Sensor networks for industrial applications

Industrial applications are moving from centralized architectures towards distributed ones, thanks to cost effectiveness, better flexibility, scalability, reliability and diagnostic functionalities. The use of sensors in industrial communications improves overall plant performance since sensor information can be used by several equipments and shared on the Web. A communication system suitable for computers and PLCs, that exchanges a large amount of data with soft real-time constrains, can be hardly adapted to sensors, especially to simple and low-cost ones. In fact, these devices typically require a cyclic, isochronous and hard realtime exchange of few data. For this reason, specific fieldbuses have been widely used to realize industrial sensor networks, while high-level industrial communication systems take advantage of Ethernet/Internet and. more recently, wireless technologies. In these years, Ethernet-based solutions that meet real-time operation requirements, called Real-Time Ethernet, are replacing traditional fieldbuses and research activities in real-time wireless sensor networking are growing. In this paper, following an overview of the state-of-art of real-time sensor networks for industrial applications, problems and possible approaches to solve them are presented, with particular reference to methods and instrumentation for performance measurement.