Extension of a Function Block General The extension of a function block is based on the concept of inheritance in object-oriented programming. A derived function block "extends" a base function block

Implementation of an Interface Implementation of an Interface Implementing interfaces is based on the concept of object-oriented programming. With common interfaces, you can use different but similar

For Custom Data Types in CODESYS V3 Libraries Identifier designation recommendation for Description Example DUTs in CODESYS V3 libraries The namespace replaces the need for the library prefix. Therefo

For POUs Identifier designation recommendation for Description Example Functions, function blocks, programs Library prefix followed by an underscore and a short, informative POU name Like for variable

For POUs in CODESYS V3 Libraries Identifier designation recommendation for Description Example POU The library prefix is omitted because the namespace replaces the function of the library prefix. FUNC

For visualizations Name recommendations for visualization objects Important Note that a visualization is not named the same as another block in the project because this may cause problems when changin

Shadowing Rules In CODESYS , you are generally allowed to use the same identifier for different elements. For example, a POU and a variable can be named the same. However, you should avoid this practi

Keywords In all editors, you must capitalize keywords that for example denote scopes, data types, or operators. Keywords cannot be used as variable names. Example 281 . Example VAR END_VAR BOOL_TO_INT

Method: FB_Init , FB_Reinit , FB_Exit You can declare the methods explicitly in order to influence the initialization of function block variables, as well as the behavior when exiting function blocks.

Global Init Slots Slot Plug-In / Library POU Description 123 GVLObject __var_persistent_write Copying of persistent variables from the persistent list to mapped instance paths 199 Compiler __var__reta