Namespace: Opc.UaFx
Assemblies: Opc.UaFx.Advanced.dll, Opc.UaFx.Advanced.dll
The OpcVariableNode type exposes the following members.
Initializes a new instance of the OpcVariableNode class accessible by the name
specified as a child node of the parent
node given.
C#
protected OpcVariableNode(IOpcNode parent, OpcName name)
Parameters
parent
IOpcNode
The IOpcNode used as the parent node or a null reference (Nothing in Visual Basic) in the case there is no parent node available.
name
OpcName
The OpcName through that the new variable node can be accessed.
Initializes a new instance of the OpcVariableNode class accessible by the name
specified with the initial value defined by value
as a child node of the parent
node given.
C#
protected OpcVariableNode(IOpcNode parent, OpcName name, object value)
Parameters
parent
IOpcNode
The IOpcNode used as the parent node or a null reference (Nothing in Visual Basic) in the case there is no parent node available.
name
OpcName
The OpcName through that the new variable node can be accessed.
value
Object
The initial value of the new variable node.
Initializes a new instance of the OpcVariableNode class accessible by the name
and id
specified as a child node of the parent
node given.
C#
protected OpcVariableNode(IOpcNode parent, OpcName name, OpcNodeId id)
Parameters
parent
IOpcNode
The IOpcNode used as the parent node or a null reference (Nothing in Visual Basic) in the case there is no parent node available.
name
OpcName
The OpcName through that the new variable node can be accessed.
id
OpcNodeId
The OpcNodeId through that the new variable node can be identified and accessed.
Initializes a new instance of the OpcVariableNode class accessible by the name
and id
specified with the initial value defined by value
as a child node of the parent
node given.
C#
protected OpcVariableNode(IOpcNode parent, OpcName name, OpcNodeId id, object value)
Parameters
parent
IOpcNode
The IOpcNode used as the parent node or a null reference (Nothing in Visual Basic) in the case there is no parent node available.
name
OpcName
The OpcName through that the new variable node can be accessed.
id
OpcNodeId
The OpcNodeId through that the new variable node can be identified and accessed.
value
Object
The initial value of the new variable node.
Initializes a new instance of the OpcVariableNode class accessible by the name
specified.
C#
protected OpcVariableNode(OpcName name)
Parameters
name
OpcName
The OpcName through that the new variable node can be accessed.
Initializes a new instance of the OpcVariableNode class accessible by the name
specified with the initial value given by value
.
C#
protected OpcVariableNode(OpcName name, object value)
Parameters
name
OpcName
The OpcName through that the new variable node can be accessed.
value
Object
The initial value of the new variable node.
Initializes a new instance of the OpcVariableNode class accessible by the name
and id
specified.
C#
protected OpcVariableNode(OpcName name, OpcNodeId id)
Parameters
name
OpcName
The OpcName through that the new variable node can be accessed.
id
OpcNodeId
The OpcNodeId through that the new variable node can be identified and accessed.
Initializes a new instance of the OpcVariableNode class accessible by the name
and id
specified with the initial value given by value
.
C#
protected OpcVariableNode(OpcName name, OpcNodeId id, object value)
Parameters
name
OpcName
The OpcName through that the new variable node can be accessed.
id
OpcNodeId
The OpcNodeId through that the new variable node can be identified and accessed.
value
Object
The initial value of the new variable node.
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.
C#
public OpcAccessLevel AccessLevel { get; set; }
Property Value
One of the members defined by the OpcAccessLevel enumeration. Which is used to indicate the ways the Value attribute of the current OpcVariableNode can be accessed (read/write) and if it provides current and/or historic data. The AccessLevel does not take any user access rights into account, although the variable is writable this may be restricted to a certain user / user group.
Gets the number/lengths of dimensions for an array Value with one or more fixed dimensions.
C#
public OpcArrayDimensions ArrayDimensions { get; set; }
Property Value
An instance of the OpcArrayDimensions class which offers the number/lengths of dimensions for an array Value.
Remarks
If the ValueRank does not identify an array of a specific dimension (i.e. ValueRank ⇐ 0) ArrayDimensions can be a null reference (Nothing in Visual Basic).
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.
C#
public virtual OpcDataType DataType { get; set; }
Property Value
One of the members defined by the OpcDataType enumeration.
Gets or stets the identifier which identifies the node that defines the type of data represented by the variable node.
C#
public OpcNodeId DataTypeId { get; set; }
Property Value
The OpcNodeId of the data type node which defines the type of data represented by the variable node. These data type node defines either a simple or a complex type of data accessible by the Value property.
Gets the default identifier which identifies the type that defines the underlying node reference within this OpcInstanceNode is referenced by its parent node.
C#
protected override OpcNodeId DefaultReferenceTypeId { get; }
Property Value
The OpcNodeId of the reference wihin this OpcInstanceNode is referenced. These reference defines the typical behaviour of an instance node and its role in the address space regarding its parent. If there exists no specific reference type a null reference (Nothing in Visual Basic).
Gets the default identifier which identifies the node that defines the underlying node type from that this OpcInstanceNode has been created.
C#
protected override OpcNodeId DefaultTypeDefinitionId { get; }
Property Value
The OpcNodeId of the type node from that this OpcInstanceNode has been created from. These type node defines the typical structure of an instance node of its type definition. If there exists no specific type definition node a null reference (Nothing in Visual Basic).
C#
public OpcHistoryConfigurationNode HistoryConfiguration { get; }
Property Value
Gets a value indicating whether the Value of the OpcVariableNode represented is an array.
C#
public bool IsArray { get; }
Property Value
The value true if the Value of the OpcVariableNode represented is an array; otherwise the false.
C#
public OpcReadAttributeValueCallback<OpcAccessLevel> ReadAccessLevelCallback { get; set; }
Property Value
C#
public OpcReadAttributeValueCallback<OpcArrayDimensions> ReadArrayDimensionsCallback { get; set; }
Property Value
C#
public OpcReadAttributeValueCallback<OpcNodeId> ReadDataTypeCallback { get; set; }
Property Value
C#
public OpcReadAttributeValueCallback<bool> ReadIsHistorizingCallback { get; set; }
Property Value
C#
public OpcReadAttributeValueCallback<OpcAccessLevel> ReadUserAccessLevelCallback { get; set; }
Property Value
C#
public OpcReadAttributeValueCallback<int> ReadValueRankCallback { get; set; }
Property Value
Gets or sets a callback used to read the variable value.
C#
public OpcReadVariableValueCallback ReadVariableValueCallback { get; set; }
Property Value
A OpcReadVariableValueCallback used to read the variable value as an Object. The value can also be a null reference (Nothing in Visual Basic).
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.
C#
public OpcAccessLevel UserAccessLevel { get; set; }
Property Value
One of the members defined by the OpcAccessLevel enumeration. Which is used to indicate the ways the Value attribute of the current OpcVariableNode can be accessed (read/write) and if it provides current and/or historic data. The UserAccessLevel takes user access rights into account therefore its access may be restricted to a certain user / user group.
C#
public OpcWriteAttributeValueCallback<OpcAccessLevel> WriteAccessLevelCallback { get; set; }
Property Value
C#
public OpcWriteAttributeValueCallback<OpcArrayDimensions> WriteArrayDimensionsCallback { get; set; }
Property Value
C#
public OpcWriteAttributeValueCallback<OpcNodeId> WriteDataTypeCallback { get; set; }
Property Value
C#
public OpcWriteAttributeValueCallback<bool> WriteIsHistorizingCallback { get; set; }
Property Value
C#
public OpcWriteAttributeValueCallback<OpcAccessLevel> WriteUserAccessLevelCallback { get; set; }
Property Value
C#
public OpcWriteAttributeValueCallback<int> WriteValueRankCallback { get; set; }
Property Value
Gets or sets a callback used to write the variable value.
C#
public OpcWriteVariableValueCallback WriteVariableValueCallback { get; set; }
Property Value
A OpcWriteVariableValueCallback used to write the variable value as an Object. The value can also be a null reference (Nothing in Visual Basic).
Initializes the default values used by the OpcVariableNode.
C#
protected override void InitializeDefaults()
Remarks
This method is used to ensure the availability of appropriate node specific default values. For more information like when this method is to be overwritten see InitializeDefaults.
C#
protected override OpcAttributeValue<T> ReadAttributeValueCore<T>(OpcReadAttributeValueContext context, OpcAttributeValue<T> value)
Parameters
context
OpcReadAttributeValueContext
value
OpcAttributeValue<T>
Returns
Reads the variable node value using the context
specified.
C#
public object ReadValue(OpcReadVariableValueContext context)
Parameters
context
OpcReadVariableValueContext
The OpcReadVariableValueContext to use to read the variable node value.
Returns
The Object variable node value associated with this node and read using the context
specified. This can also be a null reference (Nothing in Visual Basic).
Exceptions
The context
is a null reference (Nothing in Visual Basic).
C#
public OpcVariableValue<object> ReadVariableValue(OpcReadVariableValueContext context)
Parameters
context
OpcReadVariableValueContext
Returns
Exceptions
Reads the value of the variable node using the context
and value
information specified.
C#
protected virtual OpcVariableValue<object> ReadVariableValueCore(OpcReadVariableValueContext context, OpcVariableValue<object> value)
Parameters
context
OpcReadVariableValueContext
The OpcReadVariableValueContext to use to read the variable node value.
value
OpcVariableValue<Object>
The OpcVariableValue´1 containing the currently used value constructed by the value information contained in the variable node cache.
Returns
The OpcVariableValue´1 read using the ReadVariableValueCallback or the value
if there is no custom callback routine defined.
C#
protected override OpcAttributeValue<T> WriteAttributeValueCore<T>(OpcWriteAttributeValueContext context, OpcAttributeValue<T> value)
Parameters
context
OpcWriteAttributeValueContext
value
OpcAttributeValue<T>
Returns
Writes the value
to the variable node value using the context
specified.
C#
public void WriteValue(OpcWriteVariableValueContext context, object value)
Parameters
context
OpcWriteVariableValueContext
The OpcWriteVariableValueContext to use to write the variable node value
specified.
value
Object
The Object to write to the variable node value.
Exceptions
The context
is a null reference (Nothing in Visual Basic).
C#
public void WriteVariableValue(OpcWriteVariableValueContext context, OpcVariableValue<object> value)
Parameters
context
OpcWriteVariableValueContext
value
OpcVariableValue<Object>
Exceptions
Writes the value of the variable node using the context
and value
information specified.
C#
protected virtual OpcVariableValue<object> WriteVariableValueCore(OpcWriteVariableValueContext context, OpcVariableValue<object> value)
Parameters
context
OpcWriteVariableValueContext
The OpcWriteVariableValueContext to use to write the variable node value.
value
OpcVariableValue<Object>
The OpcVariableValue´1 containing the currently used value constructed by the value information contained in the variable node cache.
Returns
The OpcVariableValue´1 written using the WriteVariableValueCallback or the value
if there is no custom callback routine defined.