OPC Studio User's Guide and Reference
UnsubscribeMultipleMonitoredItems Method (_EasyUAClient)
Example 



OpcLabs.EasyOpcUA Assembly > OpcLabs.EasyOpc.UA.ComTypes Namespace > _EasyUAClient Interface : UnsubscribeMultipleMonitoredItems Method
Unsubscribe from changes of multiple monitored items, specifying an "enumerable" of integer handles.
Syntax
'Declaration
 

Sub UnsubscribeMultipleMonitoredItems( _
   ByVal handlesToUnsubscribeArray As Object _
) 
'Usage
 

Dim instance As _EasyUAClient
Dim handlesToUnsubscribeArray As Object
 
instance.UnsubscribeMultipleMonitoredItems(handlesToUnsubscribeArray)
void UnsubscribeMultipleMonitoredItems( 
   object handlesToUnsubscribeArray
)
void UnsubscribeMultipleMonitoredItems( 
   Object^ handlesToUnsubscribeArray
)

Parameters

handlesToUnsubscribeArray
Exceptions
ExceptionDescription
System.ArgumentException

One of the arguments provided to a method is not valid.

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.

System.ArgumentNullException

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

 

This method operates (at least in part) asynchronously, with respect to the caller. The actual execution of the operation may be delayed, and the outcome of the operation (if any) is provided to the calling code using an event notification, callback, or other means explained in the text. In a properly written program, this method does not throw any exceptions. You should therefore not put try/catch statements or similar constructs around calls to this method. The only exceptions thrown by this method are for usage errors, i.e. when your code violates the usage contract of the method, such as passing in invalid arguments or calling the method when the state of the object does not allow it. Any operation-related errors (i.e. errors that depend on external conditions that your code cannot reliably check) are indicated by the means the operation returns its outcome (if any), which is described in the text. For more information, see Do not catch any exceptions with asynchronous or multiple-operation methods.
Example

.NET

.NET

COM

COM

COM

// This example shows how to unsubscribe from changes of multiple items.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

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

namespace UADocExamples._EasyUAClient
{
    partial class UnsubscribeMultipleMonitoredItems
    {
        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 and hook events.
            var client = new EasyUAClient();
            client.DataChangeNotification += client_DataChangeNotification;

            Console.WriteLine("Subscribing...");
            int[] handleArray = client.SubscribeMultipleMonitoredItems(new[]
                {
                    new EasyUAMonitoredItemArguments(null, endpointDescriptor, 
                        "nsu=http://test.org/UA/Data/ ;i=10845", 1000),
                    new EasyUAMonitoredItemArguments(null, endpointDescriptor, 
                        "nsu=http://test.org/UA/Data/ ;i=10853", 1000),
                    new EasyUAMonitoredItemArguments(null, endpointDescriptor, 
                        "nsu=http://test.org/UA/Data/ ;i=10855", 1000)
                });

            Console.WriteLine("Processing monitored item changed events for 10 seconds...");
            System.Threading.Thread.Sleep(10 * 1000);

            Console.WriteLine("Unsubscribing...");
            client.UnsubscribeMultipleMonitoredItems(handleArray);

            Console.WriteLine("Waiting for 5 seconds...");
            System.Threading.Thread.Sleep(5 * 1000);

            Console.WriteLine("Finished.");
        }

        static void client_DataChangeNotification(object sender, EasyUADataChangeNotificationEventArgs e)
        {
            // Display value.
            if (e.Succeeded)
                Console.WriteLine($"{e.Arguments.NodeDescriptor}: {e.AttributeData.Value}");
            else
                Console.WriteLine($"{e.Arguments.NodeDescriptor} *** Failure: {e.ErrorMessageBrief}");
        }
    }
}
# This example shows how to unsubscribe from changes of multiple items.
#
# Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

#requires -Version 5.1
using namespace OpcLabs.EasyOpc.UA
using namespace OpcLabs.EasyOpc.UA.AddressSpace
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"

$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

# Data change notification handler
Register-ObjectEvent -InputObject $client -EventName DataChangeNotification -Action { 
    if ($EventArgs.Succeeded) {
        Write-Host "$($EventArgs.Arguments.NodeDescriptor): $($EventArgs.AttributeData.Value)"
    }
    else {
        Write-Host "$($EventArgs.Arguments.NodeDescriptor) *** Failure: $($EventArgs.ErrorMessageBrief)"
    }
}

Write-Host "Subscribing..."
$handleArray = $client.SubscribeMultipleMonitoredItems(@(
    (New-Object UAMonitoredItemArguments(
        (New-Object UAAttributeArguments($endpointDescriptor, [UANodeDescriptor]"nsu=http://test.org/UA/Data/ ;i=10845")), 
        1000)),
    (New-Object UAMonitoredItemArguments(
        (New-Object UAAttributeArguments($endpointDescriptor, [UANodeDescriptor]"nsu=http://test.org/UA/Data/ ;i=10853")), 
        1000)),
    (New-Object UAMonitoredItemArguments(
        (New-Object UAAttributeArguments($endpointDescriptor, [UANodeDescriptor]"nsu=http://test.org/UA/Data/ ;i=10855")),
        1000))
    ))

Write-Host "Processing data change events for 10 seconds..."
$stopwatch =  [System.Diagnostics.Stopwatch]::StartNew() 
while ($stopwatch.Elapsed.TotalSeconds -lt 10) {    
    Start-Sleep -Seconds 1
}

Write-Host "Unsubscribing..."
$client.UnsubscribeMultipleMonitoredItems($handleArray)

Write-Host "Waiting for 5 seconds..."
Start-Sleep -Seconds 5

Write-Host "Finished."

# This example shows how to unsubscribe from changes of multiple items.
#
# 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 .
# 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 *


def dataChangeNotification(sender, e):
    # Display value.
    if e.Succeeded:
        print(e.Arguments.NodeDescriptor, ': ', e.AttributeData.Value, sep='')
    else:
        print(e.Arguments.NodeDescriptor, ' *** Failure: ', e.ErrorMessageBrief, sep='')


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 and hook events.
client = EasyUAClient()
client.DataChangeNotification += dataChangeNotification

print('Subscribing...')
handleArray = client.SubscribeMultipleMonitoredItems([
    EasyUAMonitoredItemArguments(
        None,
        endpointDescriptor,
        UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10845'),
        UAMonitoringParameters(1000)),
    EasyUAMonitoredItemArguments(
        None,
        endpointDescriptor,
        UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10853'),
        UAMonitoringParameters(1000)),
    EasyUAMonitoredItemArguments(
        None,
        endpointDescriptor,
        UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10855'),
        UAMonitoringParameters(1000)),
    ])

print('Processing data change events for 10 seconds...')
time.sleep(10)

print('Unsubscribing...')
client.UnsubscribeMultipleMonitoredItems(handleArray)

print('Waiting for 5 seconds...')
time.sleep(5)

print('Finished.')

' This example shows how to unsubscribe from changes of multiple items.
'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

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

Namespace _EasyUAClient
    Friend Class UnsubscribeMultipleMonitoredItems
        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 and hook events
            Dim client = New EasyUAClient()
            AddHandler client.DataChangeNotification, AddressOf client_DataChangeNotification

            Console.WriteLine("Subscribing...")
            Dim handleArray() As Integer = client.SubscribeMultipleMonitoredItems(New EasyUAMonitoredItemArguments() _
               { _
                   New EasyUAMonitoredItemArguments(Nothing, endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10845", 1000), _
                   New EasyUAMonitoredItemArguments(Nothing, endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10853", 1000), _
                   New EasyUAMonitoredItemArguments(Nothing, endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10855", 1000) _
               } _
            )

            Console.WriteLine("Processing monitored item changed events for 10 seconds...")
            Threading.Thread.Sleep(10 * 1000)

            Console.WriteLine("Unsubscribing...")
            client.UnsubscribeMultipleMonitoredItems(handleArray)

            Console.WriteLine("Waiting for 5 seconds...")
            Threading.Thread.Sleep(5 * 1000)
        End Sub

        Private Shared Sub client_DataChangeNotification(ByVal sender As Object, ByVal e As EasyUADataChangeNotificationEventArgs)
            ' Display value
            If e.Succeeded Then
                Console.WriteLine("{0}: {1}", e.Arguments.NodeDescriptor, e.AttributeData.Value)
            Else
                Console.WriteLine("{0} *** Failure: {1}", e.Arguments.NodeDescriptor, e.ErrorMessageBrief)
            End If
        End Sub
    End Class
End Namespace

// This example shows how to unsubscribe from changes of just some monitored
// items.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

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

namespace UADocExamples._EasyUAClient
{
    partial class UnsubscribeMultipleMonitoredItems
    {
        public static void Some()
        {
            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 and hook events.
            var client = new EasyUAClient();
            client.DataChangeNotification += client_DataChangeNotification2;

            Console.WriteLine();
            Console.WriteLine("Subscribing...");
            int[] handleArray = client.SubscribeMultipleMonitoredItems(new[]
                {
                    new EasyUAMonitoredItemArguments(null, endpointDescriptor, 
                        "nsu=http://test.org/UA/Data/ ;i=10845", 1000),
                    new EasyUAMonitoredItemArguments(null, endpointDescriptor, 
                        "nsu=http://test.org/UA/Data/ ;i=10853", 1000),
                    new EasyUAMonitoredItemArguments(null, endpointDescriptor, 
                        "nsu=http://test.org/UA/Data/ ;i=10855", 1000)
                });

            for (int i = 0; i < handleArray.Length; i++)
                Console.WriteLine($"handleArray[{i}]: {handleArray[i]}");

            Console.WriteLine();
            Console.WriteLine("Processing monitored item changed events for 10 seconds...");
            System.Threading.Thread.Sleep(10 * 1000);

            Console.WriteLine();
            Console.WriteLine("Unsubscribing from 2 monitored items...");
            // We will unsubscribe from the first and third monitored item we have
            // previously subscribed to.
            client.UnsubscribeMultipleMonitoredItems(new [] {handleArray[0], handleArray[2]});

            Console.WriteLine();
            Console.WriteLine("Processing monitored item changed events for 10 seconds...");
            System.Threading.Thread.Sleep(10 * 1000);

            Console.WriteLine();
            Console.WriteLine("Unsubscribing from all remaining monitored items...");
            client.UnsubscribeAllMonitoredItems();

            Console.WriteLine("Waiting for 5 seconds...");
            System.Threading.Thread.Sleep(5 * 1000);

            Console.WriteLine("Finished.");
        }

        static void client_DataChangeNotification2(object sender, EasyUADataChangeNotificationEventArgs e)
        {
            // Display value.
            if (e.Succeeded)
                Console.WriteLine($"{e.Arguments.NodeDescriptor}: {e.AttributeData.Value}");
            else
                Console.WriteLine($"{e.Arguments.NodeDescriptor} *** Failure: {e.ErrorMessageBrief}");
        }
    }
}
# This example shows how to unsubscribe from changes of multiple items.
#
# Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

#requires -Version 5.1
using namespace OpcLabs.EasyOpc.UA
using namespace OpcLabs.EasyOpc.UA.AddressSpace
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"

$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

# Data change notification handler
Register-ObjectEvent -InputObject $client -EventName DataChangeNotification -Action { 
    if ($EventArgs.Succeeded) {
        Write-Host "$($EventArgs.Arguments.NodeDescriptor): $($EventArgs.AttributeData.Value)"
    }
    else {
        Write-Host "$($EventArgs.Arguments.NodeDescriptor) *** Failure: $($EventArgs.ErrorMessageBrief)"
    }
}

Write-Host "Subscribing..."
$handleArray = $client.SubscribeMultipleMonitoredItems(@(
    (New-Object UAMonitoredItemArguments(
        (New-Object UAAttributeArguments($endpointDescriptor, [UANodeDescriptor]"nsu=http://test.org/UA/Data/ ;i=10845")), 
        1000)),
    (New-Object UAMonitoredItemArguments(
        (New-Object UAAttributeArguments($endpointDescriptor, [UANodeDescriptor]"nsu=http://test.org/UA/Data/ ;i=10853")), 
        1000)),
    (New-Object UAMonitoredItemArguments(
        (New-Object UAAttributeArguments($endpointDescriptor, [UANodeDescriptor]"nsu=http://test.org/UA/Data/ ;i=10855")),
        1000))
    ))

for ($i = 0; $i -lt $handleArray.Length; $i++) {
    Write-Host "handleArray[$($i)]: $($handleArray[$i])"
}

Write-Host 
Write-Host "Processing data change events for 10 seconds..."
$stopwatch =  [System.Diagnostics.Stopwatch]::StartNew() 
while ($stopwatch.Elapsed.TotalSeconds -lt 10) {    
    Start-Sleep -Seconds 1
}

Write-Host 
Write-Host "Unsubscribing from 2 monitored items..."
# We will unsubscribe from the first and third monitored item we have
# previously subscribed to.
$client.UnsubscribeMultipleMonitoredItems([int[]]@($handleArray[0], $handleArray[2]))

Write-Host 
Write-Host "Processing data change events for 10 seconds..."
$stopwatch =  [System.Diagnostics.Stopwatch]::StartNew() 
while ($stopwatch.Elapsed.TotalSeconds -lt 10) {    
    Start-Sleep -Seconds 1
}

Write-Host 
Write-Host "Unsubscribing from all remaining monitored items..."
$client.UnsubscribeAllMonitoredItems()

Write-Host "Waiting for 5 seconds..."
Start-Sleep -Seconds 5

Write-Host "Finished."

# This example shows how to unsubscribe from changes of just some monitored
# items.
#
# 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 .
# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc
import time

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


def dataChangeNotification(sender, e):
    # Display value.
    if e.Succeeded:
        print(e.Arguments.NodeDescriptor, ': ', e.AttributeData.Value, sep='')
    else:
        print(e.Arguments.NodeDescriptor, ' *** Failure: ', e.ErrorMessageBrief, sep='')


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 and hook events.
client = EasyUAClient()
client.DataChangeNotification += dataChangeNotification

print('Subscribing...')
handleArray = client.SubscribeMultipleMonitoredItems([
    EasyUAMonitoredItemArguments(
        None,
        endpointDescriptor,
        UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10845'),
        UAMonitoringParameters(1000)),
    EasyUAMonitoredItemArguments(
        None,
        endpointDescriptor,
        UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10853'),
        UAMonitoringParameters(1000)),
    EasyUAMonitoredItemArguments(
        None,
        endpointDescriptor,
        UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10855'),
        UAMonitoringParameters(1000)),
    ])

for i, handle in enumerate(handleArray):
    print('handleArray[', i, ']: ', handle, sep='')

print()
print('Processing data change events for 10 seconds...')
time.sleep(10)

print()
print('Unsubscribing from 2 monitored items...')
handleList = List[int]()
handleList.Add(handleArray[0])
handleList.Add(handleArray[2])
client.UnsubscribeMultipleMonitoredItems(handleList)

print()
print('Processing data change events for 10 seconds...')
time.sleep(10)

print()
print('Unsubscribing from all remaining monitored items...')
client.UnsubscribeAllMonitoredItems()

print('Waiting for 5 seconds...')
time.sleep(5)

print('Finished.')

' This example shows how to unsubscribe from changes of just some monitored
' items.
'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

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

Namespace _EasyUAClient
    Partial Friend Class UnsubscribeMultipleMonitoredItems
        Public Shared Sub Some()

            ' 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 and hook events
            Dim client = New EasyUAClient()
            AddHandler client.DataChangeNotification, AddressOf client_DataChangeNotification2

            Console.WriteLine()
            Console.WriteLine("Subscribing...")
            Dim handleArray() As Integer = client.SubscribeMultipleMonitoredItems(New EasyUAMonitoredItemArguments() _
               {
                    New EasyUAMonitoredItemArguments(Nothing, endpointDescriptor,
                        "nsu=http://test.org/UA/Data/ ;i=10845", 1000),
                    New EasyUAMonitoredItemArguments(Nothing, endpointDescriptor,
                        "nsu=http://test.org/UA/Data/ ;i=10853", 1000),
                    New EasyUAMonitoredItemArguments(Nothing, endpointDescriptor,
                        "nsu=http://test.org/UA/Data/ ;i=10855", 1000)
               }
            )

            For i As Integer = 0 To handleArray.Length - 1
                Console.WriteLine($"handleArray[{i}]: {handleArray(i)}")
            Next i

            Console.WriteLine()
            Console.WriteLine("Processing monitored item changed events for 10 seconds...")
            System.Threading.Thread.Sleep(10 * 1000)

            Console.WriteLine()
            Console.WriteLine("Unsubscribing from 2 monitored items...")
            ' We will unsubscribe from the first and third monitored item we have
            ' previously subscribed to.
            client.UnsubscribeMultipleMonitoredItems(New Integer() {handleArray(0), handleArray(2)})

            Console.WriteLine()
            Console.WriteLine("Processing monitored item changed events for 10 seconds...")
            System.Threading.Thread.Sleep(10 * 1000)

            Console.WriteLine()
            Console.WriteLine("Unsubscribing from all remaining monitored items...")
            client.UnsubscribeAllMonitoredItems()

            Console.WriteLine("Waiting for 5 seconds...")
            System.Threading.Thread.Sleep(5 * 1000)

            Console.WriteLine("Finished.")
        End Sub

        Private Shared Sub client_DataChangeNotification2(ByVal sender As Object, ByVal e As EasyUADataChangeNotificationEventArgs)
            ' Display value
            If e.Succeeded Then
                Console.WriteLine($"{e.Arguments.NodeDescriptor}: {e.AttributeData.Value}")
            Else
                Console.WriteLine($"{e.Arguments.NodeDescriptor} *** Failure: {e.ErrorMessageBrief}")
            End If
        End Sub
    End Class
End Namespace

REM This example shows how to unsubscribe from changes of just some monitored
REM items.
REM
REM Find all latest examples here : https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

' The client object, with events
'Public WithEvents Client8 As EasyUAClient

Public Sub UnsubscribeMultipleMonitoredItems_Some_Command_Click()
    OutputText = ""

    Set Client8 = New EasyUAClient

    OutputText = OutputText & "Subscribing..." & vbCrLf
    Dim MonitoringParameters As New UAMonitoringParameters
    MonitoringParameters.SamplingInterval = 1000
    
    Dim MonitoredItemArguments1 As New EasyUAMonitoredItemArguments
    MonitoredItemArguments1.endpointDescriptor.UrlString = "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"
    MonitoredItemArguments1.nodeDescriptor.NodeId.expandedText = "nsu=http://test.org/UA/Data/ ;i=10845"
    Set MonitoredItemArguments1.MonitoringParameters = MonitoringParameters
    MonitoredItemArguments1.SetState ("Item1")
    
    Dim MonitoredItemArguments2 As New EasyUAMonitoredItemArguments
    MonitoredItemArguments2.endpointDescriptor.UrlString = "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"
    MonitoredItemArguments2.nodeDescriptor.NodeId.expandedText = "nsu=http://test.org/UA/Data/ ;i=10853"
    Set MonitoredItemArguments2.MonitoringParameters = MonitoringParameters
    MonitoredItemArguments2.SetState ("Item2")
    
    Dim MonitoredItemArguments3 As New EasyUAMonitoredItemArguments
    MonitoredItemArguments3.endpointDescriptor.UrlString = "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"
    MonitoredItemArguments3.nodeDescriptor.NodeId.expandedText = "nsu=http://test.org/UA/Data/ ;i=10855"
    Set MonitoredItemArguments3.MonitoringParameters = MonitoringParameters
    MonitoredItemArguments3.SetState ("Item3")
    
    Dim arguments(2) As Variant
    Set arguments(0) = MonitoredItemArguments1
    Set arguments(1) = MonitoredItemArguments2
    Set arguments(2) = MonitoredItemArguments3
    Dim handleArray As Variant
    handleArray = Client8.SubscribeMultipleMonitoredItems(arguments)

    Dim i As Long: For i = LBound(handleArray) To UBound(handleArray)
        OutputText = OutputText & "handleArray(" & i & "): " & handleArray(i) & vbCrLf
    Next

    OutputText = OutputText & vbCrLf
    OutputText = OutputText & "Processing monitored item changed events for 10 seconds..." & vbCrLf
    Pause 10000

    OutputText = OutputText & vbCrLf
    OutputText = OutputText & "Unsubscribing from 2 monitored items..." & vbCrLf

    Dim SelectedHandles(1) As Variant
    ' We will unsubscribe from the first and third monitored item we have
    ' previously subscribed to.
    SelectedHandles(0) = handleArray(0)
    SelectedHandles(1) = handleArray(2)
    Client8.UnsubscribeMultipleMonitoredItems (SelectedHandles)

    OutputText = OutputText & vbCrLf
    OutputText = OutputText & "Processing monitored item changed events for 10 seconds..." & vbCrLf
    Pause 10000

    OutputText = OutputText & vbCrLf
    OutputText = OutputText & "Unsubscribing from all remaining monitored items..." & vbCrLf
    Call Client8.UnsubscribeAllMonitoredItems

    OutputText = OutputText & "Waiting for 5 seconds..." & vbCrLf
    Pause 5000

    Set Client8 = Nothing
    OutputText = OutputText & "Finished." & vbCrLf
End Sub

Public Sub Client8_DataChangeNotification(ByVal sender As Variant, ByVal eventArgs As EasyUADataChangeNotificationEventArgs)
    ' Display the data
    If eventArgs.Succeeded Then
        OutputText = OutputText & eventArgs.arguments.nodeDescriptor & ": " & eventArgs.AttributeData & vbCrLf
    Else
        OutputText = OutputText & eventArgs.arguments.nodeDescriptor & ": " & eventArgs.ErrorMessageBrief & vbCrLf
    End If
End Sub
// This example shows how to unsubscribe from changes of multiple items.
//
// Find all latest examples here : https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

type
  TClientEventHandlers127 = class
    procedure OnDataChangeNotification(
      ASender: TObject;
      sender: OleVariant;
      const eventArgs: _EasyUADataChangeNotificationEventArgs);
  end;

procedure TClientEventHandlers127.OnDataChangeNotification(
  ASender: TObject;
  sender: OleVariant;
  const eventArgs: _EasyUADataChangeNotificationEventArgs);
begin
  // Display the data
  if eventArgs.Succeeded then
      WriteLn(eventArgs.Arguments.NodeDescriptor.ToString, ': ',
      eventArgs.AttributeData.ToString)
  else
      WriteLn(eventArgs.Arguments.NodeDescriptor.ToString, ' *** Failure: ',
      eventArgs.ErrorMessageBrief);
end;

class procedure UnsubscribeMultipleMonitoredItems.Main;
var
  Arguments: OleVariant;
  Client: TEasyUAClient;
  ClientEventHandlers: TClientEventHandlers127;
  Handle: Cardinal;
  HandleArray: OleVariant;
  HandleSafeArray: PSafeArray;
  I: Cardinal;
  MonitoredItemArguments1, MonitoredItemArguments2, MonitoredItemArguments3:
    _EasyUAMonitoredItemArguments;
  MonitoringParameters: _UAMonitoringParameters;
begin
  // Instantiate the client object and hook events
  Client := TEasyUAClient.Create(nil);
  ClientEventHandlers := TClientEventHandlers127.Create;
  Client.OnDataChangeNotification := ClientEventHandlers.OnDataChangeNotification;

  WriteLn('Subscribing...');
  MonitoringParameters := CoUAMonitoringParameters.Create;
  MonitoringParameters.SamplingInterval := 1000;
  MonitoredItemArguments1 := CoEasyUAMonitoredItemArguments.Create;
  MonitoredItemArguments1.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';
  MonitoredItemArguments1.NodeDescriptor.NodeId.ExpandedText := 'nsu=http://test.org/UA/Data/ ;i=10845';
  MonitoredItemArguments1.MonitoringParameters := MonitoringParameters;
  MonitoredItemArguments2 := CoEasyUAMonitoredItemArguments.Create;
  MonitoredItemArguments2.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';
  MonitoredItemArguments2.NodeDescriptor.NodeId.ExpandedText := 'nsu=http://test.org/UA/Data/ ;i=10853';
  MonitoredItemArguments2.MonitoringParameters := MonitoringParameters;
  MonitoredItemArguments3 := CoEasyUAMonitoredItemArguments.Create;
  MonitoredItemArguments3.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';
  MonitoredItemArguments3.NodeDescriptor.NodeId.ExpandedText := 'nsu=http://test.org/UA/Data/ ;i=10855';
  MonitoredItemArguments3.MonitoringParameters := MonitoringParameters;
  Arguments := VarArrayCreate([0, 2], varVariant);
  Arguments[0] := MonitoredItemArguments1;
  Arguments[1] := MonitoredItemArguments2;
  Arguments[2] := MonitoredItemArguments3;

  HandleSafeArray := Client.SubscribeMultipleMonitoredItems(Arguments);
  TVarData(HandleArray).VType := varArray or varVariant;
  TVarData(HandleArray).VArray := PVarArray(HandleSafeArray);

  for I := VarArrayLowBound(HandleArray, 1) to VarArrayHighBound(HandleArray, 1) do
  begin
      Handle := Cardinal(HandleArray[I]);
      WriteLn('HandleArray[', I, ']: ', Handle);
  end;

  WriteLn('Processing monitored item changed events for 10 seconds...');
  PumpSleep(10*1000);

  WriteLn('Unsubscribing...');
  Client.UnsubscribeMultipleMonitoredItems(HandleArray);

  WriteLn('Waiting for 5 seconds...');
  Sleep(5*1000);

  WriteLn('Finished.');
  VarClear(HandleArray);
  VarClear(Arguments);
  FreeAndNil(Client);
  FreeAndNil(ClientEventHandlers);
end;
Rem This example shows how to unsubscribe from changes of multiple items.
Rem
Rem Find all latest examples here : https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

Option Explicit

' Instantiate the client object and hook events
Dim Client: Set Client= CreateObject("OpcLabs.EasyOpc.UA.EasyUAClient")
WScript.ConnectObject Client, "Client_"

WScript.Echo "Subscribing..."
Dim MonitoringParameters: Set MonitoringParameters = CreateObject("OpcLabs.EasyOpc.UA.UAMonitoringParameters")
MonitoringParameters.SamplingInterval = 1000
Dim MonitoredItemArguments1: Set MonitoredItemArguments1 = CreateObject("OpcLabs.EasyOpc.UA.OperationModel.EasyUAMonitoredItemArguments")
MonitoredItemArguments1.EndpointDescriptor.UrlString = "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"
MonitoredItemArguments1.NodeDescriptor.NodeId.ExpandedText = "nsu=http://test.org/UA/Data/ ;i=10845"
MonitoredItemArguments1.MonitoringParameters = MonitoringParameters
Dim MonitoredItemArguments2: Set MonitoredItemArguments2 = CreateObject("OpcLabs.EasyOpc.UA.OperationModel.EasyUAMonitoredItemArguments")
MonitoredItemArguments2.EndpointDescriptor.UrlString = "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"
MonitoredItemArguments2.NodeDescriptor.NodeId.ExpandedText = "nsu=http://test.org/UA/Data/ ;i=10853"
MonitoredItemArguments2.MonitoringParameters = MonitoringParameters
Dim MonitoredItemArguments3: Set MonitoredItemArguments3 = CreateObject("OpcLabs.EasyOpc.UA.OperationModel.EasyUAMonitoredItemArguments")
MonitoredItemArguments3.EndpointDescriptor.UrlString = "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"
MonitoredItemArguments3.NodeDescriptor.NodeId.ExpandedText = "nsu=http://test.org/UA/Data/ ;i=10855"
MonitoredItemArguments3.MonitoringParameters = MonitoringParameters
Dim arguments(2)
Set arguments(0) = MonitoredItemArguments1
Set arguments(1) = MonitoredItemArguments2
Set arguments(2) = MonitoredItemArguments3
Dim handleArray: handleArray = Client.SubscribeMultipleMonitoredItems(arguments)

Dim i: For i = LBound(handleArray) To UBound(handleArray)
    WScript.Echo "handleArray(" & i & "): " & handleArray(i)
Next

WScript.Echo "Processing monitored item changed events for 10 seconds..."
WScript.Sleep 10 * 1000

WScript.Echo "Unsubscribing from two monitored items..."
Dim handles1(1)
handles1(0) = handleArray(1)
handles1(1) = handleArray(2)
Client.UnsubscribeMultipleMonitoredItems handles1

WScript.Echo "Processing monitored item changed events for 10 seconds..."
WScript.Sleep 10 * 1000

WScript.Echo "Unsubscribing from all remaining items..."
Client.UnsubscribeAllMonitoredItems

WScript.Echo "Waiting for 5 seconds..."
WScript.Sleep 5 * 1000



Sub Client_DataChangeNotification(Sender, e)
    ' Display the data
    Dim display: If e.Exception Is Nothing Then display = e.AttributeData Else display = e.ErrorMessageBrief
    WScript.Echo e.Arguments.NodeDescriptor & ":" & display
End Sub

// This example shows how to unsubscribe from changes of just some monitored
// items.
//
// Find all latest examples here : https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

type
  TClientEventHandlers128 = class
    procedure OnDataChangeNotification(
      ASender: TObject;
      sender: OleVariant;
      const eventArgs: _EasyUADataChangeNotificationEventArgs);
  end;

procedure TClientEventHandlers128.OnDataChangeNotification(
  ASender: TObject;
  sender: OleVariant;
  const eventArgs: _EasyUADataChangeNotificationEventArgs);
begin
  // Display the data
  if eventArgs.Succeeded then
      WriteLn(eventArgs.Arguments.NodeDescriptor.ToString, ': ',
      eventArgs.AttributeData.ToString)
  else
      WriteLn(eventArgs.Arguments.NodeDescriptor.ToString, ' *** Failure: ',
      eventArgs.ErrorMessageBrief);
end;

class procedure UnsubscribeMultipleMonitoredItems.Some;
var
  Arguments: OleVariant;
  Client: TEasyUAClient;
  ClientEventHandlers: TClientEventHandlers128;
  Handle: Cardinal;
  HandleArray: OleVariant;
  HandleSafeArray: PSafeArray;
  I: Cardinal;
  MonitoredItemArguments1, MonitoredItemArguments2, MonitoredItemArguments3:
    _EasyUAMonitoredItemArguments;
  MonitoringParameters: _UAMonitoringParameters;
  SelectedHandles: OleVariant;
begin
  // Instantiate the client object and hook events
  Client := TEasyUAClient.Create(nil);
  ClientEventHandlers := TClientEventHandlers128.Create;
  Client.OnDataChangeNotification := ClientEventHandlers.OnDataChangeNotification;

  WriteLn;
  WriteLn('Subscribing...');
  MonitoringParameters := CoUAMonitoringParameters.Create;
  MonitoringParameters.SamplingInterval := 1000;
  MonitoredItemArguments1 := CoEasyUAMonitoredItemArguments.Create;
  MonitoredItemArguments1.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';
  MonitoredItemArguments1.NodeDescriptor.NodeId.ExpandedText := 'nsu=http://test.org/UA/Data/ ;i=10845';
  MonitoredItemArguments1.MonitoringParameters := MonitoringParameters;
  MonitoredItemArguments2 := CoEasyUAMonitoredItemArguments.Create;
  MonitoredItemArguments2.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';
  MonitoredItemArguments2.NodeDescriptor.NodeId.ExpandedText := 'nsu=http://test.org/UA/Data/ ;i=10853';
  MonitoredItemArguments2.MonitoringParameters := MonitoringParameters;
  MonitoredItemArguments3 := CoEasyUAMonitoredItemArguments.Create;
  MonitoredItemArguments3.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';
  MonitoredItemArguments3.NodeDescriptor.NodeId.ExpandedText := 'nsu=http://test.org/UA/Data/ ;i=10855';
  MonitoredItemArguments3.MonitoringParameters := MonitoringParameters;
  Arguments := VarArrayCreate([0, 2], varVariant);
  Arguments[0] := MonitoredItemArguments1;
  Arguments[1] := MonitoredItemArguments2;
  Arguments[2] := MonitoredItemArguments3;

  HandleSafeArray := Client.SubscribeMultipleMonitoredItems(Arguments);
  TVarData(HandleArray).VType := varArray or varVariant;
  TVarData(HandleArray).VArray := PVarArray(HandleSafeArray);

  for I := VarArrayLowBound(HandleArray, 1) to VarArrayHighBound(HandleArray, 1) do
  begin
      Handle := Cardinal(HandleArray[I]);
      WriteLn('HandleArray[', I, ']: ', Handle);
  end;

  WriteLn;
  WriteLn('Processing monitored item changed events for 10 seconds...');
  PumpSleep(10*1000);

  WriteLn;
  WriteLn('Unsubscribing from 2 monitored items...');
  SelectedHandles := VarArrayCreate([0, 1], varVariant);
  // We will unsubscribe from the first and third monitored item we have
  // previously subscribed to.
  SelectedHandles[0] := HandleArray[0];
  SelectedHandles[1] := HandleArray[2];
  Client.UnsubscribeMultipleMonitoredItems(SelectedHandles);

  WriteLn;
  WriteLn('Processing monitored item changed events for 10 seconds...');
  PumpSleep(10*1000);

  WriteLn;
  WriteLn('Unsubscribing from all remaining monitored items...');
  Client.UnsubscribeAllMonitoredItems;

  WriteLn;
  WriteLn('Waiting for 5 seconds...');
  Sleep(5*1000);

  WriteLn;
  WriteLn('Finished.');
  VarClear(HandleArray);
  VarClear(Arguments);
  FreeAndNil(Client);
  FreeAndNil(ClientEventHandlers);
end;
// This example shows how to unsubscribe from changes of just some monitored
// items.
//
// Find all latest examples here : https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

class ClientEvents {
    function DataChangeNotification($Sender, $E)
    {
        // Display the data
        if ($E->Succeeded)
            printf(" s\n", $E->Arguments->NodeDescriptor, $E->AttributeData);
        else
            printf("s *** Failures\n", $E->Arguments->NodeDescriptor, $E->ErrorMessageBrief);
    }
}



// Instantiate the client object and hook events
$Client = new COM("OpcLabs.EasyOpc.UA.EasyUAClient");
$ClientEvents = new ClientEvents();
com_event_sink($Client, $ClientEvents, "DEasyUAClientEvents");

printf("\n");
printf("Subscribing...\n");
$MonitoringParameters = new COM("OpcLabs.EasyOpc.UA.UAMonitoringParameters");
$MonitoringParameters->SamplingInterval = 1000;
$MonitoredItemArguments1 = new COM("OpcLabs.EasyOpc.UA.OperationModel.EasyUAMonitoredItemArguments");
$MonitoredItemArguments1->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";
$MonitoredItemArguments1->NodeDescriptor->NodeId->ExpandedText = "nsu=http://test.org/UA/Data/ ;i=10845";
$MonitoredItemArguments1->MonitoringParameters = $MonitoringParameters;
$MonitoredItemArguments2 = new COM("OpcLabs.EasyOpc.UA.OperationModel.EasyUAMonitoredItemArguments");
$MonitoredItemArguments2->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";
$MonitoredItemArguments2->NodeDescriptor->NodeId->ExpandedText = "nsu=http://test.org/UA/Data/ ;i=10853";
$MonitoredItemArguments2->MonitoringParameters = $MonitoringParameters;
$MonitoredItemArguments3 = new COM("OpcLabs.EasyOpc.UA.OperationModel.EasyUAMonitoredItemArguments");
$MonitoredItemArguments3->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";
$MonitoredItemArguments3->NodeDescriptor->NodeId->ExpandedText = "nsu=http://test.org/UA/Data/ ;i=10855";
$MonitoredItemArguments3->MonitoringParameters = $MonitoringParameters;
$arguments[0] = $MonitoredItemArguments1;
$arguments[1] = $MonitoredItemArguments2;
$arguments[2] = $MonitoredItemArguments3;
$handleArray = $Client->SubscribeMultipleMonitoredItems($arguments);

for ($i = 0; $i < count($handleArray); $i++)
{
    printf("handleArray[d]d\n", $i, $handleArray[$i]);
}

printf("\n");
printf("Processing monitored item changed events for 10 seconds...\n");
$startTime = time(); do { com_message_pump(1000); } while (time() < $startTime + 10);

printf("\n");
printf("Unsubscribing from 2 monitored items...\n");
$SelectedHandles[0] = $handleArray[0];
$SelectedHandles[1] = $handleArray[2];
$Client->UnsubscribeMultipleMonitoredItems($SelectedHandles);

printf("\n");
printf("Processing monitored item changed events for 10 seconds...\n");
$startTime = time(); do { com_message_pump(1000); } while (time() < $startTime + 10);

printf("\n");
printf("Unsubscribing from all remaining monitored items...\n");
$Client->UnsubscribeAllMonitoredItems;

printf("\n");
printf("Waiting for 5 seconds...\n");
$startTime = time(); do { com_message_pump(1000); } while (time() < $startTime + 5);

REM This example shows how to unsubscribe from changes of just some monitored
REM items.
REM
REM Find all latest examples here : https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

' The client object, with events
'Public WithEvents Client8 As EasyUAClient

Public Sub UnsubscribeMultipleMonitoredItems_Some_Command_Click()
    OutputText = ""

    Set Client8 = New EasyUAClient

    OutputText = OutputText & "Subscribing..." & vbCrLf
    Dim MonitoringParameters As New UAMonitoringParameters
    MonitoringParameters.SamplingInterval = 1000
    
    Dim MonitoredItemArguments1 As New EasyUAMonitoredItemArguments
    MonitoredItemArguments1.endpointDescriptor.UrlString = "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"
    MonitoredItemArguments1.nodeDescriptor.NodeId.expandedText = "nsu=http://test.org/UA/Data/ ;i=10845"
    Set MonitoredItemArguments1.MonitoringParameters = MonitoringParameters
    MonitoredItemArguments1.SetState ("Item1")
    
    Dim MonitoredItemArguments2 As New EasyUAMonitoredItemArguments
    MonitoredItemArguments2.endpointDescriptor.UrlString = "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"
    MonitoredItemArguments2.nodeDescriptor.NodeId.expandedText = "nsu=http://test.org/UA/Data/ ;i=10853"
    Set MonitoredItemArguments2.MonitoringParameters = MonitoringParameters
    MonitoredItemArguments2.SetState ("Item2")
    
    Dim MonitoredItemArguments3 As New EasyUAMonitoredItemArguments
    MonitoredItemArguments3.endpointDescriptor.UrlString = "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"
    MonitoredItemArguments3.nodeDescriptor.NodeId.expandedText = "nsu=http://test.org/UA/Data/ ;i=10855"
    Set MonitoredItemArguments3.MonitoringParameters = MonitoringParameters
    MonitoredItemArguments3.SetState ("Item3")
    
    Dim arguments(2) As Variant
    Set arguments(0) = MonitoredItemArguments1
    Set arguments(1) = MonitoredItemArguments2
    Set arguments(2) = MonitoredItemArguments3
    Dim handleArray As Variant
    handleArray = Client8.SubscribeMultipleMonitoredItems(arguments)

    Dim i As Long: For i = LBound(handleArray) To UBound(handleArray)
        OutputText = OutputText & "handleArray(" & i & "): " & handleArray(i) & vbCrLf
    Next

    OutputText = OutputText & vbCrLf
    OutputText = OutputText & "Processing monitored item changed events for 10 seconds..." & vbCrLf
    Pause 10000

    OutputText = OutputText & vbCrLf
    OutputText = OutputText & "Unsubscribing from 2 monitored items..." & vbCrLf

    Dim SelectedHandles(1) As Variant
    ' We will unsubscribe from the first and third monitored item we have
    ' previously subscribed to.
    SelectedHandles(0) = handleArray(0)
    SelectedHandles(1) = handleArray(2)
    Client8.UnsubscribeMultipleMonitoredItems (SelectedHandles)

    OutputText = OutputText & vbCrLf
    OutputText = OutputText & "Processing monitored item changed events for 10 seconds..." & vbCrLf
    Pause 10000

    OutputText = OutputText & vbCrLf
    OutputText = OutputText & "Unsubscribing from all remaining monitored items..." & vbCrLf
    Call Client8.UnsubscribeAllMonitoredItems

    OutputText = OutputText & "Waiting for 5 seconds..." & vbCrLf
    Pause 5000

    Set Client8 = Nothing
    OutputText = OutputText & "Finished." & vbCrLf
End Sub

Public Sub Client8_DataChangeNotification(ByVal sender As Variant, ByVal eventArgs As EasyUADataChangeNotificationEventArgs)
    ' Display the data
    If eventArgs.Succeeded Then
        OutputText = OutputText & eventArgs.arguments.nodeDescriptor & ": " & eventArgs.AttributeData & vbCrLf
    Else
        OutputText = OutputText & eventArgs.arguments.nodeDescriptor & ": " & eventArgs.ErrorMessageBrief & vbCrLf
    End If
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

See Also

Reference

_EasyUAClient Interface
_EasyUAClient Members

 

 

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