Semantics-Robust Design Patterns for IEC 61499

The international standard IEC 61499 for the design of distributed industrial control systems defines an abstract model of function blocks (FB) which allows many different semantic interpretations. As a consequence, in addition, so-called execution models were proposed to specify the execution order of FBs. The variety of models leads to the incompatibility of tools and hinders the portability of automation software. To achieve a degree of execution model independence, in this paper, design patterns are suggested that make FB systems-robust to changes of execution semantics. A semantic-robust pattern is defined for a particular source execution model. The patterns themselves are implemented by means of the FB apparatus and therefore are fairly universal. The patterns can be defined and implemented using the FB transformations expressed in terms of Attributed Graph Grammars.