JP4876537B2 - Programmable controller programming device - Google Patents

Description

  The present invention is described in, for example, a structured text language (hereinafter also abbreviated as ST language), which is a text description format programming language defined in IEC standard 1131-3, and then converted into a machine code to be a programmable controller. The present invention relates to a programming device for a programmable controller having a function of restoring a sequence program stored in (abbreviated as PLC) to an original ST language program.

A programmable controller (PLC) is known as a device that performs an automatic sequence control of a control target device connected to a PLC by calculating and executing a sequence program. The sequence program is usually edited on the programming device by the user, converted into a machine code, and stored in the PLC. Here, editing means all work related to program creation, such as program creation, modification, and debugging.
Conventionally, a ladder language using a ladder diagram has been used as a programming language for creating this sequence program. However, since the ladder language requires specialized knowledge such as a relay circuit, these specialized knowledge has recently been reduced. The ST language of the text description format as described above (in other words, a format that does not use a drawing), which can be easily created by a normal software engineer who does not have, has come to be used.

By the way, when a sequence program as a text description format program (also referred to as a text program) written in the ST language is converted into a PLC machine code, text is changed as necessary to switch the program flow at present. To ignore program control English words (control terms to be described later) used in the program, and to convert only the parts in the text program that are essential for sequence control, such as executable statements and conditional expressions, into machine language instructions The program written in the original ST language cannot be restored.
Therefore, in preparation for editing the PLC machine code later, the original program written in the ST language is stored in the PLC storage device separately from the program converted into the machine code or written in the ST language. The original program is stored in a storage device such as a personal computer other than the PLC, and managed in a form linked to the program in the PLC.

A PLC sequence program created in a ladder language generally refers to a flow chart, and includes a ladder instruction composed of basic instructions for performing bit processing corresponding to a relay operation and functional instructions for causing more complicated calculation and control. Although it is drawn (programmed) and displayed as a ladder diagram using a language, Patent Document 1 does not need to analyze and process a macro program corresponding to a function instruction, and the display is the same as in the past. In order to obtain a PLC that can be used, it has a table that correlates function instructions and machine language, converts the function instructions into machine language specified in the instruction step, stores it as a sequence program, and accompanies the machine language, The corresponding restoration information is stored, and execution of the sequence process is a specific machine language that does not use a macro program. Shows the PLC configured to perform a ladder language restored from the restoration information is disclosed.
JP-A-5-274011

However, in the above-described method of storing the original program written in the ST language separately from the program converted into the machine code in the PLC, the machine code program and the original program written in the ST language are stored in the PLC. Since both are stored, a storage device having twice the capacity is required, and the cost of the PLC increases.
Further, in the method of storing the original program written in the ST language in a storage device different from the PLC described above, it is troublesome to refer to another storage device, and the program in the PLC is directly read out and edited. However, the program in the PLC converted into the machine code based on the program written in the ST language is not restored to the original ST language form for the above-mentioned reason, so that the editing of the program is difficult.
For this reason, when changing a PLC program at a remote location, instead of directly changing the program in the PLC, bring the original program written in the ST language stored in another storage device. It was necessary to edit the program, convert it to machine code, and transfer (write) it to the PLC.

  The present invention solves such a problem, and a programmable controller having a function of easily restoring a sequence program written in the ST language, converted into a machine code and stored in the PLC into the original ST language program again. It is an object of the present invention to provide a programming device.

In order to solve the above-described problem, a programming device for a programmable controller according to claim 1 comprises:
A machine language instruction (hereinafter referred to as an intrinsic machine language instruction) which is composed of a sequence of a plurality of characters or (and) symbols (hereinafter referred to as a continuous character string) and which is predetermined in the specification of the function of the processor executing this sequence program. And various conditional expressions (22 etc.) and executable statements (24, 25, etc.) that can be replaced with one or more of the above, and various continuous expressions that cannot be replaced with the intrinsic machine language instruction. Control terms (IF 21, THEN 23, END IF 26, etc.) in combination with the source program as a sequence program of a text description programming language described in accordance with the grammar specific to the programming language. Language order conversion means (save) for converting continuous character strings into corresponding machine language instructions (machine codes 111 to 117, etc.), generating an object program in a machine language form corresponding to the source program, and storing it in a programmable controller A processor (not shown) for executing the process 4 and the download process 8);
Each machine language instruction constituting the object program in the machine language form based on the text description programming language source program read from the programmable controller is sequentially analyzed, and the object program is converted into the original text description programming language. includes language inverse transformation means for restoring the source program (such as an unillustrated processor executing the upload process 9 and the display processing 5), the
The language order conversion means converts each continuous character string that does not correspond to the control term into one or a plurality of intrinsic machine language instructions that can be replaced with each of the consecutive character strings, and each serial sequence that corresponds to the control term. There is provided a means for converting a character string into a machine language instruction (hereinafter referred to as a pseudo machine language instruction) that corresponds to each of the character strings, is not included in the intrinsic machine language instruction, and does not affect the execution of the sequence program of the programmable controller. ,
The language inverse conversion means at least a pseudo machine language instruction determination means for determining whether or not the machine language instruction to be analyzed is the pseudo machine language instruction;
It is determined whether or not the true machine language instruction that is determined not to be a pseudo machine language instruction by the pseudo machine language instruction determination means has a true machine language instruction that forms a set. If the true machine language instruction determined to have no true machine language instruction is restored to the corresponding one-line text description programming language conditional expression or executable statement, and it is determined that it has a pair of intrinsic machine language instructions First, true machine language instructions from the true machine language instruction to the last true machine language instruction of the set are restored to a conditional expression or executable statement for one line of the corresponding text description type programming language. Determination restoration means,
The pseudo machine language instruction determined as the pseudo machine language instruction by the pseudo machine language instruction determination means determines whether or not the pseudo machine language instruction has a pair of pseudo machine language instructions. The pseudo machine language instruction determined not to have a machine language instruction is restored to the corresponding control term of the corresponding one-line text description programming language, and if it is determined to have a pair of pseudo machine language instructions, Among each pseudo and intrinsic machine language instruction from the machine language instruction to the pseudo machine language instruction at the end of the pair, the pseudo machine language instruction is restored to the control term of the corresponding text description programming language, and the intrinsic machine A text description type corresponding to each intrinsic machine word instruction in which a plurality of word instructions are individually or in pairs are associated with each other via the first judgment restoring means. Restore to a conditional expression or executable statement in the logging language, and all machine language instructions from the corresponding pseudo machine language instruction to the pseudo machine language instruction at the end of the pair are stored on the same line. A second determination / restoration means which is a restoration sentence for one line in a control instruction sentence of a text description type programming language including:
Restoration of one line in the control statement of the text description type programming language in which the conditional expression or executable statement of the text description type programming language restored by the first judgment restoration unit is restored by the second judgment restoration unit Indent addition means for determining whether or not the sentence is dependent on the control term that is also a single line that has been restored or that is restored, and that adds an indent to the subordinate conditional expression or executable statement. Configure.

A programmable controller programming device according to claim 2 is the programmable controller programming device according to claim 1 , wherein the text description programming language is a structured text language.
The operation of the present invention is to provide a programmable controller (PLC) programming device with the following functions to convert a sequence program described in the ST language, which is a text description format programming language, converted into machine code and stored in the PLC, This makes it possible to restore the original ST language text program from the PLC.
That is, a sequence program as a text program written in the ST language is sequentially read out in units of continuous character strings, and it is determined whether or not it is a control term. If it is a control term, it is converted into an intermediate code indicating the control term. If it is not a conditional expression or executable statement, it corresponds to an instruction that consists of a machine language instruction (intrinsic machine language instruction) predetermined in the specification of the function of the processor that executes this sequence program and that can replace this conditional expression or executable statement Respectively converted to intermediate code.

When storing the sequence program in the PLC, the intermediate code indicating the control term as a pseudo-instruction that does not affect the execution of the sequence program by the PLC is included in the pseudo-machine language instruction not included in the intrinsic machine language instruction, and other intermediate Each code is converted into a corresponding intrinsic machine language instruction.
On the other hand, when reading a machine code sequence program from the PLC, the pseudo machine language instruction is converted into the corresponding intermediate code after the pseudo or genuine machine language instruction is converted to the corresponding intermediate code. The machine language instructions are restored to text programs described in the ST language by converting them into corresponding conditional expressions and executable statements, respectively.

A sequence program as a text program described in the ST language, which is a text description format programming language, includes various execution statements and control statements, and the control statements include control terms, conditional expressions, execution statements, and the like. Of these continuous character strings, conditional expressions and executable statements can be replaced with machine language instructions (intrinsic machine language instructions) predetermined in the specification of the function of the processor that executes this sequence program. It cannot be replaced with an intrinsic machine language instruction.
Therefore, according to the present invention, the control term is treated as a pseudo-instruction that does not affect the execution of the sequence program by the PLC, and a pseudo-machine language instruction that is not included in the true machine language instruction is applied to the control term. Since the machine language form program that can be applied to the intrinsic machine language instruction to replace each of these in the expression and executable statement is stored in the PLC,
A text program sequence program (source program) written in the same ST language as that at the time of creation can be restored from a machine code sequence program (object program) stored in the PLC. In addition to the stored object program, it is not necessary to separately manage the ST language source program that is the source of this program, reducing the burden on the user.

  Also, since the original ST language source program can be restored from the machine language program in the PLC, it is not necessary to have a special storage device in the PLC, and the cost of the PLC can be reduced.

FIG. 1 shows a basic configuration of functions of a system main part as an embodiment of the present invention. In FIG. 1, 1 is a programming device, and 10 is a programmable controller (PLC) connected to the programming device 1.
Next, in the programming device 1, reference numeral 2 denotes a program editing screen, and individual continuous character strings 21 to 26 are control statements to be described later, which are part of the ST language sequence program (also abbreviated as a text program) in the above-described text description format. The description state based on the grammar of the ST language is shown for an example of a program block having.
Reference numeral 6 denotes a program memory of the programming device 1, and reference numerals 61 to 67 in the program memory 6 are obtained by converting the continuous character strings 21 to 26 on the editing screen 2 into intermediate codes unique to the programming device.

Next, in the PLC 10, reference numeral 11 denotes a program memory, and 111 to 117 in the program memory 11 are pseudo instructions or instructions generated by converting the intermediate codes 61 to 67 in the program memory 6 of the programming device 1, respectively. The machine code of the true instruction.
As will be described later, the true instruction is an instruction related to the execution of the sequence program of the PLC 10, and the pseudo instruction is an instruction not related to the execution of the sequence program. The machine code of the true instruction is one or a set of various machine language instructions (also referred to as an intrinsic machine language instruction for convenience) predetermined in the specification of the function of the processor that executes the sequence program stored in the PLC 10. In this example, each of 112 conditional (comparison) instructions, 113 conditional jump instructions, 115 executable statement # 1 instructions, and 116 executable statement # 2 machines. The code corresponds to this.

The machine code of the pseudo-instruction is not included in the machine code of the intrinsic machine language instruction, and is an individual machine code that is made similar to this. In this example, 111 “IF”, 114 “THEN”, 117 "END The machine code of the pseudo instruction indicating each of “IF” corresponds to this.
Next, 4, 5, 8, 9 are processes performed by the programming device 1, and 4 is a process of converting a text program described on the editing screen 2 into an intermediate code program and storing it in the program memory 6. On the contrary, the intermediate code program in the program memory 6 is converted into a text program and displayed on the editing screen 2 in the original format. 8 is the machine of the intermediate code program in the program memory 6 of the programming device 1 Download processing for converting the program into a code program and writing it into the program memory 11 of the PLC 10, 9 reversely converts the machine code program in the program memory 11 of the PLC 10 into an intermediate code program and writes it into the program memory 6 of the programming device 1. Upload process.

Here, the text program described on the editing screen 2 of the programming device 1 will be described. This text program corresponds to an example of a program instruction of a format called an IF statement belonging to a conditional branch statement in a control statement in the ST language. In this embodiment, each individual continuous character string 21 to 26 is an English word “ IF ”21, conditional expression (in other words, comparison expression) 22, English word“ THEN ”23, execution sentence # 1 24, execution sentence # 2 25,..., Combined English word“ END ” IF ”26.
It should be noted that the symbols “<” and “>” that sandwich conditional expression 22, executable statement # 1 24, and executable statement # 2 25 before and after are not used in the description of an actual text program. This indicates that an expression or an executable statement exists in the section including the symbol. The same applies to the text program described in FIG.

Here, the consecutive character strings of “IF” 21, conditional expression 22, and “THEN” 23 are displayed on the same line (for convenience, the first line), and executable statement # 1 24 and executable statement # 2 25 is displayed on the second and third lines with indentation (indentation at the beginning of the line) from the beginning of the first line, respectively, and the continuous character string “END” “IF” 26 is displayed on the last line of the IF sentence without any indentation.
The content of the program instruction of this IF statement is “if the condition of conditional expression 22 is satisfied (in other words, if the comparison result of conditional expression 22 is true), then executable statement # 1 24, executable statement # 2 Execute the processes 25,. If this program instruction is further decomposed into an intermediate code or machine code level, which will be described later, and expressed, “comparison of conditional expression 22 is executed. Proceed to the English word “THEN” 23 (therefore, in this example, the processing of the execution statement # 1 24, the execution statement # 2 25,... After the address “THEN” 23 is executed), and the conditional expression 22 If the comparison result is false, jump to the address of the first English word or combination English word that appears after the English word “THEN” 23 (so in this example the combined English word “END” Jump to the address “IF” 26 and finish this IF statement). ].

As will be described in detail later, the control statement is a command that is provided at a necessary position (address) in the program arranged in the order of addresses and controls the subsequent program flow (execution order) according to the conditions at that time. Say a sentence.
By the way, among the text programs on the editing screen 2, the conditional expression 22, the executable statement # 1 24, the executable statement # 2 25, etc. have their respective instruction functions as functions of the processor of the PLC 10 that executes this sequence program. Any one or a combination of the above-described intrinsic machine language instructions as various machine language instructions predetermined in the specification can be replaced by the PLC 10. It is converted into machine code created by replacement and stored.
Therefore, when trying to restore a text program as originally displayed from the machine code stored in the PLC 10 for a sequence program such as a text program on the editing screen 2, conditional expression 22, executable statement # 1, 24, executable statement No. 25 of # 2 has no problem because the correspondence relationship between the text display and the machine code based on the replacement with the genuine machine language instruction can be set.

However, “IF” 21, “THEN” 23, “END” of a continuous character string of English words (referred to as control terms for convenience) In “IF” 26, there is no replaceable intrinsic machine language instruction. Therefore, in the present invention, each of the control terms 21, 23, and 26 is set as a pseudo instruction that is not related to the execution of the sequence program of the PLC 10, and the machine code of the pseudo machine language instruction described above is stored in the PLC 10 in association with each of the control terms. Use it when restoring text programs.
By the way, for each of the intermediate codes 61 to 67 arranged in a line in the program memory 6 of the programming device 1, 61, 64 and 67 are “IF” 21 and “THEN” as control terms on the editing screen 2, respectively. 23, “END Intermediate code corresponding to “IF” 26, 62 is an intermediate code of a condition (comparison) instruction generated from conditional expression 22 on edit screen 2, and 63 does not exist on edit screen 2, but this control statement is an IF statement Therefore, an intermediate code of a conditional jump instruction which is placed next to the intermediate code 62 replacing the conditional expression 22 and has a role of designating a subsequent branch destination in accordance with the truth of the comparison result of the conditional expression 22, 65 And 66 are intermediate codes corresponding to one or a plurality of intrinsic machine language instructions that replace the executable statement # 1 24 and the executable statement # 2 25 on the edit screen 2, respectively.

The machine codes 111 to 117 arranged in order in the program memory 11 of the PLC 10 correspond to the intermediate codes 61 to 67 in the program memory 6 of the programming device 1, respectively. Of these, 111, 114, 117 are control terms “IF”, “THEN”, “END”, respectively. The machine code of the pseudo machine language instruction indicating “IF” and the other machine codes 112, 113, 115, and 116 are machine codes of the intrinsic machine language instruction.
In order to save the sequence program to the PLC 10, first, a text program described in the ST language created on the editing screen 2 of the programming device 1 is read in the saving process 4, converted into an intermediate code, and converted into a program memory of the programming device 1. 6 is stored.
Next, in the download process 8, each intermediate code stored in the program memory 6 of the programming device is read. Then, it is determined whether or not the read intermediate code is an intermediate code indicating a control term, and if it is not an intermediate code indicating a control term, it is converted into a machine code of a corresponding intrinsic machine language instruction, and on the other hand, an intermediate code indicating a control term If so, it is converted to a machine code of a pseudo machine language instruction, and the machine code of this pseudo machine language instruction is also transferred to and stored in the program memory 11 of the PLC 10 as part of the entire sequence program.

Reading the program from the PLC 10 reads the machine code program from the program memory 11 of the PLC 10 in the upload process 9. Then, it is determined whether or not the read machine code program is a pseudo-instruction, and if it is not a pseudo-instruction, it is converted to an intermediate code of the corresponding instruction if it is a true instruction, whereas if it is a pseudo-instruction, an intermediate indicating a control term It is converted into a code and stored in the program memory 6 of the programming device 1. Next, in the display process 5, each intermediate code stored in the program memory 6 of the programming device 1 is read, converted into a text program, and displayed on the editing screen 2.
FIG. 2 is a flowchart showing the procedure of the storage process 4 in FIG. 1, and S1 to S8 are step numbers. Referring to FIG. 2, a text program for one line is read from the editing screen 2 of the programming device 1 in step S1. Then, in step S2, the read text program is analyzed, and divided into consecutive character strings and extracted.

In the next step S3, it is determined whether or not the extracted continuous character string is a control term. If the control term is determined here, the process proceeds to step S4, where the continuous character string is converted into an intermediate code meaning the control term, and the converted intermediate code is stored in the program memory 6 in the next step S6.
Thus, in the example of FIG. 1, “IF” 21, “THEN” 23, “END” of each control term on the editing screen 2 of the programming device 1. As shown in the program memory 6 of the programming device 1, “IF” 26 is “IF”, “THEN”, “END”, respectively. It is converted into intermediate codes 61, 64 and 67 meaning "IF".
If it is determined in step S3 that the continuous character string is not a control term, the process proceeds to step S5. For example, if the continuous character string is the conditional expression 22, the continuous character string is converted into the conditional expression ( Depending on the intermediate code 62 of the condition (comparison) instruction to execute the comparison expression 22 and the true / false of the comparison result of the conditional expression 22 (in this example, the control terms “THEN” 23 or “END”) If the continuous character string is 24 of the executable statement # 1 or 25 of the executable statement # 2, the continuous character is converted to the intermediate code 63 of the conditional jump instruction to specify “IF” 26). The sequence is converted into an intermediate code 65 or 66 composed of one or a plurality of instructions representing each executable statement, and the converted intermediate code is shown in the program memory 6 of the programming device 1 in step S6. Store like this.

Next, in step S7, it is determined whether or not all of the read text program for one line has been converted. The process returns to step S2 until the conversion of the text program for one line is completed, and the processes in subsequent steps S2 to S7 are performed. repeat.
When the text program for one line has been converted, it is determined in the next step S8 whether or not all the text programs on the editing screen 2 have been converted. If the conversion has not been completed, the process returns to step S1. The processes in steps S1 to S8 are repeated.
FIG. 4 is a flowchart showing the procedure of the download process 8 in FIG. 1, and S21 to S23 are step numbers. Referring to FIG. 4, first, in step S21, it is determined whether or not the intermediate code read from the program memory 6 of the programming device 1 is an intermediate code indicating a control term. For example, control terms such as 61, 64, and 67 are determined. If it is an intermediate code indicating “”, the process proceeds to step S 22, where it is converted into a pseudo-instruction machine code corresponding to the control term, 111, 114, 117 in this example.

On the other hand, if the intermediate code read from the program memory 6 in step S21 is not an intermediate code indicating a control term, the process proceeds to step S23. In this example, each of the intermediate codes 62, 63, 65, and 66 is replaced with a known machine language. It converts into machine code 112, 113, 115, 116 of an intrinsic machine language instruction using a conversion process.
FIG. 5 is a flowchart showing the procedure of the upload process 9 in FIG. 1, and steps S31 to S33 are step numbers. Referring to FIG. 5, first, in step S31, it is determined whether or not the machine code of the program read from the program memory 11 of the PLC 10 is a pseudo-instruction machine code. In this example as the machine code of the instruction, 111, 114, and 117 are converted into intermediate codes 61, 64, and 67 of control terms, respectively.

On the other hand, if the machine code of the program read from the program memory 11 of the PLC 10 is not a pseudo-instruction machine code in step S31, the process proceeds to step S33. In this example, the machine code of each instruction is 112, 113, 115, 116. Are converted into the intermediate codes 62, 63, 65, 66 of the instructions using the respective known instruction conversion processes.
FIG. 3 is a flowchart showing the procedure of the display process 5 in FIG. 1, and S11 to S15 are step numbers. The display processing 5 shows processing corresponding to one line of the text program on the editing screen 2 in FIG.
Referring to FIG. 3, first, in step S11, it is determined whether or not the intermediate code read from the program memory 6 of the programming device 1 (related to the beginning of the line of the text program) is an intermediate code indicating a control term.

Here, if it is determined as an intermediate code indicating a control term, the process proceeds to step S11a, and the intermediate code of the control term is, for example, the intermediate code 61 of the control term “IF” 21 having a pair of control terms “THEN” 23. Then, it is determined whether or not the control program has a pair of control terms displayed in one line on the text program. Depending on the type of control term at the beginning of the line, there are those having a plurality of pairs of control terms as will be described later with reference to FIG.
If it is determined that the control terms have a pair, the process proceeds to step S11b, and all intermediate codes up to the control term at the end of the control terms to be paired are read out in this example, 61, 62, 63, 64. In the next step S11c, each intermediate code is controlled as a corresponding text program. Therefore, in this example, the intermediate code 61 is controlled by the control term 21, the paired intermediate codes 62 and 63 are controlled by the conditional expression 22, and the intermediate code 64 is controlled. By converting to the term 23, the converted control term “IF” 21, the conditional expression 22, and the control term “THEN” 23 are set as a text program for one line. In this case, the next step S14 is simply passed, and the text program for one line is displayed on the editing screen 2 in the next step S15.

On the other hand, in step S11a, the intermediate code of the control term is, for example, the control term "END" If it is determined that there is no pair of control terms such as the intermediate code 67 indicating “IF”, the process proceeds to step S12, and only the intermediate code of the control term is selected as the control term “END” in this example. After conversion to a text program such as “IF” 26, the process simply passes through step S14, and the text program is displayed on the editing screen 2 in an independent line in step S15.
Further, in step S11, the intermediate code 65 or 66 of each instruction consisting of a plurality of instructions corresponding to the executable statement # 1 or the executable statement # 2 is used as the intermediate code relating to the head of the text program. If it is determined that the intermediate code is other than the control term, the process proceeds to step S13 and is converted into a corresponding one line of executable statement, in this example, executable statement # 1 24 or executable statement # 2 25 text program.

Next, in step S14, it is determined whether or not the line of the converted text program is a line that needs indentation. If it is a line that is necessary, an indent is added to the head of the converted text program, and a line that does not require indentation. If so, the indent is not added, and the text program for one line converted in the next step S15 is displayed on the editing screen 2.
In this example, text statement executable statement # 1 24 and executable statement # 2 25 are executable statements following lines of text program control terms “IF” 21 to “THEN” 23, ie, conditional branch control statements. An indent is added because it is an executable statement subordinate to the text program for one line including the pair of control terms.
In addition, as shown in FIG. 6 to be described later, some control terms have execution statements that are dependent on one line, such as “ELSE” and “REPEAT”, and follow such control terms. Indentation is also added to executable statements. However, if the execution statement is an execution statement independent of the control statement, no indentation is added.

In the above embodiment, the processing method for an example of a conditional branch statement in a control statement in ST language has been described. Next, the types and functions of control statements in ST language will be described. The control statement is a command statement that is provided at a necessary position (address) in the program arranged in the order of addresses and controls the subsequent program flow (execution order) according to the conditions at that time.
That is, the program generally has a “sequential structure” that is executed in the order of addresses. However, there are times when you want to repeat a certain process, perform a different process depending on the condition, or end the process. In such a case, specify a separate execution program or specify the execution address of the program. It is necessary to change the flow of the program by switching the starting point or stopping the address update. The control statement plays the role of switching the program flow.

FIG. 6 collectively shows the types of control statements in the ST language in correspondence with the description examples in the text program. As shown in the figure, control statements in the ST language are roughly divided into two categories: 1) conditional branch statements and 2) iteration statements.
And 1) the conditional branch statement
1-1) IF statement,
1-2) CASE statements are divided into two types, and 2) repetitive statements
2-1) FOR statement,
2-2) WHILE statement,
2-3) REPEAT statement,
2-4) EXIT statement,
2-5) The RETURN statement is divided into five types.

Next, referring to FIG. 6, the above-described control statements for each type will be described.
1-1) IF statement:
The IF statement basically executes “if the condition of... Is satisfied, and... If the condition is not satisfied. ”, But there are some variations depending on the combination of control terms.
The description example of the text program on the editing screen 2 in FIG. 1 uses the description of each line of a), b), and g) in the IF statement description example in FIG. "," THEN "," END " Only the control term “IF” is included. However, the control term of the IF statement includes “ELSEIF” shown in line c) and “ELSE” shown in line e).
The contents of the instruction that summarizes all the lines from line a) to line g) in FIG. 6 are “if conditional expression # 1 is satisfied, execute statement # 1 is executed, and conditional expression # 1 is not satisfied, Execute the executable statement # 2 when the conditional expression # 2 is satisfied, and execute the executable statement # 3 when neither the conditional expression # 1 nor the conditional expression # 2 is satisfied. ].

1-2) CASE statement:
A CASE statement basically executes a corresponding executable statement if there is an executable statement selected corresponding to the value of a single integer variable or an integer value as a result of an expression. When there is no statement, it is an imperative statement that causes a separately defined executable statement to be executed. This control statement includes a pair of control terms “CASE” and “OF”, “ELSE”, “END”. The control term “CASE” is used.
The content of the instruction in the description example of the CASE statement in FIG. 6 is “if there is an executable statement with an integer selection value that matches the value of the“ integer expression ”following“ CASE ”, the corresponding executable statement is executed (in this example, If the value of the integer expression matches the integer selection value # 1 or the integer selection value # 2, the matching statement of the execution statement # 1 or the execution statement # 2 is executed), and the execution statement of the matching integer selection value is If not, execute the executable statement # 3 following “ELSE”. ].

2-1) FOR statement:
The FOR statement is a command statement that repeats several designated executable statements each time while increasing (or decreasing) the value of the iteration variable by a predetermined value from the initial value to the final value. In FIG. 6, the space for writing is inevitably divided into two lines. However, in this control statement, “FOR”, “TO”, “BY”, and “DO” that are actually paired in the same line are included. Control terms and “END” The control term “FOR” is used.
The content of the instruction in the description example of the FOR statement in FIG. 6 is “the value of the iteration variable given the initial value in the part of the expression“ iteration variable to be initialized ”is the final value specified by the“ final value expression ”. Increase (or decrease) each time a positive (or negative) difference indicated by the “increase formula” until execution reaches #, and execute the executable statement # 1 each time. ].

2-2) WHILE statement:
A WHILE statement is an imperative statement that repeatedly executes one or more executable statements while a certain Boolean expression is true. This control statement includes a pair of control terms “WHILE” and “DO” and “END”. The control term “WHILE” is used. The content of the instruction in the description example of the WHILE statement in FIG. 6 is “one including an executable statement # 1 and an executable statement not shown following the executable statement # 1 while the Boolean expression following the control term“ WHILE ”is true. Repeat the above executable statement. ].
2-3) REPEAT statement:
The REPEAT statement is an imperative statement that repeatedly executes one or more executable statements while a specific Boolean equation is true (but, unlike a WHILE statement, a Boolean equation is placed behind the executable statement). This control statement includes “REPEAT”, “UNTIL”, “END” The control term “REPEAT” is used. The contents of the instruction in the description example of REPEAT in FIG. 6 are “one or more including executable statements # 1 and executable statements # 1 that follow the executable statement # 1 while the Boolean expression following the control term“ UNTIL ”is true. Repeat the executable statement. ].

2-4) EXIT statement:
The EXIT statement is placed as a control term “EXIT” in a required position in the iteration statement. When the program execution reaches the control term “EXIT”, the remaining program of the iteration syntax is not executed immediately. This is a statement that jumps to the end of the iteration syntax and continues execution from here.
2-5) RETURN statement:
The RETURN statement is a function or function block main body program as a group of programs having a predetermined function (that is, a program group that is a processing entity following the function or function block label). An instruction that is placed in the position as the control term “RETURN”, terminates execution as soon as program execution reaches this control term “RETURN”, returns to the beginning of the main program of the function or function block, and continues execution from here It is a sentence.

  Each of the various control statements described above can be converted from a text program to an intermediate code and further from an intermediate code to a machine code by the processing of FIG. 2 and FIG. By the processing, conversion from machine code to intermediate code and further conversion from intermediate code to text program are possible.

The figure which shows the basic composition of the function of the system principal part as one Example of this invention The flowchart which shows the procedure of the preservation | save process in this invention The flowchart which shows the procedure of the display process in this invention. The flowchart which shows the procedure of the download process in this invention The flowchart which shows the procedure of the upload process in this invention Diagram showing types of control statements in ST language and description examples in text programs

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Programming apparatus 2 Edit screen 4 Storage process 5 Display process 6 Program memory of programming apparatus 8 Download process 9 Upload process 10 Programmable controller (PLC)
11 PLC program memory 21 IF (control terminology)
22 Conditional Expression 23 THEN (Control Term)
24 Executable statement # 1
25 Executable statement # 2
26 END IF (control term)
61 Intermediate code indicating IF (intermediate code indicating control terms)
62 Intermediate code of conditional (comparison) instruction 63 Intermediate code of conditional jump instruction 64 Intermediate code indicating THEN (intermediate code indicating control term)
65 Intermediate code of each instruction of executable statement # 1 66 Intermediate code of each instruction of executable statement # 2 67 END Intermediate code indicating IF (intermediate code indicating control terms)
111 Machine code of pseudo-instruction indicating IF 112 Machine code of conditional (comparison) instruction 113 Machine code of conditional jump instruction 114 Machine code of pseudo-instruction indicating THEN 115 Machine code of each instruction of executable statement # 116 Executable statement # 2 Machine code 117 END for each instruction Machine code of pseudo instruction indicating IF

Claims (2)

A machine language instruction (hereinafter referred to as an intrinsic machine language instruction) which is composed of a sequence of a plurality of characters or (and) symbols (hereinafter referred to as a continuous character string) and which is predetermined in the specification of the function of the processor executing this sequence program. This programming language combines various conditional expressions and executable statements that can be replaced with one or more of the above and various control terms that consist of the continuous character strings and cannot be replaced with the intrinsic machine language instructions. In the source program as a sequence program of a text description programming language described according to a specific grammar, each of the above-mentioned continuous character strings is read and analyzed sequentially, and each of these continuous character strings is converted into a corresponding machine language instruction. Machine language object program corresponding to the source program And language forward transform means for storing in the programmable controller to generate,
Each machine language instruction constituting the object program in the machine language form based on the text description programming language source program read from the programmable controller is sequentially analyzed, and the object program is converted into the original text description programming language. comprising a language inverse transformation means for restoring the source program, and
The language order conversion means converts each continuous character string that does not correspond to the control term into one or a plurality of intrinsic machine language instructions that can be replaced with each of the consecutive character strings, and each serial sequence that corresponds to the control term. There is provided a means for converting a character string into a machine language instruction (hereinafter referred to as a pseudo machine language instruction) that corresponds to each of the character strings, is not included in the intrinsic machine language instruction, and does not affect the execution of the sequence program of the programmable controller. ,
The language inverse conversion means at least a pseudo machine language instruction determination means for determining whether or not the machine language instruction to be analyzed is the pseudo machine language instruction;
It is determined whether or not the true machine language instruction that is determined not to be a pseudo machine language instruction by the pseudo machine language instruction determination means has a true machine language instruction that forms a set. If the true machine language instruction determined to have no true machine language instruction is restored to the corresponding one-line text description programming language conditional expression or executable statement, and it is determined that it has a pair of intrinsic machine language instructions First, true machine language instructions from the true machine language instruction to the last true machine language instruction of the set are restored to a conditional expression or executable statement for one line of the corresponding text description type programming language. Determination restoration means,
The pseudo machine language instruction determined as the pseudo machine language instruction by the pseudo machine language instruction determination means determines whether or not the pseudo machine language instruction has a pair of pseudo machine language instructions. The pseudo machine language instruction determined not to have a machine language instruction is restored to the corresponding control term of the corresponding one-line text description programming language, and if it is determined to have a pair of pseudo machine language instructions, Among each pseudo and intrinsic machine language instruction from the machine language instruction to the pseudo machine language instruction at the end of the pair, the pseudo machine language instruction is restored to the control term of the corresponding text description programming language, and the intrinsic machine A text description type corresponding to each intrinsic machine word instruction in which a plurality of word instructions are individually or in pairs are associated with each other via the first judgment restoring means. Restore to a conditional expression or executable statement in the logging language, and all machine language instructions from the corresponding pseudo machine language instruction to the pseudo machine language instruction at the end of the pair are stored on the same line. A second determination / restoration means which is a restoration sentence for one line in a control instruction sentence of a text description type programming language including:
Restoration of one line in the control statement of the text description type programming language in which the conditional expression or executable statement of the text description type programming language restored by the first judgment restoration unit is restored by the second judgment restoration unit An indentation adding means for determining whether or not the statement is dependent on the control term that is a single line that has been restored or is restored, and that adds an indent to the subordinate conditional expression or executable statement Programmable controller programming device. 2. The programmable controller programming device according to claim 1, wherein the text description programming language is a structured text language.

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