Create New Methods
If the Object Oriented feature is enabled, you can consider a Function Block as a class; in order to create a new method: open the context menu of the Function Block by right- clicking on it’s instance in the project tree, then choose New Methods.
A dialog will appear asking you which language you wish to use to implement the method body, SFC cannot be used. Once created, the new method will be shown in the project tree:
You can define any number of methods for the same class, but you cannot define more methods with the same name (even if their prototype is different).