On the necessary real-time conditions for the producer-distributor-consumer model

The producer-distributor-consumer (PDC) has been created to model the real-time, mainly periodic, traffic of variables in FIP (field instrumentation protocol) fieldbus. One of its features is to provide a buffer for each variable; a buffer on the producer side and one on each consumer. In this paper, with the help of the adapted synchronous model, we derive the necessary condition to avoid buffer overwrites in the PDC model.