“…transitions crossing the boundaries of states hierarchy), very useful to model preemption of subsequences and recovery from faults or alarms. Some authors have tried to improve the expressiveness of Grafcet/SFC-like diagrams Johnsson (1999), or to integrate SFC and Statecharts Bauer and Engell (2002), in order to fill this gap, while some others have developed translation mechanisms to design PLC programs directly with Statecharts Machado et al (2001); Chester et al (1998).…”