Reference

OpcVariableNode Class

abstract

Namespace

Opc.UaFx

Assembly

Opc.UaFx.Advanced.dll

Package

Opc.UaFx.Advanced v2.59.0

Members

OpcVariableNode Members

Defines a node to use to represent values which may be simple or complex. Variables are always defined as properties or data variables of other nodes in the address space. They are never defined by themselves. A variable is always part of at least one other node, but may be related to any number of other nodes.

Syntax

[OpcNodeType(62)]
public abstract class OpcVariableNode : OpcInstanceNode

<OpcNodeType(62)>
Public MustInherit Class OpcVariableNode
    Inherits OpcInstanceNode

Inheritance

Object → OpcNode → OpcInstanceNode → OpcVariableNode

Implements

• IOpcNode
• IOpcNodeInfo
• IOpcVariableNodeInfo

Derived types

• OpcDataVariableNode
• OpcPropertyNode

Constructors

Name	Description
OpcVariableNodeprotected · 16 overloads	Initializes a new instance of the OpcVariableNode class accessible by the name specified.

Properties

Name	Description
AccessLevel	Gets or sets a value which indicates in which ways the Value attribute of the variable node can be accessed (read/write) and if it provides current and/or historic data.
ArrayDimensionssince v2.9	Gets the number/lengths of dimensions for an array Value with one or more fixed dimensions.
DataTypevirtual	Gets or sets a value which defines a pre-defined used DataTypeId as one of the members defined by the OpcDataType enumeration to simplify querying standard data types.
DataTypeId	Gets or stets the identifier which identifies the node that defines the type of data represented by the variable node.
DefaultReferenceTypeIdprotected · override	Gets the default identifier which identifies the type that defines the underlying node reference within this OpcInstanceNode is referenced by its parent node.
DefaultTypeDefinitionIdprotected · override	Gets the default identifier which identifies the node that defines the underlying node type from that this OpcInstanceNode has been created.
HistoryConfiguration
IsArraysince v2.18	Gets a value indicating whether the Value of the OpcVariableNode represented is an array.
IsHistorizing	Gets or sets a value indiciating whether there exists an value history for the node.
ReadAccessLevelCallback
ReadArrayDimensionsCallbacksince v2.9
ReadDataTypeCallback
ReadIsHistorizingCallback
ReadUserAccessLevelCallback
ReadValueRankCallback
ReadVariableValueCallback	Gets or sets a callback used to read the variable value.
Status
Timestamp
UserAccessLevel	Gets or sets a value which indicates in which ways the Value attribute of the variable node can be accessed (read/write) and if it provides current and/or historic data taking user access rights into account.
Value	Gets or sets the value of the variable node which may be simple or complex.
ValueRank
WriteAccessLevelCallback
WriteArrayDimensionsCallbacksince v2.9
WriteDataTypeCallback
WriteIsHistorizingCallback
WriteUserAccessLevelCallback
WriteValueRankCallback
WriteVariableValueCallback	Gets or sets a callback used to write the variable value.

Methods

Name	Description
InitializeDefaultsprotected · override	Initializes the default values used by the OpcVariableNode.
ReadAttributeValueCoreprotected · override
ReadValue	Reads the variable node value using the context specified.
ReadVariableValue
ReadVariableValueCoreprotected · virtual	Reads the value of the variable node using the context and value information specified.
WriteAttributeValueCoreprotected · override
WriteValue	Writes the value to the variable node value using the context specified.
WriteVariableValue
WriteVariableValueCoreprotected · virtual	Writes the value of the variable node using the context and value information specified.

Inherits members from OpcInstanceNode, OpcNode.

Applies to

Package	Versions
Opc.UaFx.Advanced	v2.5–v2.59