ST is a structured literal programming language. A ST program is a list of statements. Each statement describes an action and must end with a semicolon (";").

The presentation of the text has no meaning for a ST program. You can insert blank characters and line breaks where you want in the program text.

Comments

Comment texts can be entered anywhere in a ST program. Comment texts have no meaning for the execution of the program. A comment text must begin with "(*" or "/*" and end with "*)" or "*/". Comments can be entered on several lines (i.e. a comment text may include line breaks). Comment texts cannot be nested.

Expressions

Each statement describes an action and may include evaluation of complex expressions. An expression is evaluated:

• From the left to the right.
• According to the default priority order of operators.
• The default priority can be changed using parenthesis.

Arguments of an expression can be:

• Declared variables.
• Constant expressions.
• Function calls.

Statements

Below are available basic statements that can be entered in a ST program:

• assignment.
• function block calling.

Below are the available conditional statements in ST language:

• IF / THEN / ELSE (simple binary switch).
• CASE (enumerated switch).

Below are the available statements for describing loops in ST language:

• WHILE (with test on loop entry).
• REPEAT (with test on loop exit).
• FOR (enumeration).

Helpful features

There are some features to simplify the programming:

• A click on the "(" keyboard button automatically inserts the ")" symbol, if the previous word is an instance or a function name. The caret is put between the brackets.
  Hint: Function blocks and UDFBs cannot be used in ST Language without an instance name. If a word is located before a function block or a UDFB the feature is not available.
• A click on the "[" keyboard button automatically inserts the "]" symbol. The caret is put between the two [].

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