Some think it will be too difficult or expensive to implement; others may question the value of it. Fortunately for us all, these questions have been asked for several years, and there are answers. The communication protocol often cited as the best fit for IoT applications has already been developed, tested and deployed in live environments around the world since it was fully released in 2009.
OPC Unified Architecture (UA) is platform-independent, service-oriented architecture developed and maintained by the OPC Foundation. As the interoperability standard for industrial automation, OPC has become an integral part of most SCADA (Supervisory Control and Data Acquisition) systems.