Synchronous-Reactive Semantic Modeling and Verification for Function Block Networks

Owing to the semantic ambiguities, it has hindered the promotion of IEC 61499 in the field of industrial automation. In order to solve the thorny problem, this paper proposes an implementation scheme for performing formal modeling and simulation verification of semantics of functional block networks. Based on the synchrony hypothesis, the formal execution model is defined according to the fixed point semantics assuming that the behavior of a component functional block is monotonic. Subsequently, through specifying the evaluation of function blocks (FBs) as a process of solving the least- fixed point problem and transforming the network topology into a directed graph, a connectivity attenuation- based algorithm is put forward to ascertain the optimal scheduling policy of FBs with the minimum overhead. Finally, by conducting the experiment for an industrial application, the feasibility and validity of the presented implementation scheme is proved.