The CharacteristicType contains the Metainformation about a characteristic of the part. Its representation in the AddressSpace is formally defined in Table 35.
Table 35 – CharacteristicType Definition
|
Attribute |
Value |
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|
BrowseName |
CharacteristicType |
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|
IsAbstract |
False |
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|
References |
NodeClass |
BrowseName |
DataType |
TypeDefinition |
Other |
|
|
Subtype of the 0:BaseObjectType defined in OPC 10000-3, which means it inherits the InstanceDeclarations of that Node. |
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|
0:HasProperty |
Variable |
CharacteristicIdentifier |
0:String |
0:PropertyType |
0:Optional |
|
|
0:HasComponent |
Variable |
ResultValue |
0:Double |
0:AnalogUnitType |
0:Optional |
|
|
0:HasComponent |
Variable |
UpperToleranceLimit |
0:Double |
0:AnalogUnitType |
0:Optional |
|
|
0:HasComponent |
Variable |
LowerToleranceLimit |
0:Double |
0:AnalogUnitType |
0:Optional |
|
|
0:HasComponent |
Variable |
Nominal |
0:Double |
0:AnalogUnitType |
0:Optional |
|
|
0:HasProperty |
Variable |
CharacteristicsClass |
0:Byte |
0:PropertyType |
0:Optional |
|
|
0:HasProperty |
Variable |
ResultEvaluation |
6:ResultEvaluationEnum |
0:PropertyType |
0:Optional |
|
|
0:HasProperty |
Variable |
IsValid |
0:Boolean |
0:PropertyType |
0:Optional |
|
|
0:HasProperty |
Variable |
Formula |
0:String |
0:PropertyType |
0:Optional |
|
|
Conformance Units |
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|
GMS CharacteristicType |
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CharacteristicIdentifier is a unique identifier of the measured characteristic.
ResultValue is the actual measurement result value.
ResultEvaluation indicates whether the result was in tolerance.
UpperToleranceLimit is the absolute upper limit where the part is still in its specification.
LowerToleranceLimit is the absolute lower limit where the part is still in its specification.
Nominal is the value given in the Geometrical Product Specification. This value indicates which theoretical value the component or the distance between two construction reference points must have (e.g., how large the bore hole must be).
CharacteristicsClass is a hint of the importance of the characteristic. The least important class is 0. Higher classes are more important. An example based on Q-DAS for the value description is given here [AQDEF 5]:
- 0 unimportant
- 1 little important
- 2 important
- 3 significant
- 4 critical
IsValid is used to mark the measured value as valid or invalid. A measurement run can be invalid within the scope of the current measurement for some reason (e.g., a hole missing in the current part). The result file could contain more information.
The Formula describes how the measurement is performed (e.g., T1-((T20-21)*0.41 + (T22-T23)*0.7))
CharacteristicType components have additional subcomponents which are defined inTable 36.
Table 36 – CharacteristicType Additional Subcomponents
|
BrowsePath |
References |
NodeClass |
BrowseName |
DataType |
TypeDefinition |
Others |
|
UpperToleranceLimit |
0:HasProperty |
Variable |
ToleranceForm |
ToleranceLimitEnum |
0:PropertyType |
0:Mandatory |
|
LowerToleranceLimit |
0:HasProperty |
Variable |
ToleranceForm |
ToleranceLimitEnum |
0:PropertyType |
0:Mandatory |