JP5459621B2 - Device control device, function control method for device control device, and function restriction system - Google Patents

Description

  The present invention relates to a device control device, a function restriction method for a device control device, and a function restriction system, and in particular, implements safe function restriction.

  In a process control system such as a chemical plant, a device control device (hereinafter referred to as “equipment control”) that performs control (hereinafter referred to as “equipment control”) for field devices such as a pressure transmitter, a temperature transmitter, a flow meter, and a valve positioner. "Host") is used.

  The host includes a DCS (Distributed Control System), a PC (Personal Computer), a portable terminal, and the like. For example, the host is connected to a field device via a field bus and performs digital communication.

  In executing device control, there are a plurality of control functions such as a setting function and an adjustment function, and the host controls field devices by executing various control functions.

  In the fieldbus standard, there is a function restriction level called Class that defines which of a plurality of control functions is restricted. This function restriction level will be described with reference to FIG.

  FIG. 3 is a configuration diagram of the process control system, FIG. 3A is a configuration diagram in which a factory that performs process control is operating, and FIG. 3B is a configuration diagram before the factory is in operation.

  3A, the process control system 10a includes hosts 20a and 21a, field devices 30a, 31a, and 32a, and a field bus FB.

  The field devices 30a, 31a, and 32a are arranged in piping, tanks, valves (not shown) and the like in the process control system 10a in order to measure pressure and flow rate and adjust flow rate, and via the field bus FB. Connected to the hosts 20a and 21a.

  Here, the host 20a is set to the function restriction level Class 62, and the host 21a is set to the function restriction level Class 61.

  The function restriction level Class 62 cannot be executed because the setting function and the adjustment function are restricted, and can only read the adjustment value of the adjustment function. As a result, the host 20a, which is a portable terminal, cannot set or adjust the field device.

  On the other hand, Class 61 of the function restriction level has no function restriction and can execute all control functions. As a result, the host 21a, which is a DCS or PC, can set and adjust the field device.

  When comparing the function restriction levels Class 62 and Class 61, it can be said that Class 62 has a higher function restriction level than Class 61. Thereby, inadvertent setting changes and adjustments to the field device from the host 20a which is a portable terminal can be prevented.

  3B has the same configuration as FIG. 3A, and the process control system 10b is configured by the hosts 20b and 21b, the field devices 30b, 31b and 32b, and the field bus FB.

  Here, the difference from FIG. 3A is the function restriction level set in the hosts 20b and 21b. Specifically, the host 20b is set to the function restriction level Class 64, and the host 21b is set to the function restriction level Class 63.

  Basically, Class 64 has the same function restriction as Class 62, and Class 63 has the same function restriction as Class 61. However, Class 64 and Class 63 cannot be used in an operating factory. Class 62 and Class 61 can be used in an operating factory. Note that different function restriction levels may be set for the same host.

  Setting of the function restriction level in the host is automatically performed by checking the license information or the user account when the control function application software is installed in the host. Further, after installation, the user can change the function restriction level by using the license information or the user account.

  Patent Documents 1 and 2 describe electronic devices that perform function restriction control by license authentication, user authentication, or the occurrence of an event.

JP 2009-38584 A JP 2003-44798 A

  The function restriction level set for the host is based on the state of the field device related to process control, such as the type of field device to be controlled, the operating state, the type of alarm, the formation state of the control loop, or the location of the control device. Preferably it is determined.

  However, since these states are not reflected in the license information or the user account described above, an inappropriate function restriction level may be set for the host. In such a case, for example, the host can change the setting to a field device that should not be changed, which may cause a great adverse effect or damage to the factory. The same applies when the user changes the function restriction level by mistake.

  In addition, when an existing host with a function restriction level is moved to another location, if the user neglects to change to the appropriate function restriction level, the factory may be similarly adversely affected or damaged. .

  An object of the present invention is to provide a device control device, a device control device function restriction method, and a function restriction system that can set an appropriate and safe function restriction level based on the state of a field device related to process control.

In order to achieve such an object, the invention of claim 1
In a device control apparatus capable of performing device control on a field device arranged in a system that performs process control and capable of restricting any of a plurality of control functions for executing this device control,
An acquisition means for acquiring a state signal related to the process control among the states of the field device;
Setting means for setting the function restriction level based on the status signal acquired by the acquisition means;
Equipped with a,
The acquisition means acquires the status signal indicating whether or not the field device is operating as a fieldbus link master,
When the field device is operating as the link master, the setting means sets the function restriction level to a higher level than the field device not operating as the link master. Features.
The invention of claim 2
In a device control apparatus capable of performing device control on a field device arranged in a system that performs process control and capable of restricting any of a plurality of control functions for executing this device control,
An acquisition means for acquiring a state signal related to the process control among the states of the field device;
Setting means for setting the function restriction level based on the status signal acquired by the acquisition means;
With
It said acquisition means, you and obtains the state signal corresponding to the formation state of the control loop of the process control by the field device.
The invention of claim 3 is the invention of claim 2,
When the acquisition unit acquires the state signal indicating that the control loop has been formed, the setting unit sets the function restriction level to a level higher than a state in which the control loop is not formed. It is characterized by that.
The invention of claim 4
In a device control apparatus capable of performing device control on a field device arranged in a system that performs process control and capable of restricting any of a plurality of control functions for executing this device control,
An acquisition means for acquiring a state signal related to the process control among the states of the field device;
Setting means for setting the function restriction level based on the status signal acquired by the acquisition means;
With
It said acquisition means, you and obtains the state signal corresponding to the arrangement position of the field device.
The invention of claim 5 is the invention of claim 4 ,
The position is obtained by GPS or wireless LAN,
When the acquisition means acquires the status signal indicating that the position is a dangerous area in the process control, the setting means sets the function restriction level from the field device arranged outside the dangerous area. Is also set to a high level .
The invention of claim 6 is the invention according to any one of claims 1 to 5 ,
The acquisition means acquires the status signal corresponding to the type of the field device.
The invention of claim 7 is the invention of claim 6 ,
When the field device is a type of device that is active with respect to the process control amount, and the status signal corresponding to the type is acquired by the acquisition unit, the setting unit sets the function restriction level to a passive type. It is characterized by being set to a level higher than that of the device.
Invention of Claim 8 is the apparatus control apparatus of Claim 7 ,
The active type device is a valve positioner or an electropneumatic converter.
The invention of claim 9 is the invention of claim 6 ,
When the field device is a type of device used for a specific application of the process control and a keyword representing this type is acquired by the acquisition unit as the status signal, the setting unit sets the function restriction level to the It is characterized in that it is set at a higher level than the type of equipment used for other than the specific purpose.
The invention of claim 10 is the invention of claim 9 , wherein
The type of device used for the specific application is a device used for drainage control of a factory that performs the process control.
The invention of claim 11 is the invention according to any one of claims 1 to 10 ,
The acquisition means acquires the status signal corresponding to the type of alarm generated by the field device.
The invention of claim 12 is the invention of claim 11 ,
When the acquisition unit acquires the status signal indicating that the device control is interrupted, the setting unit sets the function restriction level to a level higher than an alarm that does not stop the device control. It is characterized by that.
The invention of claim 13 is the invention according to any one of claims 1 to 12 , wherein the setting means can set the level of the function restriction to a custom level changed by a user. And
The invention of claim 14
In the function restriction method of the device control apparatus capable of performing device control on a field device arranged in a system that performs process control and capable of restricting any of a plurality of control functions for executing the device control.
An acquisition step of acquiring a state signal related to the process control among the states of the field device;
A setting step for setting the function restriction level based on the status signal acquired by the acquisition step;
With
In the acquisition step, the state signal indicating whether the field device is operating as a fieldbus link master is acquired;
In the setting step, when the field device is operating as the link master in the state signal, the function restriction level is set to a level higher than that of the field device not operating as the link master. It shall be the feature.
The invention of claim 15
In the function restriction method of the device control apparatus capable of performing device control on a field device arranged in a system that performs process control and capable of restricting any of a plurality of control functions for executing the device control.
An acquisition step of acquiring a state signal related to the process control among the states of the field device;
A setting step for setting the function restriction level based on the status signal acquired by the acquisition step;
With
In the acquisition step, and obtains the state signal corresponding to the formation state of the control loop of the process control by the field device.
The invention of claim 16
In the function restriction method of the device control apparatus capable of performing device control on a field device arranged in a system that performs process control and capable of restricting any of a plurality of control functions for executing the device control.
An acquisition step of acquiring a state signal related to the process control among the states of the field device;
A setting step for setting the function restriction level based on the status signal acquired by the acquisition step;
With
In the step of obtaining, you and obtains the state signal corresponding to the arrangement position of the field device.
The invention of claim 17
Field devices arranged in a system for process control;
In the function restriction system having a device control device capable of performing device control on the field device and capable of restricting any of a plurality of control functions for executing the device control,
The device control device
An acquisition means for acquiring a state signal related to the process control among the states of the field device;
Setting means for setting the function restriction level based on the status signal acquired by the acquisition means;
With
The acquisition means acquires the status signal indicating whether or not the field device is operating as a fieldbus link master,
When the field device is operating as the link master, the setting means sets the function restriction level to a higher level than the field device not operating as the link master. Features.
The invention of claim 18 provides
Field devices arranged in a system for process control;
In the function restriction system having a device control device capable of performing device control on the field device and capable of restricting any of a plurality of control functions for executing the device control,
The device control device
An acquisition means for acquiring a state signal related to the process control among the states of the field device;
Setting means for setting the function restriction level based on the status signal acquired by the acquisition means;
With
The acquisition means acquires the status signal corresponding to the position where the field device is arranged, or the status signal corresponding to the position where the field device is arranged .

  According to the present invention, a state signal related to process control is acquired from the states of field devices, and a function restriction level is set based on the state signal. By performing device control based on the set function restriction level, the device control apparatus set to an appropriate and safe function restriction level can execute safe process control.

  Further, even when an existing device control apparatus in which the function restriction level is set is moved to another place, the device control apparatus can be changed to an appropriate and safe function restriction level.

It is an example of the block diagram of the function restriction | limiting system which consists of the apparatus control apparatus and field device to which this invention is applied. It is an example of the flowchart figure of the function restriction level setting process of the apparatus control apparatus to which this invention is applied. (A) is the system block diagram in which the factory which performs process control is operating, (b) is an example of the system block diagram before a factory operates.

  FIG. 1 is a configuration diagram of a function restriction system 100 including field devices 110 and 120, a host (device control apparatus) 200, and the like to which the present embodiment is applied. The configuration diagram of the process control system using these field devices and the host is the same as FIG.

  In FIG. 1, field devices 110 and 120 are connected to a host 200 via a field bus FB. Further, a GPS (global positioning sensor) 140 and a wireless LAN (local area network) sensor 150 that detect the positions of the field devices 110 and 120 are connected to the host 200.

  The host 200 includes an acquisition unit 210, a setting unit 220, and a user setting unit 250. The setting means 220 includes search modules 221 to 229, a fieldbus network connection module 230, and a class determination module (including a class determination item selection module) 240.

  Fieldbus FB, GPS 140 and wireless LAN sensor 150 are connected to acquisition means 210. The fieldbus network connection module 230 is connected to the acquisition unit 210 and the search modules 221 to 227. The GPS module 228 and the wireless LAN strength measurement module 229 are connected to the acquisition unit 210.

  The Class determination module 240 is connected to the search modules 221 to 229 and the user setting unit 250, and receives the user account 310 and the license information 300 as external input signals.

  Next, the operation of the host 200 will be further described with reference to FIG. FIG. 2 is a flowchart of the function restriction level (Class) setting process of the host 200.

  In step S100 in FIG. 2, after the control function application software is installed in the host 200, in step S110, the class determination module 240 receives the license information 300 or the user account 310, and once sets the class based thereon.

  Subsequently, in step S120, the host 200 starts the process control operation based on the class once set.

  Subsequently, in step S130, the acquisition unit 210 acquires a state signal of the field device related to the process control from the field devices 110 and 120, or from the GPS 140 and the wireless LAN sensor 150 via the field bus FB (acquisition step). ).

  Subsequently, in steps S140, S150, and S160 to S164, the setting unit 220 sets any one of the classes 61 to 64 based on the acquired state signal, or a custom level in which the class 61 to 64 is changed by the user. Can also be set (setting step). This setting means will be described in detail later.

  Note that the setting unit 220 can set the level more finely and appropriately by acquiring and setting the custom level from the user setting unit 250.

  Subsequently, in step S170, the host 200 controls the field devices 110 and 120 in accordance with the set function restriction level, and continues the process control operation.

  In step S180, the host 200 periodically repeats the acquisition step and the setting step after step S130 while continuing the process control operation.

  Next, the setting means described above will be described in detail. Some state signals are based on the type of field device, the operating state, the type of alarm, the formation state of the control loop, or the position where the control loop is formed. The setting means based on each state signal will be described with reference to FIG. .

<Types of field devices>
(1) Specified devices Among the types of field devices, specified devices such as valve positioners or electropneumatic converters control the flow rate through the valves. There is a fear.

  When the field device 110 connected to the field bus FB is a specific device such as a valve positioner or an electro-pneumatic converter, the specific device search module 221 uses the acquisition unit 210 and the field bus network connection module 230 from the field device 110. A signal representing a specific device is received. Note that the signal representing the specific device may be given in advance by the user.

  Then, the specific device search module 221 and the class determination module 240 set Class 62, Class 64, or a custom level with a high function restriction level.

  On the other hand, when the specific device does not exist on the fieldbus FB, Class 61, Class 63 or a custom level having a low function restriction level is set.

  As described above, when a specific device exists on the fieldbus FB, setting and adjustment cannot be performed by setting Class 62, Class 64 or a custom level having a high function restriction level in the host 200. It is possible to prevent great adverse effects and damages to the factory.

(2) Input / Output equipment The above-described valve positioner or electropneumatic converter controls the flow rate flowing through the valve, that is, operates and changes a process amount such as the flow rate. Also called.

  On the other hand, pressure transmitters, temperature transmitters, flow meters, and the like are used to measure pressure, temperature, flow rate, and the like, and therefore are called passive devices and input devices.

  Similarly to the above-described specific device, when the field device 110 is an output device (active device) such as a valve positioner or an electropneumatic converter, the input / output device search module 222 passes the field device via the acquisition unit 210. A signal representing the output device is received from 110. Note that the signal representing the output device may be given in advance by the user.

  Then, the Input / Output device search module 222 and the Class determination module 240 set Class 62, Class 64, or a custom level having a high function restriction level.

  On the other hand, when the Output device does not exist on the fieldbus FB, that is, only the Input device (passive device), Class 61, Class 63 or a custom level having a low function restriction level is set.

  As described above, when the output device exists on the fieldbus FB, setting and adjustment cannot be executed by setting the class 62, class 64, or custom level having a high function restriction level in the host 200. It is possible to prevent great adverse effects and damages to the factory.

(3) Equipment used for specific applications Field equipment used for specific applications such as drainage control in factories that perform process control may cause great adverse effects and damage to the factory due to misadjustment.

  When the field device 110 connected to the field bus FB is used for factory drainage control or the like, the special purpose search module 223 receives a signal representing a special purpose device from the field device 110 via the obtaining unit 210, for example, a specific device. Receive keywords. Note that a signal representing a device for a specific application may be given in advance by a user.

  Then, the special purpose search module 223 and the class determination module 240 set Class 62, Class 64, or a custom level having a high function restriction level when the received keyword and the keyword stored in advance are matched.

  On the other hand, when a field device used for a specific application does not exist on the fieldbus FB, Class 61, Class 63, or a custom level having a low function restriction level is set.

  As described above, when a field device used for a specific purpose exists on the fieldbus FB, setting and adjustment cannot be executed by setting a high function restriction level Class 62, Class 64, or a custom level in the host 200. It is possible to prevent great adverse effects and damages to the factory due to setting and misadjustment.

<Operation status of field devices>
(1) Block mode of field device
The Block Mode of the field device is set to “Auto” when the field device is in operation, and is set to “O / S” when the field device is not in operation. Note that Block Mode is defined by the fieldbus standard.

  The Actual Mode search module 224 receives Block Mode data from the field device 110 via the acquisition unit 210.

  Then, when the received data is “Auto”, the Actual Mode search module 224 and the Class determination module 240 set Class 61, Class 62, or a custom level.

  On the other hand, if the received data is “O / S”, Class 63, Class 64 or a custom level is set.

  Thus, an appropriate and safe function restriction level can be set according to the operating state of the field device.

(2) Link master When a field device that operates as a link master defined by the fieldbus standard exists, it is in operation, and when it does not exist, it is inactive.

  The link master search module 225 receives a signal indicating whether the link master search module 225 is operating as a link master from the field device 110 via the acquisition unit 210.

  Then, when the received signal indicates that the received signal is operating as a link master, the actual mode search module 224 and the class determination module 240 set Class 62, Class 64, or a custom level having a high function restriction level.

  On the other hand, when the received signal indicates that it is not operating as a link master, Class 61, Class 63 or a custom level having a low function restriction level is set.

  Thus, an appropriate and safe function restriction level can be set according to the operating state of the field device.

<Field device alarm types>
Field devices output multiple types of alarms. This type of alarm includes not only the adjustment of the field device but also the adjustment of the field device that must be performed quickly without stopping the adjustment.

  The alarm search module 226 receives a signal indicating the type of alarm generated from the field device 110 via the acquisition unit 210.

  Then, the alarm search module 226 and the class determination module 240 set Class 62, Class 64, or a custom level having a high function restriction level when the received signal indicates an alarm that stops adjustment.

  On the other hand, when the received signal indicates an alarm that does not stop the adjustment, Class 61, Class 63, or a custom level having a low function restriction level is set.

  Thus, an appropriate and safe function restriction level can be set according to the type of alarm generated by the field device.

<Field device control loop status>
It can be determined from the topology of the field device connected to the field bus FB whether or not a process control control loop is formed by the field device.

  The topology search module 227 receives a signal representing the topology from the field device 110 via the acquisition unit 210.

  When the topology search module 227 and the class determination module 240 determine that a control loop is formed from the received signal, the topology search module 227 and the class determination module 240 set Class 62, Class 64, or a custom level having a high function restriction level.

  On the other hand, when it is determined that the control loop is not formed from the received signal, Class 61, Class 63 or a custom level having a low function restriction level is set.

  Thus, an appropriate and safe function restriction level can be set according to the formation state of the process control control loop.

<Field device layout>
If the field device is located in a hazardous area such as an explosion-proof area in the factory where process control is performed, there is a risk that the factory may have a great adverse effect or damage due to incorrect settings or adjustments.

  When the position of the field device 110 is detected by the GPS 140, the acquisition unit 210 acquires the position signal of the field device 110 from the GPS 140. The GPS module 228 receives the position signal of the field device 110 from the acquisition unit 210.

  Then, the GPS module 228 and the Class determination module 240 set Class 62, Class 64, or a custom level having a high function restriction level when the position of the field device 110 is in the dangerous area.

  On the other hand, if it is not in the danger zone, Class 61, Class 63 or a custom level having a low function restriction level is set.

  When the field device 110 is placed indoors where the GPS 140 signal does not reach, the position of the field device 110 can be detected by measuring the received radio wave intensity signal of the wireless LAN sensor 150 communicating with the field device 110.

  The acquisition unit 210 can acquire the received radio wave intensity signal from the wireless LAN sensor 150. The wireless LAN intensity measurement module 229 and the class determination module 240 obtain a position signal from the received radio wave intensity signal, and can set a function restriction level using the position signal, as in the case of the GPS 140.

  As described above, when the position of the field device 110 is in the danger zone, setting and adjustment cannot be performed by setting Class 62, Class 64 or a custom level having a high function restriction level in the host 200. Can prevent a great adverse effect and damage to the factory.

  In addition, two or more state signals indicating the type of field device, the operating state, the type of alarm, the formation state of the control loop, and the arranged position are used, and the function restriction level is set based on the two or more state signals. It may be set.

  The acquisition unit 210 and the setting unit 220 may be executed by a processor according to a predetermined program or realized by a logic circuit.

  In addition, this invention is not limited to the above-mentioned Example, In the range which does not deviate from the essence, many change and deformation | transformation are included. Moreover, combinations other than the combination of each means mentioned above can be included.

100 Function restriction system 110, 120 Field device 140 GPS
150 Wireless LAN sensor 200 Host (device control device)
210 Acquisition means 220 Setting means 230 Fieldbus network connection module 240 Class determination module 250 User setting means

Claims (18)

In a device control apparatus capable of performing device control on a field device arranged in a system that performs process control and capable of restricting any of a plurality of control functions for executing this device control,
An acquisition means for acquiring a state signal related to the process control among the states of the field device;
Setting means for setting the function restriction level based on the status signal acquired by the acquisition means;
Equipped with a,
The acquisition means acquires the status signal indicating whether or not the field device is operating as a fieldbus link master,
When the field device is operating as the link master, the setting means sets the function restriction level to a higher level than the field device not operating as the link master. Device control device characterized. In a device control apparatus capable of performing device control on a field device arranged in a system that performs process control and capable of restricting any of a plurality of control functions for executing this device control,
An acquisition means for acquiring a state signal related to the process control among the states of the field device;
Setting means for setting the function restriction level based on the status signal acquired by the acquisition means;
With
It said acquisition means, equipment controller you and obtains the state signal corresponding to the formation state of the control loop of the process control by the field device. When the acquisition unit acquires the state signal indicating that the control loop has been formed, the setting unit sets the function restriction level to a level higher than a state in which the control loop is not formed. The apparatus control apparatus according to claim 2. In a device control apparatus capable of performing device control on a field device arranged in a system that performs process control and capable of restricting any of a plurality of control functions for executing this device control,
An acquisition means for acquiring a state signal related to the process control among the states of the field device;
Setting means for setting the function restriction level based on the status signal acquired by the acquisition means;
With
It said acquisition means, equipment controller you and obtains the state signal corresponding to the arrangement position of the field device. The position is obtained by GPS or wireless LAN,
When the acquisition means acquires the status signal indicating that the position is a dangerous area in the process control, the setting means sets the function restriction level from the field device arranged outside the dangerous area. The apparatus control device according to claim 4 , wherein a higher level is set . It said acquisition means, the device control apparatus according to any one of claims 1-5, characterized in that for obtaining the status signal in accordance with the type of the field device. When the field device is a type of device that is active with respect to the process control amount, and the status signal corresponding to the type is acquired by the acquisition unit, the setting unit sets the function restriction level to a passive type. The apparatus control apparatus according to claim 6, wherein the apparatus control apparatus is set to a level higher than that of the apparatus. The device control apparatus according to claim 7, wherein the active type device is a valve positioner or an electropneumatic converter. When the field device is a type of device used for a specific application of the process control and a keyword representing this type is acquired by the acquisition unit as the status signal, the setting unit sets the function restriction level to the The device control apparatus according to claim 6, wherein the device control device is set to a level higher than that of a type of device used for a purpose other than the specific purpose. The device control apparatus according to claim 9 , wherein the type of device used for the specific application is a device used for drainage control of a factory that performs the process control. It said acquisition means, the device control apparatus according to any one of claims 1 to 10, characterized in that for obtaining the status signal in accordance with the type of alarm emitted from the field device. When the acquisition unit acquires the status signal indicating that the device control is interrupted, the setting unit sets the function restriction level to a level higher than an alarm that does not stop the device control. The apparatus control apparatus according to claim 11 . The device control apparatus according to any one of claims 1 to 12, wherein the setting unit can set the level of the function restriction to a custom level changed by a user. In the function restriction method of the device control apparatus capable of performing device control on a field device arranged in a system that performs process control and capable of restricting any of a plurality of control functions for executing the device control.
An acquisition step of acquiring a state signal related to the process control among the states of the field device;
A setting step for setting the function restriction level based on the status signal acquired by the acquisition step;
With
In the acquisition step, the state signal indicating whether the field device is operating as a fieldbus link master is acquired;
In the setting step, when the field device is operating as the link master in the state signal, the function restriction level is set to a level higher than that of the field device not operating as the link master. function limiting method for equipment control device shall be the features. In the function restriction method of the device control apparatus capable of performing device control on a field device arranged in a system that performs process control and capable of restricting any of a plurality of control functions for executing the device control.
An acquisition step of acquiring a state signal related to the process control among the states of the field device;
A setting step for setting the function restriction level based on the status signal acquired by the acquisition step;
With
Wherein in the obtaining step, function limiting method for equipment control device you and obtains the state signal corresponding to the formation state of the control loop of the process control by the field device. In the function restriction method of the device control apparatus capable of performing device control on a field device arranged in a system that performs process control and capable of restricting any of a plurality of control functions for executing the device control.
An acquisition step of acquiring a state signal related to the process control among the states of the field device;
A setting step for setting the function restriction level based on the status signal acquired by the acquisition step;
With
Wherein in the step of acquiring the function limiting method for equipment control device you and obtains the state signal corresponding to the arrangement position of the field device. Field devices arranged in a system for process control;
  In the function restriction system having a device control device capable of performing device control on the field device and capable of restricting any of a plurality of control functions for executing the device control,
  The device control device
  An acquisition means for acquiring a state signal related to the process control among the states of the field device;
  Setting means for setting the function restriction level based on the status signal acquired by the acquisition means;
With
  The acquisition means acquires the status signal indicating whether or not the field device is operating as a fieldbus link master,
  When the field device is operating as the link master, the setting means sets the function restriction level to a higher level than the field device not operating as the link master. Feature restriction system. Field devices arranged in a system for process control;
In the function restriction system having a device control device capable of performing device control on the field device and capable of restricting any of a plurality of control functions for executing the device control,
The device control device
An acquisition means for acquiring a state signal related to the process control among the states of the field device;
Setting means for setting the function restriction level based on the status signal acquired by the acquisition means;
With
The function limiting system according to claim 1, wherein the acquisition unit acquires the state signal corresponding to a position where the field device is disposed or the state signal corresponding to a position where the field device is disposed .

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