A Model-based Execution Framework for Interpreting Control Software

Industrial standards define domain-specific languages that are frequently used for developing control software. For instance, IEC 61499 standardizes a graphical modeling language that includes a platform-independent application model. The application is composed of Function Blocks. A runtime can execute the model by implementing the semantics that is described in the standard in natural language. By defining an interpreter for IEC 61499 models, we can directly execute them without prior code generation. This enables providing feedback directly on the model level. We present an interpreter for Basic Function Blocks, which encapsulate a state-based Execution Control Chart. An existing EMF meta-model for IEC 61499 was extended with an operational semantics implemented in Java and Xtend. The test cases are defined either in Java or as an interface model. Such a model is standardized in IEC 61499 as Service Sequences. We evaluate our interpreter by executing the Basic Function Blocks that are defined in the standard and compare our results to those of the open-source runtime 4diac FORTE. As a practical use case, we show how developers can use the interpreter for unit testing self-defined Basic Function Blocks.