We integrate data and control flow at the system specification level, using the two specialized and well established languages Matlab and SDL. For this we provide a modeling technique, which integrates the timing concepts and allows synchronization of vector-based computation with event based state transition. The technique is supported by a library of wrappers and communication functions, which has been implemented to make cosimulation easy to use and almost transparent to the user. A methodology formulates the rules to use the modeling technique, to partition the system, and to select communication modes. A complex industrial example illustrates the modeling technique and the methodology, and shows the efficiency of the Matlab-SDL cosimulation.