The IOrderedObjectType defines the Interface all Objects managed by an OrderedListType shall implement. It is formally defined in Table 67.

Table 67 – IOrderedObjectType Definition

Attribute	Value
BrowseName	IOrderedObjectType
IsAbstract	True
References	Node Class	BrowseName	DataType	TypeDefinition	Other
Subtype of the BaseInterfaceType defined in 6.9, i.e. inheriting the InstanceDeclarations of that Node.
HasProperty	Variable	NumberInList	Number	PropertyType	M
Conformance Units
Base Info OrderedList

The mandatory Property NumberInList provides the position of the Object in a list, managed by an instance of the OrderedListType. Ideally, the numbering should start with a 0 and have no gaps, but that is not required and Clients shall not assume this. All Objects in the same list shall use the same concrete DataType for the property NumberInList. Two Objects in a list shall never have the same value in this Property. The order shall be identical to the order managed by the HasOrderedComponent References.

Note that due to the nature of a list element, the NumberInList Property is bound to the parent instance of OrderedListType. Objects implementing the Interface can in general not be managed by two instances of OrderedListType at the same time.