JP4280964B2 - Control data protection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control data protection apparatus in a process control controller that uses a programmable logic controller (hereinafter referred to as PLC) as an execution engine.
[0002]
[Prior art]
In a controller that uses a so-called PLC, whose functions are defined in terms of software, described in a programming language that conforms to the IEC61131-3 standard as an execution engine, important control data (such as controllability adjustment results for the control target) It is common to have special hardware (such as static RAM) so that it is retained when the controller is powered off.
[0003]
[Problems to be solved by the invention]
However, since the conventional controller holds these data using only the data holding capability of the hardware, there are the following problems.
(1) The retained data is lost when a hardware failure occurs.
When it is necessary to replace a device due to a hardware failure or the like, there is no means for transferring data held in the failed hardware to new hardware to be replaced.
[0004]
(2) The retained data is lost when the application is changed.
If the application is changed and the memory location of the control data is changed, the stored control data cannot be reused and must be initialized.
[0005]
(3) An external tool is required.
By using an external tool that can communicate with the PLC and storing the mapping of the control data to be stored in another node (PC, etc.), the above case can be handled. However, this external tool and the communication function between the external tool and the PLC are indispensable, and the return procedure is complicated and takes time.
[0006]
An object of the present invention is to provide a function of holding control data held in a holding area (such as static RAM) on the controller hardware as logical information on the external storage of the controller and should be held in any case The purpose is to realize a function of restoring control data.
[0007]
[Means for Solving the Problems]
In order to achieve such an object, the present invention is characterized in that the PLC means for executing the control application program and the control data referred to by the control application program are stored together with physical attributes . In the control data protection device applied to the controller having the control data holding means, the external storage means having a backup file and the control data in the control data holding means are the logic having no physical attribute. Control data protection means for converting the information into the backup file and converting the logical information of the backup file to the control data holding means as a data value to which a physical attribute specified by the control application program is added And in the point provided.
[0009]
According to a second aspect of the present invention, the control data holding means is composed of a static RAM.
[0010]
According to a third aspect of the present invention, the external storage means is composed of a flash memory.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment in which the present invention is applied to a controller that uses a so-called PLC, whose function is defined in terms of software, described in a programming language or the like conforming to the IEC61131-3 standard as an execution engine.
[0013]
Inside the controller 1, the control application program 2 is executed by the PLC means 20.
Among the control data (variables) included in the control application program, those that need to be retained even after the controller power is turned off are stored in the storage area 3 in the controller 1 as control data 4. It is secured.
When the control application program 2 is executed, a reference / setting process (dotted arrow 5) is appropriately performed on the control data 4 on the holding area 3.
[0014]
Reference numeral 6 denotes external storage means provided outside the controller 1 and is constituted by, for example, a flash memory. Reference numeral 7 denotes a control data backup file formed in the external storage means.
[0015]
In the controller 1, reference numeral 8 denotes control data protection means. The control data 4 stored as a simple array of data values is assigned to the designated address in the holding area 3 with the data name (variable name), data type name, etc. The function of converting to the logical information accompanying it and saving it in the backup file 7 on the external storage means 6 via the save / restore means 9 and the contents of the backup file 7 in the control data 4 on the holding area 3 as required Has a function to restore.
[0016]
As described above, the feature of the present invention is that the control data on the holding area 3 is stored in the backup file 7 as pure logical information without physical attributes such as address information by the function of the control data protection means 8. There is in point.
[0017]
Therefore, when the data restoration is executed after the control application program 2 is changed and the physical attribute of the control data is changed, the backup file 6 is stored in the controller 1 as pure logical information without any physical attribute. Since they are arranged, the definition of a new physical attribute can be executed only by the function inside the controller 1, so that the control data 4 can be correctly restored.
[0018]
The outline of the operation by the controller to which the present invention is applied will be described with reference to FIG. In the controller 1, PLC means 20 for executing a control application program described in a program language compliant with the IEC61131-3 standard operates as an execution engine for the control function.
[0019]
In the controller 1, a static RAM 3 is mounted as a control data holding area when the power is turned off, and a detachable flash memory 6 is provided as an external storage.
When the control is executed by the function of the PLC means 20, the control data 4 on the static RAM 3 is sequentially referred to and set.
[0020]
The operator monitoring this controller issues a control data save request 11 on the static RAM 3 from the Web browser 10 to the controller 1 as appropriate.
[0021]
The PLC means 20 that has received the save request takes the value of the control data 4 on the static RAM together with its logical information (logical name, data type, etc. of the control data) while taking exclusion from the access by the control execution. Store in the backup file 7 above.
[0022]
When starting control such as when the controller 1 is energized or reset, the PLC means 20 automatically determines whether or not the contents of the backup file 7 on the flash memory 6 should be restored to the static RAM 3. Restore if necessary.
[0023]
At this time, using the logical name of the control data stored in the backup file 7 as a key, the position where the control data is arranged on the static RAM 3 is searched, and the data value is restored to that position. Therefore, even if the memory arrangement on the static RAM 3 is different between when the control data 4 is stored in the backup file 7 and when it is restored, the data can be restored without any problem.
[0024]
Further, when the hardware of the controller 1 fails, the flash memory 6 is taken out from the failed hardware and is attached to the new hardware so that the state before the failure is automatically restored on the new hardware. Is possible. At this time, no other external tools are required.
[0025]
The backup file 6 can be saved as a text file in a general format such as CSV (Comma Separated Value) or XML (eXtensible Markup Language). Therefore, it is easy to display, process, and print the contents using commercially available tools.
[0026]
【The invention's effect】
As is clear from the above description, according to the present invention, the control data held in the holding area (static RAM or the like) on the controller hardware realized by the PLC means 20 is stored on the external storage of the controller. By holding as logical information, a controller having a function of restoring control data to be held in any case can be realized.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment in which the present invention is applied to a controller using a PLC as an execution engine.
FIG. 2 is a block diagram illustrating an outline of operation by a controller to which the present invention is applied.
[Explanation of symbols]
1 controller 2 control application program 3 holding area 4 control data 5 reference / setting process 6 external storage means 7 backup file 8 control data protection means 9 save / restore means 20 PLC means

Claims (3)

PLC means for executing a control application program;
Control data holding means for storing control data referred to by the control application program together with physical attributes ;
In a control data protection device applied to a controller comprising:
An external storage means having a backup file;
The control data in the control data holding means is converted into logical information having no physical attribute and written to the backup file, and the logical information of the backup file is physically specified by the control application program. Control data protection means for restoring to the control data holding means as a data value with an attribute added thereto ;
A control data protection device comprising: The control data protection device according to claim 1, wherein the control data holding unit includes a static RAM. The control data protection device according to claim 1, wherein the external storage unit is configured by a flash memory.

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