Outline; Outline Of Structured Programs And Programming Languages; Outline Of Structured Programs - Mitsubishi Electric MELSEC FX Series Structured Programming Manual

FXCPU Structured Programming Manual
(Application Functions)
1.

Outline

This manual explains applied functions for structured programs provided by GX Works2.
Refer to a different manual for devices, parameters and sequence instructions.
Refer to the following manual for labels, data types and programming languages for structured programs:
1.1

Outline of Structured Programs and Programming Languages

1.1.1

Outline of structured programs

You can construct two or more programs (program blocks) into one program.
Because you can divide the entire machine processing into small sub processes and create a program for
each sub process, you can efficiently create a program for a large system.
1. Structured program
Program structuring is a technique to divide the contents of control executed by the PLC CPU into
hierarchical small units (blocks) of processing, and then construct a program. By using this technique, you
can design a program while recognizing structuring of a sequence program.
Advantages of hierarchical program
• You can examine the outline of a program at first, and then design its details gradually.
• Program blocks located at the lowest level in the hierarchy are extremely simple and highly independent.
Advantages of program consisting of program blocks
• Because the processing of each block is clear, the entire program is easy to understand.
• The entire program can be divided into several blocks that are created by several people.
• The program reusability is improved, and the development efficiency is improved accordingly.
2. Improved reusability of programs
You can save program blocks in a library. Program resources in the library can be shared, and often used
again.
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1.1 Outline of Structured Programs and Programming
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