International audienceDataflow modelling languages such as SCADE or Simulink are the de-facto standard for the Model Driven Development of safety critical embedded control and command systems. Software is mainly being produced by Automated Code Generators whose correctness can only be assessed meaningfully if the input language semantics is well known. These semantics share a common part but are mainly defined through block libraries. The writing of a complete formal specification for the block libraries of the usual languages is highly challenging due to the high variability of the structure and semantics of each block. This contribution relates the use of software product line principles in the design of a domain specific language targeti...