The WMTPMeasurementType is a subtype of the ProcessValueType defined in OPC 40001-2.
Figure 8 – Overview of the supertypes of the WMTPMeasurementType
Figure 9 shows an overview of the WMTPMeasurementType. The blue marked Variables 5:AnalogSignal and Status are inherited from the respective supertypes and are complemented by the WMTPMeasurementType.
Figure 9 – Overview of the WMTPMeasurementType
The WMTPMeasurementType is formally defined in Table 47.
Table 47 – WMTPMeasurementType Definition
|
Attribute |
Value |
||||
|
BrowseName |
WMTPMeasurementType |
||||
|
IsAbstract |
False |
||||
|
References |
Node Class |
BrowseName |
DataType |
TypeDefinition |
Other |
|
Subtype of the ProcessValueType defined in “OPC UA for Machinery – Part 2: Process Values” (OPC 40001-2) |
|||||
|
0:HasComponent |
Object |
LimitCounters |
|
3:MachineryOperationCounterType |
O |
|
0:HasComponent |
Variable |
TriggerSettings |
0:UInt32 |
0:AnalogUnitType |
M |
|
0:HasComponent |
Method |
SetTriggerSettings |
|
|
M |
|
0:HasComponent |
Variable |
DeltaCondition |
0:Double |
0:AnalogUnitType |
M |
|
0:HasComponent |
Method |
SetDeltaCondition |
|
|
M |
|
0:HasComponent |
Variable |
TypeOfMeasurement |
0:UInt32 |
0:MultiStateValueDiscreteType |
M |
|
0:HasComponent |
Variable |
TypeOfSample |
0:UInt32 |
0:MultiStateValueDiscreteType |
M |
|
0:HasComponent |
Variable |
RelativeUncertainty |
0:Double |
0:AnalogUnitType |
O |
|
0:HasComponent |
Variable |
AbsoluteUncertainty |
0:Double |
0:AnalogUnitType |
O |
|
0:HasProperty |
Variable |
Timestamp |
0:DateTime |
0:PropertyType |
O |
|
0:HasProperty |
Variable |
Index |
0:UInt32 |
0:PropertyType |
O |
|
0:HasProperty |
Variable |
MeasurementPeriod |
0:Duration |
0:PropertyType |
O |
|
0:HasProperty |
Variable |
InternalUpdateInterval |
0:Duration |
0:PropertyType |
O |
|
0:HasComponent |
Variable |
6:Status |
0:UInt16 |
0:MultiStateValueDiscreteType |
O |
|
Conformance Units |
|||||
|
WMTP Measurement LimitCounters |
|||||
|
WMTP Measurement InternalUpdateInterval |
|||||
|
WMTP Measurement Information for WorkCycleData |
|||||
LimitCounters is used as the MachineryOperationCounterType defined in OPC 40001-1. The WMTPMeasurementType is using the LimitCounters to structure the two counters OperationAboveHigh and OperationAboveHighHigh. The LimitCounters shall also be referenced as AddIn in the MachineryBuildingBlocks Folder to provide better access from a higher level.
TriggerSettings represents the time period from one measurement point to the next. If the relevant sensor of the WMTP does not define the measurement triggering using the TriggerSettings, the default value 0 shall be assumed.
SetTriggerSettings enables the TriggerSettings to be adjusted.
DeltaCondition represents the delta value that needs to be reached before the WMTP triggers the next measurement transmission. If the relevant sensor of the WMTP does not define the measurement triggering using the DeltaCondition, the default value 0 shall be assumed.
SetDeltaCondition enables the DeltaCondition to be adjusted.
NOTE: A WMTP sensor requires at least one value for the TriggerSettings or the DeltaCondition, as these variables are used to determine the measuring frequency. It is also possible to convert both conditions. If one of the variables is not required, the default value must be set for this variable. It must be ensured that both values are not zero at the same time.
TypeOfMeasurement describes which physical type of measurement is represented by this Instance of the WMTPMeasurementType. A list of possible options can be found in Table 48.
TypeOfSample defines the category of the measurement set. This specification defines standardized values for resources Table 48.
RelativeUncertainty is representing the percent uncertainty of measurement.
AbsoluteUncertainty is representing the measurement error in the same unit as the measured value.
Timestamp is representing the exact time of the measurement. Since the WMTP collects the data at a different time than when it is transferred to the OPC UA server, the time of data collection should be stored within this property.
Index is representing the number of the measurement.
MeasurementPeriod defines the time period over which the WMTPMeasurementType was recorded.
InternalUpdateInterval defines the sampling rate of the sensor.
Status is inherited from the from OPC 40001-2.
NOTE: The 6:ProcessValueType already provides the Variable SignalTag from the Object SignalType (OPC 30081), which can be used by inheritance in subtypes, is used to describe the location of the measurement. This variable can be used, for example, if several sensors are installed and the measured values must be clearly assignable.
NOTE: The 6:ProcessValueType already provides the Variable ValuePrecision from the Object 0:DataItemType, which can be used by inheritance in subtypes, is used to describe the precision (resolution) of the measured value or the sensor. It specifies the smallest increment of the measurement.
A Node of the WMTPMeasurementType has an additional Attribute value defined in Table 48.
Table 48 – WMTPMeasurementType Attribute values for child nodes
|
BrowsePath |
Value Attribute |
Description Attribute |
||
|
[ {"Value": 0, "DisplayName": "temperature", "Description": ""}, {"Value": 1, "DisplayName": "rotation speed", "Description": ""}, {"Value": 2, "DisplayName": "humidity", "Description": ""}, {"Value": 3, "DisplayName": "acceleration", "Description": ""}, {"Value": 4, "DisplayName": "force", "Description": ""}, {"Value": 5, "DisplayName": "torque", "Description": ""}, {"Value": 6, "DisplayName": "position", "Description": ""}, {"Value": 7, "DisplayName": "dimension", "Description": ""}, ] |
|
||
|
[ {"Value": 0, "DisplayName": "unspecified", "Description": ""}, {"Value": 1, "DisplayName": "instantaneous", "Description": ""}, {"Value": 2, "DisplayName": "arithmetic mean since the beginning of the work cycle", "Description": ""}, {"Value": 3, "DisplayName": "root mean square (RMS) value since the beginning of the work cycle", "Description": ""}, {"Value": 4, "DisplayName": "maximum value in the current work cycle", "Description": ""}, {"Value": 5, "DisplayName": "minimum value in the current work cycle", "Description": ""}, {"Value": 6, "DisplayName": "moving average", "Description": ""}, ] |
|
The components of the WMTPMeasurementType have additional subcomponents which are defined in Table 49.
Table 49 – WMTPMeasurementType Additional Subcomponents
|
Source Path |
Reference |
NodeClass |
BrowseName |
DataType |
TypeDefinition |
Others |
|
6:Status |
0:HasProperty |
Variable |
OperationAboveHigh |
0:Duration |
0:PropertyType |
O |
|
6:Status |
0:HasProperty |
Variable |
OperationAboveHighHigh |
0:Duration |
0:PropertyType |
O |
OperationAboveHigh represents a counter that records the time that the Status variable has the value 9 (ABOVE_HIGH_LIMIT) or 10 (ABOVE_HIGHHIGH_LIMIT). All the different statuses are defined in OPC 40001-2.
OperationAboveHighHigh represents a counter that records the time that the Status variable has the value 10 (ABOVE_HIGHHIGH_LIMIT). All the different statuses are defined in OPC 40001-2.
NOTE: The WMTPMeasurementType is a subtype of the ProcessValueType from OPC 40001-2. The additional subcomponents mentioned above are referring to the mandatory 5:AnalogSignal Variable and the Status Variable of the ProcessValueType which are inherited to the WMTPMeasurementType.
The components of the WMTPMeasurementType have additional references which are defined in Table 50.
Table 50 – WMTPMeasurementType Additional References
|
SourceBrowsePath |
Reference Type |
Is Forward |
TargetBrowsePath |
|||
|
LimitCounters |
0:HasProperty |
True |
|
|||
|
LimitCounters |
0:HasProperty |
True |
|