AttributeId Property (_UAAttributeArguments)

Attribute Id. Identifies an attribute of a node.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
Property AttributeId As UAAttributeId

'Usage
 
Dim instance As _UAAttributeArguments
Dim value As UAAttributeId
 
instance.AttributeId = value
 
value = instance.AttributeId

UAAttributeId AttributeId {get; set;}

property UAAttributeId AttributeId {
   UAAttributeId get();
   void set (    UAAttributeId value);
}

Example

COM

Object Pascal
PHP
VBScript
Visual Basic (VB 6.0)

// This example shows how to read the DataType attributes of 3 different nodes at
// once. Using the same method, it is also possible to read multiple attributes
// of the same node.

class procedure ReadMultipleValues.DataType;
var
  Client: OpcLabs_EasyOpcUA_TLB._EasyUAClient;
  ReadArguments1, ReadArguments2, ReadArguments3: _UAReadArguments;
  Arguments, Results: OleVariant;
  I: Cardinal;
  Result: _ValueResult;
begin
  // Instantiate the client object
  Client := CoEasyUAClient.Create;

  ReadArguments1 := CoUAReadArguments.Create;
  ReadArguments1.EndpointDescriptor.UrlString := 
    //'http://opcua.demo-this.com:51211/UA/SampleServer';
    //'https://opcua.demo-this.com:51212/UA/SampleServer/';
    'opc.tcp://opcua.demo-this.com:51210/UA/SampleServer';
  ReadArguments1.NodeDescriptor.NodeId.ExpandedText := 'nsu=http://test.org/UA/Data/ ;i=10845';
  ReadArguments1.AttributeId := UAAttributeId_DataType;

  ReadArguments2 := CoUAReadArguments.Create;
  ReadArguments2.EndpointDescriptor.UrlString := 
    //'http://opcua.demo-this.com:51211/UA/SampleServer';
    //'https://opcua.demo-this.com:51212/UA/SampleServer/';
    'opc.tcp://opcua.demo-this.com:51210/UA/SampleServer';
  ReadArguments2.NodeDescriptor.NodeId.ExpandedText := 'nsu=http://test.org/UA/Data/ ;i=10853';
  ReadArguments2.AttributeId := UAAttributeId_DataType;

  ReadArguments3 := CoUAReadArguments.Create;
  ReadArguments3.EndpointDescriptor.UrlString := 
    //'http://opcua.demo-this.com:51211/UA/SampleServer';
    //'https://opcua.demo-this.com:51212/UA/SampleServer/';
    'opc.tcp://opcua.demo-this.com:51210/UA/SampleServer';
  ReadArguments3.NodeDescriptor.NodeId.ExpandedText := 'nsu=http://test.org/UA/Data/ ;i=10855';
  ReadArguments3.AttributeId := UAAttributeId_DataType;

  Arguments := VarArrayCreate([0, 2], varVariant);
  Arguments[0] := ReadArguments1;
  Arguments[1] := ReadArguments2;
  Arguments[2] := ReadArguments3;

  // Obtain values. By default, the Value attributes of the nodes will be read.
  TVarData(Results).VType := varArray or varVariant;
  TVarData(Results).VArray := PVarArray(Client.ReadMultipleValues(Arguments));

  // Display results
  for I := VarArrayLowBound(Results, 1) to VarArrayHighBound(Results, 1) do
  begin
      Result := IInterface(Results[I]) as _ValueResult;
      WriteLn;
      if Result.Succeeded then
      begin
          WriteLn('Value: ', Result.Value);
          WriteLn('Value.ExpandedText: ', Result.Value.ExpandedText);
          WriteLn('Value.NamespaceUriString: ', Result.Value.NamespaceUriString);
          WriteLn('Value.NamespaceIndex: ', Result.Value.NamespaceIndex);
          WriteLn('Value.NumericIdentifier: ', Result.Value.NumericIdentifier);
      end
      else
        WriteLn('results(', I, ') *** Failure: ', Result.ErrorMessageBrief);
  end;
  
  VarClear(Results);
  VarClear(Arguments);

  // Example output:
  //
  //
  //Value: SByte
  //Value.ExpandedText: nsu=http://opcfoundation.org/UA/;i=2
  //Value.NamespaceUriString: http://opcfoundation.org/UA/
  //Value.NamespaceIndex: 0
  //Value.NumericIdentifier: 2
  //
  //Value: Float
  //Value.ExpandedText: nsu=http://opcfoundation.org/UA/;i=10
  //Value.NamespaceUriString: http://opcfoundation.org/UA/
  //Value.NamespaceIndex: 0
  //Value.NumericIdentifier: 10
  //
  //Value: String
  //Value.ExpandedText: nsu=http://opcfoundation.org/UA/;i=12
  //Value.NamespaceUriString: http://opcfoundation.org/UA/
  //Value.NamespaceIndex: 0
  //Value.NumericIdentifier: 12
end;

// This example shows how to read the DataType attributes of 3 different nodes at
// once. Using the same method, it is also possible to read multiple attributes
// of the same node.

const UAAttributeId_DataType = 14;

// Instantiate the client object
$Client = new COM("OpcLabs.EasyOpc.UA.EasyUAClient");

$ReadArguments1 = new COM("OpcLabs.EasyOpc.UA.OperationModel.UAReadArguments");
$ReadArguments1->EndpointDescriptor->UrlString = 
    //"http://opcua.demo-this.com:51211/UA/SampleServer";
    //"https://opcua.demo-this.com:51212/UA/SampleServer/";
    "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer";
$ReadArguments1->NodeDescriptor->NodeId->ExpandedText = "nsu=http://test.org/UA/Data/ ;i=10845";
$ReadArguments1->AttributeId = UAAttributeId_DataType;

$ReadArguments2 = new COM("OpcLabs.EasyOpc.UA.OperationModel.UAReadArguments");
$ReadArguments2->EndpointDescriptor->UrlString = 
    //"http://opcua.demo-this.com:51211/UA/SampleServer";
    //"https://opcua.demo-this.com:51212/UA/SampleServer/";
    "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer";
$ReadArguments2->NodeDescriptor->NodeId->ExpandedText = "nsu=http://test.org/UA/Data/ ;i=10853";
$ReadArguments2->AttributeId = UAAttributeId_DataType;

$ReadArguments3 = new COM("OpcLabs.EasyOpc.UA.OperationModel.UAReadArguments");
$ReadArguments3->EndpointDescriptor->UrlString = 
    //"http://opcua.demo-this.com:51211/UA/SampleServer";
    //"https://opcua.demo-this.com:51212/UA/SampleServer/";
    "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer";
$ReadArguments3->NodeDescriptor->NodeId->ExpandedText = "nsu=http://test.org/UA/Data/ ;i=10855";
$ReadArguments3->AttributeId = UAAttributeId_DataType;

$arguments[0] = $ReadArguments1;
$arguments[1] = $ReadArguments2;
$arguments[2] = $ReadArguments3;

// Obtain values. By default, the Value attributes of the nodes will be read.
$results = $Client->ReadMultipleValues($arguments);

// Display results
for ($i = 0; $i < count($results); $i++)
{
    $ValueResult = $results[$i];
    printf("\n");
    if ($ValueResult->Succeeded)
    {
        printf("Value: %s\n", $ValueResult->Value);
        printf("Value.ExpandedText: %s\n", $ValueResult->Value->ExpandedText);
        printf("Value.NamespaceUriString: %s\n", $ValueResult->Value->NamespaceUriString);
        printf("Value.NamespaceIndex: %s\n", $ValueResult->Value->NamespaceIndex);
        printf("Value.NumericIdentifier: %s\n", $ValueResult->Value->NumericIdentifier);
    }
    else
        printf("*** Failure: %s\n", $ValueResult->ErrorMessageBrief);
}

// Example output:
//
//
//Value: SByte
//Value.ExpandedText: nsu=http://opcfoundation.org/UA/;i=2
//Value.NamespaceUriString: http://opcfoundation.org/UA/
//Value.NamespaceIndex: 0
//Value.NumericIdentifier: 2
//
//Value: Float
//Value.ExpandedText: nsu=http://opcfoundation.org/UA/;i=10
//Value.NamespaceUriString: http://opcfoundation.org/UA/
//Value.NamespaceIndex: 0
//Value.NumericIdentifier: 10
//
//Value: String
//Value.ExpandedText: nsu=http://opcfoundation.org/UA/;i=12
//Value.NamespaceUriString: http://opcfoundation.org/UA/
//Value.NamespaceIndex: 0
//Value.NumericIdentifier: 12

Rem This example shows how to read the DataType attributes of 3 different nodes at once. Using the same method, it is also possible 
Rem to read multiple attributes of the same node.

Option Explicit

Const UAAttributeId_DataType = 14

' Instantiate the client object
Dim Client: Set Client = CreateObject("OpcLabs.EasyOpc.UA.EasyUAClient")

Dim ReadArguments1: Set ReadArguments1 = CreateObject("OpcLabs.EasyOpc.UA.OperationModel.UAReadArguments")
ReadArguments1.EndpointDescriptor.UrlString = "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"
ReadArguments1.NodeDescriptor.NodeId.ExpandedText = "nsu=http://test.org/UA/Data/ ;i=10845"
ReadArguments1.AttributeId = UAAttributeId_DataType

Dim ReadArguments2: Set ReadArguments2 = CreateObject("OpcLabs.EasyOpc.UA.OperationModel.UAReadArguments")
ReadArguments2.EndpointDescriptor.UrlString = "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"
ReadArguments2.NodeDescriptor.NodeId.ExpandedText = "nsu=http://test.org/UA/Data/ ;i=10853"
ReadArguments2.AttributeId = UAAttributeId_DataType

Dim ReadArguments3: Set ReadArguments3 = CreateObject("OpcLabs.EasyOpc.UA.OperationModel.UAReadArguments")
ReadArguments3.EndpointDescriptor.UrlString = "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"
ReadArguments3.NodeDescriptor.NodeId.ExpandedText = "nsu=http://test.org/UA/Data/ ;i=10855"
ReadArguments3.AttributeId = UAAttributeId_DataType

Dim arguments(2)
Set arguments(0) = ReadArguments1
Set arguments(1) = ReadArguments2
Set arguments(2) = ReadArguments3

' Obtain values.
Dim results: results = Client.ReadMultipleValues(arguments)

' Display results
Dim i: For i = LBound(results) To UBound(results)
    WScript.Echo

    Dim ValueResult: Set ValueResult = results(i)
    If ValueResult.Succeeded Then
        WScript.Echo "Value: " & ValueResult.Value
        On Error Resume Next
        WScript.Echo "Value.ExpandedText: " & ValueResult.Value.ExpandedText
        WScript.Echo "Value.NamespaceUriString: " & ValueResult.Value.NamespaceUriString
        WScript.Echo "Value.NamespaceIndex: " & ValueResult.Value.NamespaceIndex
        WScript.Echo "Value.NumericIdentifier: " & ValueResult.Value.NumericIdentifier
        On Error Goto 0
    Else
        WScript.Echo "*** Failure: " & ValueResult.ErrorMessageBrief
    End If
Next

' Example output:
'
'Value: SByte
'Value.ExpandedText: nsu=http://opcfoundation.org/UA/ ;i=2
'Value.NamespaceUriString: http://opcfoundation.org/UA/
'Value.NamespaceIndex: 0
'Value.NumericIdentifier: 2
'
'Value: Float
'Value.ExpandedText: nsu=http://opcfoundation.org/UA/ ;i=10
'Value.NamespaceUriString: http://opcfoundation.org/UA/
'Value.NamespaceIndex: 0
'Value.NumericIdentifier: 10
'
'Value: String
'Value.ExpandedText: nsu=http://opcfoundation.org/UA/ ;i=12
'Value.NamespaceUriString: http://opcfoundation.org/UA/
'Value.NamespaceIndex: 0
'Value.NumericIdentifier: 12

Rem This example shows how to read the Value attributes of 3 different nodes at once. Using the same method, it is also possible
Rem to read multiple attributes of the same node.

Public Sub ReadMultipleValues_DataType_Command_Click()
    OutputText = ""
    
    ' Instantiate the client object
    Dim Client As New EasyUAClient

    Dim readArguments1 As New UAReadArguments
    readArguments1.endpointDescriptor.UrlString = "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"
    readArguments1.nodeDescriptor.NodeId.expandedText = "nsu=http://test.org/UA/Data/ ;i=10845"
    readArguments1.AttributeId = UAAttributeId_DataType

    Dim ReadArguments2 As New UAReadArguments
    ReadArguments2.endpointDescriptor.UrlString = "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"
    ReadArguments2.nodeDescriptor.NodeId.expandedText = "nsu=http://test.org/UA/Data/ ;i=10853"
    ReadArguments2.AttributeId = UAAttributeId_DataType

    Dim ReadArguments3 As New UAReadArguments
    ReadArguments3.endpointDescriptor.UrlString = "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"
    ReadArguments3.nodeDescriptor.NodeId.expandedText = "nsu=http://test.org/UA/Data/ ;i=10855"
    ReadArguments3.AttributeId = UAAttributeId_DataType

    Dim arguments(2) As Variant
    Set arguments(0) = readArguments1
    Set arguments(1) = ReadArguments2
    Set arguments(2) = ReadArguments3

    ' Obtain values.
    Dim results() As Variant
    results = Client.ReadMultipleValues(arguments)

    ' Display results
    Dim i: For i = LBound(results) To UBound(results)
        OutputText = OutputText & vbCrLf
        
        Dim Result As valueResult: Set Result = results(i)
        If Result.Succeeded Then
            OutputText = OutputText & "Value: " & Result.value & vbCrLf
            On Error Resume Next
            OutputText = OutputText & "Value.ExpandedText: " & Result.value.expandedText & vbCrLf
            OutputText = OutputText & "Value.NamespaceUriString: " & Result.value.NamespaceUriString & vbCrLf
            OutputText = OutputText & "Value.NamespaceIndex: " & Result.value.NamespaceIndex & vbCrLf
            OutputText = OutputText & "Value.NumericIdentifier: " & Result.value.NumericIdentifier & vbCrLf
            On Error GoTo 0
        Else
            OutputText = OutputText & "*** Failure: " & Result.ErrorMessageBrief & vbCrLf
        End If
    Next

    ' Example output:
    '
    'Value: SByte
    'Value.ExpandedText: nsu=http://opcfoundation.org/UA/ ;i=2
    'Value.NamespaceUriString: http://opcfoundation.org/UA/
    'Value.NamespaceIndex: 0
    'Value.NumericIdentifier: 2
    '
    'Value: Float
    'Value.ExpandedText: nsu=http://opcfoundation.org/UA/ ;i=10
    'Value.NamespaceUriString: http://opcfoundation.org/UA/
    'Value.NamespaceIndex: 0
    'Value.NumericIdentifier: 10
    '
    'Value: String
    'Value.ExpandedText: nsu=http://opcfoundation.org/UA/ ;i=12
    'Value.NamespaceUriString: http://opcfoundation.org/UA/
    'Value.NamespaceIndex: 0
    'Value.NumericIdentifier: 12
End Sub

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

_UAAttributeArguments Interface
_UAAttributeArguments Members

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