Modelling of a sequential system

Growth of industry yields complex automated industrial systems, with reduced time for the system testing. Thus, importance of system modelling is increased. Sequential systems implement ordered sequence of functionally related operations. Occurrence of events marks the end, and initiates beginning of the operations. Therefore, the sequential systems are considered as event-driven systems. Modelling of discrete event system (DES) has to support asynchronous nature of the event occurrence, and different types of variables for the system representation. Due to these reasons, state diagrams, flow charts, Petri nets and automata are adopted for the DES modelling. A benchmark sequential system is modelled with the mentioned tools. Obtained models are compared with respect to information content, applicability to the system analysis, as well as design and testing of control software for programmable logic controllers.