Analysis on scheduling performance of periodic messages in industrial ethernet based on EPA

EPA (Ethernet for Plant Automation) resolves the nondeterministic problem of Ethernet through sub-segment topology and deterministic scheduling mechanism. Its deterministic scheduling mechanism makes it possible to analyze its real-time performance quantitively. In this paper, the real-time performance of EPA deterministic scheduling mechanism was analyzed from the theoretical and experimental perspective. First, the deterministic scheduling mechanism and the structure of EPA periodic messages transmission was investigated. On this basis, the influence of EPA deterministic scheduling mechanism on the real-time performance of periodic messages transmission was studied, during which the formulas for the real-time performance of EPA periodic messages transmission were presented. Furthermore, an experimental platform for the real-time performance of periodic messages transmission in a subsegment was established. According to the theoretical and experimental study, the real-time performance of EPA periodic messages transmission was concluded and the improvement methods were provided.