Definition: OPC Unified Architecture
OPC Unified Architecture, or OPC UA for short, is a TCP/IP based communication technology developed by the OPC Foundation to allow an manufacturer independent exchange of information in the field of industrial automation. OPC UA is also referred to as a machine to machine (M2M) communication protocol. Due to its generic information model, OPC UA has been adapted to other sectors as well, e.g. building automation, power generation and distribution, oil and gas exploration.
The new OPC Unified Architecture unifies all previous OPC specifications by the OPC Foundation and extends them. In particular, machine data (process values, measured data, parameters etc.) now cannot only be transmitted but also semantically described in a machine readable way.
After three years of specification work and one year of prototype implementation the first version of the Unified Architecture specification has been adopted as “Release Candidate” (RC = beta) in the fall of 2006. In February 2009, a revised version of parts 1 to 5 and 8 as well as a first version of parts 6 and 7 have been released.