OPC Studio User's Guide and Reference
Implicit Type Conversion(UAPubSubConnectionDescriptor,String) Operator
Example 



OpcLabs.EasyOpcUA Assembly > OpcLabs.EasyOpc.UA.PubSub Namespace > UAPubSubConnectionDescriptor Class > Implicit Type Conversion Operator : Implicit Type Conversion(UAPubSubConnectionDescriptor,String) Operator
Descriptor string for the PubSub connection resource.

The value of this parameter can be null (Nothing in Visual Basic).

Converts a descriptor string to a PubSub connection descriptor.
Syntax
'Declaration
 
<NotNullAttribute()>
Overloads Public Operator Widening CType( _
   ByVal descriptorString As String _
) As UAPubSubConnectionDescriptor
'Usage
 
[NotNull()]
public UAPubSubConnectionDescriptor operator implicit( 
   string descriptorString
)
[NotNull()]
public:
operator UAPubSubConnectionDescriptor^ ( 
   String^ descriptorString
)

Parameters

descriptorString
Descriptor string for the PubSub connection resource.

The value of this parameter can be null (Nothing in Visual Basic).

Return Value

This method never returns null (Nothing in Visual Basic).

Remarks

In most common cases, the descriptor string is simply a resource URL string.

This operator is equivalent to FromString.

Example
// 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 C# on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-CSharp .
// Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
// a commercial license in order to use Online Forums, and we reply to every post.

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

namespace UASubscriberDocExamples.PubSub._EasyUASubscriber
{
    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 .
# OPC client and subscriber examples in PowerShell on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-PowerShell .
# Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
# a commercial license in order to use Online Forums, and we reply to every post.

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

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

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

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

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

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

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

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

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

Write-Host "Finished."


# Example output (truncated):
#
#Subscribing...
#Processing dataset message events for 20 seconds...
#
#Dataset data: Good; Data; publisher="32", writer=1, class=eae79794-1af7-4f96-8401-4096cd1d8908, fields: 4
#[#0, True {System.Boolean} @0001-01-01T00:00:00.000 @@0001-01-01T00:00:00.000; Good]
#[#1, 7945 {System.Int32} @0001-01-01T00:00:00.000 @@0001-01-01T00:00:00.000; Good]
#[#2, 5246 {System.Int32} @0001-01-01T00:00:00.000 @@0001-01-01T00:00:00.000; Good]
#[#3, 9/30/2019 11:19:14 AM {System.DateTime} @0001-01-01T00:00:00.000 @@0001-01-01T00:00:00.000; Good]
#
#Dataset data: Good; Data; publisher="32", writer=3, class=96976b7b-0db7-46c3-a715-0979884b55ae, fields: 100
#[#0, 45 {System.Int64} @0001-01-01T00:00:00.000 @@0001-01-01T00:00:00.000; Good]
#[#1, 145 {System.Int64} @0001-01-01T00:00:00.000 @@0001-01-01T00:00:00.000; Good]
#[#2, 245 {System.Int64} @0001-01-01T00:00:00.000 @@0001-01-01T00:00:00.000; Good]
#[#3, 345 {System.Int64} @0001-01-01T00:00:00.000 @@0001-01-01T00:00:00.000; Good]
#[#4, 445 {System.Int64} @0001-01-01T00:00:00.000 @@0001-01-01T00:00:00.000; Good]
#[#5, 545 {System.Int64} @0001-01-01T00:00:00.000 @@0001-01-01T00:00:00.000; Good]
#[#6, 645 {System.Int64} @0001-01-01T00:00:00.000 @@0001-01-01T00:00:00.000; Good]
#[#7, 745 {System.Int64} @0001-01-01T00:00:00.000 @@0001-01-01T00:00:00.000; Good]
#[#8, 845 {System.Int64} @0001-01-01T00:00:00.000 @@0001-01-01T00:00:00.000; Good]
#[#9, 945 {System.Int64} @0001-01-01T00:00:00.000 @@0001-01-01T00:00:00.000; Good]
#[#10, 1045 {System.Int64} @0001-01-01T00:00:00.000 @@0001-01-01T00:00:00.000; Good]
#...
' 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 VB.NET on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-VBNET .
' Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
' a commercial license in order to use Online Forums, and we reply to every post.

Imports OpcLabs.EasyOpc.UA.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
# 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 .
# Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
# a commercial license in order to use Online Forums, and we reply to every post.
# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc
import time

# Import .NET namespaces.
from OpcLabs.EasyOpc.UA.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]
#...
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