JP6672623B2 - Control system and its control device - Google Patents

Description

  The present invention relates to a data backup method for a control device used in a control system.

The monitoring control system is used in various industrial plants, and is composed of a control device, a monitoring operation device, an input / output device for a sensor / actuator, and the like.
FIG. 5 shows a configuration example of an existing monitoring and control system.

The illustrated control system includes a control device 110, a monitoring operation device 120, an input / output device 130, and the like.
The control device 110 includes an external interface (I / F) unit 111, a control operation unit 112, a control data storage unit 113, a program storage unit 114, and the like. The input / output device 130 is connected to a device to be controlled (not shown).

  The control device 110 is connected to the monitoring operation device 120 and the input / output device 130 via the external interface (I / F) unit 111, and acquires data related to the control target device from the input / output device 130 as needed. . This data is an example of control data. The control data is stored in the control data storage unit 113.

  The monitoring and operating device 120 transmits setting data and commands to the control device 110 or acquires control data and the like from the control device 110 in order to monitor and operate the state of the plant.

  The control device 110 performs an operation using a control data and the like collected from the input / output device 130 by a program (control program; for example, a PLC program) corresponding to the system, and outputs the operation result and the like to the input / output device 130. .

  In the control device 110, a high-speed storage device (memory) is mounted as the control data storage unit 113 in order to execute the control arithmetic processing at high speed. In addition, a non-volatile storage device is provided as the program storage unit 114 that holds programs (such as control programs).

  As described above, to configure the control device 110, a high-speed memory and a storage device for holding a program are required, but the control data and the program are held even when the power of the control device 110 is cut off. Therefore, in some cases, a static RAM with a battery backup is used as the control data storage unit 113 as shown in FIG.

  In recent years, as shown in FIG. 7, as a memory for storing control data, a dynamic RAM (DRAM; high-speed volatile storage unit 144) which is high-speed but cannot be backed up by a battery is used, and a power supply voltage drop detection unit 142 is provided. Also, a configuration such as the illustrated control device 140 is known.

  The control device 140 is supplied with power from an external power supply 145. The external power supply 145 is, for example, a commercial AC power supply. Here, it is assumed that this is converted into a DC power supply and supplied to the control device 140.

  The power supply voltage drop detection unit 142 monitors, for example, the voltage of the DC power supply supplied from the external power supply 145, and when the power supply voltage becomes lower than the “voltage drop detection voltage” shown in FIG. Is detected, and the fact is notified to the control operation unit 141.

  Here, even if the voltage of the DC power supply is reduced, control device 140 is in an operable state until the voltage becomes less than “operation limit voltage” shown in FIG. As shown in FIG. 8, the "voltage drop detection voltage" is set to an arbitrary value which is lower than the normal value of the power supply voltage but higher than the "operation limit voltage".

  Then, as shown in FIG. 8, it takes some time from the detection of the voltage drop when the power is turned off to the time when the operation becomes inoperable, in other words, until the voltage becomes lower than the operation limit voltage (for example, the memory backup time shown in the drawing). Take). In other words, it can be said that the operable time from the voltage drop detection point is the memory backup time. The memory backup time is not zero “0” due to the characteristics of the power supply, but can be lengthened by providing a power storage device.

  The power storage device is, for example, a capacitor or the like, but is not limited to this example. The power storage device is charged by the power supply when the power supply voltage is normal, and is discharged when the power supply voltage decreases.

  The length of the memory backup time depends on the capacity of the power storage device (not shown) provided in the control device 140. That is, the larger the capacity of the power storage device (not shown), the longer the memory backup time. However, the cost increases as the capacity of the power storage device increases.

  In any case, the control operation unit 141 saves the data stored in the dynamic RAM (DRAM; high-speed volatile storage unit 144) to the low-speed nonvolatile storage unit 143 such as a flash memory during the memory backup time, and Need to save. For this reason, it is necessary to secure the memory backup time longer than “the time required for data evacuation”, and the capacity of the power storage device needs to be large accordingly. In other words, the larger the amount of data to be saved, the greater the required capacity of the power storage device, and the higher the cost.

  Note that the power storage device supplies power to, for example, the entire control device 140 at the time of discharging, but is not limited to this example, and is provided only for a configuration (for example, the control operation unit 141 or the like) necessary to realize the data saving. A configuration for supplying power may be used.

  After the power is turned off, control data and programs stored in the nonvolatile storage unit 143 such as the flash memory are transferred to the high-speed volatile storage unit 144 as initialization processing when the control device 140 is started. . During operation, control processing is executed using programs and control data stored in the high-speed volatile storage unit 144.

  In the case of the configuration of FIG. 7, the control device operates in the three modes shown in FIG. That is, there are an initialization mode immediately after power-on or reset, an operation mode for performing normal control calculation, and a power-off mode when a power drop is detected.

In the initialization mode, programs and control data are copied from the low-speed nonvolatile storage unit 143 (flash memory or the like) to the high-speed volatile storage unit 144 (DRAM or the like).
In the operation mode, a control operation is performed using a program and control data in the high-speed volatile storage unit 144.

  Then, in the power-off mode, the control data is backed up (evacuated) from the high-speed volatile storage unit 144 to the low-speed nonvolatile storage unit 143. The control data often includes data that changes at any time during operation, such as the state of the controlled device (temperature, pressure, number of operations, etc.). It is necessary to save the data to the nonvolatile storage unit 143. On the other hand, there is no need to back up (save) the program in that sense because it is basically unchanged.

Further, as a conventional technique, for example, a technique disclosed in Patent Document 1 is known.
The invention of Patent Literature 1 enables a backup operation to be performed on a device connected to a programmable controller with a simple operation and with a minimum number of devices.

  The invention of Patent Literature 1 is a backup processing method in a programmable controller system including a programmable controller and its peripheral device, and collectively stores backup data of the plurality of backup target devices in a plurality of backup target devices included in the programmable controller system. Provide a possible storage medium. Then, according to the backup target range set by a switch on the backup target device provided with the storage medium, backup processing for the plurality of backup target devices is executed using the storage medium.

JP 2002-297207 A

  In the case of the configuration shown in FIG. 7, saving the data to the low-speed nonvolatile storage unit 143 when the power is turned off requires "time required for data saving" according to the amount of data to be saved. It is necessary to secure the above backup time longer than "the time required for data backup".

  Therefore, it is necessary to provide a power storage device capable of operating for a short time even after the power is turned off in the control device 140. Naturally, if the amount of data to be saved is large, the time for saving the data becomes long, so It is necessary to increase the capacity of the device, and the cost increases accordingly.

  The control device uses not only the control data of the plant (control target device) collected by the input / output device, but also the control parameters (gain, target value, time constant, etc. of PID calculation) input from the monitoring and operation device. In order to perform the calculation at high speed, it is necessary to store these control parameters in the high-speed volatile storage unit during operation.

  Furthermore, control parameters may be updated during operation. For example, when a new control parameter is transmitted from the monitoring operation device, the control parameter in the high-speed volatile storage unit is updated by overwriting and storing the new control parameter in the high-speed volatile storage unit. As a result, after that, the calculation is executed using the new control parameters. In this case, in the processing in the power-off mode, not only the control data but also the control parameters need to be backed up (saved) in the low-speed nonvolatile storage unit, and the amount of saved data increases accordingly. As a result, the "time required for data saving" increases. In order to cope with this, it is necessary to increase the backup time, thereby increasing the capacity of the power storage device and the cost accordingly.

  An object of the present invention is to provide a control device or the like that can prevent an increase in data backup time and thereby prevent an increase in the capacity of a power storage device.

  The control device of the present invention is a control device that executes a predetermined program using given control parameters and control data obtained as needed from the control target device, and controls the control target device. Having.

A non-volatile storage unit for storing the program, the control data, and the control parameters;
Power supply voltage drop detection means for detecting a voltage drop of a power supply for operating the control device;
Power storage means for temporarily supplying power to the control device by discharging when the voltage of the power supply drops;
・ Control means:

The control unit has the following units (processing function units).
Initialization means for copying all or a part of the program, the control data, and the control parameters stored in the nonvolatile storage means to the volatile storage means at the time of startup;
During operation, while executing an arithmetic process for controlling the controlled device using the program, the control data, and the control parameter stored in the volatile storage unit, the calculated process is obtained from the controlled device at any time. the control data is a control execution means for updating the control data stored in the volatile memory means;
When a new control parameter is given at any time during operation, the control parameter stored in the volatile storage unit is updated by the new control parameter, and the control stored in the nonvolatile storage unit is updated. Control parameter updating means for also updating parameters;
If the power supply voltage drop is detected by the power supply voltage drop detection means, the volatile storage is performed without saving the program and the control parameters stored in the volatile storage means to the nonvolatile storage means. power-off processing means Ru is evacuated before Symbol nonvolatile storage means said control data stored in the unit.

  According to the control device of the present invention, for a control device that stores control data and control parameters in a volatile storage unit and performs an arithmetic operation during operation, it is possible to prevent an increase in backup time and thereby to reduce the capacity of the power storage device. An increase can be prevented.

It is a block diagram of the control system of this example. FIG. 2 is a diagram illustrating a specific example of the control system in FIG. 1. It is a specific example of a configuration of a control device. (A)-(c) is a processing flowchart figure of the control apparatus in the case of making it the structure of FIG. It is a figure showing the example of composition of the existing supervisory control system. This is a configuration example using an SRAM with a battery backup. 1 is a configuration example including a DRAM and a power supply voltage drop detection device. It is a figure for explaining memory backup time. FIG. 7 is a diagram for describing three modes.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram of the control system of the present example.
Note that the control system of this example may be a PLC (programmable controller) system or a distributed control system (DCS). The illustrated control system includes a control device 10, a monitoring operation device 2, an input / output device 3, and the like.

  The control device 10 receives power supply from the external power supply 5. The external power supply 5 converts, for example, commercial power (AC) to DC and supplies the DC to the control device 10. For example, the power supply from the external power supply 5 to the control device 10 may be interrupted due to a power failure or the like.

  The control device 10 is, for example, a programmable controller main body (CPU module or the like) as an example, but is not limited to this example as described above. The control device 10 is connected to the monitoring operation device 2 and the input / output device 3 via a communication line.

  The monitoring operation device 2 and the input / output device 3 may be the same as those in the related art, and will not be described in detail. However, for simplicity, the input / output device 3 is connected to a control target device (not shown). For example, state data (temperature, pressure, count, etc.) of the control target device is collected as needed. Further, the monitoring operation device 2 is, for example, a programmable display device or the like, which can monitor the state of the control target device and can perform arbitrary setting by a user.

The state data is an example of the control data, and the setting data is an example of the control parameter, but is not limited to these examples.
The control device 10 has the following components: an external interface (I / F) unit 11, a control operation unit 12, a low-speed nonvolatile storage unit 13, a high-speed volatile storage unit 14, and a power supply voltage drop detection unit 15. The control operation unit 12 includes, for example, an operation unit such as a CPU / MPU, but is not limited to this example.

  The low-speed nonvolatile storage unit 13 is a readable / writable nonvolatile memory, for example, a flash memory, but is not limited to this example. The high-speed volatile storage unit 14 is a volatile memory without a battery back and is, for example, a dynamic RAM (DRAM), but is not limited to this example. Note that “low speed” and “high speed” may be considered to be relative. That is, the high-speed volatile storage unit 14 can perform a read / write operation at a higher speed than at least the low-speed nonvolatile storage unit 13.

  The control operation unit 12 (the CPU / MPU or the like) also has, for example, an internal memory (not shown) in which a predetermined application program is stored in advance, and the CPU / MPU or the like executes the application program to execute the application program. Various processing functions of the control device 10 (control operation unit 12) described below are realized. Note that this application program is different from a program (control program) stored in the program storage areas 13a and 14a described later, and is a program for realizing the operation of the control device 10. The application program is not limited to the above example, and may be stored in the low-speed nonvolatile storage unit 13 in advance, for example.

  Further, the control device 10 is further provided with a power storage device (power storage means) not shown. As described above, this power storage device is, for example, a capacitor, and has a shorter discharge time than a battery, but is inexpensive. Note that there is a concept that a battery is also a kind of a power storage device, but here, the battery is not included in the power storage device.

  As described above, even when the external power supply 5 is lost for some reason, such as a power failure, the control device 10 can operate for a while (during the memory backup time) by the power storage device such as the capacitor. The state continues (power supply will be continued), during which the data backup (evacuation) described above will be performed. As described above, the length of the memory backup time depends on the capacity of the power storage device, and the larger the capacity, the longer the memory backup time.

  Note that, as described above, the power storage device is a capacitor as an example, but is not limited to this example. The power storage device is charged by, for example, the external power supply 5, and discharges and supplies power to the control device 10 when the external power supply 5 is lost (when the voltage drops).

  In this method, the amount of data to be saved can be reduced, whereby the “time required for data saving” can be reduced, and thus the memory backup time can be shortened, thereby reducing the capacity of the power storage device. And cost reduction can be achieved. Details will be described later.

  The external interface (I / F) unit 11 may be the same as the conventional one, and the control device 10 uses the external interface unit 11 to communicate with the monitoring operation device 2 and the input / output device 3 via the communication line (data). Transmission and reception). The power supply voltage drop detection unit 15 may be the same as the conventional one. When the power supply voltage drop detection unit 15 detects the power supply voltage drop (the power supply voltage falls below the voltage drop detection voltage) Is detected), the mode shifts to the power-off mode.

  The low-speed nonvolatile storage unit 13 includes storage areas for a program storage area 13a, a control data storage area 13b, and a monitoring operation data storage area 13c. The program storage area 13a stores a program (such as a control program). Control data is stored in the control data storage area 13b. The monitoring operation data storage area 13c stores monitoring operation data. Note that the monitoring operation data may be regarded as corresponding to the above control parameters (for example, a gain, a target value, a time constant, and the like of the PID calculation).

  Since the low-speed nonvolatile storage unit 13 is a nonvolatile memory or the like, data is stored without being lost even when the power is off. On the other hand, since the high-speed volatile storage unit 14 is a volatile memory or the like, data is lost when the power is turned off. For this reason, when the power supply voltage drop is detected, it is necessary to save the data stored in the high-speed volatile storage unit 14 to the low-speed nonvolatile storage unit 13 during the operable state. In this method, only the control data needs to be saved.

  The high-speed volatile storage unit 14 stores the above-mentioned program (the above-mentioned control program, etc.), control data, and monitoring operation data during operation. During operation, the control calculation unit 12 performs calculations for control processing of the control target device using the programs, control data, and monitoring operation data stored in the high-speed volatile storage unit 14.

  For this purpose, the control operation unit 12 reads out the program, control data, and monitoring operation data stored in the low-speed nonvolatile storage unit 13 at the time of startup (initialization mode), and respectively reads the high-speed volatile storage. The data is written to the corresponding storage area of the unit 14. Here, the high-speed volatile storage section 14 is provided with storage areas of a program storage area 14a, a control data storage area 14b, and a monitoring operation data storage area 14c. The program is written in the program storage area 14a, the control data is written in the control data storage area 14b, and the monitoring operation data is written in the monitoring operation data storage area 14c.

  During normal operation (operation mode), the control operation unit 12 executes a program in the program storage area 14a to perform control operation. At this time, control data in the control data storage area 14b and monitoring operation data storage The control operation is performed using the monitoring operation data in the area 14c. Further, the control data stored in the control data storage area 14b is updated by writing the control calculation result and the collected data of the input / output device 3 (control data) to the control data storage area 14b. The control calculation unit 12 acquires data (temperature, pressure, count number) indicating a current state of a control target device (not shown) at any time via the input / output device 3 and controls this as control data. The data is stored in the data storage area 14b.

  Therefore, if the control data stored in the control data storage area 14b is updated at least once after the processing at the time of startup (initialization mode), thereafter, the control data stored in the control data storage area 13b is: The control data stored in the control data storage area 14b is not the same as the control data. Basically, old control data is stored in the control data storage area 13b, and the latest control data is stored in the control data storage area 14b.

  The data stored in the high-speed volatile storage unit 14 is erased by turning off the power. Therefore, it is necessary to save the latest control data stored in the control data storage area 14b to the control data storage area 13b during the memory backup time described above. As a result, at the next start-up, the control is started using the latest control data, and the control is taken over without any problem.

  For this purpose, the power supply voltage drop detection unit 15 monitors the power supply voltage of the external power supply 5 as needed, and when detecting a predetermined voltage drop, notifies the control operation unit 12 of the voltage drop. Upon receiving the notification, the control operation unit 12 shifts to the power-off mode, and saves the control data in the control data storage area 14b in the control data storage area 13b. Needless to say, the data stored in the low-speed nonvolatile storage unit 13 is not lost even when the power is off.

  Here, as described above, in the control device 10, not only the control data of the control target (plant or the like) collected by the input / output device 3 but also the control parameters (monitoring operation data; PID calculation) input from the monitoring operation device 2 The control calculation is also performed using the gain, the target value, the time constant, etc.). However, in order to perform the calculation at high speed, it is necessary to store the control parameter in the high-speed volatile storage unit 14 as well.

  Therefore, it is necessary to copy from the low-speed nonvolatile storage unit 13 to the high-speed volatile storage unit 14 at the time of starting the apparatus (initialization mode). However, the monitoring operation data does not necessarily need to be backed up when the power is turned off (power-off mode).

  In this method, the control parameters are managed separately from the control data in the storage area, and when the power is turned off (power-off mode), the control data is backed up but the control parameters are not backed up. On the other hand, when a new control parameter is written from the monitoring operation device 2 during the operation mode, that is, when the control parameter is updated, the new control parameter is stored in the high-speed volatile storage unit 14 and , And also stored in the low-speed nonvolatile storage unit 13. This means that new control parameters are stored in the monitoring operation data storage area 13c and the monitoring operation data storage area 14c, which are storage areas for control parameters. In other words, with respect to the monitoring operation data, the backup processing is performed not when the power is turned off, but when the power supply is updated.

  This makes it possible to reduce the amount of backup data when the power is turned off, as much as there is no need to back up the monitoring operation data when the power is turned off. That is, the amount of backup data when the power is turned off can be limited to the amount of control data.

  The above process may be executed by, for example, the external interface (I / F) unit 11 or the control calculation unit 12. The monitoring operation device 2 transmits, for example, the new control parameter together with the parameter update request, and the external interface (I / F) unit 11 receiving the new control parameter stores the new control parameter, for example, in the monitoring operation data storage area. At the same time, the data is overwritten and stored in the corresponding area (monitoring operation data storage area 13c) of the low-speed nonvolatile storage unit 13 as well. Alternatively, the external interface (I / F) unit 11 passes the transmission data from the monitoring operation device 2 to the control calculation unit 12, and the control calculation unit 12 stores the new control parameter in the monitoring operation data storage area 14c and performs the monitoring operation. The data may be overwritten and stored in the data storage area 13c.

Here, FIG. 2 shows a specific example of the control system of FIG.
The control system in FIG. 2 is a PLC system, and includes a PLC controller 30, an HCI device 40, an I / O module 50, and the like. The HCI device 40 and the I / O module 50 are each connected to the controller 30 via an arbitrary communication line.

  The HCI device 40 is, for example, a programmable display device or the like, and is an existing device that allows a user to make arbitrary settings and monitor a control target. When the user inputs an arbitrary set value on the HCI device 40, the set value is transferred to the controller 30 and stored in the controller 30. This set value corresponds to the control parameter (monitoring operation data).

  The I / O module 50 is connected to various control target devices 51, and collects, for example, status data of the control target devices 51 at regular intervals, and stores them in, for example, the I / O memory 32 provided in the controller 30. I do. The I / O memory 32 may have a configuration corresponding to the high-speed volatile storage unit 14, or a configuration in which the high-speed volatile storage unit 14 is provided separately from the I / O memory 32. In the case of the latter configuration, the controller 30 updates the control data by transferring and storing the data (control data) stored in the I / O memory 32 to the high-speed volatile storage unit 14, for example, at regular intervals.

  The controller 30 executes, for example, a PID operation by executing the stored control program. At this time, the set values (control parameters), control data, and the like are used. In the case of this example, the set values are, for example, various constants (such as gains) and target values used for the PID calculation.

  A DC power generated by the external power source 5 (not shown) is supplied to the controller 30. The controller 30 includes the illustrated capacitor 31 provided in parallel with the DC power supply. The capacitor 31 is an example of the power storage device.

  When DC power is supplied, the capacitor 31 is in a charged state, and when DC power supply is stopped for any reason, such as a stop of commercial power supply due to a power failure or the like, the capacitor 31 is in a discharged state. During this period (the memory backup time; for example, about several hundred ms; this time depends on the capacity of the capacitor 31), the controller 30 can be supplied with power. In the meantime, the controller 30 performs the above-mentioned control data backup (backup) processing.

Although not shown in FIG. 2, the controller 30 also includes a memory (such as a flash memory) corresponding to the low-speed nonvolatile storage unit 13.
In this method, the amount of backup data when the power is turned off can be limited to the amount of control data, and the amount of backup data can be reduced, thereby reducing the time required for backup. Can be shortened (in other words, the capacity of the capacitor 31 can be reduced).

  Here, in the description of FIG. 1 described above, in the present method, the control parameter (monitoring operation data) is written to both the low-speed nonvolatile storage unit 13 and the high-speed volatile storage unit 14 at the time of updating, and both are updated. I also try to update. However, if the DC power supply is stopped during the writing process, the writing is interrupted. As a result, there is a possibility that a part of the control parameters will be updated but the rest will remain old data. It can be said that this makes it impossible to maintain consistency between a plurality of data constituting the operation monitoring data. For this reason, the control parameters particularly stored in the low-speed nonvolatile storage unit 13 may be in a mixed state of old and new, and may not operate normally even if started later.

  If a voltage drop is detected while monitoring operation data is being written in the operation mode (during backup of operation monitoring data) as described above, the backup is interrupted, and the consistency between a plurality of data constituting the operation monitoring data In this example, for example, in order to prevent the situation that the data cannot be maintained, the configuration and operation shown in FIG. 3 may be further provided.

  That is, the control device 10 is configured to have two monitoring operation data storage areas 13c in the low-speed nonvolatile storage unit 13 as shown in FIG. That is, two storage areas, that is, the illustrated monitoring operation data storage area 13c-1 and the monitoring operation data storage area 13c-2 are provided. Then, by switching and using these two storage areas each time the monitoring operation data is updated, the above problem can be solved.

  FIG. 4 is a process flowchart of the control device 10 (control operation unit 12) in the case of the configuration of FIG. FIG. 4A is a processing flowchart when initialization is performed, FIG. 4B is a processing flow when monitoring operation data is updated, and FIG. 4C is a processing flow chart when power is turned off.

In this example, the control device 10 (the control calculation unit 12) has a flag in an arbitrary storage area, and refers to the flag and switches the flag ON / OFF.
First, in the initialization processing of FIG. 4A, first, the control program and the control data stored in the low-speed nonvolatile storage unit 13 are respectively copied to the corresponding areas of the high-speed volatile storage unit 14 (step S11). ).

  Further, the monitoring operation data is also copied from the low-speed nonvolatile storage unit 13 to the high-speed volatile storage unit 14. In this case, by referring to the flag, the monitoring operation data is read from one of the two storage areas of the monitoring operation data storage areas 13c-1 and 13c-2 and copied to the corresponding area of the high-speed volatile storage unit 14. I do. In the illustrated example, if the flag is ON (step S12, YES), the monitoring operation data is read from the monitoring operation data storage area 13c-1 and copied to the corresponding area of the high-speed volatile storage unit 14 (step S12). S13). Conversely, if the flag is OFF (step S12, NO), the monitoring operation data is read from the monitoring operation data storage area 13c-2 and copied to the corresponding area of the high-speed volatile storage unit 14 (step S14).

  The corresponding area of the high-speed volatile storage unit 14 is a program storage area 14a for a control program, a control data storage area 14b for control data, and a monitoring area for monitoring operation data. It becomes the operation data storage area 14c.

  When a new control parameter (monitoring operation data) is input from the monitoring operation device 2, the control parameter is updated by storing the new control parameter in a corresponding area of the high-speed volatile storage unit 14 and updating the control parameter. By executing the processing of 4 (b), a backup of a new control parameter is generated.

The process of FIG. 4B is a process of storing the new control parameter also in a corresponding area of the low-speed nonvolatile storage unit 13. The corresponding area is determined by referring to the flag.
That is, in the example of FIG. 4, if the flag is ON (step S21, YES), the new control parameter is stored in the monitoring operation data storage area 13c-2 (step S23), and the storage is completed. Then, the flag is reversed (step S24), and in this case, the flag is switched to OFF, and this processing is ended.

  As a result, after that, the processing of FIG. 4C is executed after the power is turned off, and when the processing of FIG. 4A is further executed at the time of initialization, the processing is stored in the monitoring operation data storage area 13c-2. The latest control parameters obtained are copied to the high-speed volatile storage unit 14, and the control processing is executed using them. If the power is turned off during the processing in step S23, the monitoring operation data storage area 13c-2 is in the middle of writing and is in an abnormal state in which old data and new data are mixed. . However, in this case, since the process of step S24 is not performed, the flag remains ON. Therefore, when the processing of FIG. 4A is performed later by initialization, the data in the monitoring operation data storage area 13c-1 is copied to the high-speed volatile storage unit 14, and there is no particular problem. become.

  In this case, after the initialization, a new control parameter may be input from the monitoring operation device 2 again, and the process of FIG. 4B may be executed again. It is not limited to the example.

  If the determination in step S21 is NO (if the flag is OFF), the new control parameter is stored in the monitoring operation data storage area 13c-1 (step S22). By inverting the flag (step S24), in this case, the flag is switched to ON, and this processing ends. In this case as well, as in the case where the determination in step S21 is YES, there is no problem even if the power is turned off during the processing in step S22.

Then, in the processing in the power-off mode of FIG. 4C, only the control data is saved (step S31). That is, the control data stored in the control data storage area 14b of the high-speed volatile storage unit 14 is copied (evacuated) to the control data storage area 13b of the low-speed nonvolatile storage unit 13.

The above description is an example, and the present invention is not limited to this example. For example, in the above description, two areas are provided as the monitoring operation data storage area 13c . However, the present invention is not limited to this example, and three or more areas may be provided. In the case of the above two areas, the flag is managed by ON / OFF of the flag. However, in the case of three or more areas, information indicating in which area a new control parameter is stored instead of the flag is stored in the arbitrary area. Is written to the storage area.

  The processing of FIGS. 4A and 4C is executed by the control calculation unit 12. The process of FIG. 4B may be executed by the control operation unit 12 or may be executed by the external interface (I / F) unit 11.

  Here, it can be said that the low-speed nonvolatile storage unit 13 is a nonvolatile memory that stores a program (such as a control program), control data, and control parameters. In addition, the high-speed volatile storage unit 14 can be said to be a volatile memory for storing the program (control program and the like), the control data, and the control parameters during operation. In addition, it can be said that the power storage device is configured to temporarily supply power to the control device 10 (control operation unit 12) when the power supply voltage drops. The power storage device temporarily supplies power to the control device 10 (the control operation unit 12) by discharging when the voltage of the power supply decreases.

  The control device 10 (control operation unit 12) executes the following processing function units (initialization unit, control execution unit, It can be said that the processing of the control parameter updating unit and the power cutoff processing unit) is realized. In addition, the control device 10 executes a predetermined program (control program or the like) using control parameters, which are setting data for control, and control data obtained as needed during operation, so that the control target device is controlled. It can also be said that the device performs control.

An initialization unit for copying all or a part of the program (control program or the like), control data, and control parameters stored in the nonvolatile memory to the volatile memory at the time of startup;
Copying process of the control parameter by the initialization unit, yet good to all control parameters stored in the nonvolatile memory to be copied, but may be copied only parameters that are required in the volatile memory. The necessary parameters are arbitrarily determined and set in advance by a developer or the like. For example, a method is conceivable in which only control parameters related to processing tasks in which calculations are frequently performed are copied to a volatile memory to increase the speed.

A control execution unit that, during operation, executes control arithmetic processing using the program, control data, and control parameters stored in the volatile memory, and updates the control data stored in the volatile memory as needed;
When a new control parameter is given from an external device (for example, the monitoring operation device 2) at any time during operation, the control parameter stored in the volatile memory is updated with the new control parameter, and the new control parameter is updated. A control parameter updating unit that also updates the control parameters stored in the nonvolatile memory;
When the power supply voltage drop is detected by the power supply voltage drop detection unit 15, the volatilization is performed while the control device 10 (control calculation unit 12) is in an operable state due to temporary power supply by the power storage device. A power-off processing unit for saving control data stored in the nonvolatile memory to the nonvolatile memory;
Then, for example, the capacity of the power storage device is a capacity necessary to make the operable state until the saving of the control data to the nonvolatile memory is completed.

  Also, for example, the nonvolatile memory is provided with two storage areas for storing control parameters, and the control parameter updating unit stores the new control parameter in the nonvolatile memory every time the new control parameter is stored in the nonvolatile memory. The two storage areas are switched and used. A specific example of this usage method is the processing of FIGS. 4A and 4B, but is not limited to this example. For example, as described above, three or more storage areas may be switched and used. In any case, a plurality of storage areas are switched and used.

  Also, the control parameter updating unit, for example, when the new control parameter is given, transfers the new control parameter to the volatile memory and stores the same, and then stores the new control parameter stored in the volatile memory. The control parameters stored in the volatile memory and the non-volatile memory are updated by transferring and storing such control parameters to the non-volatile memory.

  Alternatively, for example, when the new control parameter is given, the control parameter updating unit transfers the new control parameter to the volatile memory and also transfers the new control parameter to the non-volatile memory. By storing the new control parameter in the volatile memory and the nonvolatile memory, the control parameter stored in the volatile memory and the nonvolatile memory is updated.

  Further, for example, the control execution unit controls the control target device by executing the control arithmetic processing. Further, for example, the control data includes data indicating the current state of the controlled device.

  In addition, for example, the nonvolatile memory has a first program storage area for storing the program, a first control data storage area for storing control data, and a first control parameter storage area for storing control parameters. .

  Further, for example, the volatile memory includes a second program storage area for storing the program during operation, a second control data storage area for storing control data during operation, and a control area during operation. It has a second control parameter storage area for storing parameters.

  Further, the present invention is not limited to the control device 10 itself, and may be configured as a control system including the control device 10. That is, the control device 10 includes the control device 10, the monitoring operation device 2, and the input / output device 3. The control device 10 controls the control parameters input at any time from the monitoring operation device 2 and the control data obtained at any time during operation. By executing a predetermined program using the above, a control system for controlling the control target device can be configured.

  According to this method, in the control device of the monitoring and control system, it is possible to reduce the memory backup capacity when the power is turned off, and it is possible to reduce the cost of the power storage device and the like for the memory backup.

  Further, even when the power supply voltage is reduced during the writing operation of the new monitoring operation data (due to power supply cutoff or the like), it is possible to prevent a problem from occurring. For example, the consistency between a plurality of data constituting the monitoring operation data can be improved. Can be kept.

2 monitoring operation device 3 input / output device 5 external power supply 10 control device 11 external interface (I / F) unit 12 control operation unit 13 low-speed nonvolatile storage unit 13a program storage area 13b control data storage area 13c monitoring operation data storage area 14 high speed Volatile storage unit 14
14a Program storage area 14b Control data storage area 14c Monitoring operation data storage area 15 Power supply voltage drop detector 30 Controller 31 Capacitor 32 I / O memory 40 HCI device 50 I / O module 51 Control target device 13c-1 Monitoring operation data storage area 13c-2 Monitoring operation data storage area

Claims (8)

A control device that executes a predetermined program using given control parameters and control data obtained as needed from the control target device, and controls the control target device,
A nonvolatile storage unit that stores the program, the control data, and the control parameter;
Power supply voltage drop detection means for detecting a drop in the voltage of the power supply that operates the control device,
Power storage means for temporarily supplying power to the control device by discharging when the voltage of the power supply decreases,
Control means,
The control means includes:
At startup, the program stored in the non-volatile storage means, the control data, and all or a portion of the control parameters, initialization means to copy to a volatile storage means,
During operation, the program, the control data, and the control parameters stored in the volatile storage unit are used to execute arithmetic processing for controlling the controlled device using the control parameters, and are obtained from the controlled device as needed. the control data, a control execution means for updating the control data stored in the volatile memory means,
When a new control parameter is given at any time during operation, the control parameter stored in the volatile storage unit is updated by the new control parameter, and the control parameter stored in the nonvolatile storage unit is updated. Control parameter updating means for also updating
When the power supply voltage drop is detected by the power supply voltage drop detection unit, the volatile storage unit does not save the program and the control parameters stored in the volatile storage unit to the nonvolatile storage unit. and power-off processing means for the control data stored Ru is retracted before Symbol nonvolatile storage means,
A control device comprising: The control parameter updating means,
When the new control parameter is given, the new control parameter is transferred to and stored in the volatile storage unit, and then the new control parameter stored in the volatile storage unit is stored in the nonvolatile storage unit. Transfer to and memorize,
Alternatively, when the new control parameter is given, the also transferred to the non-volatile memory means, said volatile storage means and said nonvolatile memory means and transfers the new control parameter in the volatile memory means 2. The control device according to claim 1, wherein the new control parameter is stored at the same time. The nonvolatile storage means is provided with a plurality of control parameter storage areas for storing the control parameters ,
The control parameter updating means switches and stores the new control parameter in any of the plurality of control parameter storage areas each time the new control parameter is provided ,
3. The method according to claim 1 , wherein the initialization unit copies the latest control parameter among the control parameters stored in the plurality of control parameter storage areas to the volatile storage unit at the time of startup. The control device as described. The nonvolatile storage means is provided with two control parameter storage areas,
The control parameter updating means alternately stores the new control parameter in the two control parameter storage areas each time the new control parameter is provided, and completes the storage of the new control parameter. Invert the predetermined flag in case
The initialization means refers to the flag at the time of startup and copies the latest control parameter of the control parameters stored in the two control parameter storage areas to the volatile storage means. The control device according to claim 3, wherein The nonvolatile storage means is provided with three or more control parameter storage areas,
Each time the new control parameter is provided, the control parameter updating means switches the new control parameter to one of the three or more control parameter storage areas to store the new control parameter, and stores the new control parameter. Is completed, the information indicating which of the three or more control parameter storage areas the new control parameter is stored in is stored in an arbitrary storage area,
The initialization means refers to the information at the time of startup, and copies the latest control parameter of the control parameters stored in the three or more control parameter storage areas to the volatile storage means, The control device according to claim 3, wherein:   2. The control device according to claim 1, wherein the control data includes data indicating a current state of the control target device. The nonvolatile storage unit has a first program storage area for storing the program, a first control data storage area for storing the control data, and a first control parameter storage area for storing the control parameters. And
The volatile storage means includes: a second program storage area for storing the program during operation; a second control data storage area for storing the control data during operation; The control device according to claim 1, further comprising a second control parameter storage area for storing parameters. A control device that controls a control target device by executing a predetermined program using given control parameters and control data obtained as needed from the control target device , and a control system including a monitoring operation device,
The control device includes:
A nonvolatile storage unit that stores the program, the control data, and the control parameter;
Power supply voltage drop detection means for detecting a drop in the voltage of the power supply that operates the control device,
Power storage means for temporarily supplying power to the control device by discharging when the voltage of the power supply decreases,
Control means,
The control means includes:
At startup, the program stored in the non-volatile storage means, the control data, and all or a portion of the control parameters, initialization means to copy to a volatile storage means,
During operation, the program, the control data, and the control parameters stored in the volatile storage unit are used to execute arithmetic processing for controlling the controlled device using the control parameters, and are obtained from the controlled device as needed. the control data, a control execution means for updating the control data stored in the volatile memory means,
When a new control parameter is given from the monitoring operation device at any time during operation, the control parameter stored in the volatile storage unit is updated by the new control parameter, and the nonvolatile storage unit is updated. Control parameter updating means for also updating the stored control parameters,
When the power supply voltage drop is detected by the power supply voltage drop detection unit, the volatile storage unit does not save the program and the control parameters stored in the volatile storage unit to the nonvolatile storage unit. and power-off processing means for the control data stored Ru is retracted before Symbol nonvolatile storage means,
A control system comprising: