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 get the values of these parameters on the consumer side via the Boolean outputs OperatorAckRequested and OperatorAckProvider on the SafetyConsumers SAPI (see Clause 7.4.1).
The following clauses show some examples on how to use these inputs and outputs. Dashed lines indicate that the corresponding input or output is not used in the use case. For details, see Clause 7.3 and Clause 7.4.