8.17.2 Definition

The DiscreteSignalVariableType is a subtype of the DiscreteItemType defined in OPC 10000-8 and adds optionally ActualValue and SimulationValue components. It is formally defined in Table 264.

Table 264 – DiscreteSignalVariableType definition
Attribute Value
BrowseNameDiscreteSignalVariableType
IsAbstractFalse
ValueRank−2 (−2 = ‘Any’)
DataTypeBaseDataType
References NodeClass BrowseName DataType TypeDefinition Other
Subtype of 0:DiscreteItemType defined in OPC 10000-8, i.e. inheriting the InstanceDeclarations of that Node
0:HasComponentVariableActualValue0:BaseDataType{Any}0:BaseDataVariableTypeO
0:HasComponentVariableSimulationValue0:BaseDataType{Any}0:BaseDataVariableTypeO
0:HasComponentVariableSimulationState0:Boolean0:BaseDataVariableTypeO
Conformance Units
PA-DIM DiscreteVariable
PA-DIM DiscreteVariable Simulation

ActualValue: ABN644#001 defines “parameter indicating the value of the not simulated discrete process variable of a device”.

SimulationValue: ABN613#001 defines “parameter indicating the simulated value of a variable, which can have multiple states”.

SimulationState: ABN611#002 defines “parameter indicating the state of simulation” and used also to enable/disable simulation. The value true means ‘Simulation enabled’, and false means ‘Simulation disabled’.

The components of DiscreteSignalVariableType have additional references which are defined in Table 265.

Table 265 – DiscreteSignalVariableType additional References
SourceBrowsePath Reference Type Is Forward TargetBrowsePath
ActualValue0:HasDictionaryEntryTrue 3:0112/2///61987#ABN644#001
SimulationValue0:HasDictionaryEntryTrue 3:0112/2///61987#ABN613#001
SimulationState0:HasDictionaryEntryTrue 3:0112/2///61987#ABN611#002

The child Nodes of the DiscreteSignalVariableType have additional Attribute values defined in Table 266.

Table 266 – DiscreteSignalVariableType Attribute values for child Nodes
BrowsePath Value Attribute
SimulationStateFalse