PLC Programming

Declaration Editor...
address, and that any necessary changes of an incoming or outgoing signal will only have to be made
in one place (e.g., in the declaration).
Notice that variables requiring an input cannot be accessed by writing. A further restriction is that AT
declarations can only be made for local and global variables, and not for input- and output variables
from POUs.
Examples:
counter_heat7 AT %QX0.0: BOOL;
lightcabinetimpulse AT %IX7.2: BOOL;
download AT %MX2.2: BOOL;
Note:
If boolean variables are assigned to a Byte, Word or DWORD address, they occupy one byte with
TRUE or FALSE, not just the first bit after the offset!
'Insert' 'Declaration keywords'
'Insert' 'Type'
Syntax Coloring
You can use this command to open a list of all the keywords that can be used in the declaration part
of a POU. After a keyword has been chosen and the choice has been confirmed, the word will be
inserted at the present cursor position.
You also receive the list, when you open the Input Assistant () and choose the Declarations
category.
With this command you will receive a selection of the possible types for a declaration of variables. You
also receive the list when you access the Input Assistant ().
The types are divided into these categories:
• Standard types BOOL, BYTE, etc.
• Defined types Structures, enumeration types, etc.
• Standard function blocks for instance declarations
• Defined function blocks for instance declarations
CoDeSys supports all standard types of IEC1131-3:
In all editors you receive visual support in the implementation and declaration of variables. Errors are
avoided, or discovered more quickly, because the text is displayed in color.
A comment left unclosed, thus annotating instructions, will be noticed immediately; keywords will not
be accidentally misspelled, etc.
The following color highlighting will be used:
Blue
Green
Pink
Red
Keywords
Comments in the text editors
Special constants (e.g. TRUE/FALSE, T#3s, %IX0.0)
Input error (for example, invalid time constant, keyword, written in lower case,...)
Black Variables, constants, assignment operators, ...
Shortcut Mode
The declaration editor for CoDeSys allows you to use the shortcut mode. This mode is activated when
you end a line with
The following shortcuts are supported:
5-6 CoDeSys V2.3