Table of Contents
Advertisement
Chapter 2. Program Organization
Structured Text
The Structured Text (ST) programming language is an IEC 1131-3 textual programming language. A
structured text program consists of a series of statements, which are constructed from expressions
and language keywords. A statement directs the PLC to perform a specified action. Statements
provide variable assignments, conditional evaluations, iteration, and the ability to call other blocks.
For details on ST statements, parameters, keywords, and operators supported by PACSystems, refer
to Structured Text (ST) Programming in Chapter 8.
Blocks, parameterized blocks, and UDFBs can be programmed in ST. The _MAIN program block can
also be programmed in ST.
A block programmed in ST can call blocks, parameterized blocks, and UDFBs.
GFK-2950C
February 2018
23
Advertisement
Table of Contents
