The OPC UA ReferenceType HasSafetyStates is used to describe dependencies between objects to show which (controller) object is responsible for the execution of the safety-functionality. The BrowseName HasSafetyStates and the InverseName SafetyStatesOf describe semantically the hierarchical dependency.

Example for usage in this companion specification: a controller HasSafetyStates and the reference shows to an instance of SafetyStatesType. It is possible that there are two controller in one motion device system.

The SourceNode of this type shall be an ObjectType or Object and the TargetNode shall be an Object.

Table 55 – HasSafetyStates Reference Definition

Attributes	Value
BrowseName	HasSafetyStates
InverseName	SafetyStatesOf
Symmetric	False
IsAbstract	False
Subtype of the HierarchicalReferences defined in OPC Unified Architecture Part 5
References	NodeClass	BrowseName	DataType	TypeDefinition	ModellingRule