This specification defines a Machinery building block to provide energy related information. The concept of machinery building blocks is defined in OPC 40001-1. This specification integrates into the existing building block Monitoring and therefore does not need to be referenced from the MachineryBuildingBlocks Object defined in OPC 40001-1. In Figure 1, the Monitoring building block is shown in an example, including where the information defined in this specification is added. The X:MyMachine Object of a vendor-specific X:MyMachineType provides the 2:Monitoring Object. This contains already a 2:Consumption Object intended to provide information on energy. In the example, it provides information on Electricity, CompressedAir, and Steam_Superheated. The BrowseNames of those Objects are defined in this specification (see 6.3), representing different resources. Details, on what information is provided in those Objects are described in 6.2. In addition, the X:MyMachine contains two components, X:MyComponent1 and X:MyComponent2 according to OPC 40001-1. Components may also have energy related information, as in Figure 1, where both provide information on Electricity.

Figure 1 – Integration in Monitoring Building Block

OPC 34100 defines a common infrastructure for providing energy related measurements by defining the 3:EnergyMeasurementType. An Object of that type represents a metering point that can measure several measurement values of 3:EnergyMeasurementValueType. In addition, OPC 34100 defines common measurement values by defining a predefined BrowseName, MeasurementID, EngineeringUnits, etc. for Variables of 3:EnergyMeasurementValueType.

This specification uses the OPC 34100 as base to add energy related information to a MachineryItem. Under each Object representing a resource, there may be several Objects of the 3:EnergyMeasurementType, each representing one metering point. The main metering point should use the BrowseName Main defined in this specification (see 6.3). In Figure 2, an example is given. The Main Object provides several Variables defined in OPC 34100. The MachineryItem provides two additional metering points, X:Submeasurement1 and X:Submeasurement2. The first one is referenced with a Contains Reference indicating that the measured energy is contained in the Main values, whereas the second one is not referenced and therefore independent of the Main values.

Figure 2 – Example of Measurements

In Figure 3, a more comprehensive example is given. In this case, also the components of the MachineryItem provide metering points. The metering points of the components may also be referenced by Contains Reference. This can be either done directly, as for X:MyComponent1, or indirectly via a proxy Object as in X:MyComponent2. Providing a proxy Object allows to provide anybody browsing more direct context and avoids potentially duplicated names, as many Main Objects of different components may be referenced.

Figure 3 – Extended Example of Measurements

This specification defines standardized BrowseNames as entry points to energy metering points of specific resources. They are defined in 9.1.

In addition, a standardized BrowseName is defined for the main energy metering point of a MachineryItem. This can be used for each specific resource. It is defined in 9.2.

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

This specification defines a recommended mapping of resources to Interfaces, Objects of the 3:EnergyMeasurementType should implement. In this version of the specification, not all resources defined in OPC 34100 are considered, but only a part of it.

Table 1 – Recommended Interfaces for different resources

Resource	Interfaces
Electricity	Various Interfaces as defined in OPC 34100
Compressed Air	INonElectricalEnergyType IMassFlowType IVolumeFlowType
Cooling Lubricant	INonElectricalEnergyType IVolumeFlowType
Natural Gas	IMassFlowType IVolumeFlowType
Steam, Saturated	IMassFlowType IVolumeFlowType
Steam, Superheated	IMassFlowType IVolumeFlowType
Chilled Water	IVolumeFlowType
Hot Water	IVolumeFlowType
Hot Hot Water	IVolumeFlowType
Crude Oil	IMassFlowType IVolumeFlowType
Fuel Oil #2	IMassFlowType IVolumeFlowType
Fuel Oil #5	IMassFlowType IVolumeFlowType
Fuel Oil #6	IMassFlowType IVolumeFlowType
Diesel Oil	IMassFlowType IVolumeFlowType
Gasoline	IMassFlowType IVolumeFlowType
Propane	IMassFlowType IVolumeFlowType
Biogas	IMassFlowType IVolumeFlowType

Note: As some Interfaces only define optional Variables, it is in the responsibility of the implementer of the Interface to provide enough information to allow the calculation of energy data.