Leitner, Stefan-HelmutMahnke, Wolfgang2023-05-152023-05-152006https://dl.gi.de/handle/20.500.12116/41561OPC Unified Architecture (OPC UA) is the new standard of the OPC Foundation providing interoperability in process automation and beyond. By defining abstract services, OPC UA provides a service-oriented architecture (SOA) for industrial applications – from factory floor devices to enterprise applications. OPC UA integrates the different flavors of the former OPC specifications into a unified address space accessible with a single set of services. This paper gives an overview over the architecture of OPC UA, its address space model and its services. It discusses the necessary security mechanisms needed to allow secure access over the internet. Finally, migration strategies to OPC UA applications are introduced.enText/Journal Article0720-8928