OPC 34100 already defines OPC UA Interfaces to group specific energy measurement variables for electricity. This specification defines additional OPC UA Interfaces for non-electrical energy in 7.1, 7.2 7.3, and 7.4. In Figure 4, an example is given on how to use those Interfaces. The X:MyMachine provides energy measurements for cooling lubricant, and the Main metering point, according to the recommendations in 6.5, implements the Interfaces INonElectricalEnergyType and IVolumeFlowType. By implementing the Interfaces, it provides the measurement variables as defined by the Interfaces.

Figure 4 – Example of using Interfaces for standardized measurements