General information

OPC UA (Open Platform Communications Unified Architecture) according to IEC 62541 is increasingly establishing itself as a communication standard in mechanical and plant engineering. This makes it easier to network devices and exchange information.

Unlike conventional fieldbus connections or visualization interfaces, a device has the ability to provide symbolic information about itself, which means about its properties, variables, process values, and capabilities. The other devices in the network can read and write these objects. In this way, OPC UA meets the requirements of a standardized, service-oriented architecture (SOA). Defined profiles include, for example, process data exchange (data access) and methods (historical access and alarms and conditions).

Conventional protection goals of IT security include among others to ensure that the data is only accessible to authorized participants, that the origin of the data is known, and that the data cannot be manipulated. Part 2 of the OPC UA specification (security model) describes the security mechanisms for this communication. A distinction is made between security settings (security policy and message security mode) to protect the data and authentication settings as a requirement on the clients and servers involved in the communication.