Information processing apparatus, information processing method, information processing program, and process control system

Abstract

A protocol converter 20 according to an embodiment includes a cache memory 21, an interface memory 22, and a transfer unit 23. The cache memory 21 stores therein a plurality of process values that are updated by field devices 10 and that include one or more of process values that are included in a first group and include a plurality of process values that are not included in the first group. The interface memory 22 stores therein a plurality of control data values that are associated with the plurality of respective process values. The transfer unit 23 updates, in each period, from among the plurality of control data values, together with the control data values that are associated with the respective process values that are included in the first group, a control data value that is associated with the process value that is not included in the first group and that is not updated in the last period.

Description

INFORMATION PROCESSING APPARATUS, INFORMATION PROCESSING METHOD, INFORMATION PROCESSING PROGRAM, AND PROCESS CONTROL SYSTEM

[0001] The present invention relates to an information processing apparatus, an information processing method, an information processing program, and a process control system.

[0002] There is a known process control system that performs monitoring, management, and the like of a plant on the basis of pieces of process data, such as sensor values, that are collected from field devices that are provided in the plant. For example, examples of the field devices include a device, such as a temperature sensor, an atmospheric pressure sensor, and a gas concentration sensor, a device that detects a degree of opening of a valve, a device that detects a state (on or off) of a switch, and the like.

[0003] Furthermore, the pieces of process data that have been output from each of the field devices are stored in a protocol converter as process values. Each of the field devices updates the process values stored in the protocol converter by outputting the process data.

[0004] Furthermore, the protocol converter stores, in a storage area, control data values that have been obtained by converting the process value. A process performed by the protocol converter in this way is referred to as a data exchange process. The control controller acquires, as control operation data, the data that has been obtained by the data exchange process, performs operation by using the acquired control operation data, and obtains information that is needed for the monitoring, management, and the like of the plant.

[0005] Japanese Laid-open Patent Publication No. 2021-26717

[0006] However, in the conventional protocol converter, there is a problem in that, in some cases, the data exchange process is not able to be efficiently performed.

[0007] In recent years, with the popularization of Industrial Ethernet (registered trademark), an update period of a process value output from each of the field devices is further shortened (speed up of an update process). Furthermore, various field devices became connected to the process control system in order to collect various kinds of data, and thus, a case in which field devices each having a large different update period of the process value are connected on a same field network has been increasing in number. Moreover, the field network is a communication network including the field devices and the protocol converters.

[0008] As the number of field devices connected to each of the protocol converters is increased, the number of process values to be subjected to the data exchange process performed by each of the protocol converters is increased. Furthermore, the performance of the data exchange process performed by each of the protocol converters is decreased as the number of the target process values is increased. In addition, if the performance of each of the protocol converters is decreased, a delay tends to occur in the data exchange process.

[0009] In the conventional protocol converters, in order to maintain the performance of the data exchange process on the basis of the process values that have been obtained from the field devices in each of which an update period of the process value is short, there is a need to limit the number of field devices to be connected.

[0010] As described above, it is difficult to efficiently operate the conventional protocol converters in the state in which a large number of field devices including the field devices each having a short update period of the process value are being connected.

[0011] Accordingly, it is an object in one aspect of an embodiment of the present invention to efficiently perform a data exchange process.

[0012] According to one aspect of embodiments, an information processing apparatus includes: a first storage area that stores therein a plurality of process values that are updated by a field device and that include one or more of process values that are included in a first group and include a plurality of process values that are not included in the first group; a second storage area that stores therein a plurality of control data values that are associated with the plurality of respective process values; and an updating unit that updates, in each period, from among the plurality of control data values, together with the control data values that are associated with the respective process values that are included in the first group, a control data value that is associated with the process value that is not included in the first group and that is not updated in the last period.

[0013] According to one aspect of embodiments, an information processing method that is performed by a computer, which includes a first storage area that stores therein a plurality of process values that are updated by a field device and that include one or more of process values that are included in a first group and include a plurality of process values that are not included in the first group, and a second storage area that stores therein a plurality of control data values that are associated with the plurality of respective process values, the method includes: updating, in each period, from among the plurality of control data values, together with the control data values that are associated with the respective process values that are included in the first group, a control data value that is associated with the process value that is not included in the first group and that is not updated in the last period.

[0014] According to one aspect of embodiments, an information processing program causes a computer, which includes a first storage area that stores therein a plurality of process values that are updated by a field device and that include one or more of process values that are included in a first group and include a plurality of process values that are not included in the first group, and a second storage area that stores therein a plurality of control data values that are associated with the plurality of respective process values, to execute: updating, in each period, from among the plurality of control data values, together with the control data values that are associated with the respective process values that are included in the first group, a control data value that is associated with the process value that is not included in the first group and that is not updated in the last period.

[0015] A process control system includes: a process converter; a plurality of field devices that are provided in a plant and that are connected to the process converter; and a control controller that is connected to the process converter, wherein the process converter includes a first storage area that stores therein a plurality of process values that are updated by the plurality of field devices and that include one or more of process values that are included in a first group and include a plurality of process values that are not included in the first group, a second storage area that stores therein a plurality of control data values that are associated with the plurality of respective process values, and an updating unit that updates, in each period, from among the plurality of control data values, together with the control data values that are associated with the respective process values that are included in the first group, a control data value that is associated with the process value that is not included in the first group and that is not updated in the last period, and the control controller performs an operation by using the control data values acquired from the second storage area.

[0016] According to an embodiment, it is possible to efficiently perform the data exchange process.

[0017] FIG. 1 is a diagram illustrating a configuration example of a process control system according to a first embodiment.FIG. 2 is a diagram illustrating a data exchange process.FIG. 3 is a diagram illustrating a data exchange process.FIG. 4 is a diagram illustrating a data exchange process.FIG. 5 is a diagram illustrating an IO scan.FIG. 6 is a diagram illustrating a data exchange process.FIG. 7 is a diagram illustrating a data exchange process.FIG. 8 is a flowchart illustrating the flow of a process performed by a protocol converter.FIG. 9 is a flowchart illustrating the flow of a basic data update process.FIG. 10 is a diagram illustrating an example of a hardware configuration.

[0018] Preferred embodiments of an information processing apparatus, an information processing method, an information processing program, and a process control system disclosed in the present invention will be described in detail below with reference to the accompanying drawings. Furthermore, the present invention is not limited to the embodiments. In addition, the same components are denoted by the same reference numerals and an overlapping description will be omitted. Each of the embodiments can be used in any appropriate combination as long as they do not conflict with each other. Furthermore, a protocol converter is one example of the information processing apparatus.

[0019] A configuration of the process control system according to a first embodiment will be described with reference to FIG. 1. FIG. 1 is a diagram illustrating a configuration example of the process control system according to the first embodiment.

[0020] As illustrated in FIG. 1, a process control system 1 includes field devices 10, protocol converters 20, a control controller 30, an operation monitoring terminal 40, and a device management apparatus 50.

[0021] The field devices 10 are provided in a plant. The number of field devices 10 is not limited to the number illustrated in FIG. 1.

[0022] The plant is, for example, a petroleum plant, a petrochemical plant, a chemical plant, or a gas plant. By operating the plant, a product material, such as liquefied natural gas (LNG), a resin (plastic, nylon, etc.), and a chemical substance product, is able to be obtained.

[0023] Furthermore, the plant includes, for example, a factory facility, a machine facility, a production facility, an electric-generating facility, a storage facility, and a facility in a wellhead for mining petroleum, natural gas, or the like. In addition, in the plant, a facility device that is used to generate the product material is provided.

[0024] Each of the field devices 10 acquires information related to the state of the plant. For example, examples of the field devices 10 include a device, such as a temperature sensor, a pH sensor, a velocity sensor, an acceleration sensor, an atmospheric pressure sensor, and a gas concentration sensor, a device that detects a degree of opening of a valve, a device that detects a state (on or off) of a switch, and the like.

[0025] Each of the field devices 10 transmits, to the protocol converter 20, a sensor value or a detection result as process data on the basis of a communication protocol that is determined in advance. For example, each of the field devices 10 is connected to the protocol converter 20 by a coaxial cable and an optical fiber provided with a connector, such as an RJ45 connector. Then, each of the field devices 10 transmits the process data to the protocol converter 20 by using an analog signal of 4 to 20 mA.

[0026] The protocol converter 20 stores therein, as a process value, the process data that has been received from each of the field devices 10. The process value stored in the protocol converter 20 is updated every time the protocol converter 20 receives the process data from the field device 10.

[0027] The protocol converter 20 performs a data exchange process. In other words, the protocol converter 20 converts the process value to a control data value by performing a process of protocol conversion. For example, in the case where a communication protocol between each of the field devices 10 and one of the associated protocol converters 20 is an analog signal of 4 to 20 mA, the process value is a value indicating the analog signal of 4 to 20 mA. The protocol converter 20 converts the process value to a value that indicates a digital signal functioning under the Ethernet protocol. Moreover, the communication protocol at the conversion destination is determined in accordance with the communication protocol between the protocol converter 20 and the control controller 30.

[0028] The protocol converter 20 transmits the control data value obtained from the data exchange process to the control controller 30 on the basis of the communication protocol (for example, Ethernet protocol) that is determined in advance.

[0029] The control controller 30 performs operation for converting the received control data value into a form that can be used by the operation monitoring terminal 40 or the device management apparatus 50. The control controller 30 transmits the data obtained by the operation to the operation monitoring terminal 40 or the device management apparatus 50.

[0030] For example, a case in which the communication protocol between each of the field devices 10 and one of the associated protocol converters 20 is an analog signal of 4 to 20 mA and the process value is 12 mA is considered. At this time, it is assumed that the process value represents the temperatures from 0°C to 100°C that are acquired by each of the field devices 10. As one example, the control controller 30 performs an operation of (100°C - 0°C) × (12 mA / (4 mA + 20 mA)) = 50°C. Then, the control controller 30 notifies the operation monitoring terminal 40 or the device management apparatus 50 that the temperature is 50°C.

[0031] Moreover, the operation monitoring terminal 40 is a terminal that is used to monitor the state of each of the facility devices provided in the plant. The device management apparatus 50 is a device that is used to operate each of the devices including the field devices 10.

[0032] In the following, the data exchange process performed by the protocol converter 20 and a correlated process will be described.

[0033] First, as illustrated in FIG. 2, each of the field devices 10 updates the process values that are stored in the protocol converter 20 by transmitting the pieces of process data to the protocol converter 20 in a period that has been defined for each of the field devices 10. FIG. 2 is a diagram illustrating the data exchange process.

[0034] Each of pieces of data A1, data B1, data C1, data D1, data E1, and data F1 is process data and is transmitted by the different field devices 10. Moreover, a single piece of the field device 10 may transmit a plurality of pieces of process data.

[0035] Here, a transmission speed of each of the data A1 and the data B1 is higher than a transmission speed of each of the data D1, the data E1, and the data F1. Moreover, a state in which the transmission speed is high indicates that the process data is frequently transmitted, that is, the period in which the process data is transmitted is short.

[0036] For example, the period in which the data A1 and the data B1 are transmitted is about 1 ms to 10 ms. Furthermore, for example, the period in which the data D1, the data E1, and the data F1 are transmitted is 100 ms or above.

[0037] Here, as illustrated in FIG. 1, each of the protocol converters 20 includes a cache memory 21, an interface memory 22, and a transfer unit 23.

[0038] The cache memory 21 and the interface memory 22 are implemented by a volatile or nonvolatile storage device. The cache memory 21 and the interface memory 22 may be storage areas that are physically different storage devices each other. Furthermore, each of the cache memory 21 and the interface memory 22 may be a logical storage area provided in the associated storage devices. The cache memory 21 is one example of a first storage area. Furthermore, the interface memory 22 is one example of a second storage area. Furthermore, the storage area may also be restated as a storage unit, a storage device, or the like.

[0039] The transfer unit 23 is implemented by an arithmetic unit, such as a central processing unit (CPU). The transfer unit 23 is one example of an updating unit.

[0040] The cache memory 21 stores therein a plurality of process values that are updated by the field device 10 and that include one or more of process values that are included in a high speed data group and include a plurality of process values that are not included in the high speed data group.

[0041] As illustrated in FIG. 2, the cache memory 21 stores therein data A2, data B2, data C2, data D2, data E2, and data F2. The data A2, the data B2, the data C2, the data D2, the data E2, and the data F2 are updated (overwritten) by the data A1, the data B1, the data C1, the data D1, the data E1, and the data F1, respectively, that are sent from the associated field devices 10.

[0042] Furthermore, as described above, the period of transmission of each of the data A1 and the data B1 is short. Here, it is assumed that the data A2 and the data B2 that correspond to the process values and that are associated with the data A1 and the data B1, respectively, are included in the high speed data group. In other words, the cache memory 21 stores therein one or more of the process values that are included in the high speed data group and that are more frequently updated than the plurality of process values that are not included in the high speed data group (i.e., that are included in a basic data group). The high speed data group is one example of a first group.

[0043] The data C2, the data D2, the data E2, and the data F2 are not included in the high speed data group. The data C2, the data D2, the data E2, and the data F2 are included in the basic data group.

[0044] The transfer unit 23 performs the data exchange process in each period. The period in which the transfer unit 23 performs the data exchange process is about, for example, 10 ms to 20 ms. In this case, the period in which the transfer unit 23 performs the data exchange process is longer than the period in which the process values included in the high speed data group are updated, and is shorter than the period in which the process values included in a low speed data group are updated.

[0045] The interface memory 22 stores therein a plurality of control data values that are associated with the plurality of respective process values. As illustrated in FIG. 2, the interface memory 22 stores therein data A3, data B3, data C3, data D3, data E3, and data F3 that are the control data values. The data A3, the data B3, the data C3, the data D3, the data E3, and the data F3 are associated with the data A2, the data B2, the data C2, the data D2, the data E2, and the data F2, respectively, that are the process values.

[0046] In the data exchange process, the transfer unit 23 updates, in each period, from among the plurality of control data values, together with the control data values that are associated with the respective process values that are included in the high speed data group, a control data value that is associated with the process value that is not included in the high speed data group and that is not updated in the last period. The process values that are not included in the high speed data group are the process values that are included in the basic data group.

[0047] Furthermore, in the data exchange process, the transfer unit 23 stores (updates), in the interface memory 22 as the control data value, a value that has been obtained by converting a communication protocol of the process value that is stored in the cache memory 21.

[0048] For example, the transfer unit 23 performs, in a kthperiod (k is an integer), the data exchange process on some of the process values that are included in the basic data group, together with the process values that are included in the high speed data group. Then, the transfer unit 23 performs, in a k+1thperiod, the data exchange process on some of the process values that are included in the basic data group and that are not targeted for the process in the kthperiod, together with the process values that are included in the high speed data group.

[0049] FIG. 3 and FIG. 4 are diagrams each illustrating a data exchange process performed in the kthperiod. As illustrated in FIG. 3, the transfer unit 23 performs, in the kthperiod, the data exchange process on the data A2 and the data B2 that correspond to the process values that are included in the high speed data group, and updates the data A3 and the data B3. The symbol denoted by "*" indicates the process values that are included in the high speed data group and the control data values that are associated with these process values.

[0050] Furthermore, the transfer unit 23 performs, in the kthperiod, the data exchange process on the data C2 and the data D2 that are some of the process values included in the basic data group, and updates the data C3 and the data D3.

[0051] Here, as illustrated in FIG. 5, the control controller 30 performs an IO scan. FIG. 5 is a diagram illustrating the IO scan. As illustrated in FIG. 5, the IO scan is a process in which the control controller 30 reads the control data values that are stored in the interface memory 22. The control controller 30 acquires, at the time of the IO scan, the data A3, the data B3, the data C3, the data D3, the data E3, and the data F3 as control operation data A4, control operation data B4, control operation data C4, control operation data D4, control operation data E4, and control operation data F4, respectively.

[0052] The control controller 30 is able to asynchronously perform the IO scan with respect to both of the update of the process values performed by the field devices 10 and the data exchange process performed by the protocol converter 20.

[0053] For example, the control controller 30 performs the IO scan in a period that is longer than the period of the data exchange process. In other words, the transfer unit 23 performs the data exchange process in a period that is shorter than the period of the IO scan.

[0054] FIG. 6 and FIG. 7 are diagrams each illustrating the data exchange process that is performed in the k+1thperiod. As illustrated in FIG. 6, the transfer unit 23 performs, in the k+1thperiod, the data exchange process on the data A2 and the data B2 that correspond to the process values that are included in the high speed data group, and then, updates the data A3 and the data B3.

[0055] In addition, the transfer unit 23 performs, in the k+1thperiod, the data exchange process on the data E2 and the data F2 that are some of the process values included in the basic data group, and then, updates the data E3 and the data F3.

[0056] In this way, the transfer unit 23 performs, in each period, the data exchange process on the process values that are included in the high speed data group in which the update frequency is high, and performs the data exchange process on the process values that are included in the basic data group in which the update frequency is low, with a frequency of every other period or less.

[0057] The flow of the process performed by the protocol converter 20 will be described with reference to FIG. 8. FIG. 8 is a flowchart illustrating the flow of the protocol converter.

[0058] First, as illustrated in FIG. 8, the protocol converter 20 updates the entire area that is targeted for the high speed data transfer process (Step S11). In other words, the protocol converter 20 performs the data exchange process on the data A2 and the data B2 that are the process values included in the high speed data group. Furthermore, the update illustrated in FIG. 8 and FIG. 9 indicates the update of the data control values obtained by the data exchange process.

[0059] Then, the protocol converter 20 acquires a last completion area in which a basic data update has been performed (Step S12). The last completion area is information for identifying the process values that are included in the basic data group targeted for the data exchange in the immediately previous period.

[0060] Subsequently, the protocol converter 20 performs the basic data update, that is, the data exchange process on the process values that are included in the basic data group (Step S13). The process performed at Step S13 in detail will be described later.

[0061] Then, the protocol converter 20 stores the completion area in which the basic data update has been performed (Step S14).

[0062] The protocol converter 20 performs the processes performed at Step S11 to Step S14 in each period. The completion area that is stored at Step S14 is acquired at Step S12 that is performed in the next period.

[0063] Moreover, the area in which the completion area is stored (one example of a third storage area) may be the storage area of the storage device that is provided in the protocol converter 20, and may be the same as the storage area that is used by the cache memory 21 and the interface memory 22 or may be different from the storage area that is used by the cache memory 21 and the interface memory 22.

[0064] As described above, the protocol converter 20 (the transfer unit 23) stores the completion area, in which the basic data update has been performed, in the storage area in each period. The completion area, in which the basic data update has been performed, is one example of the information for identifying the control data value that has been updated and that is associated with the process value that is not included in the high speed data group, from among the plurality of control data values.

[0065] Furthermore, the protocol converter 20 (the transfer unit 23) updates, in each period, from among the plurality of control data values, together with the control data values that are associated with the respective process values that are included in the high speed data group, the control data value to which an order has been assigned next to the control data value that is identified on the basis of the last completion area.

[0066] It is assumed that the order has been assigned to the control data values that are associated with the respective process values that are included in the basic data group in the order of the data C3, the data D3, the data E3, and the data F3. Furthermore, the order next to the data F3 returns to the first order. In other words, the control data value that is next to the data F3 is the data C3.

[0067] In this case, the protocol converter 20 updates the control data value that is in the order next to the control data value that is identified on the basis of the last completion area. For example, if the control data value that is identified on the basis of the last completion area is the data D3, the protocol converter 20 updates the data E3.

[0068] FIG. 9 is a flowchart illustrating the flow of the basic data update process (Step S13 illustrated in FIG. 8). As illustrated in FIG. 9, the protocol converter 20 updates the next area, that is, the control data value to which an order has been assigned next to the control data value that is identified on the basis of the last completion area (Step S131).

[0069] Here, the protocol converter 20 determines whether or not another next area is able to be updated (Step S132). For example, if the data E3 has been updated at Step S131, the protocol converter 20 determines whether or not the data F3 is able to be updated.

[0070] If it is possible to update the other next area (Yes at Step S132), the protocol converter 20 returns to Step S131 and repeats the process. In contrast, if it is not able to update the other next area (No at Step S132), the protocol converter 20 ends the process.

[0071] The procedure related to the determination process performed at Step S132 by the protocol converter 20 (Step S132) will be described. First, the protocol converter 20 assumes that a period T0 of the IO scan has been acquired by the control controller 30.

[0072] Here, the protocol converter 20 acquires, in the current period, time T1 needed to perform the processes up to Steps S11 and S12 illustrated in FIG. 8 and up to Step S131 illustrated in FIG. 9. At this time, in some cases, the process at Step S131 may have been multiple times due to repetition. In the time T1, the time needed to perform the process at Step S131 once or multiple times is included.

[0073] Furthermore, the protocol converter 20 acquires time T2 needed in the case where the process at Step S131 is further performed. The protocol converter 20 may estimate the time T2 on the basis of a past track record, or may acquire a fixed value that is determined as T2.

[0074] In a case of T1 + T2 < T0, the protocol converter 20 determines that the next area is able to be updated (Yes at Step S132). In contrast, in a case of T1 + T2 >= T0, the protocol converter 20 determines that the next area is not able to be updated (No at Step S132). As a result of this, the protocol converter 20 is able to complete the data exchange process by an amount corresponding to one period within the period of the IO scan.

[0075] As described above, the protocol converter 20 (information processing apparatus) according to the embodiment includes the cache memory 21, the interface memory 22, and the transfer unit 23. The cache memory 21 stores therein a plurality of process values that are updated by the field devices 10 and that include one or more of the process values that are included in the first group and include a plurality of process values that are not included in the first group. The interface memory 22 stores therein a plurality of control data values that are associated with the plurality of respective process values. The transfer unit 23 updates, in each period, from among the plurality of control data values, together with the control data values that are associated with the respective process values that are included in the first group, a control data value that is associated with the process value that is not included in the first group and that is not updated in the last period.

[0076] In this way, the plurality of process values are divided into the process values that are to be subjected to the data exchange process in every period and the process values that are to be subjected to the data exchange process with a frequency of every other period or less. On account of this, the protocol converter 20 is able to increase the number of connectable field devices while improving controllability and responsiveness in the data exchange process performed on the field devices having a short update period. As a result of this, the efficiency of the data exchange process is improved.

[0077] The cache memory 21 stores therein one or more of the process values that are included in the first group and that are more frequently updated than the plurality of process values that are not included in the first group. As a result of this, the protocol converter 20 is able to perform the data exchange process at a frequency suitable for the update period for each process value.

[0078] The transfer unit 23 stores, in the interface memory 22 as the control data value, a value obtained by converting the communication protocol of the process value that is stored in the cache memory 21. As a result of this, the protocol converter 20 is able to transfer the process data to the control controller 30.

[0079] The transfer unit 23 stores, in each period in the third storage area, the information for identifying the control data value that has been updated and that is associated with the process value that is not included in the first group, from among the plurality of control data values, and updates, from among the plurality of control data values, together with the control data values that are associated with the respective process values that are included in the first group, the control data value to which an order has been assigned next to the control data value that is identified on the basis of the information that is stored in the third storage area. In this way, the protocol converter 20 is able to perform the data exchange process without waste by storing the control data values that have been updated in each period.

[0080] The flow of the processes, the control procedures, the specific names, and the information containing various kinds of data or parameters indicated in the above specification and drawings can be arbitrarily changed unless otherwise stated.

[0081] Furthermore, the components of each unit illustrated in the drawings are only for conceptually illustrating the functions thereof and are not always physically configured as illustrated in the drawings. In other words, the specific shape of a separate or integrated device is not limited to the drawings. Specifically, all or part of the device can be configured by functionally or physically separating or integrating any of the units depending on various loads or use conditions. Furthermore, the protocol converter 20 may contain the function of the control controller 30.

[0082] Furthermore, all or any part of each of the processing functions performed by the each of the devices can be implemented by a CPU and by programs analyzed and executed by the CPU or implemented as hardware by wired logic.

[0083] In the following, an example of a hardware configuration of the protocol converter 20 will be described. FIG. 10 is a diagram illustrating an example of the hardware configuration. As illustrated in FIG. 10, the protocol converter 20 includes a communication device 20a, a hard disk drive (HDD) 20b, a memory 20c, and a processor 20d. Furthermore, each of the units illustrated in FIG. 10 is connected by a bus or the like with each other.

[0084] The communication device 20a is a network interface card or the like, and communicates with another server. The HDD 20b stores therein the programs and the DBs that operate the functions illustrated in FIG. 1.

[0085] The processor 20d operates the process that executes each of the functions described above in FIG. 1 or the like by reading the programs that execute the same process as that performed by each of the processing units illustrated in FIG. 3 from the HDD 20b or the like and loading the read programs in the memory 20c. For example, the process executes the same functions as those performed by each of the processing units included in the protocol converter 20. Specifically, the processor 20d reads, from the HDD 20b or the like, the program having the same function as that performed by the transfer unit 23. Then, the processor 20d executes the process for executing the same process as that performed by the transfer unit 23.

[0086] In this way, the protocol converter 20 is operated as an information processing apparatus that performs an information processing method by reading and executing the program. Furthermore, the protocol converter 20 is also able to implement the same functions as those described above in the embodiment by reading the above described program from a recording medium by a medium reading device and executing the read program. In addition, the program described in another embodiment are not limited to be executed by the protocol converter 20. For example, the present invention may also be similarly used in a case in which another computer or a server executes a program or in a case in which another computer and a server cooperatively execute the program with each other.

[0087] The programs may be distributed via a network, such as the Internet. Furthermore, the program may be executed by storing the programs in a recording medium that can be read by a computer readable medium, such as a hard disk, a flexible disk (FD), a CD-ROM, a magneto-optical disk (MO), a digital versatile disk (DVD), or the like, and read the program from the recording medium by the computer.

[0088] Some examples of combinations of the disclosed technical features are described in the following.

[0089] (1) An information processing apparatus comprising: a first storage area that stores therein a plurality of process values that are updated by a field device and that include one or more of process values that are included in a first group and include a plurality of process values that are not included in the first group; a second storage area that stores therein a plurality of control data values that are associated with the plurality of respective process values; and an updating unit that updates, in each period, from among the plurality of control data values, together with the control data values that are associated with the respective process values that are included in the first group, a control data value that is associated with the process value that is not included in the first group and that is not updated in the last period. (2) The information processing apparatus according to (1), wherein the first storage area stores therein one or more of the process values that are included in the first group and that are more frequently updated than the plurality of process values that are not included in the first group. (3) The information processing apparatus according to (1) or (2), wherein the updating unit stores, in the second storage area as the control data value, a value obtained by converting a communication protocol of the process value stored in the first storage area. (4) The information processing apparatus according to any one of (1) to (3), wherein the updating unit stores, in each period in a third storage area, information for identifying the control data value that has been updated and that is associated with the process value that is not included in the first group, from among the plurality of control data values, and updates, from among the plurality of control data values, together with the control data values that are associated with the respective process values that are included in the first group, the control data value to which an order has been assigned next to the control data value that is identified based on the information stored in the third storage area. (5) An information processing method that is performed by a computer, which includes a first storage area that stores therein a plurality of process values that are updated by a field device and that include one or more of process values that are included in a first group and include a plurality of process values that are not included in the first group, and a second storage area that stores therein a plurality of control data values that are associated with the plurality of respective process values, the method comprising: updating, in each period, from among the plurality of control data values, together with the control data values that are associated with the respective process values that are included in the first group, a control data value that is associated with the process value that is not included in the first group and that is not updated in the last period. (6) An information processing program that causes a computer, which includes a first storage area that stores therein a plurality of process values that are updated by a field device and that include one or more of process values that are included in a first group and include a plurality of process values that are not included in the first group, and a second storage area that stores therein a plurality of control data values that are associated with the plurality of respective process values, to execute: updating, in each period, from among the plurality of control data values, together with the control data values that are associated with the respective process values that are included in the first group, a control data value that is associated with the process value that is not included in the first group and that is not updated in the last period. (7) A process control system comprising: a process converter; a plurality of field devices that are provided in a plant and that are connected to the process converter; and a control controller that is connected to the process converter, wherein the process converter includes a first storage area that stores therein a plurality of process values that are updated by the plurality of field devices and that include one or more of process values that are included in a first group and include a plurality of process values that are not included in the first group, a second storage area that stores therein a plurality of control data values that are associated with the plurality of respective process values, and an updating unit that updates, in each period, from among the plurality of control data values, together with the control data values that are associated with the respective process values that are included in the first group, a control data value that is associated with the process value that is not included in the first group and that is not updated in the last period, and the control controller performs an operation by using the control data values acquired from the second storage area.

[0090] 1 Process control system 10 field device 20 protocol converter 20a communication device 20b HDD 20c memory 20d processor 21 cache memory 22 interface memory 23 transfer unit 30 control controller 40 operation monitoring terminal 50 device management apparatus

Claims

1. An information processing apparatus comprising: a first storage area that stores therein a plurality of process values that are updated by a field device and that include one or more of process values that are included in a first group and include a plurality of process values that are not included in the first group; a second storage area that stores therein a plurality of control data values that are associated with the plurality of respective process values; and an updating unit that updates, in each period, from among the plurality of control data values, together with the control data values that are associated with the respective process values that are included in the first group, a control data value that is associated with the process value that is not included in the first group and that is not updated in the last period.

2. The information processing apparatus according to claim 1, wherein the first storage area stores therein one or more of the process values that are included in the first group and that are more frequently updated than the plurality of process values that are not included in the first group.

3. The information processing apparatus according to claim 1, wherein the updating unit stores, in the second storage area as the control data value, a value obtained by converting a communication protocol of the process value stored in the first storage area.

4. The information processing apparatus according to claim 1, wherein the updating unit stores, in each period in a third storage area, information for identifying the control data value that has been updated and that is associated with the process value that is not included in the first group, from among the plurality of control data values, and updates, from among the plurality of control data values, together with the control data values that are associated with the respective process values that are included in the first group, the control data value to which an order has been assigned next to the control data value that is identified based on the information stored in the third storage area.

5. An information processing method that is performed by a computer, which includes a first storage area that stores therein a plurality of process values that are updated by a field device and that include one or more of process values that are included in a first group and include a plurality of process values that are not included in the first group, and a second storage area that stores therein a plurality of control data values that are associated with the plurality of respective process values, the method comprising: updating, in each period, from among the plurality of control data values, together with the control data values that are associated with the respective process values that are included in the first group, a control data value that is associated with the process value that is not included in the first group and that is not updated in the last period.

6. An information processing program that causes a computer, which includes a first storage area that stores therein a plurality of process values that are updated by a field device and that include one or more of process values that are included in a first group and include a plurality of process values that are not included in the first group, and a second storage area that stores therein a plurality of control data values that are associated with the plurality of respective process values, to execute: updating, in each period, from among the plurality of control data values, together with the control data values that are associated with the respective process values that are included in the first group, a control data value that is associated with the process value that is not included in the first group and that is not updated in the last period.

7. A process control system comprising: a process converter; a plurality of field devices that are provided in a plant and that are connected to the process converter; and a control controller that is connected to the process converter, wherein the process converter includes a first storage area that stores therein a plurality of process values that are updated by the plurality of field devices and that include one or more of process values that are included in a first group and include a plurality of process values that are not included in the first group, a second storage area that stores therein a plurality of control data values that are associated with the plurality of respective process values, and an updating unit that updates, in each period, from among the plurality of control data values, together with the control data values that are associated with the respective process values that are included in the first group, a control data value that is associated with the process value that is not included in the first group and that is not updated in the last period, and the control controller performs an operation by using the control data values acquired from the second storage area.

Images