The AnalogSignalVariableType can be used to model any analog signal type. It extends the AnalogUnitRangeType defined in OPC 10000-8 to add additional information such as values for simulation and damping as well as dictionary references.
The ActualValue contains the unsimulated value during a simulation and SimulationValue contains the value to be used during simulation, as illustrated in Figure 10. The Value attribute always represents what is being reported by the Variable.
AnalogSignalVariableType is formally defined in Table 24.
Table 24 - AnalogSignalVariableType
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Attribute |
Value |
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BrowseName |
AnalogSignalVariableType |
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IsAbstract |
False |
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ValueRank |
−2 (−2 = ‘Any’) |
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DataType |
Number |
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|
References |
NodeClass |
BrowseName |
DataType |
TypeDefinition |
Modelling Rule |
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Subtype of AnalogUnitRangeType defined in OPC 10000-8 |
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0:HasComponent |
Variable |
ActualValue |
0:Number{Any} |
0:BaseDataVariableType |
0:Optional |
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0:HasComponent |
Variable |
SimulationValue |
0:Number{Any} |
0:BaseDataVariableType |
0:Optional |
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0:HasComponent |
Variable |
SimulationState |
0:Boolean |
0:BaseDataVariableType |
0:Optional |
|
0:HasProperty |
Variable |
Damping |
0:Float |
0:PropertyType |
0:Optional |
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0:HasDictionaryEntry |
Object |
|
0:IrdiDictionaryEntryType |
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0:HasSubtype |
VariableType |
TemperatureMeasurementVariableType |
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0:HasSubtype |
VariableType |
PressureMeasurementVariableType |
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0:HasSubtype |
VariableType |
FlowMeasurementVariableType |
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0:HasSubtype |
VariableType |
LevelMeasurementVariableType |
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0:HasSubtype |
VariableType |
ActualDensityVariableType |
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0:HasSubtype |
VariableType |
ControlVariableType |
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0:HasSubtype |
VariableType |
TotalizerVariableType |
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0:HasSubtype |
VariableType |
AnalyticalMeasurementVariableType |
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AnalogSignalVariableType also extends AnalogUnitRangeType by providing additional references. These references provide dictionary entries for all of the variables defined by this addition as well as dictionary references for fields in the parent AnalogUnitRangeType. See Table 25 for a complete definition.
Table 25 - AnalogSignalVariableType Additional References
|
Source Path |
Reference Type |
Is Forward |
Target Path |
|
ActualValue |
0:HasDictionaryEntry |
0:True |
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|
SimulationValue |
0:HasDictionaryEntry |
0:True |
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|
Damping |
0:HasDictionaryEntry |
0:True |
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|
SimulationState |
0:HasDictionaryEntry |
0:True |
The VariableType is extended in this definition to include the dictionary reference. The dictionary provides an additional description of Value which is copied here for clarity – “ABN634#001 defines parameter indicating the input or output value of a device using the units of measure of the process variable.”
ActualValue reflects the measured value independent of the simulation state. It is further described by dictionary entry ABN644#001 which states “defines parameter indicating the value of the not simulated process variable of a device using the units of measure of the process variable”.
SimulationValue provides a value that substitutes Value if the simulation is enabled. It is further described by dictionary entry ABN613#001 which states “defines parameter indicating the simulated value of a variable using the units of measure of the simulated variable”.
Damping provides a value that is used to flatten changes in the value. It is further described by dictionary entry ABH526#001 which states “defines for the output of a first-order system forced by a step or an impulse, the time required to complete 63.2% of the total rise or decay at any instant during the process”.
SimulationState is defined by IRDI as ABN611#001 which states “defines parameter indicating the state of simulation” and used also to enable/disable simulation.