JP2004280306A - Device for programmable controller, method for changing program, and method for changing content to be controlled - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for a PLC that makes it possible to rewrite a program being held during the operation of a program. <P>SOLUTION: The device has a program code area P in which to store a plurality of user applications A, B constituting a program described in C language, and a data area D in which to store programs to be used among the plurality of user applications stored in the program area, as well as a task management program TCB specifying the order of execution of the programs. A variable data mapping block VMB that stores an address for accessing variables stored in a BBS area B is also provided in the data area. By updating an address that shows a program being executed within the TCB during system operation, the user application can be switched from A to B. By changing the reference address of the VMB within the TCB from a solid line to a broken line, the variables for reference can be changed from a, b to c, d. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a programmable controller device capable of executing a program described in a compilation language such as the C language, a program changing method, and a control content changing method.
[0002]
[Prior art]
A programmable controller (PLC) is used as a control device for factory automation (FA). This PLC is composed of a plurality of units. That is, a power supply unit of a power supply source, a CPU unit for directing the control of the entire PLC, an input unit for inputting a signal of a switch or a sensor installed at an appropriate position in an FA production device or an equipment device, an output for outputting a control output to an actuator or the like Various units such as a unit and a communication unit for connecting to a communication network are appropriately combined and configured.
[0003]
The control in the CPU unit of the PLC is performed by taking a signal input from the input unit into the I / O memory of the CPU unit (IN refresh), and based on a user program written in a user program description language (eg, a ladder language) registered in advance. A logical operation is performed (operation execution), the operation execution result is written to an I / O memory and sent to an output unit (OUT refresh), and thereafter, so-called peripheral processing is cyclically and repeatedly performed. Then, the above-described user program is stored in the user memory of the CPU unit.
[0004]
By the way, as a general usage of the PLC, there is a usage in which a logical operation is performed on a plurality of IN data and OUT data is output based on the operation result to control the controlled device. In this case, the user program often uses a ladder language. The reason is that the ladder programming is easy to express the logical relationship between the ON / OFF state of the contact point of the input device and the state of the OUT signal to the output device, and is easy to visually recognize.
[0005]
However, recently, the control content of the PLC may be not only a mere logical operation but also a function operation, a mathematical operation, and a process for handling analog information. In some cases, C language is used as a programming language for performing such relatively advanced calculations and processes. Therefore, some PLCs have both a CPU that executes a ladder program and a CPU that executes the C language. In such a PLC, arithmetic processing can be performed by writing a program in a compilation language such as the C language. In such a PLC, a program is created in an external programming development environment (programming tool), then converted into object code through a process of compiling, assembling, and linking, and the converted object code is converted into a CPU unit of the PLC. And stored in the CPU unit. The program is executed in the CPU unit.
[0006]
Then, to rewrite the contents of the memory so as to change the currently running program, the following procedure is usually executed. That is, (1) First, the PLC is changed to the program transfer mode by mode switching means such as a jumper pin or a dip switch. (2) Next, the object code is downloaded. Thus, the object code is stored in the memory for storing the program of the PLC. (3) When the download is completed, change the PLC to the program execution mode and restart.
[0007]
[Problems to be solved by the invention]
However, since the operation mode of the PLC is often determined when the power is turned on, the PLC may need to be restarted when the program is downloaded.
[0008]
Therefore, the contents of the control program described in the C language cannot be safely replaced while the controller is operating. That is, even if it is desired to partially replace the execution contents of the control program or change the settings of parameters and the like, it is necessary to turn off the power once and restart the PLC, which is troublesome.
[0009]
The present invention relates to a device for a programmable controller corresponding to a program described in a language such as a C language or the like in a compiling system, without modifying or recompiling the program itself recorded in a memory, and controlling the contents of the program and the reference memory area. It is an object of the present invention to provide a programmable controller device capable of performing a change and the like, a program changing method, and a control content changing method.
[0010]
[Means for Solving the Problems]
A device for a programmable controller according to the present invention is a device constituting a programmable controller, and is capable of executing a program described in a compile-type language such as C language. And a task management block for defining, in the work memory, a program area for storing a plurality of application programs constituting the program, and a program to be used and an execution order among the plurality of application programs stored in the program area. And a data area for storing. Further, the task management block includes address information for specifying an application program to be executed in each task, and the address information can be externally rewritten.
[0011]
Further, in the present invention, instead of rewriting the program to be used and the execution order thereof, a configuration is adopted in which variables used for executing the program are changed.
[0012]
Here, the “programmable controller device” may be, for example, one unit constituting the programmable controller, a device mounted on a predetermined unit such as a board, or the programmable controller itself. The “execution order” refers to the order in which the tasks are executed, and actually corresponds to the execution order for the application program.
[0013]
Further, a program changing method according to the present invention is a program changing method in a programmable controller device capable of executing a program described in a language of a compiling method such as C language, wherein the program changing method is performed in a work memory of the programmable controller device. A program area for storing a plurality of application programs constituting the program, and a data area for storing a program to be used among the plurality of application programs stored in the program area and a task management block for defining an execution order thereof. Be prepared. The task management block is configured to include address information that specifies an application program to be executed in each task, and externally rewrites the address information during operation of the system. As a result, when the task whose address information is rewritten thereafter is executed, the program to be executed without recompiling by executing the application program specified by the rewritten address information is changed.
[0014]
The information of the task management block can be rewritten from an external program. Therefore, by rewriting the address information specifying the application program to be executed in the task management block, the program to be executed can be changed. In addition, such a change merely changes the data stored in the task management block in the data area, and does not require recompilation. Of course, it is necessary to previously store the application program to be changed in the program area.
[0015]
Further, as another solution of the device for a programmable controller according to the present invention, the above-described invention is premised, and the data area further includes a data area in which variables used when executing the application program are stored. A variable data mapping block having variable address information for accessing the variable data mapping block is provided, and the task management block includes information for specifying an access destination of the variable data mapping block, and the information can be externally rewritten. is there.
[0016]
Further, the data area is provided with a variable data mapping block including variable address information for accessing a data area in which a variable used when executing the application program is stored, and the variable address information is externally provided. You may make it rewritable.
[0017]
In another solution of the program changing method according to the present invention, the above-mentioned invention is premised, and in the data area, a data area storing a variable used when executing the application program is accessed. The task management block has information specifying an access destination of the variable data mapping block, and the access destination during the operation of the system. The information specifying the access destination is rewritten from the outside, and thereafter, when executing the task in which the information specifying the access destination is rewritten, by changing the memory area used / referenced by the application program related to the task, The execution contents of the program may be changed.
[0018]
Further, the data area is provided with a variable data mapping block including variable address information for accessing a data area in which a variable used when executing the application program is stored. A memory used and referred to by an application program related to the task when executing a task that references the variable data mapping block in which the variable address information is rewritten from the outside and thereafter refers to the rewritten variable data mapping block. By changing the area, the execution contents of the program can be changed.
[0019]
In each of the above-mentioned inventions, the memory area that is referenced and used when executing the application program managed by the task changes by rewriting the information of the task management block and the information of the variable data mapping block. Thereby, the contents of the program that operates substantially can be changed.
[0020]
Since the task management block and the variable data mapping block are located in a data area that can be accessed from the outside, the operation of the system can be changed without recompiling while the operation of the system is running. Can greatly change the program.
[0021]
Further, the method of changing the control content of the programmable controller device according to the present invention is a method of changing the control content of a program in a programmable controller device capable of executing a program described in a compilation language such as C language, In a work memory of the programmable controller device, a variable area for storing a variable used when executing the program, and a variable for defining a variable to be used by a variable address among variables stored in the variable area A data area for storing a data mapping block is provided. The variable data mapping block is configured to include address information that specifies parameters used in a program, and externally rewrites the address information during operation of the system. As a result, when the program is executed thereafter, the control content executed without recompiling by executing the program using the parameters specified by the rewritten address information is changed.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 shows a preferred embodiment of the present invention. As shown in FIG. 1, the PLC 1 includes a CPU unit 10, an extended CPU unit 20, and the like. Of course, although not shown, there are other units such as a communication unit, an I / O unit, a master unit, and a power supply unit.
[0023]
In the CPU unit 10, the CPU 11 executes predetermined processing cyclically according to a system program stored in a system ROM (not shown). Here, the predetermined processing includes common processing, arithmetic processing, cycle time calculation processing, I / O refresh processing, and peripheral service processing. The arithmetic processing sequentially executes a user program stored in the program memory 12, and at the time of performing the arithmetic, accesses the IO memory 13 as appropriate, reads and writes IO data, and acquires parameters. Then, in the I / O refresh processing, the IO memory 13 is updated with IO data. The CPU 11 can access the IO memory 13 and the extended CPU unit 20 via the bus controller 14. It should be noted that the user program executed by the CPU 11 is created in a ladder language as in the prior art.
[0024]
On the other hand, the extended CPU unit 20 is a unit capable of executing a program created in a high-level language (for example, C language), and includes a flash memory 21 for holding the C language program and a work memory 22 for operating the program. Have. The form of the extended CPU unit 20 is a unit separate from the CPU unit 10 and is similar to other units (communication unit, I / O unit, etc.) via the CPU unit 10 and a PLC bus (internal bus). Unit is connected. As another form of the extension CPU unit 20, an extension board type that can be inserted into the CPU unit 10 and built in may be used. As another form, an extension unit type for the CPU unit 10 may be used. The connection bus in the case of the extension board type or the extension unit type is a bus different from the PLC bus to which other units are connected, and may be the internal bus of the CPU unit 10 itself. Connection via the Internet). In short, the CPU 11 is connected to the CPU 11 via a bus and operates independently of the CPU 11 as an extended CPU. The CPU 11 may have any form as long as it has a function of accessing the IO memory 13 of the CPU unit 10.
[0025]
The flash memory 21 is composed of a nonvolatile flash memory, and the work memory 22 is composed of a volatile RAM because it is necessary to execute the work at high speed. Then, as an initial preparation for executing the program, the program stored in the flash memory 21 is copied to the work memory 22 at the time of startup such as when the power is turned on or when a manual reset operation is performed. Then, the program stored in the work memory 22 is read, and the CPU 23 executes a predetermined algorithm based on the program.
[0026]
The extended CPU unit 20 is linked with the main CPU unit 10 via a dedicated bus. Specifically, by transmitting and receiving data between the bus controller 14 and the address decoder 25, the CPU unit 10 accesses various memories via the address decoder 25 and gives a predetermined command to the CPU 23. Further, events and the like from the extended CPU unit 20 are also transmitted from the address decoder 25 to the CPU unit 10 (CPU 11) via the bus controller 14. The event is, for example, a message communication performed to the extended CPU unit 20 in the peripheral processing during the processing of the main CPU unit 10. By the event message communication, the extended CPU unit 20 receives a read request command from the main CPU unit 10 and passes a response thereto, or receives a write command (write data) and stores it in the work memory 22.
[0027]
The context of the program stored in the work memory 22 (code arrangement after compiling the C language program) is as shown in FIG. That is, it has a program code area P, a constant area C, a data area D, a BBS area B, and a stack area Stack. The program code area P stores program logic. The constant area C stores data declared const. This data is a constant that does not change with the execution of the program. The data area D stores data not declared const, that is, variables. The variable data includes IN data taken in during the execution of the program, data generated during the execution of the program, and OUT data resulting from the execution of the program. Of course, the data stored in the data area D includes IN data taken in from the input device by the main CPU unit 10 and OUT data obtained by executing a program in the main CPU unit 10, that is, the IO memory 13 of the main CPU unit 10. May be included. The initial value of the data area D is set to an arbitrary data value by the boot loader. The BBS area B is an area in which uninitialized variables are stored, and is cleared to zero at startup. The variable data in the BBS area B may include IN data taken in when the extended CPU unit 20 executes the program, data generated during the execution of the program, and OUT data resulting from the execution result of the program. Of course, the data of the main CPU unit 10 IO memory 13 may be included.
[0028]
Note that the variable data includes so-called parameters used in the application program. Examples of the parameters include P, I, and D parameters for performing PID control, such as the number of loops for executing a program, and the temperature and humidity in control relating to temperature.
[0029]
Further, a stack is stored in the stack area Stack, and is used when linking programs. Specifically, program call destination information when performing subroutine processing, return information after subroutine processing, and the like are stored. Then, the program code and the variables are arranged in each area shown in FIG. 2 when the program is linked.
[0030]
More specifically, as shown in FIG. 3, the program stored in the program code area P refers to the task management block TCB stored in the data area D, and calls up the registered task. And a user application unit UA for performing a specific function. The user application unit UA stores a plurality of user application programs (in the example shown, user applications A and B). The user application unit UA is stored in the program code area P continuously from the start address to the address of the predetermined area.
[0031]
The task management block TCB is stored in the data area, specifies a task to be executed, and also determines the execution order. The task manager unit TM sequentially executes tasks according to the order recorded in the task management block TCB.
[0032]
Here, the task management block TCB has a data structure as shown in FIG. That is, in order from the beginning, “Task_id” that stores a task ID that is a unique number for identifying the task, “forward” that stores a task ID to be executed next and establishes a link, "Backward" for storing the executed task ID, "state" for storing a task status flag for specifying whether the task is active or inactive, and "level" for storing the task level (execution frequency). , "PProgram" for storing the start address of the program code, and "pData" for storing the start address of the variable area address definition.
[0033]
Here, the start address stored in “pProgram” is the start address of a desired user application program recorded in the user application unit UA of the program code area P. That is, the task manager unit TM accesses the task management block TCB, calls and executes the user applications sequentially according to the determined task order. In the example of the table of the task management block TCB in FIG. 4, Task_id = 0 (task 0) is first executed. Since the forward numerical value in the table row of Task_id = 0 is “1”, the next task to be executed is Task_id = 1 (task 1). Since the forward numerical value is set to “2” in the table row of Task_id = 1, task 2 is executed after execution of task 1.
[0034]
The variable address stored in “pData” registers the access destination of the variable data mapping block VMB stored in the data area D. As shown in FIG. 4, the variable data mapping block VMB includes a table in which “dname” storing a variable name is associated with an address “pAddr” indicating the substance of the variable. As this address, a desired address in the BSS area B in which specific data corresponding to the variable name is stored.
[0035]
That is, the reference address of this variable data mapping block VMB is registered in “pData” of each task in the task management block TCB, and the data actually used / referenced at the time of task execution is stored in the “pData” of the variable data mapping block VMB. The data is in the BBS area specified by the address stored in “pAddr”.
[0036]
In the present embodiment, by arranging the task management block TCB and the variable data mapping block VMB at a fixed address of the data area D accessible from the outside, the table operation from an external programming tool can be easily performed. As a result, the operating program and the memory to be referred can be changed only by editing the task management block TCB and the variable data mapping block VMB in the data area via the CPU unit using a tool or the like. More specifically, the addresses of “pProgram” and “pData” in the task management block TCB and “pAddr” of the variable data mapping block VMB are changed.
[0037]
For example, when it is assumed that the numerical value of the start address of the user application A is set in “pProgram” of a certain task (Task_id = 2) in the table of the task management block TCB in FIG. 4, a solid line in FIG. As described above, the same task (Task_id = 2) described in the task management block TCB corresponds to the user application A. Therefore, it is assumed that the start address of “pProgram” of the same task (Task_id = 2) in the table of the task management block TCB in FIG. Then, when the same task is subsequently executed, the user application B is executed as shown by the dotted line in FIG.
[0038]
Further, for example, it is assumed that the numerical value of the address of the variable data mapping block VMB that refers to the variables a and b is stored in “pData” of a certain task (Task_id = 2) in the table of the task management block TCB in FIG. In this case, as shown by the solid line in FIG. 3, the same task (Task_id = 2) described in the task management block TCB refers to the variables a and b. Therefore, by rewriting the address of “pData” of the same task (Task_id = 2) in the table of the task management block TCB in FIG. The variable to be used changes to c and d as shown by the dotted line in FIG. That is, the address of the variable data to be referred to is switched from the addresses a and b in the BBS area to c and d.
[0039]
Further, the change of the variable to be referred to is not limited to the method of changing “pData” of the task management block TCB as described above, but rewrites “pAdder” of the variable data mapping block VMB (the current variables a and b are changed). (Addresses of variables c and d).
[0040]
Note that the variable data includes so-called parameters used in the application program as described above. For example, if the number of loops of the program execution is a parameter, changing the number of loops changes the number of loops, so that the control content can be changed without changing the program itself. In addition, for example, in the case of control relating to temperature, temperature and humidity are parameters, and in a specific example, parameters can be changed between a sunny day and a rainy day, and parameters can be changed according to season and temperature / humidity of that day. Has actually been done. Optimum temperature control can be achieved by changing only these parameters without changing the program. In addition, by changing each of the parameters P, I, and D when performing the PID control, the control content or the operation content is changed without changing the logic of the program.
[0041]
In addition, the task management block TCB and the variable data mapping block VMB can independently and independently rewrite their reference addresses.
[0042]
Therefore, in this embodiment, the PLC is stopped and restarted by rewriting the reference address of the task management block TCB without changing the reference address of the variable data mapping block VMB while the program is running. By exchanging the application programs without any change, the control contents of the entire system can be largely changed.
[0043]
Also, while the program is running, the task management block TCB is not changed and the reference destination address of the variable data mapping block VMB is rewritten, so that the parameter variables used for the program execution can be changed without stopping and restarting the PLC. Can be changed. Therefore, although the logic of the application program is not changed as it is, different control operations of the entire system can be performed. This is because the control operation naturally changes when the parameter changes.
[0044]
Of course, by rewriting the reference addresses of both the task management block TCB and the variable data mapping block VMB while the program is running, both the program and the parameter variables can be replaced without stopping and restarting the PLC. The operation of the entire system can be greatly changed.
[0045]
In the above-described embodiment, the variable data mapping block VMB is provided in the data area D, and the access to the variable is performed through the variable data mapping block VBM. However, the present invention is not limited to this. Alternatively, the task management block TCB directly manages the addresses of the variables in the BBS area, and by changing the addresses, the variables to be referred can be switched without recompiling.
[0046]
【The invention's effect】
As described above, according to the present invention, the operating conditions of the program system to be executed and the system itself can be changed only by changing the task management table and / or the variable data mapping block without modifying the program source described in the C language. Can be rearranged.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of a PLC according to the present invention.
FIG. 2 is a diagram showing an example of a context of a program stored (copied / developed) in a work memory 22.
FIG. 3 is a diagram illustrating functions of the present invention.
FIG. 4 is a diagram illustrating an example of a task management block.
FIG. 5 is a diagram showing a variable data mapping block VMB.
[Explanation of symbols]
1 PLC
10 CPU unit 11 CPU
12 Program Memory 13 IO Memory 14 Bus Controller 20 Extended CPU Unit 21 Flash Memory 22 Work Memory 23 CPU
25 Address decoder

Claims (8)

A device constituting a programmable controller,
A program written in a compilation language such as C language can be executed,
In a work memory, a program area for storing a plurality of application programs constituting the program, and a task management block for defining a program to be used and an execution order among the plurality of application programs stored in the program area are stored. Data area,
The device for a programmable controller, wherein the task management block includes address information designating an application program to be executed in each task, and the address information is externally rewritable. The data area is provided with a variable data mapping block having variable address information for accessing a data area in which a variable used when executing the application program is stored,
2. The programmable controller device according to claim 1, wherein the task management block includes information for specifying an access destination of the variable data mapping block, and the information can be externally rewritten. The data area is provided with a variable data mapping block having variable address information for accessing a data area in which a variable used when executing the application program is stored,
3. The programmable controller device according to claim 1, wherein the variable address information is rewritable from outside. A device constituting a programmable controller,
A program written in a compilation language such as C language can be executed,
In a work memory, a variable area for storing variables used when executing the program and a variable data mapping block for defining a variable to be used by a variable address among the variables stored in the variable area are stored. Data area,
The variable data mapping block includes address information that specifies parameters used in a program, and the address information is externally rewritable. A program changing method in a programmable controller device capable of executing a program described in a language of a compile method such as C language,
In a work memory of the programmable controller device, a program area for storing a plurality of application programs constituting the program, and, among the plurality of application programs stored in the program area, a program to be used and an execution order thereof are defined. A data area for storing task management blocks
The task management block is configured to include address information specifying an application program to be executed in each task,
During operation of the system, the address information is externally rewritten,
Thereafter, when executing the task whose address information has been rewritten, executing the application program specified by the rewritten address information changes the program to be executed without recompiling. How to change the program. The data area includes a variable data mapping block including variable address information for accessing a data area in which a variable used when executing the application program is stored.
The task management block has information for specifying an access destination of the variable data mapping block,
While the operation of the system is in operation, the information for specifying the access destination is externally rewritten,
Thereafter, when executing a task whose information specifying the access destination has been rewritten, it is necessary to change the memory area used and referenced by the application program related to the task, thereby changing the execution contents of the program. 6. The method according to claim 5, wherein the program is changed. The data area is provided with a variable data mapping block having variable address information for accessing a data area in which a variable used when executing the application program is stored,
During operation of the system, the variable address information is externally rewritten,
Thereafter, when executing a task that refers to the variable data mapping block in which the variable address information has been rewritten, by changing the memory area used and referred to by the application program related to the task, 7. The method according to claim 5, wherein the content of execution is changed. A method for changing control contents in a device for a programmable controller capable of executing a program described in a language of a compile method such as C language,
In a work memory of the programmable controller device, a variable area for storing a variable used when executing the program, and a variable for defining a variable to be used by a variable address among variables stored in the variable area A data area for storing the data mapping block is provided,
The variable data mapping block is configured to include address information specifying parameters used in the program,
During operation of the system, the address information is externally rewritten,
Thereafter, when the program is executed, the control content executed without recompiling is changed by executing the program using the parameters specified by the rewritten address information. How to change the control content of the device.

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