From Task Scheduling in Single Processor Environments to Message Scheduling in a PROFIBUS Network

Abstract. In this paper we survey the most relevant results for the priority--based schedulability analysis of real-time tasks, both for the fixed and dynamic priority assignment schemes. We give emphasis to the worst-case response time analysis in non-preemptive contexts, which is fundamental for the communication schedulability analysis. We define an architecture to support priority-based scheduling of messages at the application process level of a specific fieldbus communication network, the PROFIBUS. The proposed architecture improves the worst-case messages ’ response time, overcoming the limitation of the first-come-first-served (FCFS) PROFIBUS queue implementations.