OPC Studio User's Guide and Reference
UADataSetSubscriptionDescriptor Class
Members  Example 



OpcLabs.EasyOpcUA Assembly > OpcLabs.EasyOpc.UA.PubSub Namespace : UADataSetSubscriptionDescriptor Class
Contains information needed to subscribe to a dataset.
Object Model
UADataSetSubscriptionDescriptor ClassUASubscriberCommunicationParameters ClassUAPubSubConnectionDescriptor ClassUADataSetMetaData ClassUASubscribeDataSetFilter ClassUADataSetSubscriptionDescriptor ClassUAPubSubResolverDescriptor Class
Syntax
'Declaration
 
<ComDefaultInterfaceAttribute(OpcLabs.EasyOpc.UA.PubSub.ComTypes._UADataSetSubscriptionDescriptor)>
<ComVisibleAttribute(True)>
<GuidAttribute("377752BF-B7E1-48BC-ABD3-F3E652C673C5")>
<TypeConverterAttribute(OpcLabs.EasyOpc.UA.PubSub.Implementation.UADataSetSubscriptionDescriptorConverter)>
<ValueControlAttribute("OpcLabs.EasyOpc.UA.Forms.Internal.PubSub.UADataSetSubscriptionDescriptorPhysicalControl, OpcLabs.EasyOpcForms, Version=5.80.82.1, Culture=neutral, PublicKeyToken=6faddca41dacb409", 
   Export=True, 
   PageId=200)>
<CLSCompliantAttribute(True)>
<SerializableAttribute()>
Public NotInheritable Class UADataSetSubscriptionDescriptor 
   Inherits OpcLabs.BaseLib.Info
   Implements LINQPad.ICustomMemberProvider, OpcLabs.BaseLib.Aliasing.ComTypes._Aliasable, OpcLabs.BaseLib.Aliasing.IAliasable, OpcLabs.BaseLib.ComTypes._Info, OpcLabs.BaseLib.ComTypes._Object2, OpcLabs.EasyOpc.UA.PubSub.ComTypes._UADataSetSubscriptionDescriptor, System.ICloneable, System.IFormattable, System.Runtime.Serialization.ISerializable, System.Xml.Serialization.IXmlSerializable 
'Usage
 
Dim instance As UADataSetSubscriptionDescriptor
[ComDefaultInterface(OpcLabs.EasyOpc.UA.PubSub.ComTypes._UADataSetSubscriptionDescriptor)]
[ComVisible(true)]
[Guid("377752BF-B7E1-48BC-ABD3-F3E652C673C5")]
[TypeConverter(OpcLabs.EasyOpc.UA.PubSub.Implementation.UADataSetSubscriptionDescriptorConverter)]
[ValueControl("OpcLabs.EasyOpc.UA.Forms.Internal.PubSub.UADataSetSubscriptionDescriptorPhysicalControl, OpcLabs.EasyOpcForms, Version=5.80.82.1, Culture=neutral, PublicKeyToken=6faddca41dacb409", 
   Export=true, 
   PageId=200)]
[CLSCompliant(true)]
[Serializable()]
public sealed class UADataSetSubscriptionDescriptor : OpcLabs.BaseLib.Info, LINQPad.ICustomMemberProvider, OpcLabs.BaseLib.Aliasing.ComTypes._Aliasable, OpcLabs.BaseLib.Aliasing.IAliasable, OpcLabs.BaseLib.ComTypes._Info, OpcLabs.BaseLib.ComTypes._Object2, OpcLabs.EasyOpc.UA.PubSub.ComTypes._UADataSetSubscriptionDescriptor, System.ICloneable, System.IFormattable, System.Runtime.Serialization.ISerializable, System.Xml.Serialization.IXmlSerializable  
[ComDefaultInterface(OpcLabs.EasyOpc.UA.PubSub.ComTypes._UADataSetSubscriptionDescriptor)]
[ComVisible(true)]
[Guid("377752BF-B7E1-48BC-ABD3-F3E652C673C5")]
[TypeConverter(OpcLabs.EasyOpc.UA.PubSub.Implementation.UADataSetSubscriptionDescriptorConverter)]
[ValueControl("OpcLabs.EasyOpc.UA.Forms.Internal.PubSub.UADataSetSubscriptionDescriptorPhysicalControl, OpcLabs.EasyOpcForms, Version=5.80.82.1, Culture=neutral, PublicKeyToken=6faddca41dacb409", 
   Export=true, 
   PageId=200)]
[CLSCompliant(true)]
[Serializable()]
public ref class UADataSetSubscriptionDescriptor sealed : public OpcLabs.BaseLib.Info, LINQPad.ICustomMemberProvider, OpcLabs.BaseLib.Aliasing.ComTypes._Aliasable, OpcLabs.BaseLib.Aliasing.IAliasable, OpcLabs.BaseLib.ComTypes._Info, OpcLabs.BaseLib.ComTypes._Object2, OpcLabs.EasyOpc.UA.PubSub.ComTypes._UADataSetSubscriptionDescriptor, System.ICloneable, System.IFormattable, System.Runtime.Serialization.ISerializable, System.Xml.Serialization.IXmlSerializable  
Remarks

 

Subscribing to dataset messages 

For quick tests and experiments with OPC UA PubSub, and especially if you do not want to lose time coding when you need to figure out the proper settings, you can use the OpcCmd Utility - see Using OpcCmd Utility as OPC UA PubSub Subscriber. The utility allows to specify all parameters of the dataset subscriptions that are accessible from code, but simply by entering them on the command line. It also has a built-in support for displaying the incoming datasets and their fields.

If you are on Windows, you can also use the OPC UA PubSub Demo Application to experiment with various settings. This allows you to try out and determine the correct parameters before you put them into the code.

 

A subscription is initiated by calling the SubscribeDataSet Method on the EasyUASubscriber Class. In its basic form, the method takes a single argument which is an instance of the EasyUASubscribeDataSetArguments Class, and this argument contains all the information necessary to perform the subscription. The object and all the sub-objects it contains are rather complex.

The picture below is meant to give you at least a general overview about what this object contains. There are more "smaller" properties to the individual objects on the picture, but we do not care about them for now.

 

The main parts of the EasyUASubscribeDataSetArguments is the DataSetSubscriptionDescriptor: it describes the dataset(s) you want to subscribe to.

The ResolverDescriptor in the DataSetSubscriptionDescriptor is for OPC UA PubSub logical resolution, if used.

Inside the dataset subscription descriptor, you always need to specify the PubSub connection, using the ConnectionDescriptor Property. You will typically also need to fill in data in the Filter Property (see Message Filtering (OPC UA PubSub)), and sometimes provide the DataSetMetaData Property (see Dataset Metadata (OPC UA PubSub)). The CommunicationParameters Property is used to specify details about the communication, message receive timeout, and parameters specific to message or transport protocol mapping.

When broker transport protocol is in use (such as MQTT or AMQP), you will typically need to specify the broker queue name inside the CommunicationParameters Property.

There are many (extension method) overloads of the SubscribeDataSet Method, with various combinations of arguments. These overloads allow you to bypass the construction of the whole EasyUASubscribeDataSetArguments hierarchy, and pass in simply the parts you need.

The example below subscribes to all dataset messages on an OPC-UA PubSub connection with UDP UADP mapping. The connection is specified by its physical parameters, using the scheme name "opc.udp" and the IP address of the multicast group to listen on.

.NET

// 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
// 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 .

using System;
using System.Collections.Generic;
using System.Threading;
using OpcLabs.EasyOpc.UA.PubSub;
using OpcLabs.EasyOpc.UA.PubSub.OperationModel;

namespace UADocExamples.PubSub._EasyUASubscriber
{
    partial class SubscribeDataSet
    {
        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";

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

            Console.WriteLine("Subscribing...");
            subscriber.SubscribeDataSet(pubSubConnectionDescriptor);

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

            Console.WriteLine("Unsubscribing...");
            subscriber.UnsubscribeAllDataSets();

            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 (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]
        //...
    }
}
# 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 .

#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]
#...

# 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
# 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 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.PubSub import *
from OpcLabs.EasyOpc.UA.PubSub.OperationModel import *


def dataSetMessage(sender, e):
    # Display the dataset.
    if e.Succeeded:
        # An event with null DataSetData just indicates a successful connection.
        if e.DataSetData is not None:
            print('')
            print('Dataset data: ', e.DataSetData, sep='')
            for pair in e.DataSetData.FieldDataDictionary:
                print(pair)
    else:
        print('')
        print('*** Failure: ', e.ErrorMessageBrief, sep='')


# Define the PubSub connection we will work with. Uses implicit conversion from a string.
pubSubConnectionDescriptor = UAPubSubConnectionDescriptor.op_Implicit('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 and hook events.
subscriber = EasyUASubscriber()
subscriber.DataSetMessage += dataSetMessage

print('Subscribing...')
IEasyUASubscriberExtension.SubscribeDataSet(subscriber, pubSubConnectionDescriptor)

print('Processing dataset message events for 20 seconds...')
time.sleep(20)

print('Unsubscribing...')
subscriber.UnsubscribeAllDataSets()

print('Waiting for 1 second...')
# Unsubscribe operation is asynchronous, messages may still come for a short while.
time.sleep(1)

subscriber.DataSetMessage -= dataSetMessage

print('Finished.')



# Example output:
#
#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]
#...

' 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
' 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 .

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

Namespace PubSub._EasyUASubscriber
    Friend Class SubscribeDataSet
        Public Shared Sub Main1()

            ' Define the PubSub connection we will work with. Uses implicit conversion from a string.
            Dim pubSubConnectionDescriptor As UAPubSubConnectionDescriptor = "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 and hook events.
            Dim subscriber = New EasyUASubscriber()
            AddHandler subscriber.DataSetMessage, AddressOf subscriber_DataSetMessage

            Console.WriteLine("Subscribing...")
            subscriber.SubscribeDataSet(pubSubConnectionDescriptor)

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

            Console.WriteLine("Unsubscribing...")
            subscriber.UnsubscribeAllDataSets()

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

            Console.WriteLine("Finished...")
        End Sub

        Private Shared Sub subscriber_DataSetMessage(ByVal sender As Object, ByVal e As EasyUADataSetMessageEventArgs)
            ' Display the dataset.
            If e.Succeeded Then
                ' An event with null DataSetData just indicates a successful connection.
                If e.DataSetData IsNot Nothing Then
                    Console.WriteLine()
                    Console.WriteLine($"Dataset data: {e.DataSetData}")
                    For Each pair As KeyValuePair(Of String, UADataSetFieldData) In e.DataSetData.FieldDataDictionary
                        Console.WriteLine(pair)
                    Next
                End If
            Else
                Console.WriteLine()
                Console.WriteLine($"*** Failure: {e.ErrorMessageBrief}")
            End If
        End Sub
    End Class



    ' Example output
    '
    '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]
    '...

End Namespace

COM

// 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
// 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 .

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

namespace PubSub
{
    namespace _EasyUASubscriber
    {
        // CEasyUASubscriberEvents

        class CEasyUASubscriberEvents : public IDispEventImpl<1, CEasyUASubscriberEvents>
        {
        public:
            BEGIN_SINK_MAP(CEasyUASubscriberEvents)
                // Event handlers must have the __stdcall calling convention
                SINK_ENTRY(1, DISPID_EASYUASUBSCRIBEREVENTS_DATASETMESSAGE, &CEasyUASubscriberEvents::DataSetMessage)
            END_SINK_MAP()

        public:
            // The handler for EasyUAClient.DataChangeNotification event
            STDMETHOD(DataSetMessage)(VARIANT varSender, _EasyUADataSetMessageEventArgs* pEventArgs)
            {
                // Display the dataset.
                if (pEventArgs->Succeeded)
                {
                    _UADataSetDataPtr DataSetDataPtr = pEventArgs->DataSetData;
                    // An event with null DataSetData just indicates a successful connection.
                    if (DataSetDataPtr != NULL)
                    {
                        _tprintf(_T("\n"));
                        _tprintf(_T("Dataset data: %s\n"), (LPCTSTR)CW2CT(DataSetDataPtr->ToString));

                        IEnumVARIANTPtr EnumDictionaryEntry2Ptr = DataSetDataPtr->FieldDataDictionary->GetEnumerator();
                        _variant_t vDictionaryEntry2;
                        while (EnumDictionaryEntry2Ptr->Next(1, &vDictionaryEntry2, NULL) == S_OK)
                        {
                            _DictionaryEntry2Ptr DictionaryEntry2Ptr(vDictionaryEntry2);
                            _tprintf(_T("%s\n"), (LPCTSTR)CW2CT(DictionaryEntry2Ptr->ToString));
                            vDictionaryEntry2.Clear();
                        }
                    }
                }
                else
                {
                    _tprintf(_T("\n"));
                    _tprintf(_T("*** Failure: %s\n"), (LPCTSTR)CW2CT(pEventArgs->ErrorMessageBrief));
                }
                return S_OK;
            }
        };



        void SubscribeDataSet::Main1()
        {
            // Initialize the COM library
            CoInitializeEx(NULL, COINIT_MULTITHREADED);
            {
                // Prepare arguments for a subscription to the dataset.
                _EasyUASubscribeDataSetArgumentsPtr SubscribeDataSetArgumentsPtr(__uuidof(EasyUASubscribeDataSetArguments));
                
                // Define the PubSub connection we will work with.
                _UAPubSubConnectionDescriptorPtr PubSubConnectionDescriptorPtr = 
                    SubscribeDataSetArgumentsPtr->DataSetSubscriptionDescriptor->ConnectionDescriptor;
                PubSubConnectionDescriptorPtr->ResourceAddress->ResourceDescriptor->UrlString = L"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.
                //PubSubConnectionDescriptorPtr->ResourceAddress->InterfaceName = L"Ethernet";
                
                // Instantiate the subscriber object.
                _EasyUASubscriberPtr SubscriberPtr(__uuidof(EasyUASubscriber));

                // Hook events.
                CEasyUASubscriberEvents* pSubscriberEvents = new CEasyUASubscriberEvents();
                AtlGetObjectSourceInterface(SubscriberPtr, &pSubscriberEvents->m_libid, &pSubscriberEvents->m_iid,
                    &pSubscriberEvents->m_wMajorVerNum, &pSubscriberEvents->m_wMinorVerNum);
                pSubscriberEvents->m_iid = _uuidof(DEasyUASubscriberEvents);
                pSubscriberEvents->DispEventAdvise(SubscriberPtr, &pSubscriberEvents->m_iid);

                _tprintf(_T("Subscribing...\n"));
                _variant_t vSubscribeDataSetArguments(SubscribeDataSetArgumentsPtr.GetInterfacePtr());
                SubscriberPtr->SubscribeDataSet(vSubscribeDataSetArguments);

                _tprintf(_T("Processing dataset message events for 20 seconds...\n"));
                Sleep(20 * 1000);

                _tprintf(_T("Unsubscribing...\n"));
                SubscriberPtr->UnsubscribeAllDataSets();

                _tprintf(_T("Waiting for 1 second...\n"));
                // Unsubscribe operation is asynchronous, messages may still come for a short while.
                Sleep(1 * 1000);

                // Unhook events
                pSubscriberEvents->DispEventUnadvise(SubscriberPtr, &pSubscriberEvents->m_iid);

                _tprintf(_T("Finished.\n"));
            }
            // Release all interface pointers BEFORE calling CoUninitialize()
            CoUninitialize();
        }



        // Example output:
        //
        //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]
        //...
    }
}
// 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
// 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 .

type
  TSubscriberEventHandlers77 = class
    procedure OnDataSetMessage(
      ASender: TObject;
      sender: OleVariant;
      const eventArgs: _EasyUADataSetMessageEventArgs);
  end;

class procedure SubscribeDataSet.Main1;
var
  ConnectionDescriptor: _UAPubSubConnectionDescriptor;
  SubscribeDataSetArguments: _EasyUASubscribeDataSetArguments;
  Subscriber: TEasyUASubscriber;
  SubscriberEventHandlers: TSubscriberEventHandlers77;
begin
  // Define the PubSub connection we will work with.
  SubscribeDataSetArguments := CoEasyUASubscribeDataSetArguments.Create;
  ConnectionDescriptor := SubscribeDataSetArguments.DataSetSubscriptionDescriptor.ConnectionDescriptor;
  ConnectionDescriptor.ResourceAddress.ResourceDescriptor.UrlString := '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.
  //ConnectionDescriptor.ResourceAddress.InterfaceName := 'Ethernet';

  // Instantiate the subscriber object and hook events.
  Subscriber := TEasyUASubscriber.Create(nil);
  SubscriberEventHandlers := TSubscriberEventHandlers77.Create;
  Subscriber.OnDataSetMessage := SubscriberEventHandlers.OnDataSetMessage;

  WriteLn('Subscribing...');
  Subscriber.SubscribeDataSet(SubscribeDataSetArguments);

  WriteLn('Processing dataset message for 20 seconds...');
  PumpSleep(20*1000);

  WriteLn('Unsubscribing...');
  Subscriber.UnsubscribeAllDataSets;

  WriteLn('Waiting for 1 second...');
  // Unsubscribe operation is asynchronous, messages may still come for a short while.
  PumpSleep(1*1000);

  WriteLn('Finished.');
  FreeAndNil(Subscriber);
  FreeAndNil(SubscriberEventHandlers);
end;

procedure TSubscriberEventHandlers77.OnDataSetMessage(
  ASender: TObject;
  sender: OleVariant;
  const eventArgs: _EasyUADataSetMessageEventArgs);
var
  Count: Cardinal;
  DictionaryEntry2: _DictionaryEntry2;
  Element: OleVariant;
  FieldDataDictionaryEnumerator: IEnumVariant;
begin
  // Display the dataset.
  if eventArgs.Succeeded then
  begin
    // An event with null DataSetData just indicates a successful connection.
    if eventArgs.DataSetData <> nil then
    begin
      WriteLn;
      WriteLn('Dataset data: ', eventArgs.DataSetData.ToString);
      FieldDataDictionaryEnumerator := eventArgs.DataSetData.FieldDataDictionary.GetEnumerator;
      while (FieldDataDictionaryEnumerator.Next(1, Element, Count) = S_OK) do
      begin
        DictionaryEntry2 := IUnknown(Element) as _DictionaryEntry2;
        WriteLn(DictionaryEntry2.ToString);
      end;
    end;
  end
  else begin
    WriteLn;
      WriteLn('*** Failure: ', eventArgs.ErrorMessageBrief);
  end;
end;

// Example output:
//
//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]
//...

// 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
// 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 .

class SubscriberEvents {
    function DataSetMessage($Sender, $E)
    {
        // Display the dataset.
        if ($E->Succeeded) {
            // An event with null DataSetData just indicates a successful connection.
            printf("\n");
            printf("Dataset data: %s\n", $E->DataSetData);
            foreach ($E->DataSetData->FieldDataDictionary as $Pair)
                printf("%s\n", $Pair);
        }
        else {
            printf("\n");
            printf("*** Failure: %s\n", $E->ErrorMessageBrief);
        }
    }
}



// Define the PubSub connection we will work with.
$SubscribeDataSetArguments = new COM("OpcLabs.EasyOpc.UA.PubSub.OperationModel.EasyUASubscribeDataSetArguments");
$ConnectionDescriptor = $SubscribeDataSetArguments->DataSetSubscriptionDescriptor->ConnectionDescriptor;
$ConnectionDescriptor->ResourceAddress->ResourceDescriptor->UrlString = "opc.udp://239.0.0.1";
// In some cases you may have to set the interface (network adapter) name that needs to be used, similarly to
// the statement below. Your actual interface name may differ, of course.
/$ConnectionDescriptor->ResourceAddress->InterfaceName = "Ethernet";

// Instantiate the subscriber object and hook events.
$Subscriber = new COM("OpcLabs.EasyOpc.UA.PubSub.EasyUASubscriber");
$SubscriberEvents = new SubscriberEvents();
com_event_sink($Subscriber, $SubscriberEvents, "DEasyUASubscriberEvents");

printf("Subscribing...\n");
$Subscriber->SubscribeDataSet($SubscribeDataSetArguments);

printf("Processing dataset message events for 20 seconds...");
$startTime = time(); 
do { 
    com_message_pump(1000); 
} while (time() < $startTime + 20);

printf("Unsubscribing...\n");
$Subscriber->UnsubscribeAllDataSets;

printf("Waiting for 1 second...");
// Unsubscribe operation is asynchronous, messages may still come for a short while.
$startTime = time(); 
do { 
    com_message_pump(1000); 
} while (time() < $startTime + 1);

printf("Finished.\n");



// Example output:
//
//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]
//...

# This example shows how to subscribe to all dataset messages on an OPC-UA PubSub connection, and pull events, and display
# the incoming datasets.
#
# 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.
#
# The Python for Windows (pywin32) extensions package is needed. Install it using "pip install pypiwin32".
# CAUTION: We now recommend using Python.NET package instead. Full set of examples with Python.NET is available!
#
# Find all latest examples here : https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
import time
import win32com.client

# Define the PubSub connection we will work with.
subscribeDataSetArguments = win32com.client.Dispatch('OpcLabs.EasyOpc.UA.PubSub.OperationModel.EasyUASubscribeDataSetArguments')
connectionDescriptor = subscribeDataSetArguments.DataSetSubscriptionDescriptor.ConnectionDescriptor
connectionDescriptor.ResourceAddress.ResourceDescriptor.UrlString = '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.
#connectionDescriptor.ResourceAddress.InterfaceName = 'Ethernet'

# Instantiate the subscriber object.
subscriber = win32com.client.Dispatch('OpcLabs.EasyOpc.UA.PubSub.EasyUASubscriber') 
# In order to use event pull, you must set a non-zero queue capacity upfront.
subscriber.PullDataSetMessageQueueCapacity = 1000

print('Subscribing...')
subscriber.SubscribeDataSet(subscribeDataSetArguments)

print('Processing dataset message events for 20 seconds...')
endTime = time.time() + 20
while time.time() < endTime:
    eventArgs = subscriber.PullDataSetMessage(2*1000)
    if eventArgs is not None:
        # Display the dataset.
        if eventArgs.Succeeded:
            # An event with null DataSetData just indicates a successful connection.
            if eventArgs.DataSetData is not None:
                print('')
                print('Dataset data: ', eventArgs.DataSetData)
                for pair in eventArgs.DataSetData.FieldDataDictionary:
                    print(pair)
        else:
            print('')
            print('*** Failure: ', eventArgs.ErrorMessageBrief)

print('Unsubscribing...')
subscriber.UnsubscribeAllDataSets

print('Waiting for 1 second...')
# Unsubscribe operation is asynchronous, messages may still come for a short while.
endTime = time.time() + 1
while time.time() < endTime:
    pass

print('Finished.')



# Example output:
#
#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]
#...

REM This example shows how to subscribe to all dataset messages on an OPC-UA PubSub connection with UDP UADP mapping.
REM
REM In order to produce network messages for this example, run the UADemoPublisher tool. For documentation, see
REM https://kb.opclabs.com/UADemoPublisher_Basics . In some cases, you may have to specify the interface name to be used.
REM
REM Find all latest examples here : https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

' The subscriber object, with events
'Public WithEvents Subscriber2 As EasyUASubscriber

Private Sub EasyUASubscriber_SubscribeDataSet_Main1_Command_Click()
    OutputText = ""

    ' Define the PubSub connection we will work with.
    Dim subscribeDataSetArguments As New EasyUASubscribeDataSetArguments
    Dim ConnectionDescriptor As UAPubSubConnectionDescriptor
    Set ConnectionDescriptor = subscribeDataSetArguments.dataSetSubscriptionDescriptor.ConnectionDescriptor
    ConnectionDescriptor.ResourceAddress.ResourceDescriptor.UrlString = "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.
    'ConnectionDescriptor.ResourceAddress.InterfaceName := 'Ethernet';

    ' Instantiate the subscriber object and hook events.
    Set Subscriber2 = New EasyUASubscriber
    
    OutputText = OutputText & "Subscribing..." & vbCrLf
    Subscriber2.SubscribeDataSet subscribeDataSetArguments

    OutputText = OutputText & "Processing dataset message for 20 seconds..." & vbCrLf
    Pause 20000

    OutputText = OutputText & "Unsubscribing..." & vbCrLf
    Subscriber2.UnsubscribeAllDataSets

    OutputText = OutputText & "Waiting for 1 second..." & vbCrLf
    ' Unsubscribe operation is asynchronous, messages may still come for a short while.
    Pause 1000

    Set Subscriber2 = Nothing

    OutputText = OutputText & "Finished." & vbCrLf
End Sub

Private Sub Subscriber2_DataSetMessage(ByVal sender As Variant, ByVal eventArgs As EasyUADataSetMessageEventArgs)
    ' Display the dataset
    If eventArgs.Succeeded Then
        ' An event with null DataSetData just indicates a successful connection.
        If Not eventArgs.DataSetData Is Nothing Then
            OutputText = OutputText & vbCrLf
            OutputText = OutputText & "Dataset data: " & eventArgs.DataSetData & vbCrLf
            Dim dictionaryEntry2 : For Each dictionaryEntry2 In eventArgs.DataSetData.FieldDataDictionary
                OutputText = OutputText & dictionaryEntry2 & vbCrLf
            Next
        End If
    Else
        OutputText = OutputText & vbCrLf
        OutputText = OutputText & eventArgs.ErrorMessageBrief & vbCrLf
    End If
End Sub
' Example output:
'
'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]
'...
Rem This example shows how to subscribe to all dataset messages on an OPC-UA PubSub connection with UDP UADP mapping.
Rem
Rem In order to produce network messages for this example, run the UADemoPublisher tool. For documentation, see
Rem https://kb.opclabs.com/UADemoPublisher_Basics . In some cases, you may have to specify the interface name to be used.
Rem
Rem Find all latest examples here : https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

Option Explicit

' Define the PubSub connection we will work with.
Dim SubscribeDataSetArguments: Set SubscribeDataSetArguments = CreateObject("OpcLabs.EasyOpc.UA.PubSub.OperationModel.EasyUASubscribeDataSetArguments")
Dim ConnectionDescriptor: Set ConnectionDescriptor = SubscribeDataSetArguments.DataSetSubscriptionDescriptor.ConnectionDescriptor
ConnectionDescriptor.ResourceAddress.ResourceDescriptor.UrlString = "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.
' ConnectionDescriptor.ResourceAddress.InterfaceName = "Ethernet"

' Instantiate the subscriber object and hook events.
Dim Subscriber: Set Subscriber = CreateObject("OpcLabs.EasyOpc.UA.PubSub.EasyUASubscriber")
WScript.ConnectObject Subscriber, "Subscriber_"

WScript.Echo "Subscribing..."
Subscriber.SubscribeDataSet SubscribeDataSetArguments

WScript.Echo "Processing dataset message events for 20 seconds..."
WScript.Sleep 20*1000

WScript.Echo "Unsubscribing..."
Subscriber.UnsubscribeAllDataSets

WScript.Echo "Waiting for 1 second..."
' Unsubscribe operation is asynchronous, messages may still come for a short while.
WScript.Sleep 1*1000

WScript.Echo "Finished."



Sub Subscriber_DataSetMessage(Sender, e)
    ' Display the dataset.
    If e.Succeeded Then
        ' An event with null DataSetData just indicates a successful connection.
        If Not (e.DataSetData Is Nothing) Then
            WScript.Echo
            WScript.Echo "Dataset data: " & e.DataSetData
            Dim Pair: For Each Pair in e.DataSetData.FieldDataDictionary
                WScript.Echo Pair
            Next
        End If
    Else
        WScript.Echo
        WScript.Echo "*** Failure: " & e.ErrorMessageBrief
    End If
End Sub



' Example output:
'
'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]
'...

 

 

The example specifies just the PubSub connection, and receives all PubSub messages it encounters. In .NET, it illustrates the use of a SubscribeDataSet Method overload that takes just the PubSub connection descriptor as an input.

Resolved or not?

The information you pass in to the SubscribeDataSet Method may either be used "as is", or it may be subject to OPC UA PubSub logical resolution first. As explained in OPC UA PubSub Descriptors, you can pass in the physical identifiers, the logical identifiers, or both. The OPC UA PubSub logical resolution mechanism will be invoked if the dataset subscription descriptor requires resolution (this term is explained in OPC UA PubSub Descriptors). 

We can reformulate it so: If you have specified physical identifiers everywhere, they will be directly used, and no logical resolution will take place - even if there are logical identifies filled in as well. If, however, you have a PubSub object somewhere in the descriptors that is only specified by its logical identifier but no physical identifier, the logical resolution mechanism will be used.

Event handlers vs. callback methods

There are two ways your program can be informed about dataset messages that you have subscribed to:

It is also possible to specify a non-null callback parameter, and hook an event handler as well. In this case, the callback method will be invoked in addition to the event handlers.

The DataSetMessage event or callback

The event arguments of the DataSetMessage Event are of type EasyUADataSetMessageEventArgs. Because it is  indirectly derived from the OperationEventArgs, it contains the Exception Property which is null for success notifications, and non-null in case of failure. You can use the Succeeded Property to make the corresponding test. The actual data of the dataset, if available, is in the DataSetData Property.

The EasyUADataSetMessageEventArgs also contain, in their Arguments Property, a copy of the arguments (EasyUASubscribeDataSetArguments Class) you have used when making the dataset subscription that caused this event or callback. You can use this property to identify the dataset subscription, in case you are using event handlers and have made more subscriptions on the same object, or if you have used the same callback methods with multiple subscriptions. Specifically, the State Property in the EasyUASubscribeDataSetArguments can be used for any information you need to pass from the code that makes the subscription to the code that handles the dataset messages.

The EasyUASubscriber invokes the DataSetMessage event or callback when a new dataset message (you have subscribed to) arrives, but also in some other cases. Below is a list of possible property value combinations and their meaning.

The main causes for failures are

If the OPC UA PubSub logical resolution took place, the ResolvedDataSetSubscriptionDescriptor Property is filled in with a dataset subscription descriptor that is derived from the one you have specified when calling the SubscribeDataSet Method, but with the logical identifiers resolved to physical ones.

The dataset message event notification has a PubSubLocators Property. This property is always non-null (even in case of errors), and contains the information that allows to relate the event to its "source" in the OPC UA PubSub model. The object (UAPubSubLocators Class) has properties for a publisher Id, writer group Id, writer group name, dataset writer Id, and dataset writer name. The component will fill in as many of these properties as possible, given the circumstances. Knowing such relation comes handy when the dataset subscription filter is not for a single dataset, but for multiple datasets. Note that all information contained in the PubSubLocators Property is also available inside the dataset data. The difference is that the PubSubLocators object is present even in cases when there is dataset data - such as in case of errors. The PubSubLocators thus allow to determine the "source" of the error programmatically.

A typical task when processing the dataset message is to extract one or more fields from the dataset and process them further. The field is identified by its name (or an index in its string form, such "#0", if field names are not available) in the FieldDataDictionary. The example below shows how it can be done.

.NET

// This example shows how to subscribe to dataset messages and extract data of a specific field.
//
// 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 .

using System;
using System.Threading;
using OpcLabs.EasyOpc.UA.PubSub;
using OpcLabs.EasyOpc.UA.PubSub.Configuration;
using OpcLabs.EasyOpc.UA.PubSub.OperationModel;

namespace UADocExamples.PubSub._EasyUASubscriber
{
    partial class SubscribeDataSet
    {
        public static void ExtractField()
        {
            // 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);

            // Define the metadata, with the use of collection initializer for its fields. For UADP, the order of field
            // metadata must correspond to the order of fields in the dataset message. If the field names were contained
            // in the dataset message (such as in JSON), or if we knew the metadata from some other source, this step would
            // not be needed.
            // Since the encoding is not RawData, we do not have to specify the type information for the fields.
            var metaData = new UADataSetMetaData
            {
                new UAFieldMetaData("BoolToggle"),
                new UAFieldMetaData("Int32"),
                new UAFieldMetaData("Int32Fast"),
                new UAFieldMetaData("DateTime")
            };

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

            Console.WriteLine("Subscribing...");
            subscriber.SubscribeDataSet(pubSubConnectionDescriptor, filter, metaData);

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

            Console.WriteLine("Unsubscribing...");
            subscriber.UnsubscribeAllDataSets();

            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_ExtractField(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))
                {
                    // Extract field data, looking up the field by its name.
                    UADataSetFieldData int32FastValueData = e.DataSetData.FieldDataDictionary["Int32Fast"];
                    Console.WriteLine(int32FastValueData);
                }
            }
            else
            {
                Console.WriteLine($"*** Failure: {e.ErrorMessageBrief}");
            }
        }

        // Example output:
        //
        //Subscribing...
        //Processing dataset message events for 20 seconds...
        //6502 {System.Int32} @2019-10-06T10:02:01.254,647,600,00; Good
        //6538 {System.Int32} @2019-10-06T10:02:01.755,010,700,00; Good
        //6615 {System.Int32} @2019-10-06T10:02:02.255,780,200,00; Good
        //6687 {System.Int32} @2019-10-06T10:02:02.756,495,900,00; Good
        //6769 {System.Int32} @2019-10-06T10:02:03.257,320,200,00; Good
        //6804 {System.Int32} @2019-10-06T10:02:03.757,667,300,00; Good
        //6877 {System.Int32} @2019-10-06T10:02:04.258,405,000,00; Good
        //6990 {System.Int32} @2019-10-06T10:02:04.759,532,900,00; Good
        //7063 {System.Int32} @2019-10-06T10:02:05.260,257,200,00; Good
        //7163 {System.Int32} @2019-10-06T10:02:05.761,261,800,00; Good
        //7255 {System.Int32} @2019-10-06T10:02:06.262,176,800,00; Good
        //7321 {System.Int32} @2019-10-06T10:02:06.762,839,800,00; Good
        //7397 {System.Int32} @2019-10-06T10:02:07.263,598,900,00; Good
        //7454 {System.Int32} @2019-10-06T10:02:07.764,168,900,00; Good
        //7472 {System.Int32} @2019-10-06T10:02:08.264,350,400,00; Good
        //...
    }
}
# This example shows how to subscribe to dataset messages and extract data of a specific field.
#
# 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 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 import *
from OpcLabs.EasyOpc.UA.PubSub import *
from OpcLabs.EasyOpc.UA.PubSub.Configuration import *
from OpcLabs.EasyOpc.UA.PubSub.OperationModel import *


def dataSetMessage(sender, e):
    # Display the dataset.
    if e.Succeeded:
        # An event with null DataSetData just indicates a successful connection.
        if e.DataSetData is not None:
            # Extract field data, looking up the field by its name.
            int32FastValueData = e.DataSetData.FieldDataDictionary.get_Item('Int32Fast')
            print(int32FastValueData)
    else:
        print('')
        print('*** Failure: ', e.ErrorMessageBrief, sep='')


# Define the PubSub connection we will work with. Uses implicit conversion from a string.
pubSubConnectionDescriptor = UAPubSubConnectionDescriptor.op_Implicit('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.
filter = UASubscribeDataSetFilter(UAPublisherId.CreateUInt64(Decimal(31)),
                                  UAWriterGroupDescriptor.Null,
                                  UADataSetWriterDescriptor(1))

# Define the metadata. For UADP, the order of field metadata must correspond to the order of fields in the dataset
# message. If the field names were contained in the dataset message (such as in JSON), or if we knew the metadata from
# some other source, this step would not be needed.
# Since the encoding is not RawData, we do not have to specify the type information for the fields.
metaData = UADataSetMetaData()
metaData.Add(UAFieldMetaData('BoolToggle'))
metaData.Add(UAFieldMetaData('Int32'))
metaData.Add(UAFieldMetaData('Int32Fast'))
metaData.Add(UAFieldMetaData('DateTime'))

# Instantiate the subscriber object and hook events.
subscriber = EasyUASubscriber()
subscriber.DataSetMessage += dataSetMessage

print('Subscribing...')
IEasyUASubscriberExtension.SubscribeDataSet(subscriber, pubSubConnectionDescriptor, filter, metaData)

print('Processing dataset message events for 20 seconds...')
time.sleep(20)

print('Unsubscribing...')
subscriber.UnsubscribeAllDataSets()

print('Waiting for 1 second...')
# Unsubscribe operation is asynchronous, messages may still come for a short while.
time.sleep(1)

subscriber.DataSetMessage -= dataSetMessage

print('Finished.')
' This example shows how to subscribe to dataset messages and extract data of a specific field.
'
' 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 .

Imports OpcLabs.EasyOpc.UA.PubSub
Imports OpcLabs.EasyOpc.UA.PubSub.Configuration
Imports OpcLabs.EasyOpc.UA.PubSub.OperationModel

Namespace PubSub._EasyUASubscriber
    Partial Friend Class SubscribeDataSet
        Public Shared Sub ExtractField()

            ' Define the PubSub connection we will work with. Uses implicit conversion from a string.
            Dim pubSubConnectionDescriptor As UAPubSubConnectionDescriptor = "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.
            Dim filter = New UASubscribeDataSetFilter(UAPublisherId.CreateUInt64(31), UAWriterGroupDescriptor.Null, 1)

            ' Define the metadata, with the use of collection initializer for its fields. For UADP, the order of field
            ' metadata must correspond to the order of fields in the dataset message. If the field names were contained
            ' in the dataset message (such as in JSON), or if we knew the metadata from some other source, this step would
            ' Not be needed.
            ' Since the encoding is not RawData, we do not have to specify the type information for the fields.
            Dim metaData = New UADataSetMetaData From {
                New UAFieldMetaData("BoolToggle"),
                New UAFieldMetaData("Int32"),
                New UAFieldMetaData("Int32Fast"),
                New UAFieldMetaData("DateTime")
            }

            ' Instantiate the subscriber object and hook events.
            Dim subscriber = New EasyUASubscriber()
            AddHandler subscriber.DataSetMessage, AddressOf subscriber_DataSetMessage_ExtractField

            Console.WriteLine("Subscribing...")
            subscriber.SubscribeDataSet(pubSubConnectionDescriptor, filter, metaData)

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

            Console.WriteLine("Unsubscribing...")
            subscriber.UnsubscribeAllDataSets()

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

            Console.WriteLine("Finished...")
        End Sub

        Private Shared Sub subscriber_DataSetMessage_ExtractField(ByVal sender As Object, ByVal e As EasyUADataSetMessageEventArgs)
            ' Display the dataset.
            If e.Succeeded Then
                ' An event with null DataSetData just indicates a successful connection.
                If e.DataSetData IsNot Nothing Then
                    ' Extract field data, looking up the field by its name.
                    Dim int32FastValueData = e.DataSetData.FieldDataDictionary("Int32Fast")
                    Console.WriteLine(int32FastValueData)
                End If
            Else
                Console.WriteLine($"*** Failure: {e.ErrorMessageBrief}")
            End If
        End Sub
    End Class

    ' Example output
    '
    'Subscribing...
    'Processing dataset message events for 20 seconds...
    '6502 {System.Int32} @2019-10-06T10:02:01.254,647,600,00; Good
    '6538 {System.Int32} @2019-10-06T10:02:01.755,010,700,00; Good
    '6615 {System.Int32} @2019-10-06T10:02:02.255,780,200,00; Good
    '6687 {System.Int32} @2019-10-06T10:02:02.756,495,900,00; Good
    '6769 {System.Int32} @2019-10-06T10:02:03.257,320,200,00; Good
    '6804 {System.Int32} @2019-10-06T10:02:03.757,667,300,00; Good
    '6877 {System.Int32} @2019-10-06T10:02:04.258,405,000,00; Good
    '6990 {System.Int32} @2019-10-06T10:02:04.759,532,900,00; Good
    '7063 {System.Int32} @2019-10-06T10:02:05.260,257,200,00; Good
    '7163 {System.Int32} @2019-10-06T10:02:05.761,261,800,00; Good
    '7255 {System.Int32} @2019-10-06T10:02:06.262,176,800,00; Good
    '7321 {System.Int32} @2019-10-06T10:02:06.762,839,800,00; Good
    '7397 {System.Int32} @2019-10-06T10:02:07.263,598,900,00; Good
    '7454 {System.Int32} @2019-10-06T10:02:07.764,168,900,00; Good
    '7472 {System.Int32} @2019-10-06T10:02:08.264,350,400,00; Good
    '...

End Namespace

COM

// This example shows how to subscribe to dataset messages and extract data of a specific field.
//
// 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 .

type
  TSubscriberEventHandlers74 = class
    procedure OnDataSetMessage(
      ASender: TObject;
      sender: OleVariant;
      const eventArgs: _EasyUADataSetMessageEventArgs);
  end;

class procedure SubscribeDataSet.ExtractField;
var
  ConnectionDescriptor: _UAPubSubConnectionDescriptor;
  Field1, Field2, Field3, Field4: _UAFieldMetaData;
  MetaData: _UADataSetMetaData;
  SubscribeDataSetArguments: _EasyUASubscribeDataSetArguments;
  Subscriber: TEasyUASubscriber;
  SubscriberEventHandlers: TSubscriberEventHandlers74;
begin
  // Define the PubSub connection we will work with.
  SubscribeDataSetArguments := CoEasyUASubscribeDataSetArguments.Create;
  ConnectionDescriptor := SubscribeDataSetArguments.DataSetSubscriptionDescriptor.ConnectionDescriptor;
  ConnectionDescriptor.ResourceAddress.ResourceDescriptor.UrlString := '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.
  //ConnectionDescriptor.ResourceAddress.InterfaceName := 'Ethernet';

  // Define the filter. Publisher Id (unsigned 64-bits) is 31, and the dataset writer Id is 1.
  SubscribeDataSetArguments.DataSetSubscriptionDescriptor.Filter.PublisherId.SetIdentifier(UAPublisherIdType_UInt64, 31);
  SubscribeDataSetArguments.DataSetSubscriptionDescriptor.Filter.DataSetWriterDescriptor.DataSetWriterId := 1;

  // Define the metadata. For UADP, the order of field metadata must correspond to the order of fields in the dataset message.
  // If the field names were contained in the dataset message (such as in JSON), or if we knew the metadata from some other
  // source, this step would not be needed.
  // Since the encoding is not RawData, we do not have to specify the type information for the fields.
  MetaData := CoUADataSetMetaData.Create;
  //
  Field1 := CoUAFieldMetaData.Create;
  Field1.Name := 'BoolToggle';
  MetaData.Add(Field1);
  //
  Field2 := CoUAFieldMetaData.Create;
  Field2.Name := 'Int32';
  MetaData.Add(Field2);
  //
  Field3 := CoUAFieldMetaData.Create;
  Field3.Name := 'Int32Fast';
  MetaData.Add(Field3);
  //
  Field4 := CoUAFieldMetaData.Create;
  Field4.Name := 'DateTime';
  MetaData.Add(Field4);
  //
  SubscribeDataSetArguments.DataSetSubscriptionDescriptor.DataSetMetaData := MetaData;

  // Instantiate the subscriber object and hook events.
  Subscriber := TEasyUASubscriber.Create(nil);
  SubscriberEventHandlers := TSubscriberEventHandlers74.Create;
  Subscriber.OnDataSetMessage := SubscriberEventHandlers.OnDataSetMessage;

  WriteLn('Subscribing...');
  Subscriber.SubscribeDataSet(SubscribeDataSetArguments);

  WriteLn('Processing dataset message for 20 seconds...');
  PumpSleep(20*1000);

  WriteLn('Unsubscribing...');
  Subscriber.UnsubscribeAllDataSets;

  WriteLn('Waiting for 1 second...');
  // Unsubscribe operation is asynchronous, messages may still come for a short while.
  PumpSleep(1*1000);

  WriteLn('Finished.');
  FreeAndNil(Subscriber);
  FreeAndNil(SubscriberEventHandlers);
end;

procedure TSubscriberEventHandlers74.OnDataSetMessage(
  ASender: TObject;
  sender: OleVariant;
  const eventArgs: _EasyUADataSetMessageEventArgs);
var
  Dnt32FastValueData: _UADataSetFieldData;
begin
  // Display the dataset.
  if eventArgs.Succeeded then
  begin
    // An event with null DataSetData just indicates a successful connection.
    if eventArgs.DataSetData <> nil then
    begin
      // Extract field data, looking up the field by its name.
      Dnt32FastValueData := eventArgs.DataSetData.FieldDataDictionary.Item['Int32Fast'];
      WriteLn(Dnt32FastValueData.ToString);
    end;
  end
  else begin
    WriteLn;
      WriteLn('*** Failure: ', eventArgs.ErrorMessageBrief);
  end;
end;

// Example output:
//
//Subscribing...
//Processing dataset message events for 20 seconds...
//6502 {System.Int32} @2019-10-06T10:02:01.254,647,600,00; Good
//6538 {System.Int32} @2019-10-06T10:02:01.755,010,700,00; Good
//6615 {System.Int32} @2019-10-06T10:02:02.255,780,200,00; Good
//6687 {System.Int32} @2019-10-06T10:02:02.756,495,900,00; Good
//6769 {System.Int32} @2019-10-06T10:02:03.257,320,200,00; Good
//6804 {System.Int32} @2019-10-06T10:02:03.757,667,300,00; Good
//6877 {System.Int32} @2019-10-06T10:02:04.258,405,000,00; Good
//6990 {System.Int32} @2019-10-06T10:02:04.759,532,900,00; Good
//7063 {System.Int32} @2019-10-06T10:02:05.260,257,200,00; Good
//7163 {System.Int32} @2019-10-06T10:02:05.761,261,800,00; Good
//7255 {System.Int32} @2019-10-06T10:02:06.262,176,800,00; Good
//7321 {System.Int32} @2019-10-06T10:02:06.762,839,800,00; Good
//7397 {System.Int32} @2019-10-06T10:02:07.263,598,900,00; Good
//7454 {System.Int32} @2019-10-06T10:02:07.764,168,900,00; Good
//7472 {System.Int32} @2019-10-06T10:02:08.264,350,400,00; Good
//...
Rem This example shows how to subscribe to dataset messages and extract data of a specific field.
Rem
Rem In order to produce network messages for this example, run the UADemoPublisher tool. For documentation, see
Rem https://kb.opclabs.com/UADemoPublisher_Basics . In some cases, you may have to specify the interface name to be used.
Rem
Rem Find all latest examples here : https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

Option Explicit

Const UAPublisherIdType_UInt64 = 4

' Define the PubSub connection we will work with.
Dim SubscribeDataSetArguments: Set SubscribeDataSetArguments = CreateObject("OpcLabs.EasyOpc.UA.PubSub.OperationModel.EasyUASubscribeDataSetArguments")
Dim ConnectionDescriptor: Set ConnectionDescriptor = SubscribeDataSetArguments.DataSetSubscriptionDescriptor.ConnectionDescriptor
ConnectionDescriptor.ResourceAddress.ResourceDescriptor.UrlString = "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.
' ConnectionDescriptor.ResourceAddress.InterfaceName = "Ethernet"

' Define the filter. Publisher Id (unsigned 64-bits) is 31, and the dataset writer Id is 1.
SubscribeDataSetArguments.DataSetSubscriptionDescriptor.Filter.PublisherId.SetIdentifier UAPublisherIdType_UInt64, 31
SubscribeDataSetArguments.DataSetSubscriptionDescriptor.Filter.DataSetWriterDescriptor.DataSetWriterId = 1

' Define the metadata. For UADP, the order of field metadata must correspond to the order of fields in the dataset message. 
' If the field names were contained in the dataset message (such as in JSON), or if we knew the metadata from some other 
' source, this step would not be needed.
' Since the encoding is not RawData, we do not have to specify the type information for the fields.
Dim MetaData: Set MetaData = CreateObject("OpcLabs.EasyOpc.UA.PubSub.Configuration.UADataSetMetaData")
'
Dim Field1: Set Field1 = CreateObject("OpcLabs.EasyOpc.UA.PubSub.Configuration.UAFieldMetaData")
Field1.Name = "BoolToggle"
MetaData.Add(Field1)
'
Dim Field2: Set Field2 = CreateObject("OpcLabs.EasyOpc.UA.PubSub.Configuration.UAFieldMetaData")
Field2.Name = "Int32"
MetaData.Add(Field2)
'
Dim Field3: Set Field3 = CreateObject("OpcLabs.EasyOpc.UA.PubSub.Configuration.UAFieldMetaData")
Field3.Name = "Int32Fast"
MetaData.Add(Field3)
'
Dim Field4: Set Field4 = CreateObject("OpcLabs.EasyOpc.UA.PubSub.Configuration.UAFieldMetaData")
Field4.Name = "DateTime"
MetaData.Add(Field4)
'
Set SubscribeDataSetArguments.DataSetSubscriptionDescriptor.DataSetMetaData = MetaData

' Instantiate the subscriber object and hook events.
Dim Subscriber: Set Subscriber = CreateObject("OpcLabs.EasyOpc.UA.PubSub.EasyUASubscriber")
WScript.ConnectObject Subscriber, "Subscriber_"

WScript.Echo "Subscribing..."
Subscriber.SubscribeDataSet SubscribeDataSetArguments

WScript.Echo "Processing dataset message events for 20 seconds..."
WScript.Sleep 20*1000

WScript.Echo "Unsubscribing..."
Subscriber.UnsubscribeAllDataSets

WScript.Echo "Waiting for 1 second..."
' Unsubscribe operation is asynchronous, messages may still come for a short while.
WScript.Sleep 1*1000

WScript.Echo "Finished."



Sub Subscriber_DataSetMessage(Sender, e)
    ' Display the dataset.
    If e.Succeeded Then
        ' An event with null DataSetData just indicates a successful connection.
        If Not (e.DataSetData Is Nothing) Then
            ' Extract field data, looking up the field by its name.
            Dim Int32FastValueData: Set Int32FastValueData = e.DataSetData.FieldDataDictionary.Item("Int32Fast")
            WScript.Echo Int32FastValueData
        End If
    Else
        WScript.Echo
        WScript.Echo "*** Failure: " & e.ErrorMessageBrief
    End If
End Sub



' Example output:
'
'Subscribing...
'Processing dataset message events for 20 seconds...
'6502 {System.Int32} @2019-10-06T10:02:01.254,647,600,00; Good
'6538 {System.Int32} @2019-10-06T10:02:01.755,010,700,00; Good
'6615 {System.Int32} @2019-10-06T10:02:02.255,780,200,00; Good
'6687 {System.Int32} @2019-10-06T10:02:02.756,495,900,00; Good
'6769 {System.Int32} @2019-10-06T10:02:03.257,320,200,00; Good
'6804 {System.Int32} @2019-10-06T10:02:03.757,667,300,00; Good
'6877 {System.Int32} @2019-10-06T10:02:04.258,405,000,00; Good
'6990 {System.Int32} @2019-10-06T10:02:04.759,532,900,00; Good
'7063 {System.Int32} @2019-10-06T10:02:05.260,257,200,00; Good
'7163 {System.Int32} @2019-10-06T10:02:05.761,261,800,00; Good
'7255 {System.Int32} @2019-10-06T10:02:06.262,176,800,00; Good
'7321 {System.Int32} @2019-10-06T10:02:06.762,839,800,00; Good
'7397 {System.Int32} @2019-10-06T10:02:07.263,598,900,00; Good
'7454 {System.Int32} @2019-10-06T10:02:07.764,168,900,00; Good
'7472 {System.Int32} @2019-10-06T10:02:08.264,350,400,00; Good
'...

REM This example shows how to subscribe to dataset messages extract data of a specific field.
REM
REM In order to produce network messages for this example, run the UADemoPublisher tool. For documentation, see
REM https://kb.opclabs.com/UADemoPublisher_Basics . In some cases, you may have to specify the interface name to be used.
REM
REM Find all latest examples here : https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

' The subscriber object, with events.
'Public WithEvents Subscriber7 As EasyUASubscriber

Private Sub EasyUASubscriber_SubscribeDataSet_ExtractField_Command_Click()
    OutputText = ""

    Const UAPublisherIdType_UInt64 = 4

    ' Define the PubSub connection we will work with.
    Dim subscribeDataSetArguments :  Set subscribeDataSetArguments = CreateObject("OpcLabs.EasyOpc.UA.PubSub.OperationModel.EasyUASubscribeDataSetArguments")
    Dim ConnectionDescriptor :  Set ConnectionDescriptor = subscribeDataSetArguments.dataSetSubscriptionDescriptor.ConnectionDescriptor
    ConnectionDescriptor.ResourceAddress.ResourceDescriptor.UrlString = "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.
    ' ConnectionDescriptor.ResourceAddress.InterfaceName = "Ethernet"

    ' Define the filter. Publisher Id (unsigned 64-bits) is 31, and the dataset writer Id is 1.
    subscribeDataSetArguments.dataSetSubscriptionDescriptor.Filter.PublisherId.SetIdentifier UAPublisherIdType_UInt64, 31
    subscribeDataSetArguments.dataSetSubscriptionDescriptor.Filter.DataSetWriterDescriptor.DataSetWriterId = 1

    ' Define the metadata. For UADP, the order of field metadata must correspond to the order of fields in the dataset message.
    ' If the field names were contained in the dataset message (such as in JSON), or if we knew the metadata from some other
    ' source, this step would not be needed.
    ' Since the encoding is not RawData, we do not have to specify the type information for the fields.
    Dim metaData :  Set metaData = CreateObject("OpcLabs.EasyOpc.UA.PubSub.Configuration.UADataSetMetaData")
    '
    Dim field1 :  Set field1 = CreateObject("OpcLabs.EasyOpc.UA.PubSub.Configuration.UAFieldMetaData")
    field1.Name = "BoolToggle"
    metaData.Add(field1)
    '
    Dim field2 :  Set field2 = CreateObject("OpcLabs.EasyOpc.UA.PubSub.Configuration.UAFieldMetaData")
    field2.Name = "Int32"
    metaData.Add(field2)
    '
    Dim field3 :  Set field3 = CreateObject("OpcLabs.EasyOpc.UA.PubSub.Configuration.UAFieldMetaData")
    field3.Name = "Int32Fast"
    metaData.Add(field3)
    '
    Dim field4 :  Set field4 = CreateObject("OpcLabs.EasyOpc.UA.PubSub.Configuration.UAFieldMetaData")
    field4.Name = "DateTime"
    metaData.Add(field4)
    '
    Set subscribeDataSetArguments.dataSetSubscriptionDescriptor.DataSetMetaData = metaData
    
    ' Instantiate the subscriber object and hook events.
    Set Subscriber7 = New EasyUASubscriber

    OutputText = OutputText & "Subscribing..." & vbCrLf
    Subscriber7.SubscribeDataSet subscribeDataSetArguments

    OutputText = OutputText & "Processing dataset message events for 20 seconds..." & vbCrLf
    Pause 20 * 1000

    OutputText = OutputText & "Unsubscribing..." & vbCrLf
    Subscriber7.UnsubscribeAllDataSets

    OutputText = OutputText & "Waiting for 1 second..." & vbCrLf
    ' Unsubscribe operation is asynchronous, messages may still come for a short while.
    Pause 1000

    Set Subscriber7 = Nothing

    OutputText = OutputText & "Finished." & vbCrLf
End Sub

Private Sub Subscriber7_DataSetMessage(ByVal sender As Variant, ByVal eventArgs As EasyUADataSetMessageEventArgs)
    ' Display the dataset.
    If eventArgs.Succeeded Then
        ' An event with null DataSetData just indicates a successful connection.
        If Not (eventArgs.DataSetData Is Nothing) Then
            ' Extract field data, looking up the field by its name.
            Dim Int32FastValueData :  Set Int32FastValueData = eventArgs.DataSetData.FieldDataDictionary.Item("Int32Fast")
            OutputText = OutputText & Int32FastValueData & vbCrLf
        End If
    Else
        OutputText = OutputText & vbCrLf
        OutputText = OutputText & "*** Failure: " & eventArgs.ErrorMessageBrief & vbCrLf
    End If
End Sub
' Example output:
'
'Subscribing...
'Processing dataset message events for 20 seconds...
'6502 {System.Int32} @2019-10-06T10:02:01.254,647,600,00; Good
'6538 {System.Int32} @2019-10-06T10:02:01.755,010,700,00; Good
'6615 {System.Int32} @2019-10-06T10:02:02.255,780,200,00; Good
'6687 {System.Int32} @2019-10-06T10:02:02.756,495,900,00; Good
'6769 {System.Int32} @2019-10-06T10:02:03.257,320,200,00; Good
'6804 {System.Int32} @2019-10-06T10:02:03.757,667,300,00; Good
'6877 {System.Int32} @2019-10-06T10:02:04.258,405,000,00; Good
'6990 {System.Int32} @2019-10-06T10:02:04.759,532,900,00; Good
'7063 {System.Int32} @2019-10-06T10:02:05.260,257,200,00; Good
'7163 {System.Int32} @2019-10-06T10:02:05.761,261,800,00; Good
'7255 {System.Int32} @2019-10-06T10:02:06.262,176,800,00; Good
'7321 {System.Int32} @2019-10-06T10:02:06.762,839,800,00; Good
'7397 {System.Int32} @2019-10-06T10:02:07.263,598,900,00; Good
'7454 {System.Int32} @2019-10-06T10:02:07.764,168,900,00; Good
'7472 {System.Int32} @2019-10-06T10:02:08.264,350,400,00; Good
'...

 

If metadata is available, you can alternatively use the FieldDataDictionaryById Property, which also contains the data for each field of the dataset message, but keyed by a datasetfield Id (a GUID).

Key Frames and Delta Frames

Depending how OPC UA PubSub is configured, the publisher might be always sending all fields of the dataset with every dataset message, or it may use a combination of key frames and delta frames. While the key frame dataset message includes values for all fields of the dataset, the delta frame only contains values of the fields that have changed since the previous dataset message.

Key frames and delta frames are a concept that exists purely to spare the network bandwidth. When you subscribe with QuickOPC, the delta frames are interpreted internally, and a full dataset is always shipped to you in the dataset message event or callback. This way, you do not have to put in any additional code to handle the distinction between key frames and delta frames.

When the publisher uses delta frames, there may be a delay before you start receiving the messages (after the connection is established). This is because QuickOPC needs to wait for the first key frame until it can start delivering the dataset data to you.

Changing existing subscription

It is not necessary to unsubscribe and subscribe again, if you want to change some parameters of existing subscription, such as its filter (Message Filtering (OPC UA PubSub)) or the associated metadata (Dataset Metadata (OPC UA PubSub)). You change the parameters by calling the ChangeDataSetSubscription Method, passing it the dataset subscription handle, and the new parameters in form of an instance of the EasyUADataSetSubscriptionChangeArguments Class.

There is also an extension method (an overload - with the same name) that allows you to easily pass in just the dataset subscription handle, and a new filter.

Unsubscribing

If you no longer want to receive dataset messages, you need to unsubscribe. This is achieved by calling the UnsubscribeDataSet Method, passing it the dataset subscription handle obtained when calling the SubscribeDataSet Method.

Example:

.NET

// 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 .

using System;
using System.Collections.Generic;
using System.Threading;
using OpcLabs.EasyOpc.UA.PubSub;
using OpcLabs.EasyOpc.UA.PubSub.OperationModel;

namespace UADocExamples.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
# 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 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 import *
from OpcLabs.EasyOpc.UA.PubSub import *
from OpcLabs.EasyOpc.UA.PubSub.OperationModel import *


def dataSetMessage(sender, e):
    # Display the dataset.
    if e.Succeeded:
        # An event with null DataSetData just indicates a successful connection.
        if e.DataSetData is not None:
            print('')
            print('Dataset data: ', e.DataSetData, sep='')
            for pair in e.DataSetData.FieldDataDictionary:
                print(pair)
    else:
        print('')
        print('*** Failure: ', e.ErrorMessageBrief, sep='')


# Define the PubSub connection we will work with. Uses implicit conversion from a string.
pubSubConnectionDescriptor = UAPubSubConnectionDescriptor.op_Implicit('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.
filter = UASubscribeDataSetFilter(UAPublisherId.CreateUInt64(Decimal(31)),
                                  UAWriterGroupDescriptor.Null,
                                  UADataSetWriterDescriptor(1))  # dataSetWriterDescriptor

# Instantiate the subscriber object and hook events.
subscriber = EasyUASubscriber()
subscriber.DataSetMessage += dataSetMessage

print('Subscribing...')
dataSetHandle = IEasyUASubscriberExtension.SubscribeDataSet(subscriber, pubSubConnectionDescriptor, filter)

print('Processing dataset message events for 20 seconds...')
time.sleep(20)

print('Unsubscribing...')
subscriber.UnsubscribeDataSet(dataSetHandle)

print('Waiting for 1 second...')
# Unsubscribe operation is asynchronous, messages may still come for a short while.
time.sleep(1)

subscriber.DataSetMessage -= dataSetMessage

print('Finished.')
' 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 .

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

Namespace PubSub._EasyUASubscriber
    Friend Class UnsubscribeDataSet
        Public Shared Sub Main1()

            ' Define the PubSub connection we will work with. Uses implicit conversion from a string.
            Dim pubSubConnectionDescriptor As UAPubSubConnectionDescriptor = "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.
            Dim filter = New UASubscribeDataSetFilter(UAPublisherId.CreateUInt64(31), UAWriterGroupDescriptor.Null, 1)

            ' Instantiate the subscriber object and hook events.
            Dim subscriber = New EasyUASubscriber()
            AddHandler subscriber.DataSetMessage, AddressOf subscriber_DataSetMessage

            Console.WriteLine("Subscribing...")
            subscriber.SubscribeDataSet(pubSubConnectionDescriptor, filter)

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

            Console.WriteLine("Unsubscribing...")
            subscriber.UnsubscribeAllDataSets()

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

            Console.WriteLine("Finished...")
        End Sub

        Private Shared Sub subscriber_DataSetMessage(ByVal sender As Object, ByVal e As EasyUADataSetMessageEventArgs)
            ' Display the dataset.
            If e.Succeeded Then
                ' An event with null DataSetData just indicates a successful connection.
                If e.DataSetData IsNot Nothing Then
                    Console.WriteLine()
                    Console.WriteLine($"Dataset data: {e.DataSetData}")
                    For Each pair As KeyValuePair(Of String, UADataSetFieldData) In e.DataSetData.FieldDataDictionary
                        Console.WriteLine(pair)
                    Next
                End If
            Else
                Console.WriteLine()
                Console.WriteLine($"*** Failure: {e.ErrorMessageBrief}")
            End If
        End Sub
    End Class



    ' 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]
    '
    '...

End Namespace

COM

// 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 .

type
  TSubscriberEventHandlers82 = class
    procedure OnDataSetMessage(
      ASender: TObject;
      sender: OleVariant;
      const eventArgs: _EasyUADataSetMessageEventArgs);
  end;

class procedure UnsubscribeDataSet.Main1;
var
  ConnectionDescriptor: _UAPubSubConnectionDescriptor;
  SubscribeDataSetArguments: _EasyUASubscribeDataSetArguments;
  Subscriber: TEasyUASubscriber;
  SubscriberEventHandlers: TSubscriberEventHandlers82;
begin
  // Define the PubSub connection we will work with.
  SubscribeDataSetArguments := CoEasyUASubscribeDataSetArguments.Create;
  ConnectionDescriptor := SubscribeDataSetArguments.DataSetSubscriptionDescriptor.ConnectionDescriptor;
  ConnectionDescriptor.ResourceAddress.ResourceDescriptor.UrlString := '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.
  //ConnectionDescriptor.ResourceAddress.InterfaceName := 'Ethernet';

  // Define the filter. Publisher Id (unsigned 64-bits) is 31, and the dataset writer Id is 1.
  SubscribeDataSetArguments.DataSetSubscriptionDescriptor.Filter.PublisherId.SetIdentifier(UAPublisherIdType_UInt64, 31);
  SubscribeDataSetArguments.DataSetSubscriptionDescriptor.Filter.DataSetWriterDescriptor.DataSetWriterId := 1;

  // Instantiate the subscriber object and hook events.
  Subscriber := TEasyUASubscriber.Create(nil);
  SubscriberEventHandlers := TSubscriberEventHandlers82.Create;
  Subscriber.OnDataSetMessage := SubscriberEventHandlers.OnDataSetMessage;

  WriteLn('Subscribing...');
  Subscriber.SubscribeDataSet(SubscribeDataSetArguments);

  WriteLn('Processing dataset message for 20 seconds...');
  PumpSleep(20*1000);

  WriteLn('Unsubscribing...');
  Subscriber.UnsubscribeAllDataSets;

  WriteLn('Waiting for 1 second...');
  // Unsubscribe operation is asynchronous, messages may still come for a short while.
  PumpSleep(1*1000);

  WriteLn('Finished.');
  FreeAndNil(Subscriber);
  FreeAndNil(SubscriberEventHandlers);
end;

procedure TSubscriberEventHandlers82.OnDataSetMessage(
  ASender: TObject;
  sender: OleVariant;
  const eventArgs: _EasyUADataSetMessageEventArgs);
var
  Count: Cardinal;
  DictionaryEntry2: _DictionaryEntry2;
  Element: OleVariant;
  FieldDataDictionaryEnumerator: IEnumVariant;
begin
  // Display the dataset.
  if eventArgs.Succeeded then
  begin
    // An event with null DataSetData just indicates a successful connection.
    if eventArgs.DataSetData <> nil then
    begin
      WriteLn;
      WriteLn('Dataset data: ', eventArgs.DataSetData.ToString);
      FieldDataDictionaryEnumerator := eventArgs.DataSetData.FieldDataDictionary.GetEnumerator;
      while (FieldDataDictionaryEnumerator.Next(1, Element, Count) = S_OK) do
      begin
        DictionaryEntry2 := IUnknown(Element) as _DictionaryEntry2;
        WriteLn(DictionaryEntry2.ToString);
      end;
    end;
  end
  else begin
    WriteLn;
      WriteLn('*** Failure: ', eventArgs.ErrorMessageBrief);
  end;
end;

// 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]
//
//...
Rem This example shows how to subscribe to dataset messages on an OPC-UA PubSub connection, and then unsubscribe from that
Rem dataset.
Rem
Rem In order to produce network messages for this example, run the UADemoPublisher tool. For documentation, see
Rem https://kb.opclabs.com/UADemoPublisher_Basics . In some cases, you may have to specify the interface name to be used.
Rem
Rem Find all latest examples here : https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

Option Explicit

Const UAPublisherIdType_UInt64 = 4

' Define the PubSub connection we will work with.
Dim SubscribeDataSetArguments: Set SubscribeDataSetArguments = CreateObject("OpcLabs.EasyOpc.UA.PubSub.OperationModel.EasyUASubscribeDataSetArguments")
Dim ConnectionDescriptor: Set ConnectionDescriptor = SubscribeDataSetArguments.DataSetSubscriptionDescriptor.ConnectionDescriptor
ConnectionDescriptor.ResourceAddress.ResourceDescriptor.UrlString = "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.
' ConnectionDescriptor.ResourceAddress.InterfaceName = "Ethernet"

' Define the filter. Publisher Id (unsigned 64-bits) is 31, and the dataset writer Id is 1.
SubscribeDataSetArguments.DataSetSubscriptionDescriptor.Filter.PublisherId.SetIdentifier UAPublisherIdType_UInt64, 31
SubscribeDataSetArguments.DataSetSubscriptionDescriptor.Filter.DataSetWriterDescriptor.DataSetWriterId = 1

' Instantiate the subscriber object and hook events.
Dim Subscriber: Set Subscriber = CreateObject("OpcLabs.EasyOpc.UA.PubSub.EasyUASubscriber")
WScript.ConnectObject Subscriber, "Subscriber_"

WScript.Echo "Subscribing..."
Dim dataSetHandle: dataSetHandle = Subscriber.SubscribeDataSet(SubscribeDataSetArguments)

WScript.Echo "Processing dataset message events for 20 seconds..."
WScript.Sleep 20*1000

WScript.Echo "Unsubscribing..."
Subscriber.UnsubscribeDataSet dataSetHandle

WScript.Echo "Waiting for 1 second..."
' Unsubscribe operation is asynchronous, messages may still come for a short while.
WScript.Sleep 1*1000

WScript.Echo "Finished."



Sub Subscriber_DataSetMessage(Sender, e)
    ' Display the dataset.
    If e.Succeeded Then
        ' An event with null DataSetData just indicates a successful connection.
        If Not (e.DataSetData Is Nothing) Then
            WScript.Echo
            WScript.Echo "Dataset data: " & e.DataSetData
            Dim Pair: For Each Pair in e.DataSetData.FieldDataDictionary
                WScript.Echo Pair
            Next
        End If
    Else
        WScript.Echo
        WScript.Echo "*** Failure: " & e.ErrorMessageBrief
    End If
End Sub



' 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]
'
'...

REM This example shows how to subscribe to dataset messages on an OPC-UA PubSub connection, and then unsubscribe from that
REM dataset.
REM
REM In order to produce network messages for this example, run the UADemoPublisher tool. For documentation, see
REM https://kb.opclabs.com/UADemoPublisher_Basics . In some cases, you may have to specify the interface name to be used.
REM
REM Find all latest examples here : https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

' The subscriber object, with events.
'Public WithEvents Subscriber11 As EasyUASubscriber

Private Sub EasyUASubscriber_UnsubscribeDataSet_Main1_Command_Click()
    OutputText = ""
    
    ' Define the PubSub connection we will work with.
    Dim subscribeDataSetArguments: Set subscribeDataSetArguments = CreateObject("OpcLabs.EasyOpc.UA.PubSub.OperationModel.EasyUASubscribeDataSetArguments")
    Dim ConnectionDescriptor: Set ConnectionDescriptor = subscribeDataSetArguments.dataSetSubscriptionDescriptor.ConnectionDescriptor
    ConnectionDescriptor.ResourceAddress.ResourceDescriptor.UrlString = "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.
    ' ConnectionDescriptor.ResourceAddress.InterfaceName = "Ethernet"

    ' Define the filter. Publisher Id (unsigned 64-bits) is 31, and the dataset writer Id is 1.
    subscribeDataSetArguments.dataSetSubscriptionDescriptor.Filter.PublisherId.SetIdentifier UAPublisherIdType_UInt64, 31
    subscribeDataSetArguments.dataSetSubscriptionDescriptor.Filter.DataSetWriterDescriptor.DataSetWriterId = 1

    ' Instantiate the subscriber object and hook events.
    Set Subscriber11 = New EasyUASubscriber

    OutputText = OutputText & "Subscribing..." & vbCrLf
    Subscriber11.SubscribeDataSet subscribeDataSetArguments

    OutputText = OutputText & "Processing dataset message events for 20 seconds..." & vbCrLf
    Pause 20 * 1000

    OutputText = OutputText & "Unsubscribing..." & vbCrLf
    Subscriber11.UnsubscribeAllDataSets

    OutputText = OutputText & "Waiting for 1 second..." & vbCrLf
    ' Unsubscribe operation is asynchronous, messages may still come for a short while.
    Pause 1000

    Set Subscriber11 = Nothing

    OutputText = OutputText & "Finished." & vbCrLf
End Sub

Private Sub Subscriber11_DataSetMessage(ByVal sender As Variant, ByVal eventArgs As EasyUADataSetMessageEventArgs)
    ' Display the dataset.
    If eventArgs.Succeeded Then
        ' An event with null DataSetData just indicates a successful connection.
        If Not (eventArgs.DataSetData Is Nothing) Then
            OutputText = OutputText & vbCrLf
            OutputText = OutputText & "Dataset data: " & eventArgs.DataSetData & vbCrLf
            Dim Pair: For Each Pair In eventArgs.DataSetData.FieldDataDictionary
                OutputText = OutputText & Pair & vbCrLf
            Next
        End If
    Else
        OutputText = OutputText & vbCrLf
        OutputText = OutputText & "*** Failure: " & eventArgs.ErrorMessageBrief & vbCrLf
    End If
End Sub
'
' 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]
'
'...
'

 

You can also unsubscribe from all dataset messages you have previously subscribed to (on the same instance of the EasyUASubscriber Class) by calling the UnsubscribeAllDataSets Method.

Subscriptions are optimized

QuickOPC merges together requests to the same PubSub objects. If, for example, you make multiple dataset subscriptions and they all use the same PubSub connection, QuickOPC will only make the connection once.

This merging is performed among all subscriptions on all EasyUASubscriber objects that have their Isolated Property set to 'false' (the default). If you set the Isolated Property on some EasyUASubscriber object to 'true', the merging is then performed on the subscriptions made on that object only.

Publisher status messages

Newer versions of OPC UA specification allow the publishers to inform interested parties about their status, either cyclically, or when the status changes. OPC Studio recognizes and processes the publisher status messages in UADP and JSON message mappings. Any non-operational publisher status is reported as an error through the dataset subscription event handler or callback.

This functionality is commonly used with OPC UA PubSub Topic Tree, in which case the topic tree rules prescribe the name of the topic where the status messages for a particular publisher are located.

 

 

Example

.NET

COM

// This example shows how to subscribe to dataset messages with RawData field encoding, specifying the metadata necessary
// for their decoding directly in the code.
//
// 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 .

using System;
using System.Collections.Generic;
using System.Threading;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.PubSub;
using OpcLabs.EasyOpc.UA.PubSub.Configuration;
using OpcLabs.EasyOpc.UA.PubSub.OperationModel;

namespace UADocExamples.PubSub._EasyUASubscriber
{
    partial class SubscribeDataSet
    {
        public static void Metadata()
        {
            // 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 16-bits) is 30, and the writer group Id is 101.
            // The dataset writer Id (1) must not be specified in the filter, because it does not appear in the message.
            var filter = new UASubscribeDataSetFilter(UAPublisherId.CreateUInt16(30), writerGroupDescriptor: 101);

            // Define the metadata, with the use of collection initializer for its fields.
            var metaData = new UADataSetMetaData
            {
                new UAFieldMetaData("BoolToggle", UABuiltInType.Boolean),
                new UAFieldMetaData("Int32", UABuiltInType.Int32),
                new UAFieldMetaData("Int32Fast", UABuiltInType.Int32),
                new UAFieldMetaData("DateTime", UABuiltInType.DateTime)
            };

            // Define the dataset subscription, with specific communication parameters.
            // The dataset offset is needed with messages that do not contain dataset writer Ids and use RawData field
            // encoding. An exception to this rule is when the dataset is the only or first in the dataset message payload,
            // which is also the case here, but we are specifying the dataset offset anyway, for illustration.
            var dataSetSubscriptionDescriptor = new UADataSetSubscriptionDescriptor(
                pubSubConnectionDescriptor, filter, metaData)
            {
                CommunicationParameters = { UadpDataSetReaderMessageParameters = { DataSetOffset = 15 }}
            };

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

            Console.WriteLine("Subscribing...");
            subscriber.SubscribeDataSet(dataSetSubscriptionDescriptor);

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

            Console.WriteLine("Unsubscribing...");
            subscriber.UnsubscribeAllDataSets();

            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_Metadata(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=(UInt16)30, group=101, fields: 4
        //[BoolToggle, False {System.Boolean}; Good]
        //[Int32, 3072 {System.Int32}; Good]
        //[Int32Fast, 894 {System.Int32}; Good]
        //[DateTime, 10/1/2019 12:21:14 PM {System.DateTime}; Good]
        //
        //Dataset data: Good; Data; publisher=(UInt16)30, group=101, fields: 4
        //[BoolToggle, False {System.Boolean}; Good]
        //[Int32, 3072 {System.Int32}; Good]
        //[Int32Fast, 920 {System.Int32}; Good]
        //[DateTime, 10/1/2019 12:21:14 PM {System.DateTime}; Good]
        //
        //Dataset data: Good; Data; publisher=(UInt16)30, group=101, fields: 4
        //[BoolToggle, False {System.Boolean}; Good]
        //[Int32, 3073 {System.Int32}; Good]
        //[Int32Fast, 1003 {System.Int32}; Good]
        //[DateTime, 10/1/2019 12:21:15 PM {System.DateTime}; Good]
        //
        //Dataset data: Good; Data; publisher=(UInt16)30, group=101, fields: 4
        //[BoolToggle, False {System.Boolean}; Good]
        //[Int32, 3073 {System.Int32}; Good]
        //[Int32Fast, 1074 {System.Int32}; Good]
        //[DateTime, 10/1/2019 12:21:15 PM {System.DateTime}; Good]
        //
        //Dataset data: Good; Data; publisher=(UInt16)30, group=101, fields: 4
        //[BoolToggle, True {System.Boolean}; Good]
        //[Int32, 3074 {System.Int32}; Good]
        //[Int32Fast, 1140 {System.Int32}; Good]
        //[DateTime, 10/1/2019 12:21:16 PM {System.DateTime}; Good]
        //
        //...
    }
}
# This example shows how to subscribe to dataset messages with RawData field encoding, specifying the metadata necessary
# for their decoding directly in the code.
#
# 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 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.PubSub import *
from OpcLabs.EasyOpc.UA.PubSub.Configuration import *
from OpcLabs.EasyOpc.UA.PubSub.OperationModel import *


def dataSetMessage(sender, e):
    # Display the dataset.
    if e.Succeeded:
        # An event with null DataSetData just indicates a successful connection.
        if e.DataSetData is not None:
            print('')
            print('Dataset data: ', e.DataSetData, sep='')
            for pair in e.DataSetData.FieldDataDictionary:
                print(pair)
    else:
        print('')
        print('*** Failure: ', e.ErrorMessageBrief, sep='')


# Define the PubSub connection we will work with. Uses implicit conversion from a string.
pubSubConnectionDescriptor = UAPubSubConnectionDescriptor.op_Implicit('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 16-bits) is 30, and the writer group Id is 101.
# The dataset writer Id (1) must not be specified in the filter, because it does not appear in the message.
filter = UASubscribeDataSetFilter(UAPublisherId.CreateUInt16(30),
                                  UAWriterGroupDescriptor(101))

# Define the metadata.
metaData = UADataSetMetaData()
metaData.Add(UAFieldMetaData('BoolToggle', UABuiltInType.Boolean))
metaData.Add(UAFieldMetaData('Int32', UABuiltInType.Int32))
metaData.Add(UAFieldMetaData('Int32Fast', UABuiltInType.Int32))
metaData.Add(UAFieldMetaData('DateTime', UABuiltInType.DateTime))

# Define the dataset subscription, with specific communication parameters.
# The dataset offset is needed with messages that do not contain dataset writer Ids and use RawData field
# encoding. An exception to this rule is when the dataset is the only or first in the dataset message payload,
# which is also the case here, but we are specifying the dataset offset anyway, for illustration.
dataSetSubscriptionDescriptor = UADataSetSubscriptionDescriptor(pubSubConnectionDescriptor, filter, metaData)
dataSetSubscriptionDescriptor.CommunicationParameters.UadpDataSetReaderMessageParameters.DataSetOffset = 15

# Instantiate the subscriber object and hook events.
subscriber = EasyUASubscriber()
subscriber.DataSetMessage += dataSetMessage

print('Subscribing...')
subscriber.SubscribeDataSet(EasyUASubscribeDataSetArguments(dataSetSubscriptionDescriptor))

print('Processing dataset message events for 20 seconds...')
time.sleep(20)

print('Unsubscribing...')
subscriber.UnsubscribeAllDataSets()

print('Waiting for 1 second...')
# Unsubscribe operation is asynchronous, messages may still come for a short while.
time.sleep(1)

subscriber.DataSetMessage -= dataSetMessage

print('Finished.')
' This example shows how to subscribe to dataset messages with RawData field encoding, specifying the metadata necessary
' for their decoding directly in the code.
'
' 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 .

Imports OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.PubSub
Imports OpcLabs.EasyOpc.UA.PubSub.Configuration
Imports OpcLabs.EasyOpc.UA.PubSub.OperationModel

Namespace PubSub._EasyUASubscriber
    Partial Friend Class SubscribeDataSet
        Public Shared Sub Metadata()

            ' Define the PubSub connection we will work with. Uses implicit conversion from a string.
            Dim pubSubConnectionDescriptor As UAPubSubConnectionDescriptor = "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 16-bits) is 30, and the writer group Id is 101.
            ' The dataset writer Id (1) must not be specified in the filter, because it does not appear in the message.
            Dim filter = New UASubscribeDataSetFilter(UAPublisherId.CreateUInt16(30))
            filter.WriterGroupDescriptor.WriterGroupId = 101

            ' Define the metadata, with the use of collection initializer for its fields.
            Dim metaData = New UADataSetMetaData From {
                New UAFieldMetaData("BoolToggle", UABuiltInType.Boolean),
                New UAFieldMetaData("Int32", UABuiltInType.Int32),
                New UAFieldMetaData("Int32Fast", UABuiltInType.Int32),
                New UAFieldMetaData("DateTime", UABuiltInType.DateTime)
            }

            ' Define the dataset subscription, with specific communication parameters.
            ' The dataset offset is needed with messages that do not contain dataset writer Ids and use RawData field
            ' encoding. An exception to this rule is when the dataset is the only or first in the dataset message payload,
            ' which is also the case here, but we are specifying the dataset offset anyway, for illustration.
            Dim dataSetSubscriptionDescriptor = New UADataSetSubscriptionDescriptor(
                pubSubConnectionDescriptor, filter, metaData)
            dataSetSubscriptionDescriptor.CommunicationParameters.UadpDataSetReaderMessageParameters.DataSetOffset = 15

            ' Instantiate the subscriber object and hook events.
            Dim subscriber = New EasyUASubscriber()
            AddHandler subscriber.DataSetMessage, AddressOf subscriber_DataSetMessage_Metadata

            Console.WriteLine("Subscribing...")
            subscriber.SubscribeDataSet(dataSetSubscriptionDescriptor)

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

            Console.WriteLine("Unsubscribing...")
            subscriber.UnsubscribeAllDataSets()

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

            Console.WriteLine("Finished...")
        End Sub

        Private Shared Sub subscriber_DataSetMessage_Metadata(ByVal sender As Object, ByVal e As EasyUADataSetMessageEventArgs)
            ' Display the dataset.
            If e.Succeeded Then
                ' An event with null DataSetData just indicates a successful connection.
                If e.DataSetData IsNot Nothing Then
                    Console.WriteLine()
                    Console.WriteLine($"Dataset data: {e.DataSetData}")
                    For Each pair As KeyValuePair(Of String, UADataSetFieldData) In e.DataSetData.FieldDataDictionary
                        Console.WriteLine(pair)
                    Next
                End If
            Else
                Console.WriteLine()
                Console.WriteLine($"*** Failure: {e.ErrorMessageBrief}")
            End If
        End Sub
    End Class

    ' Example output
    '
    'Subscribing...
    'Processing dataset message events for 20 seconds...
    '
    'Dataset data: Good; Data; publisher=(UInt16)30, group=101, fields: 4
    '[BoolToggle, False {System.Boolean}; Good]
    '[Int32, 3072 {System.Int32}; Good]
    '[Int32Fast, 894 {System.Int32}; Good]
    '[DateTime, 10/1/2019 12:21:14 PM {System.DateTime}; Good]
    '
    'Dataset data: Good; Data; publisher=(UInt16)30, group=101, fields: 4
    '[BoolToggle, False {System.Boolean}; Good]
    '[Int32, 3072 {System.Int32}; Good]
    '[Int32Fast, 920 {System.Int32}; Good]
    '[DateTime, 10/1/2019 12:21:14 PM {System.DateTime}; Good]
    '
    'Dataset data: Good; Data; publisher=(UInt16)30, group=101, fields: 4
    '[BoolToggle, False {System.Boolean}; Good]
    '[Int32, 3073 {System.Int32}; Good]
    '[Int32Fast, 1003 {System.Int32}; Good]
    '[DateTime, 10/1/2019 12:21:15 PM {System.DateTime}; Good]
    '
    'Dataset data: Good; Data; publisher=(UInt16)30, group=101, fields: 4
    '[BoolToggle, False {System.Boolean}; Good]
    '[Int32, 3073 {System.Int32}; Good]
    '[Int32Fast, 1074 {System.Int32}; Good]
    '[DateTime, 10/1/2019 12:21:15 PM {System.DateTime}; Good]
    '
    'Dataset data: Good; Data; publisher=(UInt16)30, group=101, fields: 4
    '[BoolToggle, True {System.Boolean}; Good]
    '[Int32, 3074 {System.Int32}; Good]
    '[Int32Fast, 1140 {System.Int32}; Good]
    '[DateTime, 10/1/2019 12:21:16 PM {System.DateTime}; Good]
    '
    '...

End Namespace
// This example shows how to subscribe to dataset messages with RawData field encoding, specifying the metadata necessary
// for their decoding directly in the code.
//
// 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 .

type
  TSubscriberEventHandlers78 = class
    procedure OnDataSetMessage(
      ASender: TObject;
      sender: OleVariant;
      const eventArgs: _EasyUADataSetMessageEventArgs);
  end;

class procedure SubscribeDataSet.Metadata;
var
  ConnectionDescriptor: _UAPubSubConnectionDescriptor;
  Field1, Field2, Field3, Field4: _UAFieldMetaData;
  MetaData: _UADataSetMetaData;
  SubscribeDataSetArguments: _EasyUASubscribeDataSetArguments;
  Subscriber: TEasyUASubscriber;
  SubscriberEventHandlers: TSubscriberEventHandlers78;
begin
  // Define the PubSub connection we will work with.
  SubscribeDataSetArguments := CoEasyUASubscribeDataSetArguments.Create;
  ConnectionDescriptor := SubscribeDataSetArguments.DataSetSubscriptionDescriptor.ConnectionDescriptor;
  ConnectionDescriptor.ResourceAddress.ResourceDescriptor.UrlString := '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.
  //ConnectionDescriptor.ResourceAddress.InterfaceName := 'Ethernet';

  // Define the filter. Publisher Id (unsigned 16-bits) is 30, and the writer group Id is 101.
  // The dataset writer Id (1) must not be specified in the filter, because it does not appear in the message.
  SubscribeDataSetArguments.DataSetSubscriptionDescriptor.Filter.PublisherId.SetUint16Identifier(30);
  SubscribeDataSetArguments.DataSetSubscriptionDescriptor.Filter.WriterGroupDescriptor.WriterGroupId := 101;

  // Define the metadata. For UADP, the order of field metadata must correspond to the order of fields in the dataset message.
  MetaData := CoUADataSetMetaData.Create;
  //
  Field1 := CoUAFieldMetaData.Create;
  Field1.BuiltInType := UABuiltInType_Boolean;
  Field1.Name := 'BoolToggle';
  MetaData.Add(Field1);
  //
  Field2 := CoUAFieldMetaData.Create;
  Field2.BuiltInType := UABuiltInType_Int32;
  Field2.Name := 'Int32';
  MetaData.Add(Field2);
  //
  Field3 := CoUAFieldMetaData.Create;
  Field3.BuiltInType := UABuiltInType_Int32;
  Field3.Name := 'Int32Fast';
  MetaData.Add(Field3);
  //
  Field4 := CoUAFieldMetaData.Create;
  Field4.BuiltInType := UABuiltInType_DateTime;
  Field4.Name := 'DateTime';
  MetaData.Add(Field4);
  //
  SubscribeDataSetArguments.DataSetSubscriptionDescriptor.DataSetMetaData := MetaData;

  // Define the specific communication parameters for the dataset subscription.
  // The dataset offset is needed with messages that do not contain dataset writer Ids and use RawData field
  // encoding. An exception to this rule is when the dataset is the only or first in the dataset message payload,
  // which is also the case here, but we are specifying the dataset offset anyway, for illustration.
  SubscribeDataSetArguments.DataSetSubscriptionDescriptor.CommunicationParameters.UadpDataSetReaderMessageParameters.DataSetOffset := 15;

  // Instantiate the subscriber object and hook events.
  Subscriber := TEasyUASubscriber.Create(nil);
  SubscriberEventHandlers := TSubscriberEventHandlers78.Create;
  Subscriber.OnDataSetMessage := SubscriberEventHandlers.OnDataSetMessage;

  WriteLn('Subscribing...');
  Subscriber.SubscribeDataSet(SubscribeDataSetArguments);

  WriteLn('Processing dataset message for 20 seconds...');
  PumpSleep(20*1000);

  WriteLn('Unsubscribing...');
  Subscriber.UnsubscribeAllDataSets;

  WriteLn('Waiting for 1 second...');
  // Unsubscribe operation is asynchronous, messages may still come for a short while.
  PumpSleep(1*1000);

  WriteLn('Finished.');
  FreeAndNil(Subscriber);
  FreeAndNil(SubscriberEventHandlers);
end;

procedure TSubscriberEventHandlers78.OnDataSetMessage(
  ASender: TObject;
  sender: OleVariant;
  const eventArgs: _EasyUADataSetMessageEventArgs);
var
  Count: Cardinal;
  DictionaryEntry2: _DictionaryEntry2;
  Element: OleVariant;
  FieldDataDictionaryEnumerator: IEnumVariant;
begin
  // Display the dataset.
  if eventArgs.Succeeded then
  begin
    // An event with null DataSetData just indicates a successful connection.
    if eventArgs.DataSetData <> nil then
    begin
      WriteLn;
      WriteLn('Dataset data: ', eventArgs.DataSetData.ToString);
      FieldDataDictionaryEnumerator := eventArgs.DataSetData.FieldDataDictionary.GetEnumerator;
      while (FieldDataDictionaryEnumerator.Next(1, Element, Count) = S_OK) do
      begin
        DictionaryEntry2 := IUnknown(Element) as _DictionaryEntry2;
        WriteLn(DictionaryEntry2.ToString);
      end;
    end;
  end
  else begin
    WriteLn;
      WriteLn('*** Failure: ', eventArgs.ErrorMessageBrief);
  end;
end;

// Example output:
//
//Subscribing...
//Processing dataset message events for 20 seconds...
//
//Dataset data: Good; Data; publisher=(UInt16)30, group=101, fields: 4
//[BoolToggle, False {System.Boolean}; Good]
//[Int32, 3072 {System.Int32}; Good]
//[Int32Fast, 894 {System.Int32}; Good]
//[DateTime, 10/1/2019 12:21:14 PM {System.DateTime}; Good]
//
//Dataset data: Good; Data; publisher=(UInt16)30, group=101, fields: 4
//[BoolToggle, False {System.Boolean}; Good]
//[Int32, 3072 {System.Int32}; Good]
//[Int32Fast, 920 {System.Int32}; Good]
//[DateTime, 10/1/2019 12:21:14 PM {System.DateTime}; Good]
//
//Dataset data: Good; Data; publisher=(UInt16)30, group=101, fields: 4
//[BoolToggle, False {System.Boolean}; Good]
//[Int32, 3073 {System.Int32}; Good]
//[Int32Fast, 1003 {System.Int32}; Good]
//[DateTime, 10/1/2019 12:21:15 PM {System.DateTime}; Good]
//
//Dataset data: Good; Data; publisher=(UInt16)30, group=101, fields: 4
//[BoolToggle, False {System.Boolean}; Good]
//[Int32, 3073 {System.Int32}; Good]
//[Int32Fast, 1074 {System.Int32}; Good]
//[DateTime, 10/1/2019 12:21:15 PM {System.DateTime}; Good]
//
//Dataset data: Good; Data; publisher=(UInt16)30, group=101, fields: 4
//[BoolToggle, True {System.Boolean}; Good]
//[Int32, 3074 {System.Int32}; Good]
//[Int32Fast, 1140 {System.Int32}; Good]
//[DateTime, 10/1/2019 12:21:16 PM {System.DateTime}; Good]
//
//...
Rem This example shows how to subscribe to dataset messages with RawData field encoding, specifying the metadata necessary
Rem for their decoding directly in the code.
Rem
Rem In order to produce network messages for this example, run the UADemoPublisher tool. For documentation, see
Rem https://kb.opclabs.com/UADemoPublisher_Basics . In some cases, you may have to specify the interface name to be used.
Rem
Rem Find all latest examples here : https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

Option Explicit

Const UABuiltInType_Boolean = 1
Const UABuiltInType_Int32 = 6
Const UABuiltInType_DateTime = 13

' Define the PubSub connection we will work with.
Dim SubscribeDataSetArguments: Set SubscribeDataSetArguments = CreateObject("OpcLabs.EasyOpc.UA.PubSub.OperationModel.EasyUASubscribeDataSetArguments")
Dim ConnectionDescriptor: Set ConnectionDescriptor = SubscribeDataSetArguments.DataSetSubscriptionDescriptor.ConnectionDescriptor
ConnectionDescriptor.ResourceAddress.ResourceDescriptor.UrlString = "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.
' ConnectionDescriptor.ResourceAddress.InterfaceName = "Ethernet"

' Define the filter. Publisher Id (unsigned 16-bits) is 30, and the writer group Id is 101.
' The dataset writer Id (1) must not be specified in the filter, because it does not appear in the message.
SubscribeDataSetArguments.DataSetSubscriptionDescriptor.Filter.PublisherId.SetUInt16Identifier 30
SubscribeDataSetArguments.DataSetSubscriptionDescriptor.Filter.WriterGroupDescriptor.WriterGroupId = 101

' Define the metadata. For UADP, the order of field metadata must correspond to the order of fields in the dataset message.
Dim MetaData: Set MetaData = CreateObject("OpcLabs.EasyOpc.UA.PubSub.Configuration.UADataSetMetaData")
'
Dim Field1: Set Field1 = CreateObject("OpcLabs.EasyOpc.UA.PubSub.Configuration.UAFieldMetaData")
Field1.BuiltInType = UABuiltInType_Boolean
Field1.Name = "BoolToggle"
MetaData.Add(Field1)
'
Dim Field2: Set Field2 = CreateObject("OpcLabs.EasyOpc.UA.PubSub.Configuration.UAFieldMetaData")
Field2.BuiltInType = UABuiltInType_Int32
Field2.Name = "Int32"
MetaData.Add(Field2)
'
Dim Field3: Set Field3 = CreateObject("OpcLabs.EasyOpc.UA.PubSub.Configuration.UAFieldMetaData")
Field3.BuiltInType = UABuiltInType_Int32
Field3.Name = "Int32Fast"
MetaData.Add(Field3)
'
Dim Field4: Set Field4 = CreateObject("OpcLabs.EasyOpc.UA.PubSub.Configuration.UAFieldMetaData")
Field4.BuiltInType = UABuiltInType_DateTime
Field4.Name = "DateTime"
MetaData.Add(Field4)
'
Set SubscribeDataSetArguments.DataSetSubscriptionDescriptor.DataSetMetaData = MetaData

' Define the specific communication parameters for the dataset subscription.
' The dataset offset is needed with messages that do not contain dataset writer Ids and use RawData field
' encoding. An exception to this rule is when the dataset is the only or first in the dataset message payload,
' which is also the case here, but we are specifying the dataset offset anyway, for illustration.
SubscribeDataSetArguments.DataSetSubscriptionDescriptor.CommunicationParameters.UadpDataSetReaderMessageParameters.DataSetOffset = 15

' Instantiate the subscriber object and hook events.
Dim Subscriber: Set Subscriber = CreateObject("OpcLabs.EasyOpc.UA.PubSub.EasyUASubscriber")
WScript.ConnectObject Subscriber, "Subscriber_"

WScript.Echo "Subscribing..."
Subscriber.SubscribeDataSet SubscribeDataSetArguments

WScript.Echo "Processing dataset message events for 20 seconds..."
WScript.Sleep 20*1000

WScript.Echo "Unsubscribing..."
Subscriber.UnsubscribeAllDataSets

WScript.Echo "Waiting for 1 second..."
' Unsubscribe operation is asynchronous, messages may still come for a short while.
WScript.Sleep 1*1000

WScript.Echo "Finished."



Sub Subscriber_DataSetMessage(Sender, e)
    ' Display the dataset.
    If e.Succeeded Then
        ' An event with null DataSetData just indicates a successful connection.
        If Not (e.DataSetData Is Nothing) Then
            WScript.Echo
            WScript.Echo "Dataset data: " & e.DataSetData
            Dim Pair: For Each Pair in e.DataSetData.FieldDataDictionary
                WScript.Echo Pair
            Next
        End If
    Else
        WScript.Echo
        WScript.Echo "*** Failure: " & e.ErrorMessageBrief
    End If
End Sub



' Example output:
'
'Subscribing...
'Processing dataset message events for 20 seconds...
'
'Dataset data: Good; Data; publisher=(UInt16)30, group=101, fields: 4
'[BoolToggle, False {System.Boolean}; Good]
'[Int32, 3072 {System.Int32}; Good]
'[Int32Fast, 894 {System.Int32}; Good]
'[DateTime, 10/1/2019 12:21:14 PM {System.DateTime}; Good]
'
'Dataset data: Good; Data; publisher=(UInt16)30, group=101, fields: 4
'[BoolToggle, False {System.Boolean}; Good]
'[Int32, 3072 {System.Int32}; Good]
'[Int32Fast, 920 {System.Int32}; Good]
'[DateTime, 10/1/2019 12:21:14 PM {System.DateTime}; Good]
'
'Dataset data: Good; Data; publisher=(UInt16)30, group=101, fields: 4
'[BoolToggle, False {System.Boolean}; Good]
'[Int32, 3073 {System.Int32}; Good]
'[Int32Fast, 1003 {System.Int32}; Good]
'[DateTime, 10/1/2019 12:21:15 PM {System.DateTime}; Good]
'
'Dataset data: Good; Data; publisher=(UInt16)30, group=101, fields: 4
'[BoolToggle, False {System.Boolean}; Good]
'[Int32, 3073 {System.Int32}; Good]
'[Int32Fast, 1074 {System.Int32}; Good]
'[DateTime, 10/1/2019 12:21:15 PM {System.DateTime}; Good]
'
'Dataset data: Good; Data; publisher=(UInt16)30, group=101, fields: 4
'[BoolToggle, True {System.Boolean}; Good]
'[Int32, 3074 {System.Int32}; Good]
'[Int32Fast, 1140 {System.Int32}; Good]
'[DateTime, 10/1/2019 12:21:16 PM {System.DateTime}; Good]
'
'...
REM This example shows how to subscribe to dataset messages with RawData field encoding, specifying the metadata necessary
REM for their decoding directly in the code.
REM
REM In order to produce network messages for this example, run the UADemoPublisher tool. For documentation, see
REM https://kb.opclabs.com/UADemoPublisher_Basics . In some cases, you may have to specify the interface name to be used.
REM
REM Find all latest examples here : https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

' The subscriber object, with events
'Public WithEvents Subscriber3 As EasyUASubscriber

Private Sub EasyUASubscriber_SubscribeDataSet_Metadata_Command_Click()
    OutputText = ""

    ' Define the PubSub connection we will work with.
    Dim subscribeDataSetArguments As New EasyUASubscribeDataSetArguments
    Dim ConnectionDescriptor As UAPubSubConnectionDescriptor
    Set ConnectionDescriptor = subscribeDataSetArguments.dataSetSubscriptionDescriptor.ConnectionDescriptor
    ConnectionDescriptor.ResourceAddress.ResourceDescriptor.UrlString = "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.
    'ConnectionDescriptor.ResourceAddress.InterfaceName := 'Ethernet';

    ' Define the filter. Publisher Id (unsigned 16-bits) is 30, and the writer group Id is 101.
    ' The dataset writer Id (1) must not be specified in the filter, because it does not appear in the message.
    Call subscribeDataSetArguments.dataSetSubscriptionDescriptor.Filter.PublisherId.SetUInt16Identifier(30)
    subscribeDataSetArguments.dataSetSubscriptionDescriptor.Filter.WriterGroupDescriptor.WriterGroupId = 101

    ' Define the metadata. For UADP, the order of field metadata must correspond to the order of fields in the dataset message.
    Dim metaData As New UADataSetMetaData
    '
    Dim field1 As New UAFieldMetaData
    field1.BuiltInType = UABuiltInType_Boolean
    field1.Name = "BoolToggle"
    metaData.Add field1
    '
    Dim field2 As New UAFieldMetaData
    field2.BuiltInType = UABuiltInType_Int32
    field2.Name = "Int32"
    metaData.Add field2
    '
    Dim field3 As New UAFieldMetaData
    field3.BuiltInType = UABuiltInType_Int32
    field3.Name = "Int32Fast"
    metaData.Add field3
    '
    Dim field4 As New UAFieldMetaData
    field4.BuiltInType = UABuiltInType_DateTime
    field4.Name = "DateTime"
    metaData.Add field4
    '
    Set subscribeDataSetArguments.dataSetSubscriptionDescriptor.DataSetMetaData = metaData
    
    ' Define the specific communication parameters for the dataset subscription.
    ' The dataset offset is needed with messages that do not contain dataset writer Ids and use RawData field
    ' encoding. An exception to this rule is when the dataset is the only or first in the dataset message payload,
    ' which is also the case here, but we are specifying the dataset offset anyway, for illustration.
    subscribeDataSetArguments.dataSetSubscriptionDescriptor.CommunicationParameters.UadpDataSetReaderMessageParameters.DataSetOffset = 15
    
    ' Instantiate the subscriber object and hook events.
    Set Subscriber3 = New EasyUASubscriber
    
    OutputText = OutputText & "Subscribing..." & vbCrLf
    Call Subscriber3.SubscribeDataSet(subscribeDataSetArguments)

    OutputText = OutputText & "Processing dataset message for 20 seconds..." & vbCrLf
    Pause 20000

    OutputText = OutputText & "Unsubscribing..." & vbCrLf
    Subscriber3.UnsubscribeAllDataSets

    OutputText = OutputText & "Waiting for 1 second..." & vbCrLf
    ' Unsubscribe operation is asynchronous, messages may still come for a short while.
    Pause 1000

    Set Subscriber3 = Nothing

    OutputText = OutputText & "Finished." & vbCrLf
End Sub

Private Sub Subscriber3_DataSetMessage(ByVal sender As Variant, ByVal eventArgs As EasyUADataSetMessageEventArgs)
    ' Display the dataset
    If eventArgs.Succeeded Then
        ' An event with null DataSetData just indicates a successful connection.
        If Not eventArgs.DataSetData Is Nothing Then
            OutputText = OutputText & vbCrLf
            OutputText = OutputText & "Dataset data: " & eventArgs.DataSetData & vbCrLf
            Dim dictionaryEntry2 : For Each dictionaryEntry2 In eventArgs.DataSetData.FieldDataDictionary
                OutputText = OutputText & dictionaryEntry2 & vbCrLf
            Next
        End If
    Else
        OutputText = OutputText & vbCrLf
        OutputText = OutputText & "*** Failure: " & eventArgs.ErrorMessageBrief & vbCrLf
    End If
End Sub
' Example output:
'
'Subscribing...
'Processing dataset message events for 20 seconds...
'
'Dataset data: Good; Data; publisher=(UInt16)30, group=101, fields: 4
'[BoolToggle, False {System.Boolean}; Good]
'[Int32, 3072 {System.Int32}; Good]
'[Int32Fast, 894 {System.Int32}; Good]
'[DateTime, 10/1/2019 12:21:14 PM {System.DateTime}; Good]
'
'Dataset data: Good; Data; publisher=(UInt16)30, group=101, fields: 4
'[BoolToggle, False {System.Boolean}; Good]
'[Int32, 3072 {System.Int32}; Good]
'[Int32Fast, 920 {System.Int32}; Good]
'[DateTime, 10/1/2019 12:21:14 PM {System.DateTime}; Good]
'
'Dataset data: Good; Data; publisher=(UInt16)30, group=101, fields: 4
'[BoolToggle, False {System.Boolean}; Good]
'[Int32, 3073 {System.Int32}; Good]
'[Int32Fast, 1003 {System.Int32}; Good]
'[DateTime, 10/1/2019 12:21:15 PM {System.DateTime}; Good]
'
'Dataset data: Good; Data; publisher=(UInt16)30, group=101, fields: 4
'[BoolToggle, False {System.Boolean}; Good]
'[Int32, 3073 {System.Int32}; Good]
'[Int32Fast, 1074 {System.Int32}; Good]
'[DateTime, 10/1/2019 12:21:15 PM {System.DateTime}; Good]
'
'Dataset data: Good; Data; publisher=(UInt16)30, group=101, fields: 4
'[BoolToggle, True {System.Boolean}; Good]
'[Int32, 3074 {System.Int32}; Good]
'[Int32Fast, 1140 {System.Int32}; Good]
'[DateTime, 10/1/2019 12:21:16 PM {System.DateTime}; Good]
'
'...
Inheritance Hierarchy

System.Object
   OpcLabs.BaseLib.Object2
      OpcLabs.BaseLib.Info
         OpcLabs.EasyOpc.UA.PubSub.UADataSetSubscriptionDescriptor

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