DATA PROCESSING DEVICE, DATA PROCESSING METHOD, AND COMPUTER READABLE MEDIUM

Abstract

A process data management unit receives operand data, which is iteratively transmitted from PIO units and for which a sequence number is set, from the PIO units, carries out operations for the received operand data, and transmits results of the operations to the PIO units. A sequence number management unit calculates the sequence number of the operand data, for which the process data management unit is to subsequently carry out the operations, as a next sequence number, each time the process data management unit carries out the operations, and notifies a standby controller of the calculated next sequence number through the control network. A tracking data management unit transmits tracking data through the control network to the standby controller, in case where a current controller is temporarily provided with a transmission right for the tracking data.

Description

TECHNICAL FIELD

The present invention relates to a data processing device, a data processing method, and a data processing program.

BACKGROUND ART

In plants such as power plants and chemical plants, control over opening and closing of valves or the like is automated with use of controllers. High reliability is required of the controllers for continued operations of the plants. In those plants, therefore, the reliability is maintained by duplication of the controllers.

With use of FIG. 7, initially, configurations and actions of a system in which the controller is duplicated will be described.

In the system illustrated in FIG. 7, a controller 100a and a controller 100b are connected to a control network 101. Hereinbelow, the controller 100a and the controller 100b may be collectively referred to as controllers 100 when the controller 100a and the controller 100b do not have to be distinguished. An HMI (Human Machine Interface) 102 is connected to the control network 101.

The controllers 100 are connected though an I/O (Input/Output) network 103 to process input/output units 106a, 106b, and 106c (which will be referred to as PIO units 106a, 106b, and 106c below). The PIO units 106a, 106b, and 106c may be collectively referred to as PIO units 106 when the PIO units 106a, 106b, and 106c do not have to be distinguished.

The PIO unit 106a periodically transmits, to the controllers 100, data acquired at an input/output terminal 104a and indicating a state of a plant 109.

The PIO unit 106b periodically transmits, to the controllers 100, data acquired at an input/output terminal 104b and indicating the state of the plant 109.

The PIO unit 106c periodically transmits, to the controllers 100, data acquired at an input/output terminal 104c and indicating the state of the plant 109.

The controller 100a and the controller 100b each receive the data from the PIO units 106a, 106b, and 106c.

The HMI 102 displays a control state of the plant 109 to an operator and transmits instructions for control over the plant 109 to the controller 100a and the controller 100b in accordance with input from the operator. The HMI 102 is a panel computer, for instance.

The controller 100a carries out operations based on the data (the state of the plant 109) received from the PIO units 106 and on the instructions received from the HMI 102 and periodically transmits data indicating results of the operations to the PIO units 106. The controller 100a transmits the state of the plant 109 to the HMI 102. The controller 100b stands by while the controller 100a acts normally and supersedes the controller 100a when an abnormality occurs in the controller 100a. The controller 100a may be referred to as a current controller 100 and the controller 100b may be referred to as a standby controller 100. In the drawings, the controller 100a may be described as “CURRENT” and the controller 100b may be described as “STANDBY”.

The PIO unit 106a transmits the results of the operations from the controller 100a, through the input/output terminal 104a to the plant 109.

The PIO unit 106b transmits the results of the operations from the controller 100a, through the input/output terminal 104b to the plant 109.

The PIO unit 106c transmits the results of the operations from the controller 100a, through the input/output terminal 104c to the plant 109.

The data that is transmitted and received between the controllers 100 and the PIO units 106 is referred to as process data.

The controller 100a and the controller 100b are connected through a tracking bus 105. The controller 100a transmits data inside the controller 100a so that the controller 100b may immediately take over the control, when an abnormality occurs.

In the system illustrated in FIG. 7, there are a plurality of combinations of pairs of the controllers 100 and a plurality of the PIO units 106. The pairs of controllers 100 are connected through the control network 101 to the HMI 102. The pairs of the controllers 100 are each connected through the tracking bus 105.

With use of FIG. 8, details of the actions of the system of FIG. 7 will next be described.

The PIO units 106 transmit the process data to the controllers 100 periodically in a process data period t_p. Hereinbelow, the process data may be expressed as PD # n. A character “n” in PD # n denotes a sequence number that indicates the order of transmissions of the process data. That is, n=1, 2 . . . .

The controllers 100 carry out process data acquisition processing, operational processing, process data transmission processing, and tracking data transmission processing periodically in a control period t_c.

The PIO units 106 transmit PD #1 to the controllers 100 in process data transmission 1.

The controller 100a and the controller 100b receive PD #1 (balloons designated by PD #1 in FIG. 8). Then the controller 100a and the controller 100b each store the received PD #1 in an internal memory therein.

At time t₀, the controller 100a carries out the process data acquisition processing. The process data acquisition processing is processing in which a processor in the controller 100 reads out the process data from the memory in the controller 100. At the time t₀, as the process data acquisition processing, the processor in the controller 100a reads out PD #1 that is the process data received latest from the memory and saves PD #1, having been read out, in a buffer in the processor.

Subsequently, the processor in the controller 100a carries out operations with use of PD #1. It is assumed that results of the operations are determined based only on the instructions (target values) received from the HMI 102, series of data (sizes of series for use in the operations differ among systems) transmitted to the PIO units 106 up to that point, and PIO data for use in the operations.

Further, the controller 100a transmits the results of the operations to the PIO units 106 in the process data transmission processing (illustration of an arrow of transmission is omitted).

Finally, the controller 100a carries out the tracking data transmission processing. In the tracking data transmission processing, the controller 100a transmits tracking data to the controller 100b. The tracking data is data for notification of the results of the operations and an internal state of the controller 100a. Though illustration is omitted in FIG. 8, the controller 100b receives the tracking data and stores the received tracking data in the internal memory therein.

At time t₁, subsequently, the controller 100b carries out operations with use of PD #2 that is the process data received latest. The controller 100b, however, does not transmit results of the operations to the PIO units 106. That is, in the controller 100b, the results of the operations are not actually transmitted, though there is a time span for the process data transmission processing.

At time t₂, subsequently, the controller 100b carries out tracking data acquisition processing. In the tracking data acquisition processing, the processor in the controller 100b reads out the tracking data from the memory and saves the tracking data, having been read out, in a buffer in the processor. The processor in the controller 100b carries out following updates based on the tracking data.

• • Output values (results of operations) to the PIO units 106
  • Internal state

In case where the controller 100b does not carry out the updates with use of the tracking data, the controller 100a and the controller 100b carry out the operations with use of different series of the process data. When the controller 100a breaks down in such a situation so that the control is taken over by the controller 100b, inexpediency is caused by occurrence of a phenomenon (called disturbance) in which values that are transmitted from the controller 100b to the PIO units 106 sharply change.

In the system of FIG. 7, the controller 100a and the controller 100b are connected one-on-one by the tracking bus 105 different from the control network 101. Therefore, a configuration thereof is complicated.

Patent Literature 1 discloses a method in which the tracking bus 105 is made common to the control network 101 in order that the configuration of the system illustrated in FIG. 7 may be simplified.

CITATION LIST

Patent Literature

Patent Literature 1: JP 2007-323457

SUMMARY OF INVENTION

Technical Problem

According to Patent Literature 1, which proposes the method of integrating the tracking bus with another network, the controller 100a transmits the tracking data to the controller 100b each time the controller 100a carries out operations. Accordingly, there is a problem in that a network band is oppressed by the transmissions of the tracking data.

The present invention mainly aims at solving such a problem. More specifically, the present invention mainly aims at avoiding a situation in which the network band is oppressed by the transmissions of the tracking data.

Solution to Problem

A data processing device that is connected to a backup device through a first network connected to a higher-level device and that is connected to equipment through a second network different from the first network, includes:

an operation management unit to receive operand data, which is iteratively transmitted from the equipment and for which a sequence number is set, from the equipment through the second network, to carry out operations for the received operand data, and to transmit results of the operations through the second network to the equipment;

a sequence number management unit to calculate the sequence number of the operand data, for which the operation management unit is to subsequently carry out the operations, as a next sequence number, each time the operation management unit carries out the operations and to notify the backup device of the calculated next sequence number through the first network; and

a tracking data management unit, in case where the data processing device is temporarily provided with a transmission right for tracking data for notification of the results of the operations by the operation management unit and an internal state of the data processing device, to transmit the tracking data through the first network to the backup device.

Advantageous Effects of Invention

According to the invention, the transmissions of the tracking data are reduced so that the situation in which the network band is oppressed by the transmissions of the tracking data may be avoided.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 illustrates a system configuration example according to Embodiment 1.

FIG. 2 illustrates a hardware configuration example of a controller 11 according to Embodiment 1.

FIG. 3 illustrates a functional configuration example of the controller 11 according to Embodiment 1.

FIG. 4 is a data flowchart illustrating an example of actions according to Embodiment 1.

FIG. 5 is a flowchart illustrating an example of actions of a controller 11a according to Embodiment 1.

FIG. 6 is a flowchart illustrating an example of actions of a controller 11b according to Embodiment 1.

FIG. 7 illustrates a conventional system configuration example.

FIG. 8 is a data flowchart illustrating a conventional example of actions.

DESCRIPTION OF EMBODIMENTS

Embodiment 1

Description on Configurations

FIG. 1 illustrates a system configuration example according to the present embodiment.

The control network 101, the HMI 102, an I/O network 103, the input/output terminal 104a, the input/output terminal 104b, the input/output terminal 104c, the PIO unit 106a, the PIO unit 106b, the PIO unit 106c, and the plant 109 are the same as illustrated in FIG. 7. In the present embodiment as well, the PIO units 106a, 106b, and 106c may be collectively referred to as the PIO units 106 when the PIO units 106a, 106b, and 106c do not have to be distinguished.

A controller 11a and a controller 11b are connected through the control network 101 to the HMI 102. The HMI 102 corresponds to a higher-level device. The control network 101 corresponds to a first network.

The controller 11a and the controller 11b are connected through the I/O network 103 to the PIO units 106a, 106b, and 106c. The PIO units 106a, 106b, and 106c each correspond to the equipment. The 110 network 103 corresponds to a second network.

The controller 11 a carries out operations based on data (a state of the plant 109) received from the PIO units 106 and on instructions received from the HMI 102 and periodically transmits data indicating results of the operations to the PIO units 106. The controller 11a transmits the state of the plant 109 to the HMI 102. The controller 11b stands by while the controller 11a acts normally and supersedes the controller 11a when an abnormality occurs in the controller 11a. The controller 11a may be referred to as a current controller 11 and the controller 11b may be referred to as a standby controller 11. In the drawings, the controller 11a may be described as “CURRENT” and the controller 11b may be described as “STANDBY”.

The controller 11a corresponds to the data processing device. Actions that are carried out by the controller 11a correspond to the data processing method.

The controller 11b backs up the controller 11a and corresponds to the backup device.

Hereinbelow, the controller 11a and the controller 11b may be collectively referred to as controllers 11 when the controller 11a and the controller 11b do not have to be distinguished.

FIG. 2 illustrates a hardware configuration example of the controller 11.

The controller 11 is a computer.

The controller 11 includes a processor 201, a memory 202, a ROM (Read Only Memory) 203, a PIO interface 204, and a control network interface 205, as hardware.

Programs that fulfil functions of a control unit 303 that will be described later are stored in the ROM 203.

The programs that fulfil the functions of the control unit 303 are loaded from the ROM 203 onto the memory 202 and are executed by the processor 201.

The PIO interface 204 is an interface with the I/O network 103. The PIO interface 204 receives process data from the PIO units 106 and transmits process data for the PIO units 106 to the PIO units 106.

The control network interface 205 is an interface with the control network 101. The control network interface 205 of the controller 11a transmits a message for notification of a sequence number of the process data to the controller 11b and transmits tracking data to the controller 11b. The control network interface 205 of the controller 11b receives the message for the notification of the sequence number from the controller 11a and receives the tracking data from the controller 11a.

FIG. 3 illustrates a functional configuration example of the controller 11.

A reception unit 301 receives data from the control network 101 or the I/O network 103.

A transmission unit 302 transmits data to the control network 101 or the I/O network 103.

More specifically, the reception unit 301 of the current controller 11 receives the process data from the PIO units 106 through the I/O network 103. The reception unit 301 of the controller 11a receives the instructions from the HMI 102 through the control network 101. The transmission unit 302 of the controller 11a transmits the message for the notification of the sequence number and the tracking data through the control network 101 to the controller 11b.

The reception unit 301 of the controller 11b receives the process data from the PIO units 106 through the I/O network 103. The reception unit 301 of the controller 11b receives the instructions from the HMI 102 through the control network 101. The reception unit 301 of the controller 11b receives the message for the notification of the sequence number and the tracking data from the controller 11a through the control network 101.

The reception unit 301 and the transmission unit 302 are implemented by the PIO interface 204 and the control network interface 205.

The control unit 303 controls actions of the controller 11.

The control unit 303 is composed of a process data management unit 304, a time measurement unit 305, a sequence number management unit 306, and a tracking data management unit 307.

In the current controller 11, the process data management unit 304 receives the process data (example of operand data), which is iteratively transmitted from the PIO units 106 and for which a sequence number is set, from the PIO units 106 through the I/O network 103 and the reception unit 301. The process data management unit 304 carries out operations for the received process data and transmit results of the operations through the transmission unit 302 and the I/O network 103 to the PIO units 106.

In the standby controller 11, the process data management unit 304 selects the process data to be used in the operations, based on a next sequence number (to be described later) notified from the current controller 11. Then the operations for the selected process data are carried out. In the standby controller 11, the process data management unit 304 does not transmit the results of the operations.

The process data management unit 304 of the current controller 11 corresponds to the operation management unit. Processing that is carried out by the process data management unit 304 of the current controller 11 corresponds to the operation management processing.

In the current controller 11, the time measurement unit 305 measures time t_d that will be described later.

In the current controller 11, the sequence number management unit 306 calculates a sequence number of the process data, for which the process data management unit 304 is to subsequently carry out operations, as the next sequence number, each time the process data management unit 304 carries out the operations. Then the sequence number management unit 306 notifies the standby controller 11 of the calculated next sequence number through the transmission unit 302 and the control network 101.

In the standby controller 11, the sequence number management unit 306 stores the next sequence number notified from the current controller 11, in a storage unit 308.

Processing that is carried out by the sequence number management unit 306 of the current controller 11 corresponds to the sequence number management processing.

In the current controller 11, the tracking data management unit 307 transmits the tracking data through the transmission unit 302 and the control network 101 to the standby controller 11, in case where the current controller 11 is temporarily provided with a transmission right for the tracking data. The tracking data is data for notification of the results of the operations by the process data management unit 304 and an internal state of the current controller 11.

More specifically, in case where the current controller 11 is temporarily provided with the transmission right, the tracking data management unit 307 of the current controller 11 determines whether the tracking data has been transmitted to the standby controller 11 in the past or not. In case where the tracking data has not been transmitted to the standby controller 11, the tracking data for notification of latest results of the operations by the process data management unit 304 and the current internal state of the current controller 11 is transmitted to the standby controller 11.

In the standby controller 11, the tracking data management unit 307 receives the tracking data through the control network 101 and the reception unit 301 and stores the received tracking data in the storage unit 308. In the standby controller 11, the tracking data management unit 307 carries out an update of the results of the operations and an update of the internal state of the standby controller 11, based on the tracking data.

Processing that is carried out by the tracking data management unit 307 of the current controller 11 corresponds to the tracking data management processing.

Functions of the process data management unit 304, the time measurement unit 305, the sequence number management unit 306, and the tracking data management unit 307 are implemented by programs, for instance. The programs that fulfil the functions of the process data management unit 304, the time measurement unit 305, the sequence number management unit 306, and the tracking data management unit 307 are executed by the processor 201. The programs that fulfil the functions of the process data management unit 304, the time measurement unit 305, the sequence number management unit 306, and the tracking data management unit 307 correspond to the data processing programs.

The storage unit 308 stores the received process data, the results of the operations by the process data management unit 304, measurement time given by the time measurement unit 305, the next sequence number, the tracking data, and the like.

The storage unit 308 is implemented by the memory 202.

Description on Actions

Actions according to the present embodiment will next be described with use of FIG. 4.

In the present embodiment, a concept of the transmission right for the tracking data is introduced.

The current controller 11 is temporarily provided with the transmission right for the tracking data. The current controller 11 is capable of transmitting the tracking data only while the current controller 11 is provided with the transmission right for the tracking data. When the transmission right for the tracking data is not provided, the current controller 11 is incapable of transmitting the tracking data. That is, the current controller 11 then skips the tracking data transmission processing.

Only one transmission right exists on the control network 101 at the same time. It is assumed that one node determined arbitrarily in advance has the first transmission right in the system. It is assumed hereinbelow that the HMI 102 has the first transmission right.

After the system is activated, the HMI 102 selects one current controller 11 from among a plurality of current controllers 11 and transmits the transmission right for the tracking data to the selected current controller 11.

In FIG. 4, the HMI 102 transmits the transmission right to the controller 11a.

At time t₄₀₀, the reception unit 301 of the controller 11a receives PD #1.

In the controller 11a, the time measurement unit 305 measures the time t_d from reception of PD #1 at the time t₄₀₀ to actual use of PD #1 at time t₄₀₁.

At the time t₄₀₁, the process data management unit 304 of the controller 11a carries out the process data acquisition processing as with the conventional controller 100a illustrated in FIG. 8. Then the process data management unit 304 carries out operations as with the conventional controller 100a illustrated in FIG. 8 and, at time t₄₁₂, the transmission unit 302 transmits the process data for notification of results of the operations to the PIO units 106.

In the controller 11a, at time t₄₁₃ after the transmission of the process data, the sequence number management unit 306 calculates a next sequence number P_next. The next sequence number P_next is a sequence number of the process data for which the process data management unit 304 is to subsequently carry out operations, as previously described.

Specifically, the sequence number management unit 306 calculates the next sequence number P_next in accordance with expression 1. In expression 1, P_last denotes the sequence number of the process data used in last operations. Besides, t_c denotes the control period, t_p denotes the process data period, and t_d denotes the time measured by the time measurement unit 305.

Then the sequence number management unit 306 notifies the controller 11b of the next sequence number P_next through the transmission unit 302 and the control network 101.

$\begin{array}{cc}\mathrm{FORMULA}1& \\ P_{\mathrm{next}}=P_{\mathrm{last}}+\left[\frac{t_{c^{-}}\left(t_p-t_d\right)}{t_p}+1\right]& \left(1\right)\end{array}$

In an example of FIG. 4, the controller 11a notifies the controller 11b of a sequence number 4 (PD #4). In addition, the tracking data management unit 307 of the controller 11a then determines whether two conditions that follow are satisfied or not. In case where the two conditions that follow are satisfied, the tracking data management unit 307 of the controller 11a transmits the tracking data to the controller 11b.

• • The tracking data has never been transmitted to the controller 11b since the system is activated.
  • The controller 11a has the transmission right for the tracking data.

After transmitting the tracking data, the controller 11a returns the transmission right for the tracking data to the HMI 102.

Though the controller 11b receives PD #5 at time t₄₀₃, the controller 11b discards PD #5 because PD #5 is greater than PD #4 that is the next sequence number notified from the controller 11a.

Above actions remove necessity for communication of the tracking data because the process data used in the operations in the controller 11b is the same as that in the controller 11a after the actions.

An example of actions of the controller 11a will next be described with reference to a flowchart of FIG. 5.

In step S100, the reception unit 301 receives the process data transmitted from the PIO units 106, through the I/O network 103. The process data management unit 304 stores the process data in the storage unit 308.

Simultaneously with step S100, the time measurement unit 305 starts measurement of the time span t_d.

In step S110, subsequently, the process data management unit 304 acquires the process data from the storage unit 308 and carries out operations with use of the process data. Simultaneously with step S110, the time measurement unit 305 stops the measurement of the time span t_d.

In step S120, subsequently, the transmission unit 302 transmits from the I/O network 103, to the PIO units 106, the process data for notification of results of the operations.

In step S130, subsequently, the sequence number management unit 306 calculates the next sequence number P _next in accordance with above-mentioned expression 1 and the transmission unit 302 notifies the controller 11b of the next sequence number P_next through the control network 101.

In step S140, subsequently, the tracking data management unit 307 determines whether the controller 11a is provided with the transmission right for the tracking data or not.

In case where the controller 11a is provided with the transmission right for the tracking data, the tracking data management unit 307 determines whether or not the tracking data has been transmitted to the controller 11b since the system was activated.

In case where the tracking data has not been transmitted to the controller 11b, the transmission unit 302 transmits the tracking data through the control network 101 to the controller 11b.

In step S170, finally, the transmission unit 302 returns the transmission right for the tracking data to the HMI 102.

An example of actions of the controller 11b will next be described with reference to a flowchart of FIG. 6.

When the reception unit 301 receives the tracking data in step S200, the tracking data management unit 307 updates the internal state of the controller 11b and the results of the operations in accordance with the tracking data in step S210. The tracking data management unit 307 stores the internal state and the results of the operations that have been updated, in the storage unit 308.

When notification of the next sequence number P_next is given by the controller 11a in step S220, the sequence number management unit 306 stores the next sequence number P_next in the storage unit 308 in step S230.

When the reception unit 301 receives the process data in step S240, the process data management unit 304 stores the process data in the storage unit 308 in step S250.

In step S260, subsequently, the process data management unit 304 determines whether the sequence number of the process data received in step S240 coincides with the next sequence number P_next or not.

In case where the sequence number of the process data received in step S240 does not coincide with the next sequence number P_next, the process data management unit 304 discards the process data in step S270.

On the other hand, in case where the sequence number of the process data received in step S240 coincides with the next sequence number P_next, the process data management unit 304 carries out operations with use of the process data. Then the process data management unit 304 stores results of the operations in the storage unit 308.

Description on Effects of Embodiment

In the present embodiment, as described above, the current controller 11 transmits the tracking data to the standby controller 11 only when being provided with the transmission right for the tracking data. Thus the situation in which the network band is oppressed by the transmission of the tracking data can be avoided.

In case where a technique described in the present embodiment is not used, the tracking data is transmitted from the current controller to the standby controller in each control period t_c. In case where the technique described in the present embodiment is not used, therefore, a band required for the communication of the tracking data between a pair of the current controller and the standby controller has a value obtained by multiplication of the number of repetitions n_p of the control period t_c by a data size d_t of the tracking data. On conditions of n_p=50 (times) and the data size d_t=240 Mbps, for instance, the band required for the communication of the tracking data is 12 Gbps. Costs of the control network 101 are increased in case where the technique described for the present embodiment is not used, because methods (such as 10GBASE-T) for realizing the communication over 1 Gbp are becoming widespread but are still expensive. In the present embodiment, the tracking data is transmitted only one time between one pair of the current controller and the standby controller. Accordingly, the band required for the communication of the tracking data between one pair of the current controller and the standby controller 11 is limited to the data size d_t (240 Mbps) of the tracking data.

According to the present embodiment, therefore, the control network 101 may be configured with 1000BASE-T that is widespread and inexpensive.

In the present embodiment, the standby controller 11 is notified of the next sequence number each time the operations with use of the process data are carried out by the process data management unit 304 of the current controller 11. As a result, the standby controller 11 may continue the operations with use of the same process data that is used in the current controller 11 even though the number of the transmissions of the tracking data is decreased.

According to the present embodiment, integration of the tracking bus with the control network makes it possible to connect a plurality of standby controllers 11 to one current controller 11. Therefore, the system that is more reliable may be constructed.

Description on hardware configuration

Finally, supplementary description on the hardware configuration of the controller 11 will be given.

The processor 201 illustrated in FIG. 2 is an IC (Integrated Circuit) that carries out processing.

The processor 201 is a CPU (Central Processing Unit), a DSP (Digital Signal Processor), or the like.

The memory 202 illustrated in FIG. 2 is a RAM (Random Access Memory).

A flash memory or an HDD (Hard Disk Drive) may be used in place of the ROM 23.

The PIO interface 204 and the control network interface 205 that are illustrated in FIG. 2 include a receiver that receives data and a transmitter that transmits data.

Each of the PIO interface 204 and the control network interface 205 is a communication chip or an NIC (Network Interface Card), for instance.

An OS (Operating System) is also stored in the ROM 203.

At least a portion of the OS is executed by the processor 201.

While executing at least the portion of the OS, the processor 201 executes the programs that fulfil the functions of the process data management unit 304, the time measurement unit 305, the sequence number management unit 306, and the tracking data management unit 307 (which will be collectively referred to as the “units”, hereinbelow).

The processor 201 executes the OS, so that task management, memory management, file management, communication control, and the like are carried out.

The controller 11 may include a plurality of processors that substitute for the processor 201. Execution of the programs that fulfil the functions of the “units” is shared by the plurality of processors. Each of the processors is an IC that carries out processing as with the processor 201.

Information, data, signal values, variable values, and the like that indicate results of processing in the “units” are stored in at least any of the memory 202 and a register and a cache memory in the processor 201.

The programs that fulfil the functions of the “units” may be stored in a portable storage medium such as a magnetic disk, a flexible disk, an optical disk, a compact disk, a Blu-ray (a registered trademark) disk, or a DVD.

The “units” may be read as “circuits”, “steps”, “procedures”, or “processing”.

The controller 11 may be implemented by an electronic circuit such as a logic IC (Integrated Circuit), a GA (Gate Array), an ASIC (Application Specific Integrated Circuit), or an FPGA (Field-Programmable Gate Array).

In this case, the “units” are each implemented as a portion of the electronic circuit. The processor and the electronic circuits may be collectively referred to as processing circuitry.

REFERENCE SIGNS LIST

11: controller; 100: controller; 101: control network; 102: HMI; 103: I/O network; 104: input/output terminal; 105: tracking bus; 106: PIO unit; 109: plant; 201: processor; 202: memory; 203: ROM; 204: PIO interface; 205: control network interface; 301: reception unit; 302: transmission unit; 303: control unit; 304: process data management unit; 305: time measurement unit; 306: sequence number management unit; 307: tracking data management unit; 308: storage unit

Claims

1-5. (canceled)

6. A data processing device that is connected to a backup device through a first network connected to a higher-level device and that is connected to equipment through a second network different from the first network, the data processing device comprising: processing circuitry to:receive operand data, which is iteratively transmitted from the equipment and for which a sequence number is set, from the equipment through the second network, carry out operations for the received operand data, and transmit results of the operations through the second network to the equipment;calculate the sequence number of the operand data, for which the operations are to be subsequently carried out, as a next sequence number, each time the operation s are carried out and notify the backup device of the calculated next sequence number through the first network; andin case where the data processing device is temporarily provided with a transmission right for tracking data for notification of the results of the operations and an internal state of the data processing device, transmit the tracking data through the first network to the backup device.

7. The data processing device according to claim 6, wherein in case where the data processing device is temporarily provided with the transmission right, the processing circuitry determines whether the tracking data has been transmitted to the backup device in the past or not, and in case where the tracking data has not been transmitted to the backup device, the processing circuitry transmits the tracking data through the first network to the backup device.

8. The data processing device according to claim 6, wherein in case where the data processing device is temporarily provided with the transmission right, the processing circuitry transmits the tracking data for notification of latest results of the operations and a current internal state of the data processing device, through the first network to the backup device.

9. A data processing method by a computer that is connected to a backup device through a first network connected to a higher-level device and that is connected to equipment through a second network different from the first network, the data processing method comprising: receiving operand data, which is iteratively transmitted from the equipment and for which a sequence number is set, from the equipment through the second network, carrying out operations for the received operand data, and transmitting results of the operations through the second network to the equipment;calculating the sequence number of the operand data, for which the operations are to be subsequently carried out, as a next sequence number, each time the operations are carried out, and notifying the backup device of the calculated next sequence number through the first network; andin case where the computer is temporarily provided with a transmission right for tracking data for notification of the results of the operations and an internal state of the computer, transmitting the tracking data through the first network to the backup device.

10. A non-transitory computer readable medium storing a data processing program that causes a computer, which is connected to a backup device through a first network connected to a higher-level device and which is connected to equipment through a second network different from the first network, to execute: operation management processing of receiving operand data, which is iteratively transmitted from the equipment and for which a sequence number is set, from the equipment through the second network, carrying out operations for the received operand data, and transmitting results of the operations through the second network to the equipment;sequence number management processing of calculating the sequence number of the operand data, for which the operations of the operation management processing are to be subsequently carried out, as a next sequence number, each time the operations of the operation management processing are carried out, and notifying the backup device of the calculated next sequence number through the first network; andtracking data management processing, in case where the computer is temporarily provided with a transmission right for tracking data for notification of the results of the operations of the operation management processing and an internal state of the computer, of transmitting the tracking data through the first network to the backup device.