ReadWrite(UADataVariable,UANodeId,Int32,UAAttributeData) Method

Makes the data variable into a read-write register, specifying the data type Id, array rank, and initial attribute data (value, status code, timestamp).

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<ExtensionAttribute()>
<NotNullAttribute()>
Public Overloads Shared Function ReadWrite( _
   ByVal dataVariable As UADataVariable, _
   ByVal dataTypeId As UANodeId, _
   ByVal arrayRank As Integer, _
   ByVal attributeData As UAAttributeData _
) As UADataVariable

'Usage
 
Dim dataVariable As UADataVariable
Dim dataTypeId As UANodeId
Dim arrayRank As Integer
Dim attributeData As UAAttributeData
Dim value As UADataVariable
 
value = UADataVariableExtension.ReadWrite(dataVariable, dataTypeId, arrayRank, attributeData)

[Extension()]
[NotNull()]
public static UADataVariable ReadWrite( 
   UADataVariable dataVariable,
   UANodeId dataTypeId,
   int arrayRank,
   UAAttributeData attributeData
)

[Extension()]
[NotNull()]
public:
static UADataVariable^ ReadWrite( 
   UADataVariable^ dataVariable,
   UANodeId^ dataTypeId,
   int arrayRank,
   UAAttributeData^ attributeData
)

Parameters

dataVariable

The data variable that will be modified and returned.

The value of this parameter cannot be null (Nothing in Visual Basic).

dataTypeId

Specifies the OPC UA data type of the variable value. For standard data types, see OpcLabs.EasyOpc.UA.AddressSpace.Standard.UADataTypeIds.

Because the OpcLabs.EasyOpc.UA.AddressSpace.UANodeId has an implicit conversion from System.String, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use a string (representing the expanded text of the nodeId) in place of this parameter, and the corresponding OPC UA node Id will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can use the OpcLabs.EasyOpc.UA.AddressSpace.UANodeId.UANodeId Constructor(String) constructor instead.

The value of this parameter cannot be null (Nothing in Visual Basic).

arrayRank

The array rank (number of dimensions) of the array (or 0 for scalars).

attributeData

The initial attribute data of the data variable.

The value of this parameter cannot be null (Nothing in Visual Basic).

Return Value

Returns the , internally modified as defined by the method.

This method never returns null (Nothing in Visual Basic).

Exceptions

Exception Description

Exception	Description
System.ArgumentNullException	A `null` reference (`Nothing` in Visual Basic) is passed to a method that does not accept it as a valid argument. This is a usage error, i.e. it will never occur (the exception will not be thrown) in a correctly written program. Your code should not catch this exception.
System.ArgumentOutOfRangeException	The value of an argument is outside the allowable range of values as defined by the invoked method. This is a usage error, i.e. it will never occur (the exception will not be thrown) in a correctly written program. Your code should not catch this exception.

System.ArgumentNullException

A null reference (Nothing in Visual Basic) is passed to a method that does not accept it as a valid argument.

This is a usage error, i.e. it will never occur (the exception will not be thrown) in a correctly written program. Your code should not catch this exception.

System.ArgumentOutOfRangeException

The value of an argument is outside the allowable range of values as defined by the invoked method.

This is a usage error, i.e. it will never occur (the exception will not be thrown) in a correctly written program. Your code should not catch this exception.

Remarks

This is an extension method (info: C#, VB.NET). In languages that have support for extensions methods (such as C# and VB.NET), you can use the extension method as if it were a regular method on the object that is its first parameter. In other languages (such as with Python.NET), you will call the extension as a static method, and pass it the object on which it acts as its first parameter.

Requirements

Target Platforms: .NET Framework: Windows 10 (selected versions), Windows 11 (selected versions), Windows Server 2016, Windows Server 2022; .NET: Linux, macOS, Microsoft Windows

Reference

UADataVariableExtension Class
UADataVariableExtension Members
Overload List

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