Annex B (normative) StateMachines ToC Previous Next

B.4 Representation of state machines in the AddressSpace ToC Previous Next

B.4.4 TransitionVariableType ToC Previous Next index

The TransitionVariableType is the base VariableType for Variables that store a Transition that occurred within a StateMachine as a human readable name.

The SourceTimestamp for the value specifies when the Transition occurred. This value may also be exposed with the TransitionTime Property.

The TransitionVariableType is formally defined in Table B.3.

Table B.3 – TransitionVariableType Definition

Attribute Value        
BrowseName TransitionVariableType        
DataType LocalizedText        
ValueRank −1 (−1 = Scalar)        
IsAbstract False        
References Node Class BrowseName DataType TypeDefinition Modelling Rule
Subtype of the BaseDataVariableType defined in 7.4.
Note that a Reference to this subtype is not shown in the definition of the BaseDataVariableType.
HasSubtype VariableType FiniteTransitionVariableType Defined in B.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

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

Name is a QualifiedName which uniquely identifies a transition within the StateMachineType.

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

TransitionTime specifies 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 TransitionTime stays at the point in time where StateA became active whereas the EffectiveTransitionTime changes with each change of a substate.

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