JPS635430A - Programmable controller - Google Patents

Abstract

PURPOSE:To express entire program schematically by displaying modules divided in the unit of function of the program by means of a maintenance tool, with module symbols. CONSTITUTION:The order of execution and the flow of processing information among the symbols 31-35 representing the function units of the program are expressed by means of connection symbols 36-38. Upon completion of the execution of the symbol 31, an arithmetic control part 1 actuates symbols 32 and 35. Upon completion of the execution of the symbols 33 and 35, the content of the symbol 34 is actuated upon whose execution-completion, the execution of symbol group is ended. On necessities, a group of the symbols 21-23 is expressed with higher-order symbols 40 of hierarchy, and a level 3, a type C, and execution cycle 50 are displayed. And thus the representation of the program is realized on the maintenance tool 10. Execution instructions are stored in memories 2a, 2b,... in the unit of symbol, and the connection information of the symbols are stored in a management part 7. Responding to a structure display request from the tool 10, the program is displayed in accordance with these bits of stored information with an outlook easy to see.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a stored program programmable control device in which control contents can be changed by a program.

[Conventional technology]

Figure 5 shows, for example, the Mitsubishi Electric Technical Report (1982-7vo15).
6A7P57) is a program structure diagram showing an example of functional division of a program in the conventional programmable control device shown in No. 6A7P57). In the figure, (4) and [F]) are program functions, and the programs are expressed in POL language. Here, the underlined N
OP (i.e. no operation) SNXXX
The command is a special command added so as to correspond to a program list presented separately as a document.

-Generally, this special instruction is used as a program function (
(G) and (B) to express the functional unit of the program.

Next, the creation and reading of the program will be explained.

When creating a program for a programmable control device,
Based on the required specifications, functions are divided into nine structured layers into gradually smaller functional units, the program specifications are clarified for each functional unit, and the design is tested. This method improves program productivity and reliability. It is commonly used because it improves sexual performance.

In addition, when reading a program, positioning of each functional unit based on the document with the above structure,
After understanding the internal specifications and external specifications, a detailed program is understood.However, in conventional programmable control devices, the program is read by the NOP instruction contained in the program displayed in the document and maintenance tool. I was making them understand the division of.

[Problem that the invention seeks to solve]

As shown above, the structure of a program in a conventional programmable control device is only displayed on maintenance tools in the form of special commands that correspond to delimiters. However, it is difficult to understand the program using maintenance tools alone, and it is necessary to understand the structure of the program using documentation.

This invention was made to solve the above problems, and aims to provide a programmable control device in which the functional division of a program can be easily understood on a maintenance tool.

[Means for solving problems]

The programmable control device according to the present invention allows the program structure to be made clear by expressing a program in a maintenance tool using module symbols representing its functional units and connection symbols representing mutual connections between the module symbols. This is what I did.

[For production]

The maintenance tool of the present invention graphically represents the entire program by displaying modules divided into functional units of the program using module symbols and displaying the order of execution using connection symbols.

〔Example〕

An embodiment of the present invention will be shown below with reference to the drawings.

FIG. 2 is a block diagram showing the configuration of the programmable control device of this embodiment. In the figure, l is an arithmetic control unit of the programmable control device, 2 is a program memory mounted therein, and 2a * 2b s 2 c... is a memory portion in which the program memory 2 is functionally divided; 3
is an arithmetic unit that performs processing under the control of a program, 4 is a data memory that stores data to be processed, and these are connected to external devices such as process input/output devices via an external bus 5. 6 is connected. Reference numeral 7 designates a processing unit that stores and manages the structure of the program memory 2, and reference numeral 8 designates an interface control unit that controls communication with a maintenance tool 10, which will be described later. Reference numeral 10 denotes a maintenance tool that performs maintenance on a module-by-module basis and maintenance on a command-by-instruction basis inside the module, and is composed of a control section 11, a display section 12, a setting section 13, and an interface section 14. 9 is the calculation control unit 1 and the maintenance tool 1
This is an interface line that connects to 0.

Figure 1, [F]) is the maintenance tool 10 mentioned above.
1 is a block diagram showing an example of representation of a program structure according to the present invention. In the figure, 21 to 23 and 31 to 35 are module symbols each indicating a functional unit of the program. Reference numerals 25, 26, and 36 to 38 are connection symbols that interconnect the respective module symbols, and indicate the mutual execution order of each module symbol and the flow of processing data.

Here, a group of seven joule symbols connected by connecting symbols is called a group. That is, module symbol 2
1 to 23 form one group, and module symbols 31 to 35 form another group. In reality, there are many more groups, but they are omitted here.

Next is an overview of the execution of each module symbol.

For example, in the case of a group of module symbols 31 to 35, the contents of module symbol 31 are activated first,
Upon completion of its execution, the contents of module symbol 32.35 are activated.

At this time, if the arithmetic control unit 1 has a parallel execution function, they can be executed at the same time; if the arithmetic control unit 1 does not have a parallel execution function, the contents of the module symbol 32 or module symbol 35 are activated first, and then the remaining modules are activated. However, this difference has nothing to do with the structure of the program or the method of expression.

When the contents of the module symbol 32 are completed, the contents of the next module symbol 33 are activated, and when the contents of the module symbol 33 and 35 are completed, the contents of the module symbol 34 are activated, and when the contents of the module symbol 34 are completed, the contents of the next module symbol 33 are activated. , the execution of the group of module symbols 31 to 35 has ended.

Similar execution formats are used for other groups.

In addition, programs usually have priorities, and when a program is being executed, it is necessary to process a program with a higher priority first, such as when interrupting a function or task switching. It is also important to clearly indicate the priority level in the structural representation of a program. For example, as shown in FIG. 3, a symbol for collectively managing groups is set up to display the priority level.

Furthermore, there are various types of programs, such as those that are executed periodically and those that are activated by an external signal (called an event), and these types are expressed in groups.

In the example of FIG. 3, one group consisting of a module group made up of module symbols 21 to 23 is represented by a module upper layer symbol 40, and some of the module upper layer symbols include an execution level CLEVEL=3.
), execution type (whistle E=C) (the execution type C is
It is cyclic, that is, it is executed periodically. )
, indicates that the execution cycle (CYCLE 50) is displayed.

In this way, a hierarchy of program structuring is realized as an expression on the maintenance tool 10 over two levels.

Furthermore, it goes without saying that the inside of the module is expressed at the command level, similar to conventional programmable control devices.

Execution management of the program itself will be further explained.

When creating a program, the structure shown in Figure 1 is first defined before the program is created.At this time, the main body of the program (execution instructions) is stored in each memory section 2a of the program memory 2 2b e2c...
0 is stored for each module symbol in the management unit 7. Connection information and the like of each module symbol are also stored in the management unit 7. An example of information storage is shown in FIG. 4 (4).

The program, that is, the content of each module symbol, is executed based on the stored information shown in FIG. 4 (4), but when a structure display request is made from the maintenance tool 10, the program is executed as shown in FIG. 4 G3) according to this stored information. This makes the program easier to read.

Here, 50.100.20 shown in the block,
... indicates a module number (MNO) added to each module symbol.

In addition, in the above embodiment, a group is simply composed of module symbols at the same level, but with a function equivalent to a so-called macro expression, it is also possible to express modules at multiple levels within one group. Conceivable.

In addition, although the module symbols and connection symbols are expressed using solid lines with rectangles and gates added in the above embodiments, there is no problem in using other expression methods.

〔Effect of the invention〕

As described above, according to the present invention, a program for a programmable control device is expressed by a maintenance tool using module symbols representing the functional units of the program and connection symbols representing their mutual connections, so that the structure of the program is reduced. It has the effect of being easy to understand graphically.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the program structure of a programmable control device according to an embodiment of the present invention, FIG. 2 is a block diagram showing the configuration of a programmable control device according to an embodiment of the present invention, and FIG. A block diagram of another example of the program structure according to the embodiment, FIG. 4(4) is a side view of the management information storage format of each module symbol, FIG. 4(B) is a block diagram showing a certain group of module symbols, and FIG. FIG. 5 is a side view of a conventional program structure representation format. l is an arithmetic control unit, 7 is a management unit, 10 is a maintenance tool, 21 to 23. 31 to 35 are module symbols, 2
5.26.36 to 38 are connection symbols, and 40 is a module upper layer symbol. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (4)

[Claims] (1) In a programmable control device that creates and configures a control program in functional units and executes the program independently for each functional unit, a module symbol representing the functional unit and a connection representing the mutual connection of the module symbols A programmable control device comprising: a maintenance tool that expresses program structure such as the relationship and execution order of the module symbols using symbols. (2) The programmable control device according to claim 1, wherein the maintenance tool expresses a module upper hierarchy, which is a collection of functions constituted by a plurality of the module symbols, using module upper hierarchy symbols. (3) The programmable control device according to claim 2, wherein the module upper layer symbol has a function of displaying its execution level. (4) The programmable control device according to claim 2, wherein the module upper layer symbol has a function of displaying its execution cycle.