The base function blocks of the CommonPouTypes library provide pure behavior models and do not serve any particular application.
For the implementation of the application-specific code in the user-defined function block, each base function block provides dedicated methods which are called from its state machine. The state machine itself is executed by the call SUPER^() in the implementation part of the user-defined function block. For further information, refer to SUPER Pointer. Calling the methods from the user-defined block is neither necessary nor permitted.
Thanks to the concept of object-oriented programming, the methods of the base function blocks are inherited in the user-defined function block and can be overridden.
Two types of methods are provided:
Simple methods: Simple methods are called once when a state transition to the corresponding state is performed (for example, Done).
Control methods: Control methods are intended to implement application-specific algorithm (for example, cyclic calls....until feedback) and control the state machine. They are called within the corresponding state until the control method indicates the value Done or Error (for example, Executing) through its return value (type ET_Result).