Evaluating Worst Case Response Time in Mono and Multi-master Profibus Dp

Profibus networks are often used as the communication infrastructure for supporting distributed computer-controlled applications. Very often these applications impose strict real-time requirements. A widely used class of Profibus networks is the Profibus-DP profile, which may be implemented as mono or multi-master network. The aim of this paper is to analyse the real-time behaviour of both mono and multi-master Profibus-DP networks. The authors present a novel methodology for evaluating the worst-case message response time in systems where high-priority and cyclic low-priority Profibus traffic coexist. The proposal constitutes a powerful tool to guarantee, prior to runtime, the real-time behaviour of a distributed computer-controlled system based on a Profibus network.