This ReferenceTypecan be used to expose the relation between an object controlling other objects and the controlled objects. For example, it can be used to relate a PLC to the field devices or machine-modules controlled by the PLC or a software component to the hardware components controlled by the software component.

The Controls is a concrete ReferenceTypeand can be used directly. It is a subtype of HierarchicalReferences.

The semantic of this ReferenceTypeis to relate the controlling component to the components controlled by the controlling component.

The SourceNodeof Referencesof this ReferenceTypeshall be an Objector ObjectTyperepresenting the controlling component, as for example a PLC or a software component.

The TargetNodeof Referencesof this ReferenceTypeshall be an Objectrepresenting a component that is controlled by the TargetNode.

Controls is formally defined in Table 3.

Table 3– Controls Definition

Attributes	Value
BrowseName	Controls
InverseName	IsControlledBy
Symmetric	FALSE
IsAbstract	FALSE
References	NodeClass	BrowseName	Comment
Subtype of HierarchicalReferences defined in OPC 10000-5
Conformance Units
Base Info Controls