OPC Studio User's Guide and Reference
UpdateWriteAttributeData Method (UADataVariableExtension)



OpcLabs.ServerOpcUA Assembly > OpcLabs.EasyOpc.UA.NodeSpace Namespace > UADataVariableExtension Class : UpdateWriteAttributeData Method
The data variable that will be modified.

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

The variable value modified by OPC writes.

The value of this parameter can be null (Nothing in Visual Basic).

Updates the write attribute data with given value, and current time for the timestamp.
Syntax
'Declaration
 
<ExtensionAttribute()>
Public Shared Sub UpdateWriteAttributeData( _
   ByVal dataVariable As UADataVariable, _
   ByVal writeValue As Object _
) 
'Usage
 
Dim dataVariable As UADataVariable
Dim writeValue As Object
 
UADataVariableExtension.UpdateWriteAttributeData(dataVariable, writeValue)
[Extension()]
public static void UpdateWriteAttributeData( 
   UADataVariable dataVariable,
   object writeValue
)
[Extension()]
public:
static void UpdateWriteAttributeData( 
   UADataVariable^ dataVariable,
   Object^ writeValue
) 

Parameters

dataVariable
The data variable that will be modified.

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

writeValue
The variable value modified by OPC writes.

The value of this parameter can be 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.

Remarks

You can use this method to set the initial data of a writable data variable.

This method sets the WriteAttributeData property so that it contains the specified writeValue, and the current time as its source timestamp. If WriteLoopback is true (the default), a clone of the new write attribute data is also set to the ReadAttributeData property.

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