For the reader’s convenience, some aspects of the OPC UA Safety Information Model are explained in this clause. For normative aspects, please refer to OPC 10000-15.

OPC UA Safety defines how to exchange safety data between AutomationComponents using either Client Server or PubSub as the underlying OPC UA communication model. Client Server support for logical connections will be specified in a future version of this document. The usage of PubSub is assumed for the following text.

As defined in OPC 10000-15, the SafetyProvider (representing the source for safety data, such as an emergency stop button) exposes:

The corresponding SafetyConsumer (representing the sink for safety data) mirrors input and output variables, e.g., the safety application data is contained in its input Variable. It exposes:

Refer to OPC 10000-15 for the ResponseSPDUDataType definition and on how to calculate the value of OutCRC. Figure C.1 illustrates an Information Model for a SafetyProvider and its corresponding SafetyConsumer. Safety Variables are represented as dashed yellow boxes.


Figure C.1 – SafetyProvider and SafetyConsumer Information Model