Testing communication tasks in distributed control systems with SysML and Timed Colored Petri Nets model

Abstract

Nowadays, Distributed Control Systems (DCSs) are commonly used and supersede stand-alone controllers in many industrial applications. Efficient communication is crucial for their proper operation. Unfortunately, there is a lack of appropriate methodologies and tools applicable to small- and medium-sized DCSs, especially for analysis and testing of communication tasks during early development stages. The paper proposes a flexible and efficient approach that fills this gap. It consists of the following steps. At the beginning, communication tasks and their parameters are specified using graphical diagrams from Systems Modeling Language (SysML). Then, the diagrams are used to automatically generate a model of communication subsystem in the Timed Colored Petri Nets (TCPNs) formalism. Finally, simulation of the TCPN model allows to estimate performance of a target system implementation and to predict its behavior in various cases. Thus, potential bottlenecks might be identified earlier and easier, as well as eliminated even before creation of a hardware prototype. The proposed approach has been introduced into the Control Program Developer (CPDev) engineering environment, which allows to program industrial controllers. Appropriate software tools, namely the editor for SysML communication model, the TCPN library with simulation engine, and the testing framework have been prepared.