Real-time Ethernet (RTE) control systems with critical real-time requirements are called fast real-time (FRT) systems. To improve the real-time performance of Ethernet for plant automation (EPA), we propose an EPA-FRT scheme. The minimum macrocycle of EPA networks is reduced by redefining the EPA network frame format, and the synchronization process is modified to acquire higher accuracy. A multi-segmented topology with a scheduling scheme is introduced to increase effective bandwidth utilization and reduce protocol overheads, and thus to shorten the communication cycle significantly. Performance analysis and practical tests on a prototype system show the effectiveness of the proposed scheme, which achieves the best performance at small periodic payload in large scale systems.

关键词： Ethernet for plant automation (EPA),  Fast real-time (FRT) system,  Real-time Ethernet (RTE),  Scheduling scheme