The TransitionVariableTypeis the base VariableTypefor Variablesthat store a Transitionthat occurred within a StateMachineas a human readable name.

The SourceTimestampfor the value specifies when the Transitionoccurred. This value may also be exposed with the TransitionTime Property.

The TransitionVariableTypeis formally defined in Table 3.

Table 3– TransitionVariableType definition

Attribute

Value

BrowseName

TransitionVariableType

DataType

LocalizedText

ValueRank

−1 (−1 = Scalar)

IsAbstract

False

References

NodeClass

BrowseName

DataType

TypeDefinition

ModellingRule

Subtype of the BaseDataVariableTypedefined in OPC 10000-5

Note that a Referenceto this subtype is not shown in the definition of the BaseDataVariableType.

HasSubtype

VariableType

FiniteTransitionVariableType

Defined in 4.4.7

HasProperty

Variable

Id

BaseDataType

PropertyType

Mandatory

HasProperty

Variable

Name

QualifiedName

PropertyType

Optional

HasProperty

Variable

Number

UInt32

PropertyType

Optional

HasProperty

Variable

TransitionTime

UtcTime

PropertyType

Optional

HasProperty

Variable

EffectiveTransitionTime

UtcTime

PropertyType

Optional

Conformance Units

Base Info State Machine Instance

Id is a name which uniquely identifies a Transitionwithin the StateMachineType. A subtype may restrict the DataType.

Nameis a QualifiedNamewhich uniquely identifies a transition within the StateMachineType.

Number is an integer which uniquely identifies a transition within the StateMachineType.

TransitionTimespecifies when the transition occurred.

EffectiveTransitionTime specifies the time when the current state or one of its substates was entered. If, for example, a StateA is active and – while active – switches several times between its substates SubA and SubB, then the TransitionTimestays at the point in time where StateA became active whereas the EffectiveTransitionTimechanges with each change of a substate.