EXECUTION MODELS FOR RECONFIGURABLE EMBEDDED REAL-TIME SYSTEMS

This paper deals with the verification and assignment into the execution environment of Reconfigurable Control Applications following the Component-based International Industrial Standard IEC61499. According to this Standard, a Function Block (FB) is all event-triggered component and an application is an FB network that has to meet temporal properties according to user requirements. If a reconfiguration scenario is applied at run-time, then the FB network implementing the application is totally changed or modified. To cover all possible cases, we classify such scenarios into three classes and we define an agent-based architecture designed with nested state machines to automatically handle all possible reconfigurations. To verify and assign Function Blocks corresponding to each reconfiguration scenario into the execution environment, we define an approach based on the exploration of reachability graphs to verify temporal properties. This approach constructs feasible Operating System tasks encoding the FB network that corresponds to each scenario. Therefore, the application is considered as sets of Operating System (OS) tasks where each set is to load in memory when the corresponding reconfiguration scenario is applied by the agent. We developed the tool X-Assign supporting these contributions that we apply on the FESTO production system available in our research laboratory.