The OrderedListTypeis a base type to manage an ordered list of Objects. It is formally defined in Table 64.

Table 64– OrderedListType Definition

Attribute

Value

BrowseName

OrderedListType

IsAbstract

False

References

Node Class

BrowseName

DataType

TypeDefinition

Other

Subtype of the BaseObjectTypedefined in 6.2i.e. inheriting the InstanceDeclarations of that Node.

HasOrderedComponent

Object

<OrderedObject>

BaseObjectType

OP

HasProperty

Variable

NodeVersion

String

PropertyType

O

GeneratesEvent

ObjectType

GeneralModelChangeEventType

Conformance Units

Base Info OrderedList

The <OrderedObject> Objectrepresents the ordered Objectsmanaged by Instances of the OrderedListType. The order is provided by the 0:HasOrderedComponent Referencesto the Objects. As not all Clientsconsider the order returned by the Browse Service(e.g. displaying the results in alphabetic order) each <OrderedObject>shall implement the IOrderedObjectType Interface, providing the order by a specific Property(see definition of IOrderedObjectType).

The NodeVersionis intended to be used in conjunction with the GeneralModelChangeEventTypein the way defined in OPC 10000-3. The NodeVersion should be provided if the ordered List can change (e.g. new Objectsadded or removed). This allows Clientsto subscribe to the Propertyor the GeneralModelChangeEvents, instead of polling Browse calls. Changes in the order of the List are considered as adding and deleting References, i.e. if the order changes the NodeVersionshall be changed and a GeneralModelChangeEventshall be issued, indicating that Referenceshave been added and deleted.

In Table 65the additional Referencesare defined.

Table 65– OrderedListType Additional Subcomponents

SourcePath

References

NodeClass

BrowseName

DataType

TypeDefinition

Other

<OrderedObject>

HasProperty

Variable

NumberInList

Number

PropertyType

M

<OrderedObject>

HasInterface

ObjectType

IOrderedObjectType

The <OrderedObject> Objectshall implement the Interface IOrderedObjectTypeand therefore contains the mandatory Property NumberInList.