8.15 TwoStateDiscreteSignalVariableType

The TwoStateDiscreteSignalVariableType is used for process variables, that can have two states, and illustrated in Figure 12. It is formally defined in Table 258.

Table 258 – TwoStateDiscreteSignalVariableType definition
Attribute Value
BrowseNameTwoStateDiscreteSignalVariableType
IsAbstractFalse
ValueRank−2 (−2 = ‘Any’)
DataTypeBoolean
References NodeClass BrowseName DataType TypeDefinition Other
Subtype of 0:TwoStateDiscreteType defined in OPC 10000-8, i.e. inheriting the InstanceDeclarations of that Node
0:HasComponentVariableActualValue0:Boolean{Any}0:BaseDataVariableTypeO
0:HasComponentVariableSimulationValue0:Boolean{Any}0:BaseDataVariableTypeO
0:HasComponentVariableSimulationState0:Boolean0:BaseDataVariableTypeO
0:HasDictionaryEntryObject 3:0112/2///61987#ABN635#002 0:IrdiDictionaryEntryType
Conformance Units
PA-DIM TwoStateDiscreteVariable
PA-DIM TwoStateDiscreteVariable Simulation

ActualValue: ABN645#001 defines parameter indicating the binary value of a not simulated binary process variable of a device.

SimulationValue: ABN632#001 parameter indicating the simulated value of a binary variable.

SimulationState is defined by IRDI as ABN611#002 which states “parameter indicating the state of simulation” and used also to enable/disable simulation. The value true means ‘Simulation enabled’, and false means ‘Simulation disabled’.

ABN635#001 defines parameter indicating the binary input or output value of a device.

The components of TwoStateDiscreteSignalVariableType have additional references which are defined in Table 259.

Table 259 – TwoStateDiscreteSignalVariableType additional References
SourceBrowsePath Reference Type Is Forward TargetBrowsePath
ActualValue0:HasDictionaryEntryTrue 3:0112/2///61987#ABN645#002
SimulationValue0:HasDictionaryEntryTrue 3:0112/2///61987#ABN632#002
SimulationState0:HasDictionaryEntryTrue 3:0112/2///61987#ABN611#002

The child Nodes of the TwoStateDiscreteSignalVariableType have additional Attribute values defined in Table 260.

Table 260 – TwoStateDiscreteSignalVariableType Attribute values for child Nodes
BrowsePath Value Attribute
ActualValueFalse
SimulationValueFalse
SimulationStateFalse