From a highly distributed timed automata specification, the paper analyses an implementation in the form of a looping controller, launching possibly many tasks in each cycle. Qualitative and quantitative constraints are distinguished on the specification to allow such an implementation, and the analysis of the semantic differences between the specification and the implementation leads to define an overapproximating model. The implementation is then "sandwiched" between the original specification and the new model, allowing to check if the important properties of the specification are preserved by the implementation.