On the analysis and simulation of temporal behaviour of real time distributed systems using PROFIBUS

The design of hard real time systems involves complex issues because requirements of time, performance and security must be met. Many authors have developed methods in order to assure delays are bounded in the system, but there is not so much work that assures bounding delays in distributed real time systems over industrial fieldbuses. The article applies well-known scheduling theories and previous work in the field of response time analysis for PROFIBUS messages in the analysis and simulation of the overall distributed system. The first step was to get together previous studies (E. Tovar and F. Vasques, 1999). After that, a tool called BERTA (Basic Environment for Real Time Analysis) was designed in order to embody deduced algorithms for schedulability analysis as well as simulation of the distributed system. BERTA is presented in its very first version