JP2001022413A - Programmable controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure a local variable area independent for every task and program, to freely define a variable for every task and program to use a program controller. SOLUTION: A programmable controller is provided with a central arithmetic processor 1 controlling the execution of a whole controller, a program memory 2 storing a sequence program being a program that the central arithmetic processor 1 executes, a sequence arithmetic unit 4 executing the sequence program stored in the program memory 2 and a data memory 6 storing data of a variable used for control. An independent data area is allocated for every task constituting the sequence program and for every program in the task as the allocation constitution of the data memory 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a programmable controller (generally referred to as a PLC) widely used for controlling industrial systems such as steel, papermaking plants, water and sewage systems, and the automotive industry. ,
In particular, the present invention relates to a programmable controller capable of securing an independent local variable area for each task and program.

[0002]

2. Description of the Related Art Conventionally, in a programmable controller, a register is often used as a target of an operation. Since this is a so-called global variable, it can be accessed from any program,
Restrictions due to duplicate use of registers, etc., also cause program bugs.

[0003]

For this reason, recently,
Although there is a strong demand for a programmable controller that can use local variables, there is no programmable controller implemented at the hardware level.

An object of the present invention is to make it possible to secure an independent local variable area for each task and program, and to freely define variables for each task and program without being restricted by duplication of registers. It is to provide a programmable controller that can be used.

[0005]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a sequence operation device for executing a sequence program stored in a sequence program memory, and a sequence operation device such as a variable used for control. In a programmable controller including a data memory for storing data, an independent data area is allocated to a task constituting a sequence program and a program in the task as an arrangement of the data memory.

According to the second aspect of the present invention, the central processing unit controls execution of the whole controller, a program memory storing a program executed by the central processing unit, and a sequence program memory. In a programmable controller configured to include a sequence operation device that executes a sequence program and a data memory that stores data such as variables used for control, a task that configures the sequence program as a data memory allocation configuration and the task An independent data area is allocated to each program in the program.

Therefore, in the programmable controller according to the first or second aspect of the present invention, an independent data area is allocated to each task and program, so that an independent local variable area can be secured for each task and program. Variables can be freely defined and used for each task and program without being limited by duplication of registers as in the related art.

On the other hand, according to the invention of claim 3, the above-mentioned claim 1 is provided.
Alternatively, in the programmable controller according to the second aspect, when accessing a variable unique to the program,
Variables are accessed based on a base address unique to the program.

Therefore, in the programmable controller according to the third aspect of the present invention, by accessing the variable based on the base address unique to the program, the base address is changed when the program is switched, thereby changing the base address. You can access variables.

[0010] In the invention of claim 4, the above-mentioned claim 1 is provided.
Alternatively, in the programmable controller according to the second aspect of the present invention, the sequence operation device includes a base address register for storing a base address serving as a base when accessing a variable unique to the program, and the base is controlled by a predetermined instruction when switching the program. The contents of the address register are changed.

Therefore, in the programmable controller according to the fourth aspect of the present invention, by providing a base register for storing a base address for accessing a variable for each program, the contents of the base address register are changed when the program is switched. By doing so, it is possible to access variables unique to the program.

On the other hand, according to the invention of claim 5, the above-mentioned claim 4
In the programmable controller according to the invention, a program is provided by providing a task base address setting instruction for storing an address indicating a data area occupied by the task in the base address register, and executing the task base address setting instruction when switching tasks. The data area to be used is specified.

Therefore, in the programmable controller according to the fifth aspect of the present invention, when the task is switched, the task base address setting instruction is executed so that the address indicating the data area occupied by the task is stored in the base address register. Therefore, a data area to be occupied can be designated for each task.

[0014] According to the sixth aspect of the present invention, there is provided the fourth aspect of the present invention.
In the programmable controller according to the invention, when a certain program calls another program, an address of a data area occupied by the called program is set in a base address register by a program call instruction, so that the called program becomes a dedicated program. Use the data area.

Therefore, in the programmable controller according to the present invention, when a certain program is called from another program, the local variable occupied by the called program is based on the value currently set in the base address register. By changing the base address register to reflect the size of the area, another program called from one program can use the dedicated data area, and the local variable area used by the higher-level program. And an area that is a lower area that is continuous with the above can be occupied.

According to a seventh aspect of the present invention, in the programmable controller according to the first or second aspect of the present invention, a base address used as a base when a variable unique to the program is accessed is stored in the sequence operation device. It has a base address register and a data range register that stores the size of a variable area unique to a program. When a program calls another program, the start address and data amount of the data area occupied by the called program are determined. By setting the base address register and the data range register by a program call instruction, an access to the outside of the dedicated data area of the called program is detected.

Therefore, in the programmable controller according to the present invention, the program call instruction is
By setting the range of the local variable area used by the called program in the data range register, the program-specific data area can be stored in the data range register, so that the program does not access the data area of another program. , That is, control can be performed so that the called program does not access data outside the dedicated data area.

On the other hand, according to the invention of claim 8, the above-mentioned claim 1 is provided.
Alternatively, in the programmable controller according to the second aspect of the present invention, a base address register for storing a base address serving as a base when accessing a variable unique to the program, and a size of a variable area unique to the program are stored in the sequence operation device. When a task is switched, the start address and data amount of the temporary use data area unique to the task are stored in the base address register and the data range register for the temporary use data by a dedicated task switching instruction. By setting, the data used by the called program uses the dedicated data area and detects an access to the outside of the dedicated data area.

Therefore, in the programmable controller according to the present invention, when a task is switched, a dedicated task switching instruction sets a temporary use data base address register and a temporary use data range register, thereby enabling a In addition, an independent temporary use data area can be used, and by monitoring the data range, access outside the dedicated temporary use data area can be prohibited.

According to the ninth aspect of the present invention, in the first aspect,
Alternatively, in the programmable controller according to the second aspect of the invention, the amount of data unique to the program is stored in the program call instruction so as to instruct the compiler of the amount of data unique to the program.

Therefore, in the programmable controller according to the ninth aspect of the present invention, the data amount of the local variable used by the program is included in the program call instruction, so that the compiler uses the local variable used by the entire program and the downstream program. It becomes easy to find the variable area.

According to a tenth aspect of the present invention, in the programmable controller according to the first or second aspect of the invention, when a program is called, a start address of the program is designated by a program number assigned to the program. When a dedicated program used only in the program is called from the program, the program is called by a relative address from the calling address.

Therefore, in the programmable controller according to the tenth aspect of the present invention, the program is managed by a unique number assigned to the program, so that related data such as a head address and a used data amount are included in the program call instruction. Is no longer required, so that the program can be configured with a small amount of program code. When a program used only in a certain program is called, the program can be called at high speed by calling using a relative address instead of a program number.

[0024]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(First Embodiment) FIG. 1 is a block diagram showing a configuration example of a main part of a programmable controller according to the present invention.

That is, in the programmable controller of the present invention, as shown in FIG. 1, a central processing unit (hereinafter referred to as a CPU) 1 includes a program memory 2, a work memory 3, a sequence operation device 4, It comprises a program memory 5, a data memory 6, a microcomputer bus 7, a communication interface 8, an I / O 9, and a monitor device 20.

The CPU 1 is a central part of the programmable controller and controls execution of the whole controller.

The program memory 2 is a memory for storing a program to be executed by the CPU 1.
And control programs.

The work memory 3 is a memory used as a work area when the CPU 1 executes the overall control.

The sequence operation device 4 is a processor that executes a sequence program stored in the sequence program memory 5.

The sequence program memory 5 is a memory for storing a sequence program created by a user.

The data memory 6 is a memory for storing data such as variables used for control used by the user.

The microcomputer bus 7 is a bus for connecting elements in the programmable controller to the CPU 1 and the sequence operation device 4, and is a total of an address bus, a data bus, and a control bus.

The communication interface 8 is an interface circuit for connecting the programmable controller to the monitor device 20 and the like via a communication medium.

The I / O 9 is an input / output device for connecting the programmable controller to an external control object.

The monitor device 20 is used to monitor the execution state of the sequence program of the programmable controller and to create and modify the sequence program.

The programmable controller according to the present embodiment handles a sequence program as shown in a conceptual diagram in FIG. 2, for example.

In FIG. 2, the sequence program is:
It is composed of two tasks A and B.

In task A, program A1 calls programs B1 and C1 from among them. The program C1 calls the program B2.

Here, program B1 and program B2
Are programs that use the same object program and differ only in the variables they handle.

On the other hand, similarly, the task B is the program A
2 calls the program B3 and the program C2 from among them.

Here, the program A2 is the program A
The programs B3 and C2 use the same object program as the programs B1 and C1, respectively.

As described above, when the same object program is used and only the variables to be handled are changed to configure the program, the capacity of the program memory 2 can be saved.

In the programmable controller according to the present embodiment, as an allocation configuration of the data memory 6 in FIG. 1, for example, as shown in FIG. 3, each task constituting the sequence program and each program in this task are independent. It is configured to allocate the specified data area.

In this embodiment, the allocation of the independent data area is performed by the CPU 1, that is, the compiler is run by the CPU 1.

In FIG. 3, the data areas used by task A and task B are independent, and the data area of the called program (hereinafter referred to as a lower-order program) is replaced by the calling program (hereinafter referred to as the lower program). (Referred to as an upper-level program) in an area following the data area.

Therefore, in the programmable controller of this embodiment, an independent data area can be used for each task and each program.

As described above, in the programmable controller according to the present embodiment, for each task and program,
Since we allocate independent data areas,
Since an independent local variable area can be secured for each task and program, it is possible to freely define and use variables for each task and program without being limited by duplication of registers as in the past. .

(Second Embodiment) FIG. 4 is a block diagram showing a configuration example of a sequence operation device 4 in a programmable controller according to the present embodiment. .

That is, the sequence arithmetic unit 4
As shown in the figure, a sequence operation circuit 4-1, an instruction register 4-2, a base address register 4-3, an address range register 4-4, a MUX 4-5, and an adder 4
-6, a memory address register 4-7, a bus I / F
4-8 and the temporary memory address register 4-9
And the temporary memory address range register 4-10
, A MUX 4-11, and a comparison circuit 4-12.

The sequence operation circuit 4-1 is a circuit for sequentially reading a sequence program from the sequence program memory 5 and processing it.

The instruction register 4-2 is a register for temporarily storing the sequence instruction read by the sequence operation circuit 4-1.

The instruction register 4-2 also contains the operand address of the sequence instruction.

The base address register 4-3 is a register for storing an address used as a basis for calculating an address of the data memory 6 when the data memory 6 is accessed in a program. The contents are changed when the program is switched.

The address range register 4-4 is a register that stores the start address and the end address of the data memory 6 used by the program currently being executed. Used to determine if

MUX 4-5 and MUX 4-11 are multiplexers.

The adder 4-6 adds the base address stored in the base address register 4-3 and the operand address stored in the instruction register 4-2 to generate a target memory address. .

The memory address register 4-7 is a register for storing a memory address to be accessed.

A bus I / F 4-8 is an I / F for connecting the microcomputer bus 7 to a bus in the sequence operation device 4.
It is.

The temporary memory address register 4-9
Is a register for storing a base address of a temporary memory (hereinafter referred to as a temporary memory), and its contents are changed at the time of task switching.

Temporary memory address range register 4
A register -10 stores the start address and end address of the temporary memory used by the currently executed task, and is used to determine whether the addresses are appropriate when accessing the temporary memory. used.

The comparison circuit 4-12 determines the contents of the memory address register 4-7 and the address range register 4 in order to determine whether the memory address to be accessed is within the normal address range of the currently executed task or program. Used to compare with the contents of -4, 4-10.

When the contents of the memory address register 4-7 are out of the address range, an error signal is output from the comparison circuit 4-12 to the sequence operation circuit 4-1.

In the programmable controller according to the present embodiment, when accessing a variable unique to a program,
The variable is accessed based on a base address unique to this program.

More specifically, when a variable unique to a program is accessed, the base address of the data memory 6 used by the program is stored in the base address register 4-3 before execution of the program. When accessing the address 6, the base address is added to the operand address to create an actual memory address.

Therefore, in the programmable controller of the present embodiment, an independent data area can be used for each program.

As described above, in the programmable controller according to the present embodiment, the variable is accessed based on the base address unique to the program. Therefore, when the program is switched, the base address is changed. Variables unique to the program can be accessed.

(Third Embodiment) In the programmable controller according to the present embodiment, as shown in FIG. 4, the sequence arithmetic unit 4 is provided with a variable which is a basis of calculation of a memory address, that is, a variable unique to a program. And a base address register 4-3 for storing a base address serving as a base when accessing the program. When the program is switched, the contents of the base address register 4-3 are changed by an instruction described later.

Therefore, in the programmable controller according to the present embodiment, when the program B1 and the program B3 use the same object program as shown in the conceptual diagram of FIG. Because the base address is different,
When accessing the variable X in each program, different variables can be accessed using the same offset.

As a result, it is possible to use independent local variables for each program, instead of using global resources such as registers and devices using fixed addresses as computation targets as in a conventional programmable controller.

As described above, in the programmable controller according to the present embodiment, the base register 4- which stores the base address when accessing the variable for each program is used.
3 is provided, by changing the contents of the base address register 4-3 when switching the program, it is possible to access a variable unique to the program.

(Fourth Embodiment) In the programmable controller of this embodiment, a task base address setting (hereinafter, ASSIG) having a configuration as shown in FIG. 6 for storing an address indicating a data area occupied by a task is stored.
N) to the base address register 4-
3 to execute the ASSIGN instruction when the task is switched, thereby designating a data area used by the program.

This ASSIGN instruction uses a task number as an operand, and, for example, from a task base address table shown in the conceptual diagram of FIG. It serves to read the corresponding base address and store it in base address register 4-3.

Therefore, in the programmable controller according to the present embodiment, the ASSIGN instruction is executed at the start of a task, for example, as shown in a program example shown in FIG. Can be set.

The program shown in FIG. 8 means that the program A1 of the task number 1 is executed. In the machine language expression, a program call instruction is placed after the ASSIGN instruction.

The contents of the base address table 4-3 are as follows:
The program can be downloaded from the monitor device 20 before the program is executed, and can be changed from the CPU 1 or the sequence operation device 4 for a change after the program is started.

As described above, in the programmable controller according to the present embodiment, the ASS
Since the IGN instruction is executed, the address indicating the data area occupied by the task can be stored in the base address register 4-3, so that the data area occupied by each task can be specified. .

(Fifth Embodiment) In the programmable controller of this embodiment, when a certain program calls another program, the address of a data area occupied by the called program is changed to a program call (hereinafter referred to as PROGRAM). By setting in the base address register 4-3 by an instruction, the called program uses a dedicated data area.

That is, in the fourth embodiment, the base address at the time of task switching is set by the ASSIGN instruction, but in this embodiment, the base address at the time of program switching is changed by the PROGRAM instruction. I do.

Therefore, in the programmable controller of this embodiment, as shown in the conceptual diagram of FIG. 9, for example, when the program B1 is called from the program A1, the data memory 6 of the program A1 and the data memory 6 of the program B1 are used. The arrangement is in the relationship as shown in FIG.

Although the program A1 uses the base address set by the task A, when the program B1 is called, it needs to be shifted by the offset of the program B1 (indicated by in FIG. 3).

This change can be made, for example, by changing P as shown in FIG.
The ROGRAM instruction executes.

The PROGRAM instruction has the data amount (the number of words) used by the called program and the program number as operands.

The PROGRAM instruction includes an auxiliary instruction P OFF is attached, and stores the offset address set by the PROGRAM instruction.

The PROGRAM instruction saves the contents of the current base address register 4-3, and stores a value obtained by adding the above offset value to the current value in the base address register 4-3 as a new base address.

When the program execution is completed, the saved base address is stored in the base address register 4 again.
Set to -3.

When a program is called in a task, the contents of the base address register 4-3 are rewritten using the offset address from the base address of the higher-order program as described above, so that An independent data area can be secured.

Although the PROGRAM instruction and the auxiliary instruction are used here for convenience, it is needless to say that the present embodiment can be configured with one instruction if the word length of the program memory 2 permits. When a certain program calls another program, the programmable controller reflects the size of the local variable area occupied by the called program based on the value currently set in the base address register 4-3. Since the base address register 4-3 is changed,
Another program called from one program can also use the dedicated data area, and it can occupy an area that is continuous with the local variable area used by the upper program and is the lower area. Become.

(Sixth Embodiment) In the programmable controller according to the present embodiment, as shown in FIG. 4, the sequence operation device 4 stores, in the variable , A base address register 4-3 for storing a base address serving as a base when accessing the program, an address range register 4-4 as a data range register for storing the size of a variable area unique to the program, and a temporary memory address range register 4-10, when a program is called from another program, the start address and data amount of a data area occupied by the called program are determined by a PROGRAM instruction using a base address register 4-3 and an address serving as a data range register. Range register 4-4 and Polaritons by setting the Li memory address range register 4-10, it is configured to detect access to a dedicated data area outside the called program.

That is, in the fifth embodiment, P
In the present embodiment, the execution is performed by changing the base address at the time of program switching by the ROGRAM instruction. However, in the present embodiment, not only the content of the base address register 4-3 is changed but also the address range register 4-4 and the PROGRAM instruction. The change of the temporary memory address range register 4-10 is also executed.

Therefore, in the programmable controller of the present embodiment, for example, the PR as shown in FIG.
When the OGRAM instruction is executed, the start address and the end address of the data memory 6 used by the program having the program number specified in the operand are read from the data memory range table as shown in the conceptual diagram of FIG. It is stored in the range register 4-4.

As described above, these addresses are compared with the contents of the memory address register 4-7 by the comparison circuit 4-12 each time the memory is accessed, and the program does not refer to data outside the unique data area. Is checked.

If an attempt is made to access an address outside the unique data area, an error signal is sent from the comparison circuit 4-12 to the sequence operation circuit 4-1 to invalidate the memory access as described above. Can be

As described above, in the programmable controller of the present embodiment, the PROGRAM instruction sets the range of the local variable area used by the called program to the address range register 4-4 which is the data range register.
And temporary memory address range register 4-10
, The address range register 4-4 and the temporary memory address range register 4
-10 can store a program-specific data area, so that the program does not access the data area of another program, that is, the called program does not access data outside the dedicated data area. It becomes possible to control.

(Seventh Embodiment) The programmable controller of the present embodiment is configured to use an independent temporary memory for each task.

More specifically, as shown in FIG. 4, the base address for the calculation of the memory address, that is, the base address for accessing a variable unique to the program is stored in the sequence operation device 4. And a temporary memory address register 4-9, which is a data range register for storing the size of a variable area unique to the program. By setting the start address and data amount of the data area in the base address register 4-3 for temporary use data and the temporary memory address register 4-9 by a dedicated task switching instruction (ASSSIGN instruction), the called program can be executed. While the data to be used uses a dedicated data area, It is configured to detect access to data outside the region.

Here, since the temporary memory is used for exchanging data between programs and the like, it is preferable that the temporary memory be independent for each task.

Therefore, in the programmable controller according to the present embodiment, when the above-described ASSIGN instruction is executed, the base address and the address range of the temporary memory are also changed at the same time as the base address is changed. As shown in the conceptual diagram of FIG. 12, independent temporary memories can be used for task A and task B.

That is, in the task base address table as shown in FIG. 7, the start address and the end address of the corresponding temporary memory are also stored, and the ASSIGN instruction reads them out and stores them in the temporary memory address register 4. -9 and the temporary address range register 4-10.

The method of calculating the memory address and the method of verifying the validity of the address range are the same as those of the data memory 6 described above.

As described above, in the programmable controller according to the present embodiment, when a task is switched, the start address and the data amount of the temporary use data area unique to the task are determined by the dedicated task switching instruction (ASSIGN instruction). Base address register 4 for temporary use data
3. Since the temporary memory address register 4-9 and the temporary address range register 4-10 are set, an independent temporary data area can be used for each task, and the data range can be monitored. Accordingly, it is possible to prohibit access to outside the dedicated temporary use data area.

(Eighth Embodiment) In the programmable controller of the present embodiment, the amount of data unique to a program is stored in the PROGRAM instruction so as to instruct the compiler of the amount of data unique to each program. It is configured to store.

Therefore, in the programmable controller according to the present embodiment, the amount of data unique to the program is obtained by calculation when compiling the sequence program. For example, as shown in the conceptual diagram of FIG.
It is stored as a part of the operand of the OGRAM instruction.

Thus, when the program is called while being nested one after another, the change amount of the base address of the data memory 6 can be easily calculated.

Further, when calculating the offset value which is the operand of the auxiliary instruction attached to the PROGRAM instruction, the compiler of the sequence program simply adds the data amount included in the PROGRAM instruction from the upper program to the target program. Thus, the change amount of the base address can be obtained.

This is particularly effective when it is desired to reduce the compile time of a program, such as when changing a program online.

As described above, in the programmable controller according to the present embodiment, the data amount of the local variable used by the program is included in the PROGRAM instruction. The variable area can be easily obtained.

(Ninth Embodiment) In the programmable controller according to the ninth embodiment, when a program is called, the start address of the program is specified by the program number assigned to the program, and the program is executed from within the program. When a dedicated program that is used only is called, the program is configured to be called by an address relative to the calling address.

That is, in each of the above-described embodiments, when a program is called, the program number is used as a source to determine the address of the target program. However, in the present embodiment, in addition to this, the relative Call instructions using addresses are also available.

For example, the PR shown in FIG.
The upper instruction of the OGRAM instruction is the same as that shown in FIG. 10, but the lower instruction is called not by using the program number of the program but by using a relative address from a calling address.

In this case, calling by the program number is useful when sharing a program with another program or task, but has a problem that the calling time is required.

In this respect, in the programmable controller according to the present embodiment, a program used only at a lower level of a certain program can be called by the above-mentioned relative address, so that the calling time can be reduced. .

As described above, in the programmable controller according to the present embodiment, programs are managed by unique numbers assigned to the programs.
PR related data such as the start address and the amount of data used
Since it is not necessary to include it in the OGRAM instruction, it is possible to configure the program with a small amount of program code.

When a program used only within a certain program is called, the program can be called at a high speed by calling using a relative address instead of a program number.

(Other Embodiments) (a) In the above embodiment, independent data areas are allocated by the CPU 1, that is, the compiler
The case of running with U1 has been described. However, the present invention is not limited to this.
, That is, the compiler can be run on the monitor device 20.

(B) In the above embodiment, the case where the CPU 1 and the sequence operation device 4 are separately provided has been described. However, the present invention is not limited to this, and the CPU 1 and the sequence operation device 4 may be integrally provided. Is also possible.

[0117]

As described above, according to the programmable controller of the present invention, an independent data area is allocated to each task and program, so that an independent local variable area is secured for each task and program. Therefore, it is possible to freely define and use variables for each task and program without being limited by the overlapping use of registers as in the related art.

Further, at the time of task switching or program switching, the base address of the data memory used by each task or program is automatically set by a dedicated instruction. Data area can be used, and each variable is specified by an offset from the base address.
Local variables can be realized.

Further, at the time of data access, the validity of the memory area is also verified at the same time, so that it is possible to prevent erroneous access to an area used by another program. In addition, such a function,
This can be realized not only for local variables but also for temporary data.

Furthermore, since the method using the program number and the method using the relative address are used together to call the program, it is possible to reduce the calling time of the program.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration example of a main part of a programmable controller according to the present invention.

FIG. 2 is a conceptual diagram showing a configuration example of tasks and programs in the programmable controller according to the first embodiment of the present invention.

FIG. 3 is a conceptual diagram showing a configuration example of a data memory used by a program in a task in the programmable controller according to the first embodiment;

FIG. 4 is a block diagram showing a configuration example of a main part of a sequence operation device in a programmable controller according to a second embodiment of the present invention.

FIG. 5 is a conceptual diagram for explaining a method of accessing a variable in a program in a programmable controller according to a third embodiment of the present invention.

FIG. 6 is a conceptual diagram showing a configuration example of a task switching instruction in a programmable controller according to a fourth embodiment of the present invention.

FIG. 7 is a conceptual diagram showing a configuration example of a task base address table in the programmable controller according to the fourth embodiment.

FIG. 8 is a diagram showing a program example of a task switching instruction in the programmable controller according to the fourth embodiment.

FIG. 9 is a conceptual diagram illustrating an example of calling a program in a programmable controller according to a fifth embodiment of the present invention.

FIG. 10 is a conceptual diagram showing a configuration example of a program switching instruction in a programmable controller according to each of the fifth, sixth, and eighth embodiments of the present invention.

FIG. 11 is a conceptual diagram showing a configuration example of a data memory range table in the programmable controller according to the sixth embodiment.

FIG. 12 is a conceptual diagram showing a configuration example of a temporary memory in a programmable controller according to a seventh embodiment of the present invention.

FIG. 13 is a conceptual diagram showing a configuration example of a program call instruction by a relative address in a programmable controller according to a ninth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... CPU 2 ... Program memory 3 ... Work memory 4 ... Sequence operation device 5 ... Sequence program memory 6 ... Data memory 7 ... Microcomputer bus 8 ... Communication interface 9 ... I / O 20 ... Monitor device.

Claims (10)

[Claims] 1. A programmable controller comprising: a sequence operation device that executes a sequence program stored in a sequence program memory; and a data memory that stores data such as variables used for control. A programmable controller, wherein an independent data area is allocated to each task constituting the sequence program and each program in the task. 2. A central processing unit for controlling execution of the whole controller, a program memory storing a program executed by the central processing unit, and a sequence for executing a sequence program stored in a sequence program memory. In a programmable controller including an arithmetic unit and a data memory for storing data such as variables used for control, the allocation of the data memory includes a task constituting the sequence program and a program in the task. A programmable controller, wherein an independent data area is assigned to the controller. 3. The programmable controller according to claim 1, wherein when a variable unique to the program is accessed, the variable is accessed based on a base address unique to the program. A programmable controller, characterized in that: 4. The programmable controller according to claim 1, wherein the sequence operation device includes a base address register that stores a base address serving as a base when a variable unique to the program is accessed. A programmable controller characterized in that the contents of the base address register are changed by a predetermined instruction when the program is switched. 5. The programmable controller according to claim 4, wherein a task base address setting instruction for storing an address indicating a data area occupied by the task is provided in the base address register; A programmable controller, wherein a data area used by the program is specified by executing a task base address setting instruction. 6. The programmable controller according to claim 4, wherein when a certain program calls another program, an address of a data area occupied by the called program is set in the base address register by a program call instruction. Thereby, the called program uses a dedicated data area. 7. The programmable controller according to claim 1, wherein a base address register that stores a base address serving as a base when accessing a variable unique to the program in the sequence operation device; A data range register for storing the size of a variable area unique to the program, wherein when a certain program is called from another program, a start address and a data amount of a data area occupied by the called program are determined by a program call instruction. A setting of the base address register and the data range register to detect access of the called program to outside the dedicated data area. 8. The programmable controller according to claim 1, wherein a base address register that stores a base address serving as a base when accessing a variable unique to the program in the sequence operation device; A data range register for storing the size of a variable area unique to the program, and when switching the task, the head address and data amount of the temporary use data area unique to the task are changed by a dedicated task switching instruction. By setting the base address register and the data range register for temporary use data, the data used by the called program uses a dedicated data area and detects access to the outside of the dedicated data area. Programmable feature Controller. 9. The programmable controller according to claim 1, wherein an amount of data unique to the program is included in a program call instruction so as to instruct a compiler of an amount of data unique to the program. A programmable controller characterized in that the program is stored in a programmable controller. 10. The programmable controller according to claim 1, wherein, when the program is called, a start address of the program is designated by a program number assigned to the program, and the program is designated from within the program. A programmable controller characterized in that when a dedicated program used only in a program is called, the program is called by a relative address from a calling address.