Action programs can be edited in IL, FBD or LD.
All variables including Boolean variables maintain their current value when a step is deactivated and the next step is activated. In order to assign another value after a step has been deactivated, you must evaluate the step flag, which is FALSE during the last scan. This may be particularly useful for Boolean variables, which are not automatically reset to FALSE when a step is deactivated.
Action programs can be associated to several different steps. Please note that step flags can lead to unpredicted results when reusing action programs in different steps.