Comparison of high-availability automation networks

Design recommendations are made for fault-tolerant communication networks used in automation applications, on the basis of reliability and availability criteria, using Markov modeling. The study is illustrated on a trainborne communication network as found in modern high-speed rail applications. Markov models are used in order to represent redundancies and maintenance policy. It is concluded that, for service reliability and availability, the two compared solutions, Multifunction Vehicle Bus (MVB) and Ethernet, are roughly equivalent; while, for asset availability, Ethernet is the preferred solution because its lesser reliability is more than offset by its more-efficient diagnostic capabilities.