A configurable running level model of a runtime system (RTS) for the control tasks of an industrial controller (S) for cyclical machines is created in a simple manner, it being possible for the programming of the machine sequence to take place in a sequential program. The wait_for_condition command in this case enables a user to wait for any desired conditions and respond with higher priority in the program flow. User programs (AP1-AP4) can be additionally loaded into the user levels of the running level model.