OPC Studio User's Guide and Reference
UnsubscribeDataSet Method (_EasyUASubscriber)
Example 



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OpcLabs.EasyOpcUA Assembly > OpcLabs.EasyOpc.UA.PubSub.ComTypes Namespace > _EasyUASubscriber Interface : UnsubscribeDataSet Method
The dataset handle.
Unsubscribes from a dataset specified by its integer handle.
Syntax
'Declaration
 
Sub UnsubscribeDataSet( _
   ByVal dataSetHandle As Integer _
) 
 
'Usage
 
Dim instance As _EasyUASubscriber
Dim dataSetHandle As Integer
 
instance.UnsubscribeDataSet(dataSetHandle)

Parameters

dataSetHandle
The dataset handle.
Exceptions
ExceptionDescription

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.

Remarks

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 subscribe to dataset messages on an OPC-UA PubSub connection, and then unsubscribe from that
// dataset.
//
// In order to produce network messages for this example, run the UADemoPublisher tool. For documentation, see
// https://kb.opclabs.com/UADemoPublisher_Basics . In some cases, you may have to specify the interface name to be used.
//
// 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 System.Collections.Generic;
using System.Threading;
using OpcLabs.EasyOpc.UA.PubSub;
using OpcLabs.EasyOpc.UA.PubSub.OperationModel;

namespace UASubscriberDocExamples.PubSub._EasyUASubscriber
{
    class UnsubscribeDataSet
    {
        public static void Main1()
        {
            // Define the PubSub connection we will work with. Uses implicit conversion from a string.
            UAPubSubConnectionDescriptor pubSubConnectionDescriptor = "opc.udp://239.0.0.1";
            // In some cases you may have to set the interface (network adapter) name that needs to be used, similarly to
            // the statement below. Your actual interface name may differ, of course.
            //pubSubConnectionDescriptor.ResourceAddress.InterfaceName = "Ethernet";

            // Define the filter. Publisher Id (unsigned 64-bits) is 31, and the dataset writer Id is 1.
            var filter = new UASubscribeDataSetFilter(UAPublisherId.CreateUInt64(31), UAWriterGroupDescriptor.Null, 1);

            // Instantiate the subscriber object and hook events.
            var subscriber = new EasyUASubscriber();
            subscriber.DataSetMessage += subscriber_DataSetMessage;

            Console.WriteLine("Subscribing...");
            int dataSetHandle = subscriber.SubscribeDataSet(pubSubConnectionDescriptor, filter);

            Console.WriteLine("Processing dataset message events for 20 seconds...");
            Thread.Sleep(20 * 1000);

            Console.WriteLine("Unsubscribing...");
            subscriber.UnsubscribeDataSet(dataSetHandle);

            Console.WriteLine("Waiting for 1 second...");
            // Unsubscribe operation is asynchronous, messages may still come for a short while.
            Thread.Sleep(1 * 1000);

            Console.WriteLine("Finished.");
        }

        static void subscriber_DataSetMessage(object sender, EasyUADataSetMessageEventArgs e)
        {
            // Display the dataset.
            if (e.Succeeded)
            {
                // An event with null DataSetData just indicates a successful connection.
                if (!(e.DataSetData is null))
                {
                    Console.WriteLine();
                    Console.WriteLine($"Dataset data: {e.DataSetData}");
                    foreach (KeyValuePair<string, UADataSetFieldData> pair in e.DataSetData.FieldDataDictionary)
                        Console.WriteLine(pair);
                }
            }
            else
            {
                Console.WriteLine();
                Console.WriteLine($"*** Failure: {e.ErrorMessageBrief}");
            }
        }

        // Example output:
        //
        //Subscribing...
        //Processing dataset message events for 20 seconds...
        //
        //Dataset data: Good; Data; publisher=(UInt64)31, writer=1, fields: 4
        //[#0, True {System.Boolean}; Good]
        //[#1, 7134 {System.Int32}; Good]
        //[#2, 7364 {System.Int32}; Good]
        //[#3, 10/1/2019 10:42:16 AM {System.DateTime}; Good]
        //
        //Dataset data: Good; Data; publisher=(UInt64)31, writer=1, fields: 4
        //[#1, 7135 {System.Int32}; Good]
        //[#2, 7429 {System.Int32}; Good]
        //[#3, 10/1/2019 10:42:17 AM {System.DateTime}; Good]
        //[#0, True {System.Boolean}; Good]
        //
        //Dataset data: Good; Data; publisher=(UInt64)31, writer=1, fields: 4
        //[#2, 7495 {System.Int32}; Good]
        //[#3, 10/1/2019 10:42:17 AM {System.DateTime}; Good]
        //[#0, True {System.Boolean}; Good]
        //[#1, 7135 {System.Int32}; Good]
        //
        //Dataset data: Good; Data; publisher=(UInt64)31, writer=1, fields: 4
        //[#1, 7136 {System.Int32}; Good]
        //[#2, 7560 {System.Int32}; Good]
        //[#3, 10/1/2019 10:42:18 AM {System.DateTime}; Good]
        //[#0, True {System.Boolean}; Good]
        //
        //Dataset data: Good; Data; publisher=(UInt64)31, writer=1, fields: 4
        //[#2, 7626 {System.Int32}; Good]
        //[#3, 10/1/2019 10:42:18 AM {System.DateTime}; Good]
        //[#0, True {System.Boolean}; Good]
        //[#1, 7136 {System.Int32}; Good]
        //
        //...
    }
}
# This example shows how to subscribe to all dataset messages on an OPC-UA PubSub connection with UDP UADP mapping.
#
# In order to produce network messages for this example, run the UADemoPublisher tool. For documentation, see
# http:#kb.opclabs.com/UADemoPublisher_Basics . In some cases, you may have to specify the interface name to be used.
#
# 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.BaseLib.Networking
using namespace OpcLabs.EasyOpc.UA
using namespace OpcLabs.EasyOpc.UA.PubSub
using namespace OpcLabs.EasyOpc.UA.PubSub.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"

# Define the PubSub connection we will work with. Uses implicit conversion from a string.
[UAPubSubConnectionDescriptor]$pubSubConnectionDescriptor = [ResourceAddress]"opc.udp://239.0.0.1"
# In some cases you may have to set the interface (network adapter) name that needs to be used, similarly to
# the statement below. Your actual interface name may differ, of course.
#$pubSubConnectionDescriptor.ResourceAddress.InterfaceName = "Ethernet"

# Instantiate the subscriber object.
$subscriber = New-Object EasyUASubscriber

# Event notification handler
Register-ObjectEvent -InputObject $subscriber -EventName DataSetMessage -Action { 
    # Display the dataset.
    if ($EventArgs.Succeeded) {
        # An event with null DataSetData just indicates a successful connection.
        if ($EventArgs.DataSetData -ne $null) {
            Write-Host 
            Write-Host "Dataset data: $($EventArgs.DataSetData)"
            foreach ($pair in $EventArgs.DataSetData.FieldDataDictionary.GetEnumerator()) {
                Write-Host $pair
            }
        }
    }
    else {
        Write-Host 
        Write-Host "*** Failure: $($EventArgs.ErrorMessageBrief)"
    }
}

Write-Host "Subscribing..."
[IEasyUASubscriberExtension]::SubscribeDataSet($subscriber, $pubSubConnectionDescriptor)

Write-Host "Processing dataset message events for 20 seconds..."
$stopwatch =  [System.Diagnostics.Stopwatch]::StartNew() 
while ($stopwatch.Elapsed.TotalSeconds -lt 20) {    
    Start-Sleep -Seconds 1
}

Write-Host "Unsubscribing..."
$subscriber.UnsubscribeAllDataSets()

Write-Host "Waiting for 1 second..."
# Unsubscribe operation is asynchronous, messages may still come for a short while.
Start-Sleep -Seconds 1

Write-Host "Finished."


# Example output (truncated):
#
#Subscribing...
#Processing dataset message events for 20 seconds...
#
#Dataset data: Good; Data; publisher="32", writer=1, class=eae79794-1af7-4f96-8401-4096cd1d8908, fields: 4
#[#0, True {System.Boolean} @0001-01-01T00:00:00.000 @@0001-01-01T00:00:00.000; Good]
#[#1, 7945 {System.Int32} @0001-01-01T00:00:00.000 @@0001-01-01T00:00:00.000; Good]
#[#2, 5246 {System.Int32} @0001-01-01T00:00:00.000 @@0001-01-01T00:00:00.000; Good]
#[#3, 9/30/2019 11:19:14 AM {System.DateTime} @0001-01-01T00:00:00.000 @@0001-01-01T00:00:00.000; Good]
#
#Dataset data: Good; Data; publisher="32", writer=3, class=96976b7b-0db7-46c3-a715-0979884b55ae, fields: 100
#[#0, 45 {System.Int64} @0001-01-01T00:00:00.000 @@0001-01-01T00:00:00.000; Good]
#[#1, 145 {System.Int64} @0001-01-01T00:00:00.000 @@0001-01-01T00:00:00.000; Good]
#[#2, 245 {System.Int64} @0001-01-01T00:00:00.000 @@0001-01-01T00:00:00.000; Good]
#[#3, 345 {System.Int64} @0001-01-01T00:00:00.000 @@0001-01-01T00:00:00.000; Good]
#[#4, 445 {System.Int64} @0001-01-01T00:00:00.000 @@0001-01-01T00:00:00.000; Good]
#[#5, 545 {System.Int64} @0001-01-01T00:00:00.000 @@0001-01-01T00:00:00.000; Good]
#[#6, 645 {System.Int64} @0001-01-01T00:00:00.000 @@0001-01-01T00:00:00.000; Good]
#[#7, 745 {System.Int64} @0001-01-01T00:00:00.000 @@0001-01-01T00:00:00.000; Good]
#[#8, 845 {System.Int64} @0001-01-01T00:00:00.000 @@0001-01-01T00:00:00.000; Good]
#[#9, 945 {System.Int64} @0001-01-01T00:00:00.000 @@0001-01-01T00:00:00.000; Good]
#[#10, 1045 {System.Int64} @0001-01-01T00:00:00.000 @@0001-01-01T00:00:00.000; Good]
#...
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