Designing real-time systems based on mono-master Profibus-DP networks

• Author(s): Monforte, Salvatore ; Alves, Mário ; Vasques, Francisco ; Tovar, Eduardo
• Date: 2000
• Persistent ID: http://hdl.handle.net/10400.22/3515
• Origin: Repositório Científico do Instituto Politécnico do Porto
• Subject(s): Fieldbus networks; Real-time communication
• Document Type: Report
• Language: English

Description

Profibus networks are widely used as the communication infrastructure for supporting distributed computer-controlled applications. Most of the times, these applications impose strict real-time requirements. Profibus-DP has gradually become the preferred Profibus application profile. It is usually implemented as a mono-master Profibus network, and is optimised for speed and efficiency. The aim of this paper is to analyse the real-time behaviour of this class of Profibus networks. Importantly, we develop a new methodology for evaluating the worst-case message response time in systems where high-priority and cyclic low-priority Profibus traffic coexist. The proposed analysis constitutes a powerful tool to guarantee prior to runtime the real-time behaviour of a distributed computer-controlled system based on a Profibus network, where the realtime traffic is supported either by high-priority or by cyclic poll Profibus messages.