SIEMENS
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Siemens PM 21 · 2017
SIMOTION Motion Control System
SIMOTION engineering software
SIMOTION SCOUT
> Structured Text (ST)
2
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Overview
The high-level language ST (Structured Text) provides all
language elements as text commands. This enables well-
structured applications to be created.
The basic scope of commands includes:
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Commands for data management
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Arithmetic functions
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Control structures
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Commands for accessing I/O
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Communication functions
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Object-oriented programming according to IEC 61131-3 ED3
The addition of technology packages for Motion Control adds
powerful, extremely flexible Motion Control commands to the
instruction set (e.g.: _pos(...) for positioning axes). The system
functions can be selected from a clearly arranged library and
can be used in the ST source by means of drag & drop.
An ST source file basically consists of continuous text. This text
can be structured by dividing it into sections. These sections
represent logical units of an ST source.
These sections can be:
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a program that is assigned to a runtime level,
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a class with its subordinate methods,
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a function block with its own memory, or
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a function without its own memory
Function blocks, classes and functions are not allocated to a
runtime level, but are instead called and supplied with
parameters in programs.
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Benefits
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Motion Control, PLC and technology functions in a single
language
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Well-structured programs with comment capability
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High-performance editor functions such as syntax coloring,
Autocomplete and automatic indenting
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Easy-to-use debug functions for online testing and
diagnostics: for example, the display of the current variable
contents of the code sequence and breakpoints visible in the
editor.
© Siemens AG 2017