PROFIBUS Timing Analysis Under Transient Faults

Abstract

Fieldbus applications suffer from severe environmental conditions. These conditions may affect the communication process among different nodes. Because of the real-time nature of such applications, timing behaviour must be well designed and studied. PROFIBUS as one of the widely applied fieldbus protocols is considered here. This paper evaluates inaccessibility overheads in PROFIBUS protocol in the presence of transient faults. It introduces a novel analytical model for the inaccessibility of PROFIBUS message/token transmission in the presence of transient faults. Different error scenarios are investigated to produce best-case (BC) and worst-case (WC) error overhead evaluation that are based on the integration of single bit errors together with burst errors into a bounded fault arrival model. The introduced error components are included in the worst-case response time (WCRT) of PROFIBUS message cycles. Such a work is essential to assess the real-time behaviour of the protocol under the incidence of errors.