OPC Studio User's Guide and Reference
Examples - OPC Unified Architecture - Read multiple nodes or attributes

.NET

// This example shows how to read data (value, timestamps, and status code) of 3 attributes at once. In this example,
// we are reading a Value attribute of 3 different nodes, but the method can also be used 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 C# on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-CSharp .
// 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.

using System;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.OperationModel;

namespace UADocExamples._EasyUAClient
{
    partial class ReadMultiple
    {
        public static void Main1()
        {
            UAEndpointDescriptor endpointDescriptor =
                "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer";
            // or "http://opcua.demo-this.com:51211/UA/SampleServer" (currently not supported)
            // or "https://opcua.demo-this.com:51212/UA/SampleServer/"

            // Instantiate the client object.
            var client = new EasyUAClient();

            // Obtain attribute data. By default, the Value attributes of the nodes will be read.
            UAAttributeDataResult[] attributeDataResultArray = client.ReadMultiple(new[]
                {
                    new UAReadArguments(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10845"),
                    new UAReadArguments(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10853"),
                    new UAReadArguments(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10855")
                });

            // Display results.
            foreach (UAAttributeDataResult attributeDataResult in attributeDataResultArray)
            {
                if (attributeDataResult.Succeeded)
                    Console.WriteLine($"AttributeData: {attributeDataResult.AttributeData}");
                else
                    Console.WriteLine($"*** Failure: {attributeDataResult.ErrorMessageBrief}");
            }
        }

        // Example output:
        //
        //AttributeData: 51 {Int16} @11/6/2011 1:49:19 PM @11/6/2011 1:49:19 PM; Good
        //AttributeData: -1993984 {Single} @11/6/2011 1:49:19 PM @11/6/2011 1:49:19 PM; Good
        //AttributeData: Yellow% Dragon Cat) White Blue Dog# Green Banana- {String} @11/6/2011 1:49:19 PM @11/6/2011 1:49:19 PM; Good            
    }
}

# This example shows how to read data (value, timestamps, and status code) of 3 attributes at once. In this example,
# we are reading a Value attribute of 3 different nodes, but the method can also be used 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 PowerShell on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-PowerShell .
# 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.

#requires -Version 5.1
using namespace OpcLabs.EasyOpc.UA
using namespace OpcLabs.EasyOpc.UA.OperationModel

# The path below assumes that the current directory is [ProductDir]/Examples-NET/PowerShell/Windows .
Add-Type -Path "../../../Components/Opclabs.QuickOpc/net472/OpcLabs.EasyOpcUA.dll"
Add-Type -Path "../../../Components/Opclabs.QuickOpc/net472/OpcLabs.EasyOpcUAComponents.dll"

[UAEndpointDescriptor]$endpointDescriptor =
    "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"
# or "http://opcua.demo-this.com:51211/UA/SampleServer" (currently not supported)
# or "https://opcua.demo-this.com:51212/UA/SampleServer/"

# Instantiate the client object.
$client = New-Object EasyUAClient

# Obtain attribute data. By default, the Value attributes of the nodes will be read.
$attributeDataResultArray = $client.ReadMultiple(@(
        (New-Object UAReadArguments($endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10845")), 
        (New-Object UAReadArguments($endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10853")), 
        (New-Object UAReadArguments($endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10855"))
    ))

foreach ($attributeDataResult in $attributeDataResultArray) {
    if ($attributeDataResult.Succeeded) {
        Write-Host "AttributeData: $($attributeDataResult.AttributeData)"
    }
    else {
        Write-Host "*** Failure: $($attributeDataResult.ErrorMessageBrief)"
    }
}


# Example output:
#
#AttributeData: 51 {Int16} @11/6/2011 1:49:19 PM @11/6/2011 1:49:19 PM; Good
#AttributeData: -1993984 {Single} @11/6/2011 1:49:19 PM @11/6/2011 1:49:19 PM; Good
#AttributeData: Yellow% Dragon Cat) White Blue Dog# Green Banana- {String} @11/6/2011 1:49:19 PM @11/6/2011 1:49:19 PM; Good            


' This example shows how to read data (value, timestamps, and status code) of 3 attributes at once. In this example,
' we are reading a Value attribute of 3 different nodes, but the method can also be used 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 VB.NET on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-VBNET .
' 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.

Imports OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.OperationModel

Namespace _EasyUAClient
    Partial Friend Class ReadMultiple
        Public Shared Sub Main1()

            ' Define which server we will work with.
            Dim endpointDescriptor As UAEndpointDescriptor =
                    "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"
            ' or "http://opcua.demo-this.com:51211/UA/SampleServer" (currently not supported)
            ' or "https://opcua.demo-this.com:51212/UA/SampleServer/"

            ' Instantiate the client object
            Dim client = New EasyUAClient()

            ' Obtain attribute data. By default, the Value attributes of the nodes will be read.
            Dim attributeDataResultArray() As UAAttributeDataResult = client.ReadMultiple(New UAReadArguments() _
               {
                   New UAReadArguments(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10845"),
                   New UAReadArguments(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10853"),
                   New UAReadArguments(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10855")
               })

            ' Display results
            For Each attributeDataResult As UAAttributeDataResult In attributeDataResultArray
                If attributeDataResult.Succeeded Then
                    Console.WriteLine("AttributeData: {0}", attributeDataResult.AttributeData)
                Else
                    Console.WriteLine("*** Failure: {0}", attributeDataResult.ErrorMessageBrief)
                End If
            Next attributeDataResult

            ' Example output:
            '
            'AttributeData: 51 {System.Int16} @11/6/2011 1:49:19 PM @11/6/2011 1:49:19 PM; Good
            'AttributeData: -1993984 {System.Single} @11/6/2011 1:49:19 PM @11/6/2011 1:49:19 PM; Good
            'AttributeData: Yellow% Dragon Cat) White Blue Dog# Green Banana- {System.String} @11/6/2011 1:49:19 PM @11/6/2011 1:49:19 PM; Good            
        End Sub
    End Class
End Namespace

COM

// This example shows how to read the attributes of 4 OPC-UA nodes at once, and display the results.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
// 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.

#include "stdafx.h"    // Includes "QuickOpc.h", and other commonly used files
#include <atlsafe.h>
#include "ReadMultiple.h"

namespace _EasyUAClient
{
    void ReadMultiple::Main()
    {
        // Initialize the COM library
        CoInitializeEx(NULL, COINIT_MULTITHREADED);
        {
            _UAReadArgumentsPtr ReadArguments1Ptr(_uuidof(UAReadArguments));
            ReadArguments1Ptr->EndpointDescriptor->UrlString = 
                //L"http://opcua.demo-this.com:51211/UA/SampleServer";
                L"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer";
            ReadArguments1Ptr->NodeDescriptor->NodeId->ExpandedText = L"nsu=http://test.org/UA/Data/ ;i=10853";

            _UAReadArgumentsPtr ReadArguments2Ptr(_uuidof(UAReadArguments));
            ReadArguments2Ptr->EndpointDescriptor->UrlString = 
                //L"http://opcua.demo-this.com:51211/UA/SampleServer";
                L"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer";
            ReadArguments2Ptr->NodeDescriptor->NodeId->ExpandedText = L"nsu=http://test.org/UA/Data/ ;i=10845";

            _UAReadArgumentsPtr ReadArguments3Ptr(_uuidof(UAReadArguments));
            ReadArguments3Ptr->EndpointDescriptor->UrlString = 
                //L"http://opcua.demo-this.com:51211/UA/SampleServer";
                L"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer";
            ReadArguments3Ptr->NodeDescriptor->NodeId->ExpandedText = L"nsu=http://test.org/UA/Data/ ;i=10304";

            _UAReadArgumentsPtr ReadArguments4Ptr(_uuidof(UAReadArguments));
            ReadArguments4Ptr->EndpointDescriptor->UrlString = 
                //L"http://opcua.demo-this.com:51211/UA/SampleServer";
                L"opc.tcp://opcua.demo-this.com:51210/UA/SampleServer";
            ReadArguments4Ptr->NodeDescriptor->NodeId->ExpandedText = L"nsu=http://test.org/UA/Data/ ;i=10389";

            CComSafeArray<VARIANT> arguments(4);
            arguments.SetAt(0, _variant_t((IDispatch*)ReadArguments1Ptr));
            arguments.SetAt(1, _variant_t((IDispatch*)ReadArguments2Ptr));
            arguments.SetAt(2, _variant_t((IDispatch*)ReadArguments3Ptr));
            arguments.SetAt(3, _variant_t((IDispatch*)ReadArguments4Ptr));
            CComVariant vArguments(arguments);

            // Instantiate the client object
            _EasyUAClientPtr ClientPtr(__uuidof(EasyUAClient));

            // Obtain values. By default, the Value attributes of the nodes will be read.
            CComSafeArray<VARIANT> results;
            results.Attach(ClientPtr->ReadMultiple(&vArguments));
            
            // Display results
            for (int i = results.GetLowerBound(); i <= results.GetUpperBound(); i++)
            {
                _UAAttributeDataResultPtr ResultPtr = results[i];

                _variant_t vString;
                vString.ChangeType(VT_BSTR, &_variant_t((IDispatch*)ResultPtr->AttributeData));
                _tprintf(_T("results(d).AttributeDatas\n"), i, (LPCTSTR)CW2CT((_bstr_t)vString));
            }
        }
         // Release all interface pointers BEFORE calling CoUninitialize()
        CoUninitialize();
    }
}

// This example shows how to read the attributes of 4 OPC-UA nodes at once, and
// display the results.
//
// 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 ReadMultiple.Main;
var
  Arguments: OleVariant;
  Client: OpcLabs_EasyOpcUA_TLB._EasyUAClient;
  I: Cardinal;
  ReadArguments1, ReadArguments2, ReadArguments3, ReadArguments4: _UAReadArguments;
  Result: _UAAttributeDataResult;
  Results: OleVariant;
begin
  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=10853';

  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=10845';

  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=10304';

  ReadArguments4 := CoUAReadArguments.Create;
  ReadArguments4.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';
  ReadArguments4.NodeDescriptor.NodeId.ExpandedText := 'nsu=http://test.org/UA/Data/ ;i=10389';

  Arguments := VarArrayCreate([0, 3], varVariant);
  Arguments[0] := ReadArguments1;
  Arguments[1] := ReadArguments2;
  Arguments[2] := ReadArguments3;
  Arguments[3] := ReadArguments4;

  // Instantiate the client object
  Client := CoEasyUAClient.Create;

  // Perform the operation
  TVarData(Results).VType := varArray or varVariant;
  TVarData(Results).VArray := PVarArray(Client.ReadMultiple(Arguments));

  // Display results
  for I := VarArrayLowBound(Results, 1) to VarArrayHighBound(Results, 1) do
  begin
    Result := IInterface(Results[I]) as _UAAttributeDataResult;
    if Result.Succeeded then
      WriteLn('results(', I, ').AttributeData: ', Result.AttributeData.ToString)
    else
      WriteLn('results(', I, ') *** Failure: ', Result.ErrorMessageBrief);
  end;

  VarClear(Results);
  VarClear(Arguments);
end;

// This example shows how to read the attributes of 4 OPC-UA nodes at once, and display the results.
//
// 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.

$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=10853";

$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=10845";

$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=10304";

$ReadArguments4 = new COM("OpcLabs.EasyOpc.UA.OperationModel.UAReadArguments");
$ReadArguments4->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";
$ReadArguments4->NodeDescriptor->NodeId->ExpandedText = "nsu=http://test.org/UA/Data/ ;i=10389";

$arguments[0] = $ReadArguments1;
$arguments[1] = $ReadArguments2;
$arguments[2] = $ReadArguments3;
$arguments[3] = $ReadArguments4;

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

// Perform the operation
$results = $Client->ReadMultiple($arguments);

// Display results
for ($i = 0; $i < count($results); $i++)
{
    $attributeDataResult = $results[$i];
    if ($attributeDataResult->Succeeded)
        printf("results[d].AttributeDatas\n", $i, $attributeDataResult->AttributeData);
    else
        printf("results[d]: *** Failures\n", $i, $attributeDataResult->ErrorMessageBrief);
}

// This example shows how to read data (value, timestamps, and status code) of 3 attributes at once. In this example,
// we are reading a Value attribute of 3 different nodes, but the method can also be used to read multiple attributes
// of the same node.

mle_outputtext.Text = ""

// Instantiate the client object
OLEObject client
client = CREATE OLEObject
client.ConnectToNewObject("OpcLabs.EasyOpc.UA.EasyUAClient")

// Prepare arguments. By default, the Value attributes of the nodes will be read.

OLEObject readArguments1
readArguments1 = CREATE OLEObject
readArguments1.ConnectToNewObject("OpcLabs.EasyOpc.UA.OperationModel.UAReadArguments")
readArguments1.EndpointDescriptor.UrlString = "http://opcua.demo-this.com:51211/UA/SampleServer"
readArguments1.NodeDescriptor.NodeId.ExpandedText = "nsu=http://test.org/UA/Data/ ;i=10845"

OLEObject readArguments2
readArguments2 = CREATE OLEObject
readArguments2.ConnectToNewObject("OpcLabs.EasyOpc.UA.OperationModel.UAReadArguments")
readArguments2.EndpointDescriptor.UrlString = "http://opcua.demo-this.com:51211/UA/SampleServer"
readArguments2.NodeDescriptor.NodeId.ExpandedText = "nsu=http://test.org/UA/Data/ ;i=10853"

OLEObject readArguments3
readArguments3 = CREATE OLEObject
readArguments3.ConnectToNewObject("OpcLabs.EasyOpc.UA.OperationModel.UAReadArguments")
readArguments3.EndpointDescriptor.UrlString = "http://opcua.demo-this.com:51211/UA/SampleServer"
readArguments3.NodeDescriptor.NodeId.ExpandedText = "nsu=http://test.org/UA/Data/ ;i=10855"

OLEObject readArgumentsList
readArgumentsList = CREATE OLEObject
readArgumentsList.ConnectToNewObject("OpcLabs.BaseLib.Collections.ElasticVector")
readArgumentsList.Add(readArguments1)
readArgumentsList.Add(readArguments2)
readArgumentsList.Add(readArguments3)

// Obtain attribute data. 
OLEObject attributeDataResultList
attributeDataResultList = client.ReadList(readArgumentsList)

// Display results
Int i
FOR i = 0 TO attributeDataResultList.Count - 1
    OLEObject attributeDataResult
    attributeDataResult = attributeDataResultList.Item[i]
    IF attributeDataResult.Succeeded THEN
        mle_outputtext.Text = mle_outputtext.Text + "AttributeData: " + String(attributeDataResult.AttributeData) + "~r~n"
    ELSE
        mle_outputtext.Text = mle_outputtext.Text + "*** Failure: " + attributeDataResult.ErrorMessageBrief + "~r~n"
    END IF    
NEXT

// Example output:
//
//AttributeData: 51 {System.Int16} @11/6/2011 1:49:19 PM @11/6/2011 1:49:19 PM; Good
//AttributeData: -1993984 {System.Single} @11/6/2011 1:49:19 PM @11/6/2011 1:49:19 PM; Good
//AttributeData: Yellow% Dragon Cat) White Blue Dog# Green Banana- {System.String} @11/6/2011 1:49:19 PM @11/6/2011 1:49:19 PM; Good            


REM This example shows how to read the attributes of 4 OPC-UA nodes at once, and
REM display the results.
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 ReadMultiple_Main_Command_Click()
    OutputText = ""

    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=10853"

    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=10845"

    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=10304"

    Dim ReadArguments4 As New UAReadArguments
    ReadArguments4.endpointDescriptor.UrlString = "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"
    ReadArguments4.nodeDescriptor.NodeId.expandedText = "nsu=http://test.org/UA/Data/ ;i=10389"

    Dim arguments(3) As Variant
    Set arguments(0) = readArguments1
    Set arguments(1) = ReadArguments2
    Set arguments(2) = ReadArguments3
    Set arguments(3) = ReadArguments4

    ' Instantiate the client object
    Dim Client As New EasyUAClient

    ' Obtain values. By default, the Value attributes of the nodes will be read.
    Dim results() As Variant
    results = Client.ReadMultiple(arguments)

    ' Display results
    Dim i: For i = LBound(results) To UBound(results)
        Dim Result As UAAttributeDataResult: Set Result = results(i)
        If Result.Succeeded Then
            OutputText = OutputText & "results(" & i & ").AttributeData: " & Result.AttributeData & vbCrLf
        Else
            OutputText = OutputText & "results(" & i & ") *** Failure: " & Result.ErrorMessageBrief & vbCrLf
        End If
    Next
End Sub

Rem This example shows how to read the attributes of 4 OPC-UA nodes at once, and display the results.
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

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=10853"

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=10845"

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=10304"

Dim ReadArguments4: Set ReadArguments4 = CreateObject("OpcLabs.EasyOpc.UA.OperationModel.UAReadArguments")
ReadArguments4.EndpointDescriptor.UrlString = "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"
ReadArguments4.NodeDescriptor.NodeId.ExpandedText = "nsu=http://test.org/UA/Data/ ;i=10389"

Dim arguments(3)
Set arguments(0) = ReadArguments1
Set arguments(1) = ReadArguments2
Set arguments(2) = ReadArguments3
Set arguments(3) = ReadArguments4

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

' Perform the operation
Dim results: results = Client.ReadMultiple(arguments)

' Display results
Dim i: For i = LBound(results) To UBound(results)
    Dim AttributeDataResult: Set AttributeDataResult = results(i)
    If AttributeDataResult.Succeeded Then
        WScript.Echo "results(" & i & ").AttributeData: " & AttributeDataResult.AttributeData
    Else
        WScript.Echo "results(" & i & ") *** Failure: " & AttributeDataResult.ErrorMessageBrief
    End If
Next

Python

# This example shows how to read data (value, timestamps, and status code) of 3 attributes at once. In this example,
# we are reading a Value attribute of 3 different nodes, but the method can also be used 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 Python on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-Python .
# 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.
# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc
import time

# Import .NET namespaces.
from OpcLabs.EasyOpc.UA import *
from OpcLabs.EasyOpc.UA.OperationModel import *


endpointDescriptor = UAEndpointDescriptor('opc.tcp://opcua.demo-this.com:51210/UA/SampleServer')
# or 'http://opcua.demo-this.com:51211/UA/SampleServer' (currently not supported)
# or 'https://opcua.demo-this.com:51212/UA/SampleServer/'

# Instantiate the client object.
client = EasyUAClient()

# Obtain attribute data. By default, the Value attributes of the nodes will be read.
attributeDataResultArray = client.ReadMultiple([
    UAReadArguments(endpointDescriptor, UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10845')),
    UAReadArguments(endpointDescriptor, UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10853')),
    UAReadArguments(endpointDescriptor, UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10855')),
    ])

# Display results.
for attributeDataResult in attributeDataResultArray:
    if attributeDataResult.Succeeded:
        print('AttributeData: ', attributeDataResult.AttributeData, sep='')
    else:
        print('*** Failure: ', attributeDataResult.ErrorMessageBrief, sep='')

print()
print('Finished.')

 

See Also
Examples - OPC Unified Architecture - Read multiple values
Examples - OPC Unified Architecture - Read a single attribute of a single node
Examples - OPC Unified Architecture - Subscribe to multiple nodes for data changes
Examples - OPC Unified Architecture - Read nodes specified by browse paths
Examples - OPC Unified Architecture - Read DataType attributes
Examples - OPC Unified Architecture - Read multiple nodes from device

Concepts

Reading Attributes of OPC UA Nodes

Examples - Client OPC Data Access

Examples - OPC Data Access - Read multiple items

Examples - Client OPC UA Specialized

Examples - OPC UA Specialized - Softing OPC UA .NET Demo Server - Repeatedly read many

Examples - Client OPC UA Services

Examples - OPC UA Services - Register and unregister multiple nodes, with connection locking

 

 

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