OPC UA (Unified Architecture) represents the OPC Foundation’s most recent set of specifications for Process Control and Automation system interconnectivity. This paper explains OPC UA from the perspective of the organization that will benefit from the connectivity, in other words: the End User. The first form of OPC relied on DCOM for its data transportation, which was very powerful and versatile, but posed a problem for those who did not understand how to configure DCOM. Instead of DCOM, OPC UA relies on Web Services for its data transportation. OPC UA also uses objects to help with data description. Even though these are major additions and modification to OPC, OPC UA will be backwards compatible with older products through the use of wrappers. All this will ensure that OPC UA will be even better suited to penetrate the entire plant enterprise. Of course, with all the new connectivity that OPC UA offers, the new challenge will be system security.
OPC Training Institute (2008) OPC UA An End-Users Perspective