. OPC Unified Architecture. Part 1: Overview and Concepts. Release 1.04. 2017-11-22. , OPC Foundation, 2017.

This document presents the general concepts and fundamental principles of the OPC Unified Architecture (OPC UA) standard. It explains the application of OPC UA as a platform-independent standard that enables information exchange among various industrial systems and devices. The document provides information on the OPC UA information model, message and communication models, Client-Server and Publish-Subscribe architectures, security mechanisms, AddressSpace, object model, sessions, service sets, and cross-system interactions. It also outlines the structure and functional purpose of other parts of the OPC UA specification. This document serves as an informative, non-normative resource explaining the key concepts and architectural principles for professionals developing OPC UA applications.