ANSI C Based OPC UA Client/Server/PubSub SDK
OPC UA Fundamentals

OPC UA consists of an information model layer and a communication layer. The information model layer is used to create an address space that exposes the application specific information. The communication layer is implemented by the SDK and provides the communication capabilities of OPC UA applications.

OPC UA Architecture Overview

The basic concepts of the information model layer and the rules on how to create an OPC UA address space are defined in OPC UA specification Part 3. Part 5 provides the base information model. See OPC UA Specifications for a list of OPC defined information models.

The Client / Server communication model is defined in Part 4 and Part 6. Part 4 defines the services to access the information model and Part 6 defines the protocol mappings for the services.

The Publish / Subscribe (PubSub) communication model is defined in Part 14.

See OPC UA Specifications for a list of OPC UA specifications.

The first chapter provides a general OPC Unified Architecture Overview with more details for the different building blocks of the OPC UA Unified Architecture.