Work area

Every structured text file is presented as follows.

Figure 1: Structured Text File

The structured text editor has the following components:

1. ST Editor Toolbar

Icon	Description	Shortcut
	Go to last edited line	Ctrl + Q
	Search for selected characters	Ctrl + F3
	Go to next selection of found characters	F3
	Go to the next selection of found characters (reverse)	Shift + F3
	Toggle highlighting of found character selections on and off	Alt + Shift + H
	Toggle frame selection on and off	Ctrl + Shift + R
	Go to the previous line marker
	Go to the next line marker
	Toggle line marker on and off
	Shift line left	Alt + Shift + ←
	Shift line right	Alt + Shift + →
	Comment
	Uncomment

2. Initializing Local Variables

Local variables in Structured Text must be created and initialized at the beginning of the document, between the VAR and END_VAR keywords.

Examples:

(*Variables Initialization*)
VAR

   A : INT;
   B : INT := 100;
   C, D : BOOL;
   F : FB_CTU;

END_VAR

Function Implementation

ST instructions must be programmed after the END_VAR keyword, which closes the area designated for declaring local variables.