prerequisite for executing this flowchart, it is assumed that an access period table 51 is stored in the register 41 of the interface module 110.

First, the control circuit 400 acquires the module type 62a-62b, slot number, and input data 61a-61b from each input module 120a-120k, and stores them in the register 41. This generates the input data table 52a described in FIG. 4. The control circuit 400 then transfers the input data table 52a in the register 41 to the shared memory 410 (S1).

More specifically, the control circuit 400 reads the input data 61a-61k and the module types 62a-62k from the memories 600a-600k of the input modules 120a-120k inserted in the slots 11c-11m. When accessing the input modules 120a-120k inserted in the slots 11c-11m, the control circuit 400 is capable of identifying the slot numbers of the slots 11c-11m.

Then, the control circuit 400 associates the input data 61a-61k and module types 62a-62k with the slot numbers of the slots 11c-11m into which the input modules 120a-120k are inserted, and stores them in the order of the slot numbers at each address in the register 41.

More specifically, the transfer of the input data table 52a of the register 41 to the shared memory 410 involves copying the input data table 52a to the shared memory 410. The control circuit 400 copies the input data table 52a of the register 41 to the shared memory 410 while associating the slot number, module type, and input data. Through this process, an input data table 52b is generated in the shared memory 410.

Processing in S1 enables the interface module 210 of the plant control device 2 to read the input data stored in the input data table 52b of the shared memory 410.

Next, the control circuit 400 determines the data update period of each of the input modules 120a to 120k based on the acquired module type of each of the input modules 120a to 120k and the access period for each module type stored in the access period table 51 (S2).

Then, the control circuit 400 starts the access process to each of the input modules 120a to 120k based on the identified access period (S3).

Figure 7 is a flowchart showing an example of the flow of the process of accessing the input module executed by the control circuit 400 of the interface module 110 according to this embodiment.

The processing in this flowchart is executed individually for each of the input modules 120a to 120k. Here, we will explain the flow of access processing in input module 120a as an example.

The control circuit 400 accesses the memory 600a of the input module 120a to acquire the input data 61a, and stores the acquired input data 61a in the input data table 52a of the register 41. After storing, the input data table 52a of the register 41 is transferred to the shared memory 410 (S31).

Then, the control circuit 400 waits until the time equivalent to the access cycle of the input module 120a identified in the process of S2 in FIG. 6 has elapsed from the time of access to the input module 120a in the process of S31 (S32 "No").

If the time equivalent to the access period of the input module 120a has elapsed since the time of access to the input module 120a in the process of S31 (S32 "Yes"), the process returns to S31. While the plant control device 1 is operating, the processes of S31 to S32 are repeated. When the power supply of the plant control device 1 is turned off, the process of this flowchart ends.

For the input modules 120b to 120k, the control circuit 400 acquires the input data 61b to 61k according to the access period of each of the input modules 120b to 120k, in the same manner as the processing flow shown in FIG. 7.

In this flowchart, the transfer process of the input data table 52a from the register 41 to the shared memory 410 is executed each time the input data table 52a of the register 41 is updated, but the timing of the transfer process is not limited to this. For example, the control circuit 400 may repeatedly execute the transfer process of the input data table 52a from the register 41 to the shared memory 410 at regular intervals, regardless of the timing of the update process of the input data table 52a of the register 41. The time interval of the transfer process of the input data table 52a from the register 41 to the shared memory 410 is set to be equal to or shorter than the shortest time interval among the data update periods of the input modules 120a to 120k.

Thus, the plant control device 1 of this embodiment includes a plurality of input modules 120b to 120k and an interface module 110. The interface module 110 acquires the module type of each of the plurality of input modules 120b to 120k from the plurality of input modules 120b to 120k, and identifies the access period of each of the plurality of input modules 120b to 120k by referring to the acquired module type and the access period table 51 stored in the register 41. The interface module 110 accesses the plurality of input modules 120b to 120k for each access period of the identified plurality of input modules to acquire data. Therefore, according to the plant control device 1 of this embodiment, it is possible to acquire input data 61a to 61k from the plurality of input modules 120a to 120k at an access period according to the module type of each of the input modules 120a to 120k.

In addition, in the plant control device 1 of this embodiment, each of the multiple input modules 120b to 120k receives data input from an external device at a data update period defined by the module type. The register 41 of the interface module 110 stores the data update period for each module type as the access period for each module type. Therefore, according to the plant control device 1 of this embodiment, the interface module 110 can acquire the updated input data 61a to 61k each time the input data 61a to 61k is updated in the multiple input modules 120b to 120k, even if the update periods of the input data 61a to 61k of the multiple input modules 120b to 120k are different.

In addition, in the plant control device 1 of this embodiment, the register 41 in the interface module 110 stores the data update period for each of the multiple input modules 120a to 120k, allowing the interface module 110 to centrally manage data collection from the multiple input modules 120a to 120k. As a comparative example, if each of the multiple input modules accesses the interface module at a separate timing, access collisions may occur between buses in the plant control device. In contrast, in the plant control device 1 of this embodiment, the interface module 110 centrally manages access to the multiple input modules 120a to 120k, reducing the occurrence of data collisions during access.

The interface module 110 of this embodiment also includes interface ports 111a, 111b that can be connected to the interface module 210 of the plant control device 2, and a shared memory 410 that can be accessed from the interface module 210. The control circuit 400 transfers the input data table 52a stored in the register 41 to the shared memory 410. Therefore, according to the interface module 110 of this embodiment, the input data 61a to 61k acquired from the multiple input modules 120a to 120k can be provided in a state that can be read from the interface module 210 of the plant control device 2.

In addition, each of the multiple input modules 120a to 120k connected to the interface module 110 of this embodiment includes a memory 600a to 600k and a control circuit 610a to 610k. The control circuits 610a to 610k store input data 61a to 61k input from an external device in the memory 600a to 600k at the data update period of each of the input modules 120a to 120k. The control circuit 400 of the interface module 110 of this embodiment acquires the input data 61a to 61k from the memory 600a to 600k of each of the input modules 120a to 120k.

In addition, the data update period of the input modules 120a to 120k in this embodiment differs for each module type. The register 41 of the interface module 110 in this embodiment stores the module type and the data update period in association with each other. The control circuit 400 of the interface module 110 in this embodiment acquires the module types 62a to 62k of the input modules 120a to 120k from the memories 600a to 600k of the input modules 120a to 120k. The control circuit 400 identifies the data update period of each of the input modules 120a to 120k based on the data update period stored in the register 41 in association with the module type and the module types of the input modules 120a to 120k acquired from each of the memories 600a to 600k. The control circuit 400 acquires the input data 61a-61k from the memories 600a-600k once for each data update period of the identified input modules 120a-120k. Therefore, according to the interface module 110 of this embodiment, the input data 61a-61k can be acquired every time the input data 61a-61k is updated.

In addition, the input modules 120a-120k of this embodiment are stored in the slots 11c-11m one by one. The control circuit 400 of the interface module 110 of this embodiment stores the module types 62a-62k and input data 61a-61k acquired from each of the multiple input modules 120a-120k in the register 41 in association with the slot numbers of the slots 11c-11m. According to the interface module 110 of this embodiment, the input modules 120a-120k can be uniquely identified by the slot number, so the input data 61a-61k acquired from each of the input modules 120a-120k can be managed individually.

In this embodiment, the access period table 51 has been described as a table, but the data storage format is not limited to the table format, and it is sufficient that data update period information in which the module type and the data update period are associated with each other is stored in the register 41. Similarly, the data storage format of the input data tables 52a and 52b is not limited to the table format, and it is sufficient that input data information in which the slot number, module type, and input data are associated with each other is stored in the register 41 and the shared memory 410.

In this embodiment, an example has been described in which the access period from the interface module 110 to the input modules 120a to 120k is synchronized with the data update period of the input modules 120a to 120k. However, if there is no need to obtain the input data each time the input data is updated, the access period may be set to a constant multiple of the data update period.

In this embodiment, a register is used as an example of a storage device for the interface module 110, but other storage devices may also be used.

The program executed by the interface module 110 of this embodiment is provided in a state where it is pre-installed in a ROM or the like. The program executed by the interface module 110 of this embodiment may also be provided by being recorded in an installable or executable format on a computer-readable recording medium such as a CD-ROM, a flexible disk (FD), a CD-R, or a digital versatile disk (DVD).

Furthermore, the program executed by the interface module 110 of this embodiment may be configured to be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network. Also, the program executed by the interface module 110 of this embodiment may be configured to be provided or distributed via a network such as the Internet.

The program executed by the interface module 110 in this embodiment has a modular configuration that can realize the functions of the control circuit 400 described above.

Although an embodiment of the present invention has been described, this embodiment is presented as an example and is not intended to limit the scope of the invention. This novel embodiment can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. This embodiment and its modifications are included within the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims.

1, 2 Plant control device 3 Cable 10, 20 Basic base 11, 11a to 11m Slot 41 Register 51 Access period table 52, 52a, 52b Input data table 61, 61a to 61k Input data 62, 62a to 62k Module type 70a to 70j, 71a, 71b Arrow 90 Bus 91 Power supply cable 110 Interface module 111a, 111b, 211a to 211d Interface port 120, 120a to 120k Input module 130, 230 Power supply module 210 Interface module 220a to 220i I/O and transmission module 240 Controller 400 Control circuit 410 Shared memory 600, 600a to 600k Memory 610, 610a to 610k Control circuit S Control System

Claims (5)

A plurality of input modules for receiving data input from external devices;
an interface module connected to the plurality of input modules;
The plurality of input modules include:
storing a module type of each of the plurality of input modules;
The interface module includes:
a register for storing an access cycle for each module type;
a control circuit that acquires the module type of each of the plurality of input modules from the plurality of input modules, identifies the access period of each of the plurality of input modules by referring to the acquired module type and the access period stored in the register, and accesses the plurality of input modules for each of the identified access periods of the plurality of input modules to acquire the data.
Plant control device. each of the plurality of input modules receives data input from the external device at a data update period defined by the module type;
the register stores the data update period for each of the module types as an access period for each of the module types;
The plant control device according to claim 1 . The interface module includes:
A shared memory accessible from an interface module of another plant control device is provided,
storing the data acquired from the plurality of input modules in the shared memory;
The plant control device according to claim 1 or 2. The control circuit includes:
storing the data acquired from the plurality of input modules in the register;
transferring the data stored in the register to the shared memory at regular intervals;
The plant control device according to claim 3 . A base having a plurality of slots;
the input modules and the interface module are stored in the slots one by one;
the control circuit stores in the register the module type and the data acquired from each of the plurality of input modules in association with identification information of the slot in which each of the plurality of input modules is stored;
The plant control device according to any one of claims 1 to 4.

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