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7.5 OPC UA VariableType ToC Previous Next

7.5.1 CalibrationValueType ToC Previous Next index

The CalibrationValueType is a subtype of the DataItemType. It represents the specific quantity and value (with engineering unit) that a calibration target provides for calibration of equipment. The VariableType is formally defined in Table 55.

Table 55 – CalibrationValueType Definition

Attribute Value
BrowseName CalibrationValueType
IsAbstract False
ValueRank −2 (−2 = Any)
DataType 0:Number
Description Represents the specific quantity and value (with engineering unit) that a calibration target provides for calibration of equipment.

Subtype of the 0:DataItemType defined in OPC 10000-8, i.e. inheriting the InstanceDeclarations of that Node

References NodeClass BrowseName DataType TypeDefinition Other
0:HasProperty Variable 0:EngineeringUnits 0:EUInformation 0:PropertyType M

The CalibrationValueType inherits the Properties of the DataItemType. That does include the optional 0:ValuePrecision, defining the precision of the calibration value.

The mandatory 0:EngineeringUnits defines the engineering unit of the calibration values.

Remark: The quantity of the calibration value is of importance. This specification waits for this to be solved in the base OPC UA specification (OPC 10000-8), and will use this afterwards.

The VariableType can be used with an (multi-dimensional) array or scalar values. When a calibration target provides several independent values, e.g., lengths, that can be used for calibration, each one should get its own instance of CalibrationValueType. If the calibration target provides for example a scale for length, the CapacityRangeType should be used. The array of the CalibrationValueType shall only be used, when it represents one overall value consisting of a number of distinct values for example the spatial frequency of line pattern blocks on a resolution test chart for calibration of optical instruments.

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