Simulating Rhapsody SysML Blocks in Hybrid Models with FMI

The Functional Mockup Interface (FMI) standard enables hybrid simulation of models from different tools. Such tools can have different underlying behavioral semantics, creating challenges when models are combined. A case in point is the combination of the Rhapsody tool, widely used to describe and implement discrete control behavior, and Modelica, widely used to describe continuous plant behavior. This paper describes a plugin we developed for exporting Functional Mockup Units (FMUs) from Rhapsody, and the results of combining generated FMUs with continuous models. When a Rhapsody FMU is used in a different environment, some basic assumptions on its behavior are challenged. We describe the semantic mismatches between the tools, to what extent they can be overcome, and what modelers need to do in order to preserve the intended semantics of an