RTAI-based execution environments for function block based control applications

The IEC 61499 standard has been recently adopted to promote a more flexible development process in the control and automation domain. The standard mainly deals with modeling issues leaving a lot of model execution details open. Different research groups are already working for the development of execution environments for the defined component model, proposing implementations with different execution semantics. This paper discuss the semantics of the execution environment and presents two execution environments, which although independently developed share a similar view of IEC61499 execution semantics and are both implemented over RTAI (real time application interface), a real-time Linux-based platform.