OPC Studio User's Guide and Reference
ReadWrite(UADataVariable,TypeCode,UAAttributeData) Method



OpcLabs.ServerOpcUA Assembly > OpcLabs.EasyOpc.UA.NodeSpace Namespace > UADataVariableExtension Class > ReadWrite Method : ReadWrite(UADataVariable,TypeCode,UAAttributeData) Method
The data variable that will be modified and returned.

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

The type of the data variable, expressed as .NET type code (System.TypeCode).
The initial attribute data of the data variable.

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

Makes the data variable into a read-write register, specifying value type code and initial attribute data (value, status code, timestamp).
Syntax
'Declaration
 
<ExtensionAttribute()>
<NotNullAttribute()>
Public Overloads Shared Function ReadWrite( _
   ByVal dataVariable As UADataVariable, _
   ByVal valueTypeCode As TypeCode, _
   ByVal attributeData As UAAttributeData _
) As UADataVariable
'Usage
 
Dim dataVariable As UADataVariable
Dim valueTypeCode As TypeCode
Dim attributeData As UAAttributeData
Dim value As UADataVariable
 
value = UADataVariableExtension.ReadWrite(dataVariable, valueTypeCode, attributeData)

Parameters

dataVariable
The data variable that will be modified and returned.

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

valueTypeCode
The type of the data variable, expressed as .NET type code (System.TypeCode).
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 dataVariable, internally modified as defined by the method.

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

Exceptions
ExceptionDescription

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.

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.

An invalid enumeration value was used.

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

See Also