To facilitate the calculation of different KPIs like for example OEE, the Machine Tools interface offers different machine times. These times allow to calculate the durations of different machine modes. To calculate the KPI, additional data not provided by the interface may be necessary.
All of these relevant times are transferred via the event mechanism in OPC UA.
This happens with the ProductionStateMachineType, which is a part of the ProductionJobType, the ProductionProgramType and the ProductionPartType. This means, every Job, Program, and Part has its own state machine with start, end, abortion and interruption states. Each state change sends an appropriate event as a notification. This event can be received by the OPC UA client, and the timestamp can be used to calculate the time durations needed for KPI compilation.