Reference

IOpcNode Members

Type

IOpcNode

Namespace

Opc.UaFx

Assembly

Opc.UaFx.Advanced.dll

Package

Opc.UaFx.Advanced v2.59.0

Also in

Opc.UaFx.Client

Inherits members from IOpcNodeInfo.

Properties

Description

Gets or sets the value of the optional Description attribute which shall explain the meaning of the node.

OpcText Description { get; set; }

Property Description As OpcText

Property value

OpcText

A localizable instance of the OpcText class which optionally explains the meaning of the node or a null reference (Nothing in Visual Basic) if there is no description associated with the node.

Remarks

The menaning of the node defines the usage, the context and the purpose of the node.

DisplayName

since v2.7

Gets or sets the value of the DisplayName attribute which defines the localizable name of the node.

OpcText DisplayName { get; set; }

Property DisplayName As OpcText

Property value

OpcText

An instance of the OpcText class which defines the localizable name of the node.

Remarks

Client application should use this attribute if they want to display the name of the node to the user. The string part of the DisplayName is restricted to 512 characters.

HasPendingChanges

Gets a value indicating whether there exists any pending change on the node.

bool HasPendingChanges { get; }

ReadOnly Property HasPendingChanges As Boolean

Property value

Boolean

The value true if PendingChanges is not equals to None; otherwise the value false.

Name

since v2.7

Gets or sets the value of the BrowseName attribute which defines the non-localizable human-readable name used when browsing the address space.

OpcName Name { get; set; }

Property Name As OpcName

Property value

OpcName

Remarks

The Name should never be used to display the name of the a node. Use the DisplayName instead for this purpose.

Unlike node identifiers the Name cannot be used to unambiguously identify the node. Different nodes may have the same browse name. The namespace is provided to make the browse name unique in some cases in the context of a node (e.g. properties of a node) although not unique in the context of the server. If different organizations define browse names for properties, the namespace of the Name provided by the organization makes the Name unique, although different organizations may use the same string having a slightly different meaning. Servers may often choose to use the same namespace for the node identifier and the browse name. However, if they want to provide a standard property, its browse name shall have the namespace of the standards body although the namespace of the node identifier reflects something else, for example the local server.

It is recommended that standard bodies defining standard type definitions use their namespace for the node identifier of the type definition node as well as for the browse name of the type definition node.

The string-part of the browse name is case sensitive. That is, clients shall consider them case sensitive. Server are allowed to handle browse names passed in service requests as case insensitive.

Use the value of this property to construct browse paths (see OpcNamePath).

Namespace

Gets the namespace of the node.

OpcNamespace Namespace { get; }

ReadOnly Property [Namespace] As OpcNamespace

Property value

OpcNamespace

The OpcNamespace assigned to the node or, if no namespace has been assigned to the node, the Namespace of its Id.

Parent

Gets the parent node of the node.

IOpcNode Parent { get; }

ReadOnly Property Parent As IOpcNode

Property value

IOpcNode

An instance implementing the IOpcNode interface which represents the physical parent of the node, or a null reference (Nothing in Visual Basic) if the node only has logical parent nodes.

PendingChanges

Gets a value indicating the changes performed on the node since their last notification.

OpcNodeChanges PendingChanges { get; }

ReadOnly Property PendingChanges As OpcNodeChanges

Property value

OpcNodeChanges

A bitwise combination of OpcNodeChanges members identifying the changes made on the node, or None if there was no change on the node since the last notification.

Remarks

Use one of the ApplyChanges overloads to notify about the changes and to reset the value of this property to None.

Tag

Gets or sets the object that contains additional user data about the node.

object Tag { get; set; }

Property Tag As Object

Property value

Object

An object that contains additional user data about the node. The default is null (Nothing in Visual Basic).

UserWriteAccess

Gets or sets the value of the optional UserWriteAccess attribute which exposes the possibilities of a client to write the attributes of the node taking user access rights into account.

OpcAttributeWriteAccess UserWriteAccess { get; set; }

Property UserWriteAccess As OpcAttributeWriteAccess

Property value

OpcAttributeWriteAccess

A combination of the members defined by the OpcAttributeWriteAccess enumeration.

Remarks

The mask value of this attribute can only further restrict the WriteAccess attribute, when it is set to not writable in the general case that applies for every user.

WriteAccess

Gets or sets the value of the optional WriteAccess attribute which exposes the posibilities of a client to write the attributes of the node.

OpcAttributeWriteAccess WriteAccess { get; set; }

Property WriteAccess As OpcAttributeWriteAccess

Property value

OpcAttributeWriteAccess

A combination of the members defined by the OpcAttributeWriteAccess enumeration.

Remarks

The mask value of this attribute does not take any user access rights into account, that is, altough an attribute is writable this may be restricted to a certain user / user group.

If a server does not have the ability to get the write mask information for a specific attribute from the underlying system, it should state that it is writable. If a write opertation is called on the attribute, the server should transfer this request and return the corresponding OpcStatusCode if such a request is rejected.

Only in case there a corresponding attribute is set in the mask of this attribute the according attribute is writable; otherwise it can not accessed for writing.

Methods

AddNotifier

Adds the node to the collection of notifiers (= event sources) of this node.

void AddNotifier(OpcContext context, IOpcNode node)

Sub AddNotifier(context As OpcContext, node As IOpcNode)

Parameters

Name	Type	Description
context	OpcContext	The OpcContext to use to add the node as the notifying event source.
node	IOpcNode	The IOpcNode instance acting as the notifier.

Exceptions

Exception	Condition
ArgumentNullException	The context or node is a null reference (Nothing in Visual Basic).
NotSupportedException	This node does not support notifiers; only object nodes do.

ApplyChanges

2 overloads

Overload	Description
ApplyChanges(OpcContext)	Notifies about changes performed on the node since the last notification and resets the pending changes to None.
ApplyChanges(OpcContext, bool)	Notifies about changes performed on the node (and optionally on its children) since the last notification and resets the pending changes to None.

Exceptions (all overloads)

Exception	Condition
ArgumentNullException	The context is a null reference (Nothing in Visual Basic).

ApplyChanges(OpcContext)

Notifies about changes performed on the node since the last notification and resets the pending changes to None.

void ApplyChanges(OpcContext context)

Sub ApplyChanges(context As OpcContext)

Parameters

Name	Type	Description
context	OpcContext	The OpcContext to use to notify about changes performed on the node.

ApplyChanges(OpcContext, bool)

Notifies about changes performed on the node (and optionally on its children) since the last notification and resets the pending changes to None.

void ApplyChanges(OpcContext context, bool recursive)

Sub ApplyChanges(context As OpcContext, recursive As Boolean)

Parameters

Name	Type	Description
context	OpcContext	The OpcContext to use to notify about changes performed on the node.
recursive	Boolean	The value true if pending changes are to be notified for all children as well; otherwise the value false.

Child

since v2.7

Retrieves the child node its Name property matches exactly the name specified.

IOpcNode Child(OpcContext context, OpcName name)

Function Child(context As OpcContext, name As OpcName) As IOpcNode

Parameters

Name	Type	Description
context	OpcContext	The OpcContext to use to lookup the requested child node.
name	OpcName	The full qualified OpcName of the node to lookup.

Returns

IOpcNode

An instance implementing the IOpcNode interface its Name exactly matches the name specified, if such a node is a known child node of this node. Otherwise a null reference (Nothing in Visual Basic).

Exceptions

Exception	Condition
ArgumentNullException	The context or name is a null reference (Nothing in Visual Basic).

Children

Retrieves a sequence of all nodes organized as children of this node.

IEnumerable<IOpcNode> Children(OpcContext context)

Function Children(context As OpcContext) As IEnumerable(Of IOpcNode)

Parameters

Name	Type	Description
context	OpcContext	The OpcContext to use to lookup the child nodes.

Returns

IEnumerable<IOpcNode>

A sequence of instances implementing the IOpcNode interface which representing the nodes organized as child nodes of this node.

Exceptions

Exception	Condition
ArgumentNullException	The context is a null reference (Nothing in Visual Basic).

IsChangePending

Determines whether all of the changes specified by the change are pending on the node (see PendingChanges).

bool IsChangePending(OpcNodeChanges change)

Function IsChangePending(change As OpcNodeChanges) As Boolean

Parameters

Name	Type	Description
change	OpcNodeChanges	A bitwise combination of OpcNodeChanges members identifying the changes to check.

Returns

Boolean

The value true if all of the changes specified by the change are pending on the node; otherwise the value false.

RemoveNotifier

Removes the node from the collection of notifiers (= event sources) of this node.

void RemoveNotifier(OpcContext context, IOpcNode node)

Sub RemoveNotifier(context As OpcContext, node As IOpcNode)

Parameters

Name	Type	Description
context	OpcContext	The OpcContext to use to remove the node as the notifying event source.
node	IOpcNode	The IOpcNode instance no longer acting as the notifier.

Exceptions

Exception	Condition
ArgumentNullException	The context or node is a null reference (Nothing in Visual Basic).