Title :
Correctness analysis of Petri net based logic controllers
Author :
Frey, Georg ; Litz, Lothar
Author_Institution :
Inst. of Process Autom., Kaiserslautern Univ., Germany
Abstract :
Petri nets are able to express the causality as well as the concurrency of a control algorithm. Signal interpreted Petri nets (SIPN) show good properties for model logic controllers. In SIPN the firing of a transition depends on input signals from the environment and the SIPN influences the environment via output signals. Since the function of a logic controller is basically determined by software, the question of software quality arises in this area. ISO/IEC 9126 defines six characteristics of software that can be used as quality criteria. In the six characteristics are set in the framework of controller design: the functionality and reliability of the software rely on the correctness of the algorithm. In this criteria for formal correctness of SIPN control algorithms are given, and it is shown how they can be evaluated using the SIPN reachability graph. Due to a close relation between sequential function chart (SFC) according to IEC 1131-3 standard [IEC 1992] and SIPN the criteria are also valid for SFC
Keywords :
IEC standards; ISO standards; Petri nets; controllability; digital control; formal logic; software quality; IEC 1131-3 standard; ISO/IEC 9126; formal correctness; functionality; logic controllers; reachability graph; sequential function chart; signal interpreted Petri nets; software quality; synchronisation; Automatic control; Automation; Concurrent computing; Fires; IEC standards; Logic; Petri nets; Signal mapping; Software algorithms; Software quality;
Conference_Titel :
American Control Conference, 2000. Proceedings of the 2000
Conference_Location :
Chicago, IL
Print_ISBN :
0-7803-5519-9
DOI :
10.1109/ACC.2000.879148