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 196.

Table 196 – DiscreteSignalVariableType definition

Attribute

Value

BrowseName

DiscreteSignalVariableType

IsAbstract

False

ValueRank

−2 (−2 = ‘Any’)

DataType

BaseDataType

References

NodeClass

BrowseName

DataType

TypeDefinition

Other

Subtype of 0:DiscreteItemType defined in OPC 10000-8, i.e. inheriting the InstanceDeclarations of that Node

0:HasComponent

Variable

ActualValue

0:BaseDataType{Any}

0:BaseDataVariableType

O

0:HasComponent

Variable

SimulationValue

0:BaseDataType{Any}

0:BaseDataVariableType

O

0:HasComponent

Variable

SimulationState

0:Boolean

0:BaseDataVariableType

O

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#001 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 197.

Table 197 – DiscreteSignalVariableType additional References

SourceBrowsePath

Reference Type

Is Forward

TargetBrowsePath

ActualValue

0:HasDictionaryEntry

True

3:0112/2///61987#ABN644#001

SimulationValue

0:HasDictionaryEntry

True

3:0112/2///61987#ABN613#001

SimulationState

0:HasDictionaryEntry

True

3:0112/2///61987#ABN611#001

The child Nodes of the DiscreteSignalVariableType have additional Attribute values defined in Table 198.

Table 198 – DiscreteSignalVariableType Attribute values for child Nodes

BrowsePath

Value Attribute

SimulationState

False