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);
}

Property Value

The default value of this property is Value (UAAttributeId.Value).

Exceptions

Exception	Description
System.ComponentModel.InvalidEnumArgumentException	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.

Exception

Description

System.ComponentModel.InvalidEnumArgumentException

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

The getter method of this property is pure, i.e. it does not have observable side effects.

This member or type is for use from COM. It is not meant to be used from .NET or Python. Refer to the corresponding .NET member or type instead, if you are developing in .NET or Python.

Example

// 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.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
// OPC client and subscriber examples in Object Pascal (Delphi) on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-OP .
// Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
// a commercial license in order to use Online Forums, and we reply to every post.

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.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
// OPC client and subscriber examples in PHP on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-PHP .
// Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
// a commercial license in order to use Online Forums, and we reply to every post.

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.
Rem
Rem Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
Rem OPC client and subscriber examples in VBScript on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-VBScript .
Rem Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
Rem a commercial license in order to use Online Forums, and we reply to every post.

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 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.
REM
REM Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
REM OPC client and subscriber examples in Visual Basic on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-VB .
REM Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
REM a commercial license in order to use Online Forums, and we reply to every post.

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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