OPC UA
OPC UA (OPC Unified Architecture) is the IEC 62541 international standard for secure, reliable, cross-platform information exchange between industrial devices, controllers, and enterprise systems. OPC UA defines both a transport mechanism and an information model, enabling industrial devices to expose their data in a structured, semantic way that any OPC UA-compliant client can consume without vendor-specific drivers. OPC UA supports both client-server (polling) and publish-subscribe communication models, and includes security specifications for authentication, encryption, and certificate-based trust. Modern implementations are platform-independent — OPC UA runs on PLCs, industrial PCs, cloud services, and embedded devices.
Why it matters
OPC UA is the P-layer standard that allows IIoT architectures to normalize device data from thousands of machines, controllers, and instruments from hundreds of vendors into a consistent semantic model. Without OPC UA (or a similar protocol normalization layer), every device requires a custom integration — which is the root cause of the IoT spaghetti problem. OPC UA servers like Kepware and Matrikon provide the 150+ driver libraries that bridge legacy industrial protocols (Modbus, EtherNet/IP, PROFINET, BACnet, proprietary vendor formats) into a standard OPC UA information model that the rest of the IIoT architecture can depend on.
External References
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Cite this definition
Finocchiaro, Michael. “OPC UA.” DemystifyingPLM PLM Glossary, 2026, https://www.demystifyingplm.com/glossary/opc-ua