JP2014071862A - Peripheral device for programmable controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a peripheral device for a programmable controller which can easily be standardized as a sub-program in reusing an existing sequence program.SOLUTION: A sequence program edition processing part 400 is provided with: a sequence program display processing part 440; a selection processing part 410 and a copy processing part 420 for selecting and copying a ladder circuit within a designated range; a sub-programming processing part 431 for inputting a sub-program name and putting it into a sub-program format; a sub-program paste processing part 430 for pasting the ladder circuit put into the sub-program format to a sub-program area; a sub-program instruction insertion processing part 433; a sub-program display development processing part 441 for developing the sub-program display between a sub-program call instruction and its next step; a sub-program folding processing part 442 for folding display; and a display switch processing part 443 for switching display development and folding.

Description

  The present invention relates to a peripheral device for a programmable controller.

  Many programmable controllers that control equipment constituting the equipment are used for production equipment. The sequence program of these programmable controllers is created by a programming language such as a ladder circuit using a peripheral device. In this programming, a method of describing by a conventional device address is generally used. However, in recent years, a method of describing by using a variable name and separately associating the variable name with the device address has been generalized. In programming using such a variable (hereinafter referred to as variable programming), a sequence program is a description that does not depend on an address via a variable name for a device. Therefore, in the variable programming, the sequence program can be reused by changing the association between the variable name and the device address according to the device to be controlled. Thus, variable programming is more flexible for reuse than programming using devices.

  For example, in Patent Document 1, when developing a control system in which a plurality of programmable controllers having exactly the same function are controlled by a single programmable controller that plays a central role, the same variable is used between the programmable controllers. A peripheral device of a programmable controller capable of variable programming using a name (label name) is disclosed.

JP 2007-265252 A

  However, there are cases in which reusing an existing sequence program cannot be performed by simply changing the association between variable names and device addresses. For example, when creating a sequence program for controlling equipment in which two identical transfer devices are arranged on the left and right, the existing sequence program for controlling equipment in which this transfer device is arranged is reused It is.

  In such reuse, there is a method of controlling two units by creating two sets of copies of the control part related to the above-mentioned transport device. In this method, variable names are duplicated between sets. Therefore, before changing the association between the variable name and the device address, it is necessary to reassign the variable name to eliminate the duplication. It can be said that this program configuration has low maintainability.

  In addition, there is a reusing method for controlling two transport devices by using a control part related to the transport device as a sub-program and calling the sub-program in multiple times. This program configuration is highly maintainable. For this purpose, it is necessary not only to change the control part to the form of a subprogram but also to change the subprogram so that multiple calls can be made. In this way, changing a subprogram so that it can be called multiple times is referred to as standardization of the subprogram.

  Reuse by standardization of subprograms can be performed with a larger scale of reuse and higher convenience compared to reusing functions that are frequently used as functions or function blocks. Also, the program structure can be highly maintainable.

  Subprogram standardization includes separation of input / output circuits, internalization of variables, correspondence of variables that hold execution results, and the input circuit that passes values to subprogram input elements on the main program side as well Creating an output circuit for transferring the value of an output element from a subprogram, and there is a problem that it takes time.

  The present invention has been made to solve the above-described problems, and the problem to be solved by the present invention is a programmable that can be easily standardized as a subprogram in reuse of an existing sequence program. It is to provide a peripheral device of a controller.

  The invention according to claim 1 is a peripheral device of a programmable controller comprising a sequence program edit processing unit for editing a sequence program for controlling a device, wherein the sequence program includes circuit elements such as contacts and coils. It is described by a ladder circuit and is composed of a main program and a plurality of subprograms having a subprogram format, and the sequence / program edit processing unit includes a sequence / program display processing unit that displays the sequence program on a display device, A selection processing unit that selects a ladder circuit in a range designated from the sequence program displayed on the display device; a copy processing unit that copies a ladder circuit in a range selected by the selection processing unit; and the copy processing unit. The copied ladder A subprogram processing unit that inputs a subprogram name into a circuit and converts the subprogram format into a subprogram format, and a subprogram paste processing unit that pastes a ladder circuit in the subprogram format into a subprogram area of the sequence program A subprogram instruction insertion processing unit that inserts a subprogram call instruction at a specified position, and a subprogram display expansion processing unit that expands the display of the subprogram between the subprogram call instruction and the next step. A subprogram display folding processing unit that folds the display of the subprogram between the subprogram call instruction and the next step, and a display switching processing unit that switches between expansion and folding of the display of the subprogram. Features.

  According to invention of Claim 1 comprised as mentioned above, the sequence program edit process part of the peripheral device of a programmable controller reads the sequence program to recycle separately from the sequence program currently edited, It can be displayed on the display device by the sequence program display processing unit. Then, from the sequence program displayed on the display device, the selection processing unit can select a ladder circuit in the range of the control part to be standardized as a subprogram related to the device to be controlled. When the “copy” editing command is executed, the copy processing unit is called. The copy processing unit temporarily copies and holds the ladder circuit in the selected range on the buffer memory. Next, when the edit command “Paste as Subprogram” is executed at the step position for controlling the device to be controlled in the sequence program currently being edited, the subprogram processing unit and the subprogram paste The attachment processing unit is called. The subprogram processing unit instructs the input of a subprogram name. When the subprogram name is input, the subprogram instruction insertion processing unit is called. The subprogram instruction insertion processing unit inserts a subprogram call instruction at the step position where the command is executed. The previously entered subprogram name is set in the operand of this subprogram call instruction. On the other hand, the ladder circuit on the buffer memory is pasted to the subprogram area by the subprogram pasting processing unit, and is converted into a subprogram format by the subprogramming processing unit.

  The sequence / program display processing unit displays the subprogram call instruction, and the subprogram display expansion processing unit expands the display of the subprogram between the subprogram call instruction and the next step. The display of the expanded subprogram can be folded by the subprogram display folding processing unit by calling the display switching processing unit.

  The sequence program edit processing unit can edit regardless of whether the subprogram display is expanded or folded, and by editing the subprogram display while expanding it, a ladder circuit in which the main program and subprogram are continuous in the same area. Can be edited as if Thus, the editing between the main program and the subprogram can be performed smoothly, so that the work of standardizing the subprogram can be easily performed.

  The invention according to claim 2 is the peripheral device of the programmable controller according to claim 1, wherein the sequence program is described using a variable and holds variable information corresponding to the sequence program. A variable information table, and a variable information table editing processing unit for associating the variable of the variable information table with a device address, wherein the subprogram processing unit is configured to execute the ladder program in the subprogram format. The transfer instruction for transferring the value of the variable to the save area provided in the internal device is inserted in the step before the return instruction at the end of the subprogram, and the step from the save area to the step after the label instruction at the top of the subprogram is inserted. A subprogram variable holding processing unit for inserting a transfer instruction for transferring a value to the variable; The information table editing processing unit associates an address of an internal device with the variable used in the subprogram so that the address of the save area is different for each invocation of the subprogram. .

  According to the invention of claim 2 configured as described above, the subprogram variable holding processing unit of the peripheral device of the programmable controller is internally provided at the beginning and the end of the subprogram with respect to the ladder circuit in the subprogram format. A transfer instruction for transferring a value from the save area provided in the device to the variable and a transfer instruction for transferring the value of the variable to the save area are inserted.

  Further, the variable information table editing processing unit associates the address of the internal device with the variable used in the subprogram so that the address of the internal device in the save area becomes a different address for each invocation of the subprogram. Since the ladder circuit subprogrammed in this way can hold the previous value of the variable, it can cope with multiple calls.

  According to the present invention, it is possible to provide a peripheral device of a programmable controller that can be easily standardized as a subprogram in reuse of an existing sequence program.

1 is a system configuration diagram of a peripheral device according to an embodiment of the present invention. It is a block diagram of the programmable controller which concerns on embodiment of this invention. 3 is a programming model of a peripheral device according to an embodiment of the present invention. It is a program block diagram of the sequence program edit process part of the peripheral device which concerns on embodiment of this invention. It is a screen example of the dialog box of the peripheral device according to the embodiment of the present invention. It is the sequence program display example 1 of the peripheral device which concerns on embodiment of this invention. It is a sequence program display example 2 of the peripheral device which concerns on embodiment of this invention. It is operation | movement explanatory drawing of the sequence program which concerns on embodiment of this invention. It is explanatory drawing of the variable information table which concerns on embodiment of this invention.

There are various types of peripheral devices for programmable controllers, such as those composed of dedicated hardware and those composed of general-purpose personal computers (hereinafter referred to as PCs). FIG. 1 is a system configuration diagram when a PC on which peripheral device software of this embodiment is installed is used as the peripheral device 10.
Hereinafter, the system configuration of the peripheral device 10 of the programmable controller according to the embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the peripheral device 10 includes a system memory 28, a hard disk drive (HDD) 24, a communication interface 27, a keyboard 22, a mouse 23, and the like via a system bus 12 of a CPU (central processing unit) 11. A display 21 is connected. Peripheral device software 26 is installed in the HDD 24.

  The system memory 28 is a storage means including a RAM (random access memory) 14 and a ROM (read only memory) 13. The RAM 14 is used by the CPU 11 to read out and execute each program from the HDD 24. The RAM 14 is used as a data area for temporarily storing data required for executing each program and a work area for generating various information. The ROM 13 stores a basic input / output system (BIOS) program 13a, which performs initial settings when the peripheral device 10 is activated, and activates an operating system (OS) 25 installed in the HDD 24. . The communication interface 27 communicates with the programmable controller via a communication cable (not shown). The display 21 is an output device, and is used to output a screen display when the peripheral device software 26 edits a sequence program. The keyboard 22 and the mouse 23 are input devices, respectively, and are used for inputting information when the peripheral device software 26 edits a sequence program. The HDD 24 is a storage device composed of a hard disk, and has peripheral device software 26 and an OS 25 installed therein.

  The peripheral device software 26 includes a sequence / program editing program 26a, a conversion program 26b, a compile processing program 26c, a variable information table editing program 26d, and the like. Each function of the peripheral device 10 is implemented by each program of the peripheral device software 26. For example, Windows 7 (registered trademark of Microsoft Corporation) or the like is applied to the OS 25.

  The sequence program editing program 26a edits a sequence program (source code) 14a in the form of a ladder circuit diagram. The variable information table editing program 26d edits the variable information table used in the sequence program (source code) 14a. The sequence program (source code) 14a is obtained by reading a sequence program (binary code) (not shown) and converting it into a conversion program 26b. The edited sequence program (source code) 14a is compiled by the compile processing program 27b together with the variable information number table 14b, and converted to a sequence program (binary code) by the conversion program 26b.

FIG. 2 is a configuration diagram of the programmable controller 100.
The CPU unit 110 is connected to a ROM 115, a RAM 114, a program memory 113, an input / output control circuit 118, and a communication interface 119 via an internal bus 112 of the CPU 111. The communication interface 119 communicates with the peripheral device 10 via a communication cable (not shown). The sequence program and parameters written by the peripheral device 10 via the communication interface 119 are stored in the program memory 113. The ROM 115 stores a system program 115a, and the RAM 114 stores an internal memory 114a. The system program 115a controls the CPU unit 110 and executes sequence control by executing the sequence program 113a.

FIG. 3 is a programming model 200 of the programmable controller 100 in the peripheral device 10.
The sequence program 113a includes a main program 113b and a subprogram 113c having a subprogram format, and has a main program area 211 in which the main program 113b is stored and a subprogram area 212 in which a plurality of subprograms 113c are stored. ing. The main program area 211 and the subprogram area 212 are divided by a program end instruction indicating the last step of the main program 113b. The capacity of the sequence program 113a is defined by the specifications and parameters of the corresponding programmable controller 100.

  The sequence program 113a is stored in the program memory of the programmable controller 100 and executed. The main program 113b is executed sequentially from the first step to the last step for each scan of the programmable controller 100. The subprogram 113c is called from the main program 113b and executed.

  The subprogram 113c is a subprogram type program, and has a label instruction (LABEL) at the top step and a return instruction (RETURN) at the end step, and the section between these two instructions is configured as a program body. The label instruction has a subprogram name as an operand, and is distinguished from other subprograms 113c by this subprogram name.

  The subprogram 113c is called by a subprogram call instruction (CALL). The subprogram 113c to be called is the subprogram 113c having the subprogram name set in the operand. The subprogram 113c called from the main program 113b is executed sequentially from the label instruction (LABEL) at the head step, and then returns to the main program 113b as the caller by a return instruction (RETURN) at the tail step.

  The internal device 231 is an internal memory of the programmable controller 100. The variable information table 220 shows the association between the address of the internal device 231 and the variable name. Normally, the internal device 231 of the variable information table 220 is assigned a different address for each variable name by the compilation process.

  The input / output device 232 is an input / output unit of the programmable controller 100 connected to the device 160 to be controlled via an input / output control circuit. The variable information table 220 shows the association between the address of the input / output device 232 and the variable name. Normally, the input / output device 232 of the variable information table 220 is assigned an address depending on the connection position with the device 160. That is, the address of the input / output device 232 is determined at the time of design.

  In variable programming, each element of the sequence program 113a is described by a variable name, and the sequence program 113a is associated with a device type and an address via the variable information table 220.

FIG. 4 shows a program configuration of the sequence / program edit processing unit 400 of the peripheral device 10 of the programmable controller 100.
In the sequence program editing processing section 400 configured as described above, a process for standardizing as a subprogram in reuse of an existing sequence program will be described.

  First, the sequence program edit processing unit 400 reads out a sequence program to be reused, which is different from the sequence program currently being edited, and displays the sequence program on the display device by the sequence program display processing unit 440.

  Then, the selection processing unit 410 identifies the range of the ladder circuit of the control portion related to the device to be controlled from the sequence program displayed on the display device, and selects the range of the ladder circuit.

Next, when the “copy” editing command is executed, the copy processing unit 420 is called.
The copy processing unit 420 temporarily copies and stores the ladder circuit and variable information table in the selected range on the buffer memory.

  Next, in the sequence program that is currently being edited, when the edit command “Paste as subprogram” is executed at the step position for controlling the device to be controlled, the subprogram processing unit 431 and the subprogram The paste processing unit 430 is called.

  The subprogram processing unit 431 displays a dialog box 310 for inquiring about the subprogram name shown in FIG. 5 and instructs the input of the subprogram name 311.

  When the subprogram name 311 (FIG. 5) is input to the dialog box 310, the subprogram instruction insertion processing unit 433 of FIG. 4 is called. The subprogram instruction insertion processing unit 433 inserts a subprogram call instruction (CALL) at the position of the edit cursor that executed the command. In the operand of this subprogram call instruction (CALL), the subprogram name 311 (FIG. 5) input in the dialog box 310 (FIG. 5) and the address of a save area described later are set.

  On the other hand, the subprogram pasting processing unit 430 pastes the ladder circuit on the buffer memory to the subprogram area. Further, the subprogramming processing unit 431 converts the ladder circuit pasted into the subprogram area into a subprogram format. That is, a label instruction (LABEL) is inserted in the first step, and a return instruction (RETURN) is added in the last step. In this operand, the previously input subprogram name 311 (FIG. 5) is set.

  The subprogram variable holding processing unit 432 inserts a transfer instruction (MOVE) that transfers the value of the variable to the save area provided in the internal device in the step before the return instruction (RETURN) of the last step, and labels the first step. A transfer instruction (MOVE) for transferring a value from the save area to the variable is inserted in a step subsequent to the instruction (LABEL). The address of this save area is set by the operand of the subprogram call instruction (CALL) so that it becomes a different address for each subprogram call. The data size to be transferred is the size of all variable areas used in the subprogram.

  Further, the variable information table on the buffer memory is added to the variable information table of the sequence program currently being edited, and the internal device is associated with all variables used in the subprogram. Then, the variable information table edit processing unit 450 associates addresses with these internal devices. The variable addresses are packed in order from the empty address, and the variable area used in the subprogram is a continuous memory block.

  The sequence / program display processing unit 400 displays the above-mentioned subprogram call instruction (CALL), and the subprogram display expansion processing unit 441 causes the subprogram display instruction (CALL) to be displayed between the subprogram call instruction (CALL) and the next step. Expand the display. On the other hand, the subprogram display folding processing unit 442 can fold the display of the expanded subprogram.

  The sequence / program display processing unit 400 can switch between expansion and folding of the display of the subprogram by calling the display switching processing unit 443. Note that the subprogram displayed here is the subprogram itself, but the substance of the subprogram exists in the subprogram area, not at the displayed position.

6 and 7 are sequence program display examples by the sequence program display processing unit 400. FIG.
As shown in FIG. 6, the sequence program is displayed by arranging circuit elements such as contacts and coils constituting the ladder circuit on a grid sheet. An edit cursor 340 is displayed on one of the grids, and can be moved between the grids with a direction key of a mouse or a keyboard. Then, the circuit element at the position indicated by the editing cursor 340 can be edited by the editing operation.

  FIG. 6 shows a state in which the display of the subprogram SUB010 is expanded between the subprogram call instruction (CALL) in step 0103 and the next step 0104 by the subprogram display expansion processing unit 441 (FIG. 4). . Further, the range of the subprogram SUB010 is indicated by dividing lines 331 and 332.

  FIG. 7 shows a state in which the display of the subprogram SUB010 between the subprogram call instruction (CALL) in step 0103 and the next step 0104 is folded by the subprogram display folding processing unit 442 (FIG. 4).

  When the mouse cursor (arrow icon) 380 in FIG. 6 is moved onto the dividing lines 331 and 332, the mouse cursor (arrow icon) 380 is switched to the mouse cursor (folding icon) 381. When the mouse cursor (folding icon) 381 is clicked, the sub-program display folding processing unit 442 (FIG. 4) is called from the display switching processing unit 443 (FIG. 4), and the sub-program SUB010 is displayed as shown in FIG. Can be folded. At this time, there is only one separator line 331, 332.

  When the mouse cursor (arrow icon) 380 is moved onto a single dividing line 331, 332, the mouse cursor (arrow icon) 381 is switched to a mouse cursor (expanded icon) 382. When the mouse cursor (development icon) 382 is clicked, the display switching processing unit 443 (FIG. 4) calls the subprogram display development processing unit 441 (FIG. 4) to return to the display shown in FIG. 6, and the subprogram SUB010 is displayed. The display can be expanded.

  The edit cursor 340 can be moved across the dividing lines 331 and 332 regardless of whether the subprogram display is expanded or folded.

  In this way, the sequence / program edit processing unit 400 can edit regardless of the expansion and folding of the subprogram display, and the main program and the subprogram can be in the same area by editing the subprogram display while expanding it. Can be edited as if it were a continuous ladder circuit.

Next, the operation of the sequence program created in this way will be described.
The peripheral device 10 in FIG. 1 stores the sequence program 113a in the program memory 113 of the programmable controller 100 in FIG. 2 connected via a communication cable (not shown).

  The sequence program 113a shown in FIG. 8 is a main program and a standardized subprogram SUB010 stored in the program memory 113 of FIG. 2 and executed by the system program 115a. This subprogram SUB010 is called by a sequence program 113a that controls equipment in which two identical devices (device 1 and device 2) are arranged on the left and right, and controls device 1 and device 2 individually. It is.

  FIG. 9 is a variable information table 500 corresponding to the subprogram SUB010. Due to the standardization of subprograms, all variables used by subprograms are assigned internal devices. The sequence program 113a is stored in the program memory 113 of the programmable controller 100 in a state in which addresses are associated with all the variables to be used with reference to a variable information table associated with variable names and device addresses. ing.

  The internal device shown in FIG. 8 is the internal memory 114a of the RAM 114 in FIG. 2, and the subprogram SUB010 is executed with reference to the variable value in the area sp0. The areas sp1 and sp2 are save areas, and are set by operands so that different addresses are provided for each subprogram call instruction (CALL). The sizes of the areas sp0, sp1, and sp2 are the same as the sizes of all the variable areas used in the subprogram.

  As shown in FIG. 8, the sequence program 113 a executes a subprogram call instruction (CALL) 601 at a step position where the device 1 is controlled. In this operand, the subprogram name SUB010 and the save area address (sp1) are set. When the subprogram call instruction (CALL) 601 is executed, the execution step pointer moves to the label instruction (LABEL) of the subprogram SUB010.

  Next, when the transfer instruction (MOVE) of the next step of the label instruction (LABEL) is executed, the previous value of the variable is transferred from the area sp1 to the area sp0 of the internal device. The subprogram SUB010 executes control of the device 1 by referring to the variable value in the area sp0 and executing the program body. Then, by executing the transfer instruction (MOVE) in the previous step of the return instruction (RETURN), the current value of the variable is transferred from the area sp0 to the area sp1.

  In addition, the sequence program 113a executes a subprogram call instruction (CALL) 602 at a step position where the device 2 is controlled. In this operand, the subprogram name SUB010 and the save area address (sp2) are set. When the subprogram call instruction (CALL) 602 is executed, the pointer of the execution step moves to the label instruction (LABEL) of the subprogram SUB010.

  Next, when the transfer instruction (MOVE) of the next step of the label instruction (LABEL) is executed, the previous value of the variable is transferred from the area sp2 of the internal device to the area sp0. The subprogram SUB010 executes control of the device 2 by referring to the variable value in the area sp0 and executing the program main body. Then, by executing the transfer instruction (MOVE) in the previous step of the return instruction (RETURN), the current value of the variable is transferred from the area sp0 to the area sp2.

  Thus, since the standardized subprogram SUB010 can restore the previous value of the variable and hold the current value, the subprogram SUB010 can be called in multiple times to control the devices 1 and 2 separately. Can do. According to the present embodiment, the work of standardizing such a subprogram can be easily performed.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed within the scope of the invention described in the claims. For example, in this embodiment, the display switching of the subprogram is performed by clicking the mouse cursor on the dividing line, but for example, a method using a display command “subprogram display switching” may be used. In addition, the boundary between the main program and the subprogram is indicated by a dividing line, but the boundary may be indicated by a background color or the like.

10: peripheral device, 11: CPU, 12: internal bus, 13: ROM,
13a: BIOS, 14: RAM,
14a: sequence program (source code), 14b: variable information table,
14c: parameter, 21: display, 22: keyboard, 23: mouse
24: HDD, 25: OS, 26: Peripheral device software,
26a: sequence program editing program, 26b: conversion program,
26c: compilation processing program, 26d: variable information table editing program,
27: Communication interface, 28: System memory,
100: Programmable controller, 110: CPU unit, 111: CPU,
112: Internal bus 113: Program memory 113a: Sequence program
113b: main program, 113c: subprogram, 114: RAM,
114a: internal memory, 115: ROM, 115a: system program,
118: Input / output control circuit, 119: Communication interface, 160: Device
200: Programming model, 220: Variable information table,
231: Internal device, 232: Input / output device,
310: Paste as subprogram dialog box,
311: Subprogram name, 331, 332: Separator line, 340: Edit cursor,
380: Mouse cursor (arrow icon),
381: Mouse cursor (folding icon),
382: Mouse cursor (expanded icon),
400: Sequence program editing processing unit 410: Selection processing unit
420: Copy processing unit, 430: Subprogram pasting processing unit,
431: Subprogram processing unit, 432: Subprogram variable holding processing unit,
433: Subprogram instruction insertion processing unit, 440: Sequence program display processing unit,
441: Subprogram display development processing unit, 442: Subprogram display folding processing unit,
443: display switching processing unit, 450: variable information table editing processing unit,
500: Variable information table, 601 and 602: Subprogram call instruction

Claims (2)

In a peripheral device of a programmable controller comprising a sequence / program edit processing unit for editing a sequence / program for controlling a device,
The sequence program is described by a ladder circuit including circuit elements such as contacts and coils, and includes a main program and a plurality of subprograms having a subprogram format.
The sequence program edit processing unit
A sequence program display processing unit for displaying the sequence program on a display device;
A selection processing unit for selecting a ladder circuit in a specified range from the sequence program displayed on the display device;
A copy processing unit for copying a ladder circuit in a range selected by the selection processing unit;
A subprogram processing unit that inputs a subprogram name to the ladder circuit copied by the copy processing unit, and converts the program into the subprogram format;
A sub-program pasting processing unit for pasting the ladder circuit in the sub-program format into the sub-program area of the sequence program;
A subprogram instruction insertion processing unit for inserting a subprogram call instruction at a specified position;
A subprogram display expansion processing unit for expanding the display of the subprogram between the subprogram call instruction and the next step;
A subprogram display folding processing unit for folding the display of the subprogram between the subprogram call instruction and the next step;
A peripheral device for a programmable controller, comprising: a display switching processing unit that switches between expansion and folding of display of the subprogram. The peripheral device of the programmable controller according to claim 1,
The sequence program is described using variables,
A variable information table for holding variable information corresponding to the sequence program;
A variable information table editing processing unit for associating the variable of the variable information table with a device address;
The subprogramming processing unit includes:
For the ladder circuit in the subprogram format,
Insert a transfer instruction to transfer the value of the variable to the save area provided in the internal device in the previous step of the return instruction at the end of the subprogram,
Insert a transfer instruction to transfer a value from the save area to the variable after the label instruction at the top of the subprogram.
It has a subprogram variable holding processing unit,
The variable information table edit processing unit
Associate an internal device address with the variable used in the subprogram,
A peripheral device of a programmable controller, wherein the address of the save area is different for each call of the subprogram.

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