PLC Programming

5 - Editors in CoDeSys
• All identifiers up to the last identifier of a line will become declaration variable identifiers
• The type of declaration is determined by the last identifier of the line. In this context, the following
will apply:
B or BOOL gives the result BOOL
I or INT gives the result INT
R or REAL gives the result REAL
S or string gives the result STRING
• If no type has been established through these rules, then the type is BOOL and the last identifier
will not be used as a type (Example 1.).
• Every constant, depending on the type of declaration, will turn into an initialization or a string
(Examples 2. and 3.).
• An address (as in %MD12) is extended around the ATATDeclaration>Proc... attribute(Example 4.).
• A text after a semicolon (;) becomes a comment (Example 4.).
• All other characters in the line are ignored (e.g., the exclamation point in Example 5.).
Examples:
Shortcut
Declaration
A
A: BOOL;
A B I 2 A, B: INT := 2;
ST S 2; A string ST:STRING(2); (* A string *)
X %MD12 R 5 Real
Number
B !
X AT %MD12: REAL := 5.0;(* Real Number *)
B: BOOL;
Autodeclaration
If the Autodeclaration option has been chosen in the Editor category of the Options dialog box , then a
dialog box will appear in all editors after the input of a variable that has not yet been declared. With
the help of this dialog box, the variable can now be declared.
Dialog Box for Declaration of Variables
With the help of the Class combobox, select whether you are dealing with a local variable (VAR),
input variable( (VAR_INPUT), output variable (VAR_OUTPUT), input/output variable (VAR_INOUT),
or a global variable (VAR_GLOBAL).
With the CONSTANT, RETAIN, PERSISTENT options, you can define whether you are dealing with a
constant or a retain variable
CoDeSys V2.3 5-7