An IOPT-net State-Space Generator Tool

This paper presents the IOPT2SS tool, used to automatically generate state-space graphs associated with IOPT (Input-Output Place-Transition) Petri nets models. The new tool accounts with the non autonomous nature of the IOPT Petri net class, where transition firing is constrained by external input events and input signals (expressed in transition guards); on the other hand, transitions can trigger the occurrence of output signal events and place marking can activate output signals. To achieve the performance level necessary for the fast generation of complex state-spaces during reasonable time, the tool employs a compilation strategy, starting with the automatic creation of an optimized C program. When executed, the program will create an hierarchical XML file containing the state-space graph. The output XML file can subsequently be used for model checking and property analysis, applying standard XML query languages. Finally, the output file can be converted to SVG (Scalable Vector Graphics), enabling the graphical visualization of small to medium size state-space graphs. The new tool was implemented using a set of XSL transformations and can be used as a standalone tool or as a building block in higher level frameworks, with easy integration in Web applications and graphical integrated development environments.