Plug-n-play smart sensor based on web service

In this paper, the authors present an implementation of a plug-n-play Web sensor based on Web service approach utilizing open source software and adopting low cost hardware architecture. After an introduction to the Web service technology, the problem of the dynamic services and one solution will be dealt. In this way, if it inserted a new sensor in a network, its services are automatically published without network reconfiguration. The sensor is presented in the framework of a hierarchical distributed system for metrological application of monitoring. Particular attention is devoted to synchronization problems among all devices that compose the proposed distributed system accounting characteristics of main synchronization standards. Measurement results are made available as Web services so that all users can build up their own applications. The particular metrological application chosen to show some preliminary results of distributed monitoring network is the monitoring of root mean square (RMS) values in three-phase power networks. A proper synchronization protocol was adopted in order to synchronize to different hardware sections of the sensor performing measurement.