In: Proc. 2000 American Control Conference, 28-30 June 2000, Chicago, IL, Vol. 4, pages 2819-2823. 2000.
Abstract: Signal interpreted Petri nets (SIPNs) show good properties in modeling and analyzing control algorithms. With SIPN, logic controllers are modeled by places - setting output signals - and transitions between these places -- depending on Boolean functions of input signals. This model has interesting dynamics. Firstly, several transitions can fire simultaneously. Secondly, there can be iterated firing of transitions before a new stable marking is reached. In standard PLC programming languages, there is no direct means to implement these dynamics.. In this contribution, a method for a generation of transparent PLC code from SIPN is presented (using instruction list or ladder diagram). The code is transparent because there is one-to-one correspondence between SIPN elements and code segments. A new analytical method to guarantee the correct dynamics of the implemented code is presented and compared to existing approaches. The new method results in a special ordering of the code segments.
Keywords: SIPNs, control algorithms, signal interpreted Petri nets.