The AirnetOperationalType extends its supertype by Airnet specific Variables and is formally defined in Table 97.
Table 97 – AirnetOperationalType Definition
|Subtype of the OperationalType defined in 7.45, i.e. inheriting the InstanceDeclarations of that Node.|
|The following nodes override nodes added by the OperationalType|
Three KPIs were defined for an Airnet. Each of these KPIs is derived from ISO 11011 and is described below. The KPIs do not have to be calculated by the OPC UA Server but may be calculated by the Main Control System. The definition of the KPIs is intentionally flexible so that the KPIs can be adapted to the respective system. The integrator of a KPI shall provide a detailed description via the Definition Property. For the description it is important to define system boundaries and which Components of an Airnet are included in the calculation. The EngineeringUnits Property shall be used to specify the used quantities in calculating the KPI, e.g., “€/m³” as possible unit for SpecificEnergyCost.
In practice, the values of and calculations attached to the following KPIs are vendor and system specific and may not be used to compare systems from different manufacturers, or different systems from one manufacturer unless stated otherwise in the Definition Property.
The optional Variable AirDeliveryRate indicates how much compressed air is generated in a specified time frame. Usually, the AirDeliveryRate uses the denominator 1 hour. There can be multiple KPIs of this kind for different time frames, e.g., Volume per day (24 hours), week (7 days), year (52 weeks). The value is calculated according to the following formula:
The optional Variable SpecificEnergy indicates how much electrical energy is consumed in the generation of a specific volume of compressed air. Usually, the SpecificEnergy uses the denominator 1 m³ or 1 l. The value is calculated according to the following formula:
The optional Variable SpecificEnergyCost indicates what the generation of a specific volume of compressed air costs. Usually, the SpecificEnergyCost uses the denominator 1 m³ or 1 l. The value is calculated according to the following formula:
The optional Variable HealthState describes if the Requirements of an Airnet can be fulfilled.
The optional Variable IntegratedState describes the degree of control over the compressors for compressed air generation.
The optional Variable OperatingState describes if the Requirements of an Airnet should be fulfilled.
The Variable OnOff of the OperationalType should not be used for an instance of this AirnetOperationalType.
The InstanceDeclarations of the AirnetOperationalType have additional Attributes defined in Table 98.
Table 98 – AirnetOperationalType Attribute values for child Nodes
|Source Path||Value Attribute||Description Attribute|
|AirDeliveryRate||Volume of generated compressed air per time frame.|
|CompressorsIntegrated||Number of integrated compressors in the airnet.|
|CompressorsIsolated||Number of isolated compressors in the airnet.|
|CompressorsNotAvailable||Number of unavailable compressors in the airnet.|
|ControlPressure||Current pressure in the airnet.|
|HealthState||Actual health state of the airnet.|
|IntegratedState||Actual integrated state of the airnet.|
|OperatingState||Actual operating state of the airnet.|
|SpecificEnergy||Electrical energy consumed in the generation of a volume of compressed air.|
|SpecificEnergyCost||Costs for generating a volume of compressed air.|
|VolumeFlowRateAvailable||Measured or calculated available volume flow rate of the process fluid in the airnet.|
|VolumeFlowRateUnavailable||Calculated unavailable volume flow rate of the process fluid in the airnet.|