OPC UA Safety supports Operator Acknowledgment both on the SafetyProvider side and on the SafetyConsumer side. For this purpose, both the interface of the SafetyProvider and the SafetyConsumer comprise a Boolean input called OperatorAckProvider and OperatorAckConsumer, respectively. The safety application can read the status of these inputs on the consumer side via the Boolean outputs OperatorAckRequested and OperatorAckProvider, respectively.

The following sections show some examples on how to use these inputs and outputs. Dashed lines indicate that the corresponding input or output are not used in this use case. For details, see Clause 7.3 and Clause 7.4.