Specifications

4.2 POUs
4.2.7 Programming languages for POUs
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PROGRAM CONFIGURATION
4.2.7 Programming languages for POUs
Two types of programming language are available for programs of POU.
The following explains the features of each programming language.
(1) ST: Structured text
Control syntax such as selection branch by conditional syntax or repetitions by iterative
syntax can be described in the structured text language, as in the high-level language such
as C language. Clear and simple programs can be written by using these syntax.
(2) Structured ladder/FBD: (ladder diagram)
The structured ladder or FBD is a graphical language developed based on the relay ladder
programming technique. They are commonly used for the sequence programming because
they can be understood intuitively.
• Structured ladder
•FBD