B.6 StateMachine Extensions for ChoiceStates and Guards ToC Next

B.6.6 ElseGuardVariableType ToC Previous Next index

The ElseGuardVariableType is a specialization of the GuardVariableType defining a concrete semantic for the Guard. The value of the Guard should always be {“en”, “Else”} or a translation of this. The ElseGuardVariableType shall only be used on pseudo states like the ChoiceStateType. That means, that it shall only be referenced from Transitions having such a StateType as SourceNode. The ElseGuardVariableType shall only be used once for each State. That means, that each State shall at most have one Transition (referenced as SourceNode) referencing an ElseGuardVariableType. The ElseGuardVariableType shall be the only Guard of a Transition. That means, if a Transition references an instance of an ElseGuardVariableType, it shall not reference any other Guards.

The semantic of the ElseGuardVariableType is, that if a pseudo state is reached and no other Transition exists on the State where all its Guards are validated to “True”, this Guards validates to “True” and thus its Transition is used.

The ElseGuardVariableType is formally defined in Table B.22.

Table B.22 – ElseGuardVariableType Definition

Attribute Value        
BrowseName ElseGuardVariableType        
DataType LocalizedText        
ValueRank −1 (−1 = Scalar)        
IsAbstract False        
References Node Class BrowseName DataType TypeDefinition Modelling Rule
Subtype of the GuardVariableType defined in B.6.4.          

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