'Declaration
 
<ExtensionAttribute()>
<NotNullAttribute()>
Public Overloads Shared Function ReadWriteValue( _
   ByVal dataVariable As UADataVariable, _
   ByVal valueType As Type, _
   ByVal value As Object _
) As UADataVariable

'Usage
 
Dim dataVariable As UADataVariable
Dim valueType As Type
Dim value As Object
Dim value As UADataVariable
 
value = UADataVariableExtension.ReadWriteValue(dataVariable, valueType, value)

[Extension()]
[NotNull()]
public static UADataVariable ReadWriteValue( 
   UADataVariable dataVariable,
   Type valueType,
   object value
)

[Extension()]
[NotNull()]
public:
static UADataVariable^ ReadWriteValue( 
   UADataVariable^ dataVariable,
   Type^ valueType,
   Object^ value
) 

Parameters

dataVariable

The data variable that will be modified and returned.

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

valueType

The type of the data variable, expressed as .NET System.Type.

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

value

The initial value of the data variable.

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

Return Value

This method makes the data variable both readable and writable. The data written to the data variable will become the data subsequently read from the data variable.

This method keeps the settings of UADataVariable.WritableStatusCode and UADataVariable.WritableSourceTimestamp. This means that by default, the status code and source timestamp of the data variable will not writable. i.e. OPC UA clients will not be able to modify them. If you need a different behavior, call the Writable(UADataVariable,Boolean,Boolean,Boolean) method subsequently, with desired parameters, or modify the UADataVariable.WritableStatusCode and/or UADataVariable.WritableSourceTimestamp accordingly (set one or both to true).

In order to make a read-write register of certain type, but without having to specify initial data, consider simply using one of the ValueType(UADataVariable,Type) overloads.

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.

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