JP4849078B2 - Programmable logic controller and programmable logic controller logic update support tool - Google Patents

Description

  The present invention relates to a programmable logic controller (hereinafter sometimes simply referred to as “PLC”) and a logic update support tool for a programmable logic controller (hereinafter simply referred to as “support tool”).

  A PLC used for machine control such as FA (factory automation) has been developed as an alternative circuit of a relay circuit, and even if it has an MPU (microprocessor), its operation method is It is completely different from a normal computer. That is, the PLC inputs ON / OFF information of an input device such as a switch or a sensor, executes a logical operation in accordance with a sequence program (user program) written in a ladder language, etc. It is used to control these devices by outputting ON / OFF information signals to output devices such as valves and actuators.

  When creating / editing a user program, writing a user program into a predetermined memory of the PLC (hereinafter referred to as “download”), or reading a user program from the predetermined memory of the PLC (hereinafter referred to as “upload”) In this case, a dedicated logic update support tool (that is, a support tool) is used.

  Conventionally, as an example of such a PLC, a configuration in which a plurality of units created for each function are prepared and these units are electrically and mechanically connected has been developed. Examples of such units include a power supply unit that supplies power to other units, a CPU unit that executes a user program stored in a program memory based on an input signal input by IN refresh, and a CPU unit. There are I / O units for connecting buses and connecting input devices or output devices.

  Recently, a CPU (MPU) and a program memory are also installed in the I / O unit, and a desired user program is stored in the program memory, and the user program is also stored on the I / O unit side. A configuration that can perform predetermined control by performing the above-described calculation has been developed.

  Note that the flash memory cannot be accessed by a tool, and such a flash memory is loaded as the program memory of the I / O unit mounted on the PLC, and a part or all of the user program is stored in the flash memory as a library. A technique for preventing unauthorized access by a third party by storing the converted data so that it cannot be read by a tool such as a loader is disclosed (see Patent Document 1).

FIG. 6 is an explanatory diagram showing a flow of information between a support terminal device (support tool) and a PLC in a conventional PLC support system.
As shown in the figure, an object code of a function library that is conventionally used by being quoted in a PLC application program is stored in a nonvolatile memory (ROM) inside the PLC as fixed embedded information 901 in the case of a system library described later. A part of the programmable application program (PLC object 900) that is stored in advance or is generated by compiling and linking the user editing / creation information 800 with reference to the fixed embedded information 801 by a support tool. Are downloaded to the PLC (step P9).

  When the object code is stored in the PLC main body in advance, this object code often realizes a basic function, and is therefore called a “system library” or the like. On the other hand, when a user creates a library of subroutines as part of an application and downloads them to the PLC for use, this library is called a “user library” or the like.

  On the other hand, on the support tool side, application information (API) information of the system library used for programming and graphic information of parts required for program editing in a graphic language such as FBD (Function Block Diagram) And property information. In the prior art, necessary information is held in advance in the support tool as the fixed embedded information 801, or the user has created it according to a given specification.

  As for the system library (that is, a library provided in a form incorporated in the PLC main body in advance), the object code is stored in the PLC main body as fixed embedded information 901, and the object code is stored in the support tool. In many cases, the graphic information, property information, and the like that are necessary for using the program for programming are incorporated and provided as fixed embedded information 801 (system library information) in the support tool.

In recent years, the PLC application description language is not limited to the conventional ladder language. For example, in the case of a PLC application description language compliant with “IEC61131-3”, which has been popular recently, programming using a normal C language is possible. Structured programming can be done in the same way as By the way, in this program that can be structured, information required when a certain function is used as a system library includes:
(1) Object code (binary code that the PLC actually executes),
(2) Information such as application interface (API) information (that is, variable name, variable type, variable attribute),
(3) Graphic information of parts (that is, graphic information for drawing a program,
(4) Property information (that is, information on the creator of the library, creation time, etc.),
and so on.

However, among these, the information shown in (1) is information necessary for the operation of the PLC main body, but the information shown in (2) to (4) is originally unnecessary when executing the PLC application. However, since it is information that can be provided on the support tool side, conventionally, the information shown in (2) to (4) has been stored in the support tool.
JP 2004-5389 A

  However, in the conventional PLC and its update support tool described in the above background art, the update support tool side by step up to the inherent information that should be originally attached to the PLC such as the system library for each of the diversified PLCs. This increases the storage capacity burden of the update support tool and the burden of the update procedure, which is not preferable in terms of system design and system functionality / operability. There was a point.

In general, the system library is often a function group for operating functions depending on hardware of an embedded device such as a PLC. Therefore, when a microcontroller or ASIC used in a certain PLC product group is different, for example, the internal object code is modified according to the hardware without changing the user interface (API). It is often implemented later. Here, if we examine the difference between the system library and the user library,
(1) The system library is a function group equivalent to the PLC firmware that the execution object is pre-installed in the PLC main body side non-volatile memory, etc., whereas the user library is edited on the support tool side as a user application including object code ,keeping.
(2) The object of the system library is generally described in a program language for producing an internal function of the PLC, such as C language, and can generally operate a hardware-dependent function. However, the user library is a PLC application. It is described in a language (ladder, FBD, etc.), and the operation / processing object is a memory space accessible by the PLC.
(3) As for the system library, only the compiled object exists in the non-volatile memory on the PLC body side. However, the source of the user library exists in the support tool, and it is compiled, linked and downloaded to the PLC like the PLC application. And use it.

  For this reason, in the conventional technology, the support tool tracks the update of the system library on the support side in order to provide an editing function using the system library as a product pre-installed on the PLC main body side in advance. And had a need to do. An object of the present invention is to eliminate this point.

  Note that this problem is not a major problem as long as the system library is sold as a function group embedded in advance as a function group, as in a conventional general product. However, considering the case where a system library function group itself can be updated online after product purchase without updating the firmware version of the PLC body, in this case, it is stored in the PLC body. The firmware that is a basic part is not updated, but the system library that is a peripheral and ancillary function group is updated as necessary.

In such a case, it is conceivable that the contents of the function group of the system library respectively stored in a certain PLC and another PLC are different.
In this state, for example, if the version of the support tool is different, inconsistency between the system library on the PLC main body and information for the library of the support tool is likely to occur.

  For example, if a company A employee adds or updates a system library as a PLC customization, creates a program based on the system library, and installs a device, then the company B employee in charge of equipment maintenance However, when monitoring is performed with the same support tool software, it is possible that some of the monitoring and maintenance may not be possible due to a library mismatch even though the software is the same. .

  In order to avoid the occurrence of such a situation, together with the object code of the system library, the above-mentioned information used for programming, that is, the graphic information of the parts necessary for program editing in a graphic language, the system library A method may be considered in which application interface (API) information, FBD (Function Block Diagram) information, system library property information, etc. are all provided on the PLC main body side and uploaded from the PLC main body side to the support tool. .

  However, in the case of this method, a system library (and related information) that is originally incorporated in advance and also has a technical asset aspect that should be hidden as an internal function is handled in the same way as a general user library. The problem arises. For this reason, it is impossible to prevent device duplication by blind copy of the object code and leak of know-how of the function group of the system library.

  The present invention has been made in view of the above-described conventional problems, and includes means for preventing unauthorized access to an object code of a system library, and information necessary for programming or editing the system library with a support tool. Is intended to provide a programmable logic controller that can be uploaded to a support tool and used.

  Another object of the present invention is to provide a programmable logic controller that can eliminate the need to upgrade a support tool required when updating a system library.

  Another object of the present invention is to provide a programmable logic controller capable of easily and surely protecting a part or all of a program created by a user without preparing a dedicated program development environment. There is.

  Another object of the present invention is to provide the PLC with means for preventing unauthorized access to the object code of the system library, and to upload and use information necessary for programming and editing of the system library. An object of the present invention is to provide a logic update support tool for a programmable logic controller which can be used.

  Another object of the present invention is to provide a logic update support tool for a programmable logic controller that can eliminate the need for version upgrade required when updating a system library provided on the PLC main body side.

In order to solve the above problem, the programmable logic controller according to the present invention is a programmable logic controller which can be used as a control device for controlling the external device, the programmable logic controller, control the external device A user application program to be executed and a function dependent on the hardware of the programmable logic controller, and object code called from the user application program and actually executed by the programmable logic controller and editing of the user application program A system library configured with auxiliary information required in the case of, and means for storing the system library in a storage device having a protection function,
In support tool provided outside of the program logic controller, the accessory information that Do necessary when editing the protected the user application program stored in the storage device, the programmable logic Means for uploading from the controller, and in the support tool, the user application program is compiled by referring to the attached information necessary for editing the user application program uploaded by the uploading means, and the object code generating and means for downloading to the programmable logic controller the object code as the user application program, characterized by having.

Here, in the programmable logic controller, before Symbol attached information, the user application program, application interface system library that is required when editing the object code logically (hereinafter, abbreviated to "API" to) information, characterized in that it contains must become FBD (Function Block Diagram) component graphic information including the category in graphics program edited by graphic language, and system library property information, is .

In the programmable logic controller, the function library in the subroutine format is preferably described in a general PLC application description language including a ladder language.

Further, in the programmable logic controller, it functions library of subroutines format language, including C language categories, i.e. not a typical PLC application description language, are preferably described only in general-purpose language.

  As described above, according to the programmable logic controller and the programmable logic controller logic update support tool of the present invention, the support loader environment does not have the subroutine library object and API information stored in the PLC. However, partial editing of the application is possible, and the support tool does not need to be updated following the function update of the system library group of the PLC main body, and inconsistency in the program does not occur.

  In addition, by editing the program using API information that guarantees an interface to the object code and the system library, it is possible to obtain only necessary information, leaking know-how to users and blind copying There is an effect that can be prevented.

  Furthermore, by configuring the system library so that it can be added and expanded by dividing it into function groups, for engineers who have edited or added some of the system library functions, clarify the existence of that part. Therefore, the use right can be established and disclosed.

  BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a programmable logic controller and a logic update support tool for the programmable logic controller of the present invention will be described in detail in the order of [First Embodiment] to [Third Embodiment] with reference to the drawings. explain.

[First Embodiment]
FIG. 1 is a block diagram showing a functional block configuration of a PLC support system including a programmable logic controller and a logic update support tool for the programmable logic controller according to the first embodiment of the present invention.

  In the figure, the PLC support system of this embodiment includes a support terminal device 1 (a logic update support tool for a programmable logic controller according to this embodiment) and a PLC 2 (a programmable logic controller according to this embodiment). Configured.

  The function block of the support terminal device 1 includes a control unit 11 that controls the whole, a data input unit 12 that controls input devices such as a keyboard and a memory stick to input command information, data, programs, and the like, and a process such as a compiler A processing unit 13 that includes a program and performs processing such as compiling, updating, editing, and linking data, and a storage unit that controls information storage of a semiconductor storage device such as a RAM and a ROM, and a nonvolatile semiconductor (flash memory, etc.) 14 and a transmission / reception unit 15 that transmits and receives data and programs to and from the PLC.

The functional blocks of the PLC 2 belong to a communication port 22 that transmits and receives data and programs to and from terminal devices including the support terminal device 1, input processing that inputs state information from input devices, and a controlled system. An input / output unit 23 that performs output processing for outputting command information to an output device, a semiconductor storage device such as a RAM and a ROM, a storage unit 24 that controls information storage of a nonvolatile semiconductor (flash memory, etc.) , and a communication port 22 And a processing unit 25 that analyzes and processes state information from the input device and generates command information to the output device.

  In addition to the above, the support terminal device 1 includes, as function blocks, a communication unit that performs communication with other terminal devices, a line control unit that selectively controls communication lines including a LAN and the Internet network, and a web page that is disclosed to the Internet network. A web server unit responsible for management of data, an unauthorized access prevention unit responsible for security functions and encryption processing of programs and data to be stored, and the like.

  When the storage unit 24 is configured by a flash memory that is a non-volatile semiconductor memory, a function that protects stored information from a simple tool or the like, that is, when the control unit 21 executes a function other than an object program. The function of making reading impossible is exhibited. Therefore, it is preferable to store an object of a system library described later in such a flash memory.

FIG. 2 is an explanatory diagram showing a flow of information between the support tool and the PLC in the PLC support system according to the first embodiment of the present invention.
Hereinafter, the operation of the support terminal device 1 will be described with reference to FIGS. 1 and 2.

  An update command for the PLC object 200 (FIG. 2 (b)) of the PLC storage information 20 (FIG. 2 (b)) stored in the storage unit 24 (FIG. 1) of the PLC 2 is input from the data input unit of the support terminal device 1. Subsequently, when a part or the whole of the PLC source program that is the contents of the update information is input, the control unit 11 passes the processing unit 13 and the user editing / creation information stored in the storage unit 14 with the update information. 100 contents are updated. Next, the control unit 11 includes “system library / part information” and “system library” related to the system library among the embedded information 201 (FIG. 2B) stored in the storage unit 24 (FIG. 1) of the PLC 2. Upload “API information” and “system library property information” as upload information to the storage device controlled by the storage unit 14 (step P1).

  Thereafter, the control unit 11 refers to the upload information 101 and the partial information of the user editing / creation information 100 via the processing unit 13 while referring to the “PLC user application program / source code” of the user editing / creation information 100. ”Are edited, compiled, linked (linked), and the like to obtain a“ PLC user application program object ”written in the PLC user application program object code. Finally, the control unit 11 downloads the obtained “PLC user application program object” to the storage device controlled by the storage unit 24 (FIG. 1) of the PLC 2 as the PLC object 200 (step P2).

  According to this embodiment, even a support loader that does not have the subroutine library object and API information stored in the PLC 2 can partially edit the application, and the support tool can store the system library group in the PLC 2. There is no need to update following function update, and there is no inconsistency in the program.

  In addition, by editing the program using API information that guarantees an interface to the object code and the system library, it is possible to provide only necessary information, leaking know-how to users and blind copying There is an effect that can be prevented.

  Furthermore, by configuring the system library so that it can be added and expanded by dividing it into function groups, for engineers who have edited or added some of the system library functions, clarify the existence of that part. Therefore, the use right can be established and disclosed.

FIG. 3 is a flowchart showing the control operation of the control unit 11 of the support tool of the PLC support system according to the first embodiment of the present invention.
Hereinafter, the control operation of the control unit 11 of the support tool of the PLC support system according to the present embodiment will be described with reference to FIGS.

  Here, the operation after the update command for the PLC object 200 of the PLC storage information 20 stored in the storage unit 24 (FIG. 1) of the PLC 2 is input to the support terminal device 1 will be described.

(Step S1)
First, in step S <b> 1, the control unit 11 receives a part or the whole of the PLC source program that is the content of the update information from the data input unit 12 and temporarily stores it in the storage unit 14.

(Step S2)
Next, in step S <b> 2, the control unit 11 updates the contents of the user editing / creation information 100 stored in the storage unit 14 with the received update information via the processing unit 13.

(Step S3)
Next, in step S3, the control unit 11 includes “system library / part information”, “system library / API information”, “system library” related to the system library among the embedded information 201 stored in the storage unit 24 of the PLC 2. Library property information "is uploaded to the storage device controlled by the storage unit 14 as upload information.

(Step S4)
Next, in step S <b> 4, the control unit 11 refers to the “PLC user application” of the user editing / creation information 100 while referring to the upload information 101 and partial information of the user editing / creation information 100 via the processing unit 13. Processing such as editing, compiling and linking (linkage) is performed on the “program source code” to obtain a “PLC user application program object” written in the PLC user application program object code.

(Step S5)
Finally, in step S5, the control unit 11 downloads the obtained “PLC user application program object” as the PLC object 200 to the storage device controlled by the storage unit 24 of the PLC2.

[Second Embodiment]
The configuration of the functional block in the programmable logic controller according to the second embodiment of the present invention and the logic update support tool of the programmable logic controller is the same as the programmable logic controller and the programmable logic controller according to the first embodiment of the present invention. This is the same as the configuration of the functional blocks in the logic update support tool, and only the control function of the control unit 11 that controls the flow of information between the support tool and the PLC is different. A flow of information between the support tool and the PLC will be described. In the following description, the support tool of the present embodiment is sometimes referred to as support tool A, but this is to clarify that support tool A is mainly used for editing and adding system libraries. It explains the role in an easy-to-understand manner.

FIG. 4 is an explanatory diagram showing a flow of information between the support tool and the PLC in the PLC support system according to the second embodiment of the present invention.
Hereinafter, the operation of the support terminal device 1 (support tool) will be described with reference to FIGS. 1 and 4.

  The function group 1 information 401 (object code) is incorporated in advance in the system library of the embedded information 400 (FIG. 4B) stored in the storage unit 24 (FIG. 1) of the PLC2. The function group 1 information 301 (source code format) is also incorporated in the storage unit 14 of the support terminal device 1 in advance. Specifically, the information 401 of the function group 1 is “system library component information”, “system library API information”, and “system library property information”. Here, an addition command for the function group of the system library is input from the data input unit of the support terminal device 1, and the function group 2 information 302 (specifically, “system library component” is subsequently added as a function group to be added to the PLC 2. When “information” and “system library API information” source code formats) are input, the control unit 11 is configured to combine the information 301 of the function group 1 and the information 302 of the function group 2 via the processing unit 13. Edit, compile, link (linkage), etc., to obtain a system library object. Thereafter, the control unit 11 downloads the system library object to the storage unit 24 of the PLC 2 (Step P3), updates the system library of the embedded information 400 (FIG. 4B), and uses the system library object as the PLC 2 system library. , (Function group 1 information 401) + (function group 2 information 402) is newly set in the embedded information 400.

  According to the present embodiment, the support tool A holds the source code format such as the API information, part information, and property information of the system library function group 2 in advance, and the system library function previously incorporated in the PLC main body. In addition to group 1 (source code format), system library function group 2 can be edited, compiled, and downloaded to update the system library object to an object of (system library function group 1 + system library function group 2). it can.

[Third Embodiment]
The configuration of the functional block in the programmable logic controller according to the third embodiment of the present invention and the logic update support tool of the programmable logic controller includes the programmable logic controller and the programmable logic controller according to the first embodiment of the present invention. This is the same as the configuration of the functional blocks in the logic update support tool, and only the control function of the control unit 11 that controls the flow of information between the support tool and the PLC is different. A flow of information between the support tool and the PLC will be described.

  FIG. 5 is an explanatory diagram showing a flow of information between the support tool and the PLC in the PLC support system according to the third embodiment of the present invention. In this embodiment, the notation of support tool B is used to distinguish from the support tool A in the second embodiment described above. This is to clarify that the support tool B uses programming using a system library as a main point.

  In this embodiment, first, information is exchanged between the support terminal device 1A (support tool A) -PLC2, and thereafter, information is exchanged between the support terminal device 1B (support tool B) -PLC2.

  First, the flow of information between the support terminal device 1A (support tool A) and the PLC 2 will be described with reference to FIG. 1, FIG. 4, and FIG. 5, but basically the same as in the second embodiment described above. It is.

  The function group 1 information 611 (object code) is incorporated in advance in the system library of the embedded information 610 (FIG. 5B) stored in the storage unit 24 (FIG. 1) of the PLC 2. Further, the information 511 (source code format) of the function group 1 is incorporated in advance in the storage unit 14 of the support terminal device 1A (support tool A). Specifically, the information 611 of the function group 1 is “system library component information”, “system library API information”, and “system library property information”. Here, an addition command for the function group of the system library is input from the data input unit of the support terminal device 1A, and subsequently, the function group 2 information 512 (specifically, “system library component”) is added as a function group to be added to the PLC 2. When “information” and “system library API information” source code formats) are input, the control unit 11 is configured to combine information 511 of the function group 1 and information 512 of the function group 2 via the processing unit 13. Edit, compile, link (linkage), etc., to obtain a system library object. After that, the control unit 11 downloads this system library object to the storage unit 24 of the PLC 2 (see step P3 in FIG. 4), updates the system library of the embedded information 610 (FIG. 5B), and the PLC 2 (Function group 1 information 611) + (function group 2 information 612) is newly set in the embedded information 610.

Next, the flow of information between the support terminal device 1B (support tool B) and the PLC 2 will be described with reference to FIGS.
An update command for the PLC object 600 (FIG. 5B) of the PLC storage information 60 (FIG. 5B) stored in the storage unit 24 (FIG. 1) of the PLC 2 is input from the data input unit of the support terminal device 1B. Subsequently, when a part or the whole of the PLC source program that is the contents of the update information is input, the control unit 11 passes the processing unit 13 and the user editing / creation information stored in the storage unit 14 with the update information. 500 contents are updated. Next, the control unit 11 is a system library of the function group 1 information 611 and the function group 2 information 612 in the embedded information 610 (FIG. 5B) stored in the storage unit 24 (FIG. 1) of the PLC 2. "System library / part information", "system library / API information", and "system library / property information" related to the file are uploaded to the storage device controlled by the storage unit 14 by issuing a command such as library update. (Step P5).

  After that, the control unit 11 refers to the upload information 510 and the partial information of the user editing / creation information 500 via the processing unit 13 while referring to the “PLC user application program / source code” of the user editing / creation information 500. ”Are edited, compiled, linked (linked), and the like to obtain a“ PLC user application program object ”written in the PLC user application program object code. Finally, the control unit 11 downloads the obtained “PLC user application program object” to the storage device controlled by the storage unit 24 (FIG. 1) of the PLC 2 as the PLC object 600 (step P4).

  According to this embodiment, after the information 612 of the system library function group 2 is set in the PLC 2 by exchanging information with the support tool A, the support tool B having no information 512 of the system library function group 2 is set. When connected, the support tool B issues a command such as library update, so that the API information and component information of the information 611 of the system library function group 1 and the information 612 of the system library function group 2 from the PLC main body side. Only the property information can be uploaded as the function group 1 information 511 and the function group 2 information 512. Since it is not held in the source code format as in the support tool A, the support tool B cannot edit the system library function group 2, but there is an effect that it is possible to monitor and edit the PLC application using them. In other words, the source code is kept secret, but an environment where functions are used is realized.

  A program that causes a computer to execute the control of the support terminal device 1 according to the present invention by the procedure shown in the flowchart of FIG. 3 is a computer-readable recording medium such as a semiconductor memory, a CD-ROM, or a magnetic tape. You may store in and distribute. A computer including at least a microcomputer, a personal computer, and a general-purpose computer may read the program from the recording medium and execute the program.

It is a block diagram which shows the structure of the functional block of the PLC assistance system containing the logic update assistance tool of the programmable logic controller which concerns on the 1st Embodiment of this invention, and a programmable logic controller. It is explanatory drawing which shows the flow of the information between the support tool and PLC in the PLC support system which concerns on the 1st Embodiment of this invention. It is a flowchart figure which shows the control action of the control part 11 of the assistance tool of the PLC assistance system which concerns on the 1st Embodiment of this invention. It is explanatory drawing which shows the flow of the information between the support tool and PLC in the PLC support system which concerns on the 2nd Embodiment of this invention. It is explanatory drawing which shows the flow of the information between the assistance tool and PLC in the PLC assistance system which concerns on the 3rd Embodiment of this invention. It is explanatory drawing which shows the flow of the information between the support terminal device (support tool) -PLC in the conventional PLC support system.

Explanation of symbols

1 Support terminal device 2 PLC
DESCRIPTION OF SYMBOLS 10 Support tool memory | storage information 11,21 Control part 12 Data input part 13 Processing part 14,24 Storage part 15 Transmission / reception part 20 PLC memory | storage information 22 Communication port 23 Input / output unit 25 Processing unit 100 User edit / creation information 101 Upload information 200 PLC Object 201 Embedded information

Claims (2)

A programmable logic controller can be used as a control device for controlling the external device, the programmable logic controller,
A user application program for controlling the external device;
This is a function that depends on the hardware of the programmable logic controller, and is an object code that is called from the user application program and is actually executed by the programmable logic controller, and an attachment that is necessary when editing the user application program A system library composed of information,
Means for storing the system library in a storage device having a protection function;
With
In support tool provided outside of the program logic controller, the accessory information that Do necessary when editing the protected the user application program stored in the storage device, the programmable logic Means to upload from the controller ,
In the support tool, the object application code is generated by compiling the user application program with reference to attached information necessary for editing the user application program uploaded by the uploading means, and the object code Means for downloading to the programmable logic controller as the user application program,
Programmable logic controller, comprising a. The front SL comes information, the user application program, it requires the object code API system library that is required when editing logically (application interface) information, when graphics program edited by graphic language become FBD (Function Block Diagram) component graphic information including the category, and programmable logic controller according to claim 1, wherein the property information of the system library, is included.

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