JPH10326105A - Programmable controller and its programming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the breakdown of data areas used by other tasks without managing the data areas for every program that performs the writing into a data area via a user program of a programmable controller. SOLUTION: At a conversion processing part of the control part of a programming device, the use of a specific data area where a label is added is declared in a program (P1). When the data word length and the number of words are designated for the specific data area, the capacity of the data area is decided based on these decided data word length and number of words. Then the specific data area is allocated to a part of an RAM of a programmable controller (P3). The specific data area can be accessed by a user program only via the label.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a programming device for programming a user program to be executed by a programmable controller, and a programmable controller for executing a user program programmed by the programming device.

[0002]

In recent years, equipment to be controlled by a programmable controller (hereinafter, referred to as a PC) has become large-scale and complicated, and accordingly, a control program of the PC and data accompanying the PC have been accompanied. Are also increasing in capacity.

On the other hand, in a conventional PC programming device, a part of a memory area of a PC is disclosed as a data area that can be used by a user.
By specifying the start address of the data area, an array-like area is used.

[0004] However, the data area is an area commonly used by each task of the user program, and unless the memory area used by itself is managed for each task,
In some cases, a memory area used by another task may be destroyed beyond its own memory area.

[0005] Therefore, in the task of writing to the data area, whether or not the writing to be performed is possible is determined by comparing the capacity of its own memory area with the amount of write data, and writing is possible. If it is, write
It is necessary to write a program for managing the memory area as described above, and there has been a problem that the programming operation becomes complicated.

Further, since the set data area is merely an array of addresses, even in a task which does not need to use the data area, if the address of the data area is described due to a programming mistake or the like, carelessness is required. May be accessed, and a malfunction such as an unexpected operation may occur. Also from this point, data protection was not sufficient.

The present invention has been made in view of the above circumstances, and an object of the present invention is to allow a user program to manage a data area for each task for writing to the data area without using the data area for management. It is an object of the present invention to provide a programmable controller programming device and a programmable controller that do not destroy a data area.

[0008]

According to a first aspect of the present invention, a user simply declares the use of a data area to which an identification name has been assigned in a user program. The data area is automatically allocated to a part of the memory area of the programmable controller with a predetermined capacity.

Therefore, the user does not need to specify each assigned address or capacity to use the data area, which facilitates programming. Also, since the data area can be accessed only through the identification name, even if an address is carelessly described in the user program, access to the data area can be prevented. In addition, data protection management can be performed reliably and easily.

According to the second aspect of the present invention, when the data word length and the number of data are specified by the identification name assigning means, the area allocating means is configured to store the data based on the data word length and the data number. Since the predetermined capacity of the area is determined, the user can use a plurality of data areas having different data word lengths and the number of data according to purposes, thereby increasing the degree of freedom of the user program.

According to the third aspect of the present invention, the number of data for accessing the corresponding data area in the user program can be specified as a parameter for the identifier assigned by the identifier assigning means. . Therefore, even when the user program uses a plurality of data areas having different data word lengths and data numbers in the user program, for example, the user does not need to calculate the address offset according to the different data word length for each data area. Since it is only necessary to specify a large number of data, the degree of freedom of the user program is increased and the description is easier.

According to a fourth aspect of the present invention, when the conversion means converts the user program into a format executable by the target programmable controller, the identification name is described in any of the steps. If so, an identification flag indicating that the identification name is used is set in the step.
Therefore, by referring to the identification flag, the programmable controller can determine whether or not what is specified in the operand of the step is a data area declared to be used in the user program.

According to a fifth aspect of the present invention, when the simulation means simulates the execution state of the user program, the identification flag is set in the step of executing the write instruction. If you have
If a comparison is made between the writable capacity of the data area to which the identification name is assigned and the write capacity specified for the data area, and execution of the write command determines that the data area is exceeded, an error will occur. Output a message.

Therefore, for example, for a step in which the number of data of the parameter assigned to the identification name is specified by an immediate value, the data area is overrun by performing a simulation before the program is actually executed by the programmable controller. Since it is possible to check in advance whether or not writing is performed, debugging can be performed more efficiently.

According to a sixth aspect of the present invention, the transmitting means transmits the data area information relating to the data area allocated by the area allocating means together with the user program converted into an executable form. Transmit to the programmable controller side. Therefore, the programmable controller can obtain information such as the address of the data area to which the identification name is given by referring to the presence or absence of the identification flag and the data area information in each step of the user program.

According to the seventh aspect of the present invention, when the identification flag is set in the step of executing the write instruction when the user program converted into the execution form is executed, the write determination means may execute the data area information. Compare the writable capacity of the data area with the identification name specified by the operand of the step with the write capacity specified for the data area, and execute the write instruction. If the area is exceeded, an error flag indicating a write error is set in the execution status register of the CPU.

Therefore, when the user program is executed, for example, when the number of data of the parameter assigned to the identification name is given by a variable whose value changes according to the actual processing result, the writing is actually executed. Before being
It is possible to check whether or not the write is a write that exceeds the data area by referring to the error flag of the execution status register. Therefore, it is possible to prevent data stored in other areas from being destroyed. Can be prevented.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. 7 and 8 are functional block diagrams showing the configuration of the programmable controller and its programming device. In FIG. 8, a programming device 1 is constituted by a personal computer, for example, and includes a keyboard 2, a control unit (identification name assigning means, transmitting means) centered on a microcomputer 3,
It comprises a display 4 and the like.

A user program (hereinafter, simply referred to as a program) to be executed by a programmable controller (hereinafter, referred to as PC; see FIG. 7) 5 is input to the control unit 3.
An editor 3a which is software for correction, a conversion processing unit (area allocation means, conversion means) 3b for performing a conversion process of an input program, and a simulator for simulating a program execution state by the PC 5 (simulation means, It is assumed that the write determination simulation means 3c is read from the hard disk 6 and is resident on the RAM, which is a work area (not shown).

The programming device 1 further has a communication interface (transmission means) 7 for transferring data to and from the PC 5. The communication interface 7 performs data transfer via a communication cable 8 by a serial communication method such as RS-232C or RS-485.

On the other hand, as shown in FIG.
PU 9, a ROM 10 and a RAM 11 connected to the CPU 9 via a system bus, a communication interface 7 connected to a communication interface 7 of the programming device 1 via a communication cable 8, and also connected to the CPU 9 via a communication bus. 12 and the like.

The ROM 10 stores firmware (see FIG. 9) which is a program for performing basic control of the CPU 9, and the RAM 11 stores a user program and data transmitted from the programming device 1 side. It has become so. Also, the CPU 9 has an I / O
Another I / O device (not shown) is connected via a bus.

FIG. 9 conceptually shows a hierarchical structure of hardware and software when the CPU 9 of the PC 5 executes a program. In this FIG.
The hardware 13 of U9 is at the lowest layer, and the upper layer is C
The firmware 14 of the PU 9 exists, and a ladder program 15 as a user program exists above the firmware 14. The firmware 14 of the CPU 9 includes a resource access unit 14a for directly operating the hardware 13 to input and output basic data. As a part of the resource access unit 14a, an execution determination unit (write determination unit) ) 14b.

In the upper layer of the resource access unit 14b, when the ladder program 15 is executed, a native decoding unit 14c for decoding a part which has already been converted into a machine language (native code), and a user program 1
There is an interpreter unit 14d which converts the other parts of the code No. 5 into native codes and passes them to the native decode unit 14c.

Next, the operation of the present embodiment will be described with reference to FIGS. When the operator starts the editor 3a of the programming device 1, the operator operates the keyboard 2 and creates a ladder program (hereinafter, simply referred to as a program) while watching the display on the display 4. FIG.
Is a process chart showing a processing procedure of a programming operation.

In FIG. 3, first, the process of step P1 of "declare use of label" is executed. here,
If the user who wants to use a part of the system area set as the user-defined memory area in the RAM 11 of the PC 5 as the data area, the user makes a declaration at the beginning of the program in the following format, for example. . DUM label [data word length, number of words] (1) Here, "DUM" is a command for declaring that a part of the user-defined memory area is used as a data area with a label (identification name). Yes, specifically, it is described as follows (see FIG. 4).

DUM BMEM [8, 2048] DUM WMEM [16, 1024] (2) DUM LMEM [32, 512] For example, “WMEM [16, 1024]” has a data word length of 16 bits and a word number ( This means that an area having 1024 words, that is, 16 × 1024 = 2 Kbytes, is secured in a part of the user-defined memory area as a label “WMEM”. Note that the labeled data area is hereinafter referred to as a specific data area.

Next, in step P2 of the "program description", the worker describes the program using the label of the specific data area declared to be used. When the description of the program is completed and, for example, the "input confirmation" key of the keyboard 2 is operated, the input of the described program is confirmed.

Then, in step P3 of "assignment of specific data area", assignment of each specific data area is performed by the conversion processing unit 3b of the control unit 3. For example, if the user-defined memory area has addresses from 800H (hexadecimal) to 4000H and the specific data area is allocated from 1000H, if the description is made as in (2), BMEM 1000H to 17FFH WMEM 1800H to 1BFFH (3) Allocated as 2 Kbyte areas of LMEM 1C00H to 1FFFH (see FIG. 5). Also, as a result of the allocation, specific data area information is generated.

Next, step P4 of "program conversion"
In, the described program is converted by the conversion processing unit 3b into a format executable by the PC 5. For example,
It is assumed that a specific data area “WMEM” is specified as an operand in a program and the following description is made (see FIG. 6A). COPY 10000H WMEM [256] (4) This is from the address 10000H to the specific data area “WM
Transfer 256 bits of 16-bit data to EM ",
It means.

FIG. 6B shows an example in which the command line (step) of (4) is converted into a format executable by the PC 5. In this case, an identification flag indicating that a specific data area with a label is used is set to “1” in the identification flag storage area corresponding to the operand. Then, the label “WMEM” itself is not converted into the assigned dress, and the text code is set as it is.

The bits arranged after the identification flag shown in FIG. 6B are bits for designating the addressing mode of the operand. Actually, for example, 3 to 4 bits are assigned to each operand. About the number of bits are assigned.

On the other hand, if the command is, for example, "LD" and reads from a specific data area, the label is converted to the immediate value of the address to which the label "WMEM" is assigned, and the identification flag is not set. Good.

In the program conversion process, an error check on the program description grammar and the like is also performed. If the address is assigned in step P3 to the specific data area in which the use of the label is declared in step P1 and the address corresponding to the specific data area is described as an immediate value in the program, the conversion processing unit 3b Determines that the description is incorrect and causes the display 4 to output an error message.

That is, the specific data area can be accessed only through the label name declared to be used in the program, and the address corresponding to the specific data area is inadvertently described. The data in the area is prevented from being destroyed.

The programming operation is completed as described above. The program and the specific data area information converted into the execution format are written and stored in the hard disk 6 when a "save" command is input to the programming device 1, for example, and a "send (upload)" command is input. Is transmitted to the PC 5 via the communication interface 7. And the programming device 1
When an execution start instruction is given from the CPU 5, the CPU 9 of the PC 5
Runs the program.

FIG. 2 is a flowchart schematically showing a procedure for describing a process of writing in a specific data area with a label in a user program.
In FIG. 2, first, “write to specific data area”
In the processing step A1, a write command such as the command line of (4) is described. Here, "write" comprehensively means instructions such as "MOV" and "COPY".

Next, in the determination step A2 of "error flag set?", As will be described in detail later, referring to the execution status register of the CPU 9, whether or not an error flag indicating that writing could not be executed has been set. Judge. Error flag is not set and "NO"
, The writing process is terminated.

If the error flag has been set and the judgment is "YES", the processing shifts to the processing step A3 of "set the area full flag", and the RAM 9 or the hardware is set as an external register of the CPU 9, for example. The full area flag is set in the storage area of the full area flag. Then, the writing process ends.

That is, as for the user program, after issuing the write command, it is only necessary to refer to the execution status register of the CPU 9 and determine whether or not the write has been normally performed. If the writing is not performed normally, the area full flag is set, for example, to turn on a lamp for notifying a writing error or to perform writing to a specific data area separately set as a spare. Error processing such as

FIG. 1 is a flowchart showing a cycle of fetching, decoding and execution when the CPU 9 of the PC 5 executes a user program, focusing on a writing process to a specific data area.

In FIG. 1, first, at step B1 of "fetch", the CPU 9 reads one step (hereinafter, referred to as P step) of the program from the RAM 11, and then at step B2 of "instruction decode". , Decodes the instruction code (op code) of the P step. Then, the process proceeds to the judgment step B3 of "write command?"

In the decision step B3, the CPU 9
It is determined whether or not the instruction decoded in step B2 is a write instruction. If it is determined to be “NO” instead of the write instruction, the process shifts to the processing step B4 of “other processing” to perform processing according to the other instruction. If the decoded instruction is a write instruction and the judgment is "YES", the flow shifts to "identification flag set?" Judgment step B5.

In the decision step B5, the CPU 9
It is determined whether or not the identification flag is set in the read P step. If it is determined that the identification flag is not set and the determination is "NO", the process proceeds to the processing step B6 of "write execution".

That is, the P for which the identification flag is not set
No label indicating a specific area is used for the destination address of the operand in the step.
The immediate value of the address is set. In this case, in the processing step B6, the CPU 9 passes the processing to the native decoding unit 14c, accesses the address, and executes the write instruction. Then, the process proceeds to step B1 to read the next P step of the program.

On the other hand, in the judgment step B5, if the identification flag is set and the CPU 9 judges "YES", the processing shifts to the processing step B7 of "obtaining information of a specific data area". In the processing step B7, the processing is performed by the interpreter unit 14d. CPU 9
The label name “WMEM” in the operand of the P step is determined, and information such as the allocation address, the data word length, and the number of words relating to the specific data area “WMEM” is stored in the specific data area transmitted from the programming device 1 to the RAM 11. Gain from information. Then, the process shifts to processing step B8 of “calculation of writable capacity”.

The processing of the processing steps B8 to B12 is performed by the execution determining unit 14b. In the processing step B8, the CPU 9 calculates the writable capacity of the specific data area “WMEM”. Here, the specific data area “WM
EM "is used as a temporary buffer for temporarily storing data used for calculation in other processing. When a write instruction is issued in a user program, data is written from the beginning of the data area every time a write instruction is issued. Is written.

Therefore, in this case, the specific data area "WM
The writable capacity for EM "indicates the capacity of the entire data area. Further, since the write command specifies the number of write words as a parameter as shown in (4), from the information obtained in step B5, Specific data area "W
The number of words (1024) of “MEM” is set as the writable capacity. Next, the processing shifts to processing step B9 of “calculation of write capacity”.

In the processing step B9, the CPU 9
The number of write words 100H (256) specified as the parameter of the label "WMEM" shown in (4) is obtained, and is set as the write capacity in this case. Then, the process shifts to processing step B10 of “calculation of write enable / disable value”.

In the processing step B10, the CPU 9
Calculates the writability value by subtracting the write capacity obtained in step B9 from the writable capacity obtained in step B8. In this case, the write enable / disable value is 1024-
256 = 768. Then, in the next determination step B11 of “writability value <0?”, The CPU 9
It is determined whether the writability value calculated in step B10 is less than 0.

In this case, since the write enable / disable value is equal to or greater than 0 and the CPU 9 determines "NO", the process shifts to step B6 to store the first address 1 in the specific data area "WMEM".
Writing is performed from 800H to 256 words, that is, a capacity of 512 bytes. Also, the write enable / disable value is less than 0 and “YE
S ”, the process proceeds to“ Error flag set ”processing step B12, and the execution determination unit 14b
A flag is set in the write error flag bit of the execution status register inside U9. Then, step B
Move to 1.

That is, the result of the determination in step B11 performed by the execution determining unit 14b of the CPU 9 is shown in FIG.
In the step A2 of the user program shown in FIG.

The flowchart shown in FIG.
This is a process when the CPU 9 of C5 actually executes the user program. On the other hand, the simulator 3c included in the control unit 3 of the programming device 1 simulates the execution state of the user program of the CPU 9 on the programming device 1 side. , According to the flowchart shown in FIG.

Then, as a result of the execution state of the CPU 9, for example, when the simulator 3 c uses a variable that is not defined in the program or performs an illegal operation such as division by zero, An error message is output on the display 4 to urge the operator to correct the program.

Also, for example, when it is determined “YES” in the processing corresponding to step B 12, the simulator 3 c causes the display 4 to output an error message. However, in this case, the simulator 3c can check whether the parameter given to the writing of the specific data area is an immediate value like a command line shown in (4), or the given known parameter. Limited to variables whose values can be determined from data.

Conversely, the parameter given to the writing of the specific data area is a variable “DATAIN” such as, for example, COPY 20000H WMEM [DATAIN] (5).
If TAIN "is determined by the amount of data transmitted from the external device to the PC 5 when the PC 5 actually operates, the simulator 3c on the programming device 1 side checks whether writing is possible. Can not.

However, on the PC 5 side, when the user program is actually executed, the execution determination unit 14b of the CPU 9 performs the processing of the processing steps B8 to B12 shown in FIG. Can be checked whether writing is possible or not.

As described above, according to this embodiment, the conversion processing unit 3b in the control unit 3 of the programming device 1 declares in the user program that the specific data area to which the label has been assigned is used, and When the data word length and the number of words of the specific data area are designated, the capacity of the specific data area is determined based on the data word length and the number of words, and the specific data area is allocated to a part of the RAM 11 of the PC 5. The specific data area can be accessed from the user program only via the label.

Therefore, it is not necessary for the operator to specify the assigned addresses and the capacities one by one in order to use the specific data area in the user program, and a plurality of specific data areas having different data word lengths and word numbers according to the purpose are not required. Can be used, the degree of freedom of programming is increased, and description can be easily performed. In addition, since access is not performed by an address corresponding to a specific data area described carelessly in a user program, data protection management can be easily performed.

Further, according to the present embodiment, the number of words for accessing the corresponding specific data area in the user program can be designated as a parameter. Even when a plurality of specific data areas having the number of words are used, it is sufficient to specify only the necessary number of data without calculating an address offset according to a data word length different for each specific data area. Is easier to describe.

Further, according to the present embodiment, the conversion processing unit 3b
When converting a user program into a format executable by the PC 5, if a label is described in any step, an identification flag indicating that the label is used is set in the step. By referring to the identification flag, the PC 5 can determine whether or not the one specified in the operand of the step is a specific data area declared to be used in the user program.

In addition, according to this embodiment, the simulator 3c in the control unit 3 of the programming device 1
When the identification flag is set in the step of executing the write instruction when simulating the execution state of the user program according to No. 5, the writable capacity of the specific data area and the specified data area are designated. By comparing with the write capacity, if it is determined that the execution of the write command exceeds the specific data area, an error message is output to the display 4.

Therefore, regarding the step in which the number of words of the parameter attached to the label is specified by an immediate value or a definite value, before the actual execution by the PC 5, whether writing is performed so as to exceed the specific data area. Since it is possible to check in advance whether or not it is possible, debugging can be performed more efficiently.

Further, according to the present embodiment, the control unit 3 transmits the specific data area information relating to the specific data area allocated by the conversion processing unit 3b together with the user program converted into an executable format to the PC 5 side. Therefore, the PC 5 can obtain information such as the address of the specific data area by referring to the presence or absence of the identification flag and the specific data area information in each step of the user program.

According to the present embodiment, the CPU of the PC 5
9, when the identification flag is set in the step of executing the write instruction during execution of the user program, the execution determination unit 14b refers to the specific data area information to write the specific data area specified by the operand. The available capacity is compared with the write capacity specified for the data area, and if it is determined that the execution of the write command exceeds the specific data area, the CPU 9
, A write error flag indicating a write error is set in the execution status register.

Therefore, when the user program is executed, for example, even if the number of words of the parameter attached to the label is given by a variable whose value changes according to the actual processing result, the writing is actually executed. Before the writing, it is possible to check whether the writing is a writing exceeding a specific data area, so that it is possible to prevent data stored in other areas from being destroyed beforehand. .

The present invention is not limited to the embodiment described above and shown in the drawings, and the following modifications or extensions are possible. When declaring the use of a specific data area with a label in a user program,
It is not always necessary to specify the data word length and the number of words.For example, if only the data word length is specified, the number of words is determined by the default value. In this case, the data word length may be set to a default value. Alternatively, when both are unspecified and only the label name is declared, both the data word length and the number of words may be given a predetermined capacity determined by default values.

When a specific data area is accessed, the parameter is not limited to the one specifying the number of words, but may be specified without specifying the parameter, for example, starting from the address XXXXXH according to the instruction description format. The contents up to address XXXH may be transferred to the specific data area. Alternatively, only a capacity frame such as 2 Kbytes may be given to the specific data area, and the write data word length and the number of words may be given as parameters at the time of issuing a write command. When converting the user program into a format executable by the PC 5, the conversion processing unit 3b does not necessarily need to set the identification flag according to the use of the label.
In step 9, when the text code is described by directly referring to the operand of the instruction, it may be determined that the label is used. The simulator 3c of the programming device 1 may be provided as needed.

The specific data area is not limited to the one used as a temporary buffer in which writing is performed from the beginning of the area every time a write instruction in a program is issued. May be used as a stack in which data is sequentially written from the head of the area. In this case, as the writable capacity in step B8, the remaining capacity in which writing has not yet been performed in the specific data area is calculated. The management of the capacity already written to the specific data area may be performed on the user program side, and the capacity may be given as a parameter when the write command is issued, or as in the above embodiment, On the user program side, only the write capacity at the time of issuing each write instruction may be given as a parameter and managed by the execution determination unit 14b of the CPU 9. The writable capacity may be calculated by subtracting the start address from the end address of the specific data area. When the data word length and the number of words are specified as parameters, the calculation of the write capacity in the processing step B9 may be calculated by (data word length) × (number of words).

[Brief description of the drawings]

FIG. 1 is a flowchart of a processing content when a CPU of a programmable controller executes a user program according to an embodiment of the present invention;

FIG. 2 is a flowchart schematically showing a procedure for describing a write process for a specific data area in a user program;

FIG. 3 is a process chart showing a processing procedure of a programming operation.

FIG. 4 is a diagram showing a description example in a case where a specific data area with a label name is declared in a user program;

FIG. 5 is a diagram conceptually showing a state in which a specific data area is allocated to a user-defined memory area.

FIG. 6A is a diagram showing a description example of a user program when accessing a specific data area to which a label name is added, and FIG. 6B is a diagram in which FIG. Diagram showing an example of the data format when converted

FIG. 7 is a functional block diagram showing the overall configuration of a programming device and a programmable controller.

FIG. 8 is a functional block diagram showing a detailed configuration of a programming device.

FIG. 9 is a diagram conceptually showing a hardware-software hierarchical structure in a CPU of a programmable controller.

[Explanation of symbols]

1 is a programming device, 3 is a control unit (identifier giving means, transmission means), 3b is a conversion processing unit (area allocating means, conversion means), 3c is a simulator (simulation means, writing judgment simulation means), 5 is a programmable controller , 7 indicate a communication interface (transmitting means), and 14b indicates an execution determining unit (writing determining means).

Claims (7)

[Claims] 1. An identification name assigning means for assigning an identification name to a data area used in a user program of a programmable controller, and when the use of the data area with the identification name is declared in the user program. Area allocation means for allocating the data area to a part of the memory area of the programmable controller with a predetermined capacity, and enabling the data area to be accessed only from the user program via the identification name. A programming device for a programmable controller, comprising: 2. The method according to claim 1, wherein the identification name assigning means is capable of designating a data word length and a data number of the data area when assigning the identification name. 2. The programming device according to claim 1, wherein when a word length and the number of data are designated, the capacity of the data area is determined based on the data word length and the number of data. 3. An identification name assigned by the identification name assigning means, wherein a number of data for accessing a corresponding data area can be designated as a parameter in a user program. Or 2
A programming device for a programmable controller as described. 4. When converting the user program into a format executable by a target programmable controller, if the identification name is described in any step in the user program, the identification name is 4. The programming device for a programmable controller according to claim 1, further comprising a conversion unit that sets an identification flag indicating that the program is being used in the step. 5. A simulation means capable of simulating an execution state of a user program converted into a form executable by a programmable controller, and writing the simulation program when simulating the execution state of the user program. When the identification flag is set in the step of executing the instruction,
If a comparison is made between the writable capacity of the data area to which the identification name is assigned and the write capacity specified for the data area, and execution of the write command determines that the data area is exceeded, an error will occur. 5. The programming device for a programmable controller according to claim 4, further comprising a write determination simulation means for outputting a message. 6. The data area information on the data area allocated by the area allocation means,
The programming device for a programmable controller according to claim 3, further comprising a transmission unit configured to transmit the user program converted to an executable format to the programmable controller. 7. When the identification flag is set in a step of executing a write instruction at the time of executing a user program converted into an executable form by the programming device of the programmable controller according to claim 6, the data area is set. By referring to the information, the writable capacity of the data area with the identification name specified by the operand of the step is compared with the write capacity specified for the data area, and the write A programmable controller, comprising: a write determination unit that sets an error flag indicating a write error in an execution status register of a CPU when it is determined that the data area is exceeded when an instruction is executed.