What is OPC UA?

The classic OPC (COM based) specifications have served the OPC Community well over the past 10 years, but as technology moves on so must our interoperability standards. Several factors influenced the decision to create a new architecture:

 

• Microsoft has deemphasized COM in favor of cross-platform capable Web Services and SOA (Service Oriented Architecture)
• OPC Vendors want a single set of services to expose the OPC data models (DA, A&E, HDA, Security)
• OPC Vendors want to implement OPC on non-Microsoft systems, including embedded devices
• Other collaborating organizations need a reliable, efficient way to move higher level structured data

 

The Unified Architecture (OPC UA) is described in a layered set of specifications broken into Parts. It is purposely described in abstract terms and in later parts married to existing technology on which software can be built.  This layering is on purpose and helps isolate changes in OPC-UA from changes in the technology used to implement it.

 

The whitepaper “OPC UA: 5 Things Everyone Needs to Know” is also a good resource.