OPC Studio User's Guide and Reference
QueueName Property (_UABrokerDataSetReaderTransportParameters)
Example 



OpcLabs.EasyOpcUA Assembly > OpcLabs.EasyOpc.UA.PubSub.Configuration.ComTypes Namespace > _UABrokerDataSetReaderTransportParameters Interface : QueueName Property
Specifies the queue in the broker where the dataset reader can receive network messages with the dataset of interest sent by the publisher.
Syntax
'Declaration
 
<NotNullAttribute()>
Property QueueName As String
'Usage
 
Dim instance As _UABrokerDataSetReaderTransportParameters
Dim value As String
 
instance.QueueName = value
 
value = instance.QueueName
[NotNull()]
string QueueName {get; set;}
[NotNull()]
property String^ QueueName {
   String^ get();
   void set (    String^ value);
}
Remarks

This could be the name of a queue or topic defined in the broker. This parameter is only valid if the network messages from the writer group contain only one dataset message.

With topic tree, if the metadata queue name is not specified, the name of the metadata queue will be constructed according to the topic tree rules.

When all queue names (such as QueueName and MetaDataQueueName) are unspecified (empty strings, which are the default), and the EffectiveTransportProfileUriString in the ConnectionDescriptor is for transport that uses the topic tree (such as MQTT), the EffectiveAssumeTopicTree becomes true, and you do not have to set AssumeTopicTree to true explicitly in order for the topic tree to be assumed.

CAUTION: With the topic tree (AssumeTopicTree set to true), do not set the queue names by setting values of QueueName or MetaDataQueueName, except in very special circumstances. Leave the queue names at their default values, i.e. empty strings. Setting queue names can interfere negatively with the built-in mechanism that determines the proper topic filters.

Example

.NET

COM

.NET

// This example shows how to subscribe to all dataset messages on an OPC-UA PubSub connection with MQTT JSON mapping using
// TCP.
//
// The following package needs to be referenced in your project (or otherwise made available) for the MQTT transport to 
// work.
// - OpcLabs.MqttNet
// Refer to the documentation for more information.
//
// 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.Engine;
using OpcLabs.EasyOpc.UA.PubSub.OperationModel;

namespace UADocExamples.PubSub._EasyUASubscriber
{
    partial class SubscribeDataSet
    {
        public static void MqttJsonTcp()
        {
            // Define the PubSub connection we will work with. Uses implicit conversion from a string.
            // Default port with MQTT is 1883.
            UAPubSubConnectionDescriptor pubSubConnectionDescriptor = "mqtt://opcua-pubsub.demo-this.com";
            // Specify the transport protocol mapping.
            // The statement below isn't actually necessary, due to automatic message mapping recognition feature; see
            // https://kb.opclabs.com/OPC_UA_PubSub_Automatic_Message_Mapping_Recognition for more details.
            pubSubConnectionDescriptor.TransportProfileUriString = UAPubSubTransportProfileUriStrings.MqttJson;

            // Define the arguments for subscribing to the dataset, specifying the MQTT topic name.
            var subscribeDataSetArguments = new UASubscribeDataSetArguments(pubSubConnectionDescriptor)
            {
                DataSetSubscriptionDescriptor = {CommunicationParameters = {BrokerDataSetReaderTransportParameters =
                {
                    QueueName = "opcuademo/json"
                }}}
            };

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

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

            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_MqttJsonTcp(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.ErrorMessage}");
            }
        }

        // Example output:
        //
        //Subscribing...
        //Processing dataset message events for 20 seconds...
        //
        //Dataset data: 2020-01-21T17:07:19.778,836,700,00; Good; Data; publisher=[String]31, class=eae79794-1af7-4f96-8401-4096cd1d8908, fields: 4
        //[BoolToggle, True {System.Boolean} @2020-01-21T16:07:19.778,836,700,00; Good]
        //[Int32, 482 {System.Int64} @2020-01-21T16:07:19.778,836,700,00; Good]
        //[Int32Fast, 2287 {System.Int64} @2020-01-21T16:07:19.778,836,700,00; Good]
        //[DateTime, 1/21/2020 5:07:19 PM {System.DateTime} @2020-01-21T16:07:19.778,836,700,00; Good]
        //
        //Dataset data: Good; Data; publisher=[String]32, fields: 4
        //[BoolToggle, True {System.Boolean}; Good]
        //[Int32, 482 {System.Int32}; Good]
        //[Int32Fast, 2287 {System.Int32}; Good]
        //[DateTime, 1/21/2020 5:07:19 PM {System.DateTime}; Good]
        //
        //Dataset data: Good; Data; publisher=[String]32, fields: 100
        //[Mass_0, 82 {System.Int64}; Good]
        //[Mass_1, 182 {System.Int64}; Good]
        //[Mass_2, 282 {System.Int64}; Good]
        //[Mass_3, 382 {System.Int64}; Good]
        //[Mass_4, 482 {System.Int64}; Good]
        //[Mass_5, 582 {System.Int64}; Good]
        //[Mass_6, 682 {System.Int64}; Good]
        //[Mass_7, 782 {System.Int64}; Good]
        //[Mass_8, 882 {System.Int64}; Good]
        //[Mass_9, 982 {System.Int64}; Good]
        //[Mass_10, 1082 {System.Int64}; Good]
        ////...
    }
}
# This example shows how to subscribe to all dataset messages on an OPC-UA PubSub connection with MQTT JSON mapping using
# TCP.
#
# The following package needs to be referenced in your project (or otherwise made available) for the MQTT transport to
# work.
# - OpcLabs.MqttNet
# Refer to the documentation for more information.
#
# 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 opclabs_mqttnet
import time

# Import .NET namespaces.
from OpcLabs.EasyOpc.UA.PubSub import *
from OpcLabs.EasyOpc.UA.PubSub.Engine 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='')
        print('*** Failure: ', e.Exception, sep='')


# Define the PubSub connection we will work with. Uses implicit conversion from a string.
# Default port with MQTT is 1883.
pubSubConnectionDescriptor = UAPubSubConnectionDescriptor.op_Implicit('mqtt://opcua-pubsub.demo-this.com')
# Specify the transport protocol mapping.
# The statement below isn't actually necessary, due to automatic message mapping recognition feature; see
# https://kb.opclabs.com/OPC_UA_PubSub_Automatic_Message_Mapping_Recognition for more details.
pubSubConnectionDescriptor.TransportProfileUriString = UAPubSubTransportProfileUriStrings.MqttJson

# Define the arguments for subscribing to the dataset, specifying the MQTT topic name.
subscribeDataSetArguments = UASubscribeDataSetArguments(pubSubConnectionDescriptor)
subscribeDataSetArguments.DataSetSubscriptionDescriptor.CommunicationParameters.BrokerDataSetReaderTransportParameters.\
    QueueName = 'opcuademo/json'

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

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

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 all dataset messages on an OPC-UA PubSub connection with MQTT JSON mapping using
' TCP.
'
' The following package needs to be referenced in your project (or otherwise made available) for the MQTT transport to 
' work.
' - OpcLabs.MqttNet
' Refer to the documentation for more information.
'
' 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.Engine
Imports OpcLabs.EasyOpc.UA.PubSub.OperationModel

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

            ' Define the PubSub connection we will work with. Uses implicit conversion from a string.
            ' Default port with MQTT is 1883.
            Dim pubSubConnectionDescriptor As UAPubSubConnectionDescriptor = "mqtt://opcua-pubsub.demo-this.com"

            ' Specify the transport protocol mapping.
            ' The statement below isn't actually necessary, due to automatic message mapping recognition feature; see
            ' https://kb.opclabs.com/OPC_UA_PubSub_Automatic_Message_Mapping_Recognition for more details.
            pubSubConnectionDescriptor.TransportProfileUriString = UAPubSubTransportProfileUriStrings.MqttJson

            ' Define the arguments for subscribing to the dataset, specifying the MQTT topic name.
            Dim subscribeDataSetArguments = New UASubscribeDataSetArguments(pubSubConnectionDescriptor)
            subscribeDataSetArguments.DataSetSubscriptionDescriptor.CommunicationParameters.BrokerDataSetReaderTransportParameters.QueueName = "opcuademo/json"

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

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

            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_MqttJsonTcp(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.ErrorMessage}")
            End If
        End Sub

        ' Example output:
        '
        'Subscribing...
        'Processing dataset message events for 20 seconds...
        '
        'Dataset data: 2020-01-21T17:07:19.778,836,700,00; Good; Data; publisher=[String]31, class=eae79794-1af7-4f96-8401-4096cd1d8908, fields: 4
        '[BoolToggle, True {System.Boolean} @2020-01-21T16:07:19.778,836,700,00; Good]
        '[Int32, 482 {System.Int64} @2020-01-21T16:07:19.778,836,700,00; Good]
        '[Int32Fast, 2287 {System.Int64} @2020-01-21T16:07:19.778,836,700,00; Good]
        '[DateTime, 1/21/2020 5:07:19 PM {System.DateTime} @2020-01-21T16:07:19.778,836,700,00; Good]
        '
        'Dataset data: Good; Data; publisher=[String]32, fields: 4
        '[BoolToggle, True {System.Boolean}; Good]
        '[Int32, 482 {System.Int32}; Good]
        '[Int32Fast, 2287 {System.Int32}; Good]
        '[DateTime, 1/21/2020 5:07:19 PM {System.DateTime}; Good]
        '
        'Dataset data: Good; Data; publisher=[String]32, fields: 100
        '[Mass_0, 82 {System.Int64}; Good]
        '[Mass_1, 182 {System.Int64}; Good]
        '[Mass_2, 282 {System.Int64}; Good]
        '[Mass_3, 382 {System.Int64}; Good]
        '[Mass_4, 482 {System.Int64}; Good]
        '[Mass_5, 582 {System.Int64}; Good]
        '[Mass_6, 682 {System.Int64}; Good]
        '[Mass_7, 782 {System.Int64}; Good]
        '[Mass_8, 882 {System.Int64}; Good]
        '[Mass_9, 982 {System.Int64}; Good]
        '[Mass_10, 1082 {System.Int64}; Good]
        '...
    End Class
End Namespace
REM The following package needs to be referenced in your project (or otherwise made available) for the MQTT transport to 
REM work.
REM - OpcLabs.MqttNet
REM Refer to the documentation for more information.
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 Subscriber4 As EasyUASubscriber

Private Sub EasyUASubscriber_SubscribeDataSet_MqttJsonTcp_Command_Click()
    OutputText = ""

    ' Define the PubSub connection we will work with. Uses implicit conversion from a string.
    ' Default port with MQTT is 1883.
    Dim subscribeDataSetArguments As New EasyUASubscribeDataSetArguments
    Dim pubSubConnectionDescriptor As UAPubSubConnectionDescriptor
    Set pubSubConnectionDescriptor = subscribeDataSetArguments.dataSetSubscriptionDescriptor.ConnectionDescriptor
    pubSubConnectionDescriptor.ResourceAddress.ResourceDescriptor.UrlString = "mqtt://opcua-pubsub.demo-this.com:1883"
    ' Specify the transport protocol mapping.
    ' The statement below isn't actually necessary, due to automatic message mapping recognition feature; see
    ' https://kb.opclabs.com/OPC_UA_PubSub_Automatic_Message_Mapping_Recognition for more details.
    pubSubConnectionDescriptor.TransportProfileUriString = "http://opcfoundation.org/UA-Profile/Transport/pubsub-mqtt-json" ' UAPubSubTransportProfileUriStrings.MqttJson

    ' Define the arguments for subscribing to the dataset, specifying the MQTT topic name.
    subscribeDataSetArguments.dataSetSubscriptionDescriptor.CommunicationParameters.BrokerDataSetReaderTransportParameters.QueueName = "opcuademo/json"
    
    ' Instantiate the subscriber object and hook events.
    Set Subscriber4 = New EasyUASubscriber
    
    OutputText = OutputText & "Subscribing..." & vbCrLf
    Call Subscriber4.SubscribeDataSet(subscribeDataSetArguments)

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

    OutputText = OutputText & "Unsubscribing..." & vbCrLf
    Subscriber4.UnsubscribeAllDataSets

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

    Set Subscriber1 = Nothing

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

Private Sub Subscriber4_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: 2020-01-21T17:07:19.778,836,700,00; Good; Data; publisher=[String]31, class=eae79794-1af7-4f96-8401-4096cd1d8908, fields: 4
'[BoolToggle, True {System.Boolean} @2020-01-21T16:07:19.778,836,700,00; Good]
'[Int32, 482 {System.Int64} @2020-01-21T16:07:19.778,836,700,00; Good]
'[Int32Fast, 2287 {System.Int64} @2020-01-21T16:07:19.778,836,700,00; Good]
'[DateTime, 1/21/2020 5:07:19 PM {System.DateTime} @2020-01-21T16:07:19.778,836,700,00; Good]
'
'Dataset data: Good; Data; publisher=[String]32, fields: 4
'[BoolToggle, True {System.Boolean}; Good]
'[Int32, 482 {System.Int32}; Good]
'[Int32Fast, 2287 {System.Int32}; Good]
'[DateTime, 1/21/2020 5:07:19 PM {System.DateTime}; Good]
'
'Dataset data: Good; Data; publisher=[String]32, fields: 100
'[Mass_0, 82 {System.Int64}; Good]
'[Mass_1, 182 {System.Int64}; Good]
'[Mass_2, 282 {System.Int64}; Good]
'[Mass_3, 382 {System.Int64}; Good]
'[Mass_4, 482 {System.Int64}; Good]
'[Mass_5, 582 {System.Int64}; Good]
'[Mass_6, 682 {System.Int64}; Good]
'[Mass_7, 782 {System.Int64}; Good]
'[Mass_8, 882 {System.Int64}; Good]
'[Mass_9, 982 {System.Int64}; Good]
'[Mass_10, 1082 {System.Int64}; Good]
'...
// This example shows how to subscribe to all dataset messages on an OPC-UA PubSub connection with MQTT UADP mapping using
// TCP.
//
// The OpcLabs.MqttNet assembly needs to be referenced in your project (or otherwise made available, together with its
// dependencies) for the MQTT transport to work. Refer to the documentation for more information.
//
// 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.Engine;
using OpcLabs.EasyOpc.UA.PubSub.OperationModel;

namespace UADocExamples.PubSub._EasyUASubscriber
{
    partial class SubscribeDataSet
    {
        public static void MqttUadpTcp()
        {
            // Define the PubSub connection we will work with. Uses implicit conversion from a string.
            // Default port with MQTT is 1883.
            UAPubSubConnectionDescriptor pubSubConnectionDescriptor = "mqtt://opcua-pubsub.demo-this.com";
            // Specify the transport protocol mapping.
            // The statement below isn't actually necessary, due to automatic message mapping recognition feature; see
            // https://kb.opclabs.com/OPC_UA_PubSub_Automatic_Message_Mapping_Recognition for more details.
            pubSubConnectionDescriptor.TransportProfileUriString = UAPubSubTransportProfileUriStrings.MqttUadp;

            // Define the arguments for subscribing to the dataset, specifying the MQTT topic name.
            var subscribeDataSetArguments = new UASubscribeDataSetArguments(pubSubConnectionDescriptor)
            {
                DataSetSubscriptionDescriptor = {CommunicationParameters = {BrokerDataSetReaderTransportParameters =
                {
                    QueueName = "opcuademo/uadp/none"
                }}}
            };

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

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

            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_MqttUadpTcp(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.ErrorMessage}");
            }
        }

        // 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, False {System.Boolean}; Good]
        //[#1, 6685 {System.Int32}; Good]
        //[#2, 1444 {System.Int32}; Good]
        //[#3, 1/4/2020 6:06:20 PM {System.DateTime}; Good]
        //
        //Dataset data: Good; Data; publisher="32", writer=3, class=96976b7b-0db7-46c3-a715-0979884b55ae, fields: 100
        //[#0, 85 {System.Int64}; Good]
        //[#1, 185 {System.Int64}; Good]
        //[#2, 285 {System.Int64}; Good]
        //[#3, 385 {System.Int64}; Good]
        //[#4, 485 {System.Int64}; Good]
        //[#5, 585 {System.Int64}; Good]
        //[#6, 685 {System.Int64}; Good]
        //[#7, 785 {System.Int64}; Good]
        //[#8, 885 {System.Int64}; Good]
        //[#9, 985 {System.Int64}; Good]
        //[#10, 1085 {System.Int64}; Good]
        //...
    }
}
# This example shows how to subscribe to all dataset messages on an OPC-UA PubSub connection with MQTT UADP mapping
# using TCP.
#
# The following package needs to be referenced in your project (or otherwise made available) for the MQTT transport to
# work.
# - OpcLabs.MqttNet
# Refer to the documentation for more information.
#
# 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.Engine 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.
# Default port with MQTT is 1883.
pubSubConnectionDescriptor = UAPubSubConnectionDescriptor.op_Implicit('mqtt://opcua-pubsub.demo-this.com')
# Specify the transport protocol mapping.
# The statement below isn't actually necessary, due to automatic message mapping recognition feature; see
# https://kb.opclabs.com/OPC_UA_PubSub_Automatic_Message_Mapping_Recognition for more details.
pubSubConnectionDescriptor.TransportProfileUriString = UAPubSubTransportProfileUriStrings.MqttUadp

# Define the arguments for subscribing to the dataset, specifying the MQTT topic name.
subscribeDataSetArguments = UASubscribeDataSetArguments(pubSubConnectionDescriptor)
subscribeDataSetArguments.DataSetSubscriptionDescriptor.CommunicationParameters.BrokerDataSetReaderTransportParameters.\
    QueueName = 'opcuademo/uadp/none'

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

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

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 all dataset messages on an OPC-UA PubSub connection with MQTT UADP mapping using
' TCP.
'
' The OpcLabs.MqttNet assembly needs to be referenced in your project (or otherwise made available, together with its
' dependencies) for the MQTT transport to work. Refer to the documentation for more information.
'
' 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.Engine
Imports OpcLabs.EasyOpc.UA.PubSub.OperationModel

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

            ' Define the PubSub connection we will work with. Uses implicit conversion from a string.
            ' Default port with MQTT is 1883.
            Dim pubSubConnectionDescriptor As UAPubSubConnectionDescriptor = "mqtt://opcua-pubsub.demo-this.com"
            ' Specify the transport protocol mapping.
            ' The statement below isn't actually necessary, due to automatic message mapping recognition feature; see
            ' https://kb.opclabs.com/OPC_UA_PubSub_Automatic_Message_Mapping_Recognition for more details.
            pubSubConnectionDescriptor.TransportProfileUriString = UAPubSubTransportProfileUriStrings.MqttUadp

            ' Define the arguments for subscribing to the dataset, specifying the MQTT topic name.
            Dim subscribeDataSetArguments = New UASubscribeDataSetArguments(pubSubConnectionDescriptor)
            subscribeDataSetArguments.DataSetSubscriptionDescriptor.CommunicationParameters.BrokerDataSetReaderTransportParameters.QueueName = "opcuademo/uadp/none"

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

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

            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_MqttUadpTcp(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.ErrorMessage}")
            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, False {System.Boolean}; Good]
        '[#1, 6685 {System.Int32}; Good]
        '[#2, 1444 {System.Int32}; Good]
        '[#3, 1/4/2020 6:06:20 PM {System.DateTime}; Good]
        '
        'Dataset data: Good; Data; publisher="32", writer=3, class=96976b7b-0db7-46c3-a715-0979884b55ae, fields: 100
        '[#0, 85 {System.Int64}; Good]
        '[#1, 185 {System.Int64}; Good]
        '[#2, 285 {System.Int64}; Good]
        '[#3, 385 {System.Int64}; Good]
        '[#4, 485 {System.Int64}; Good]
        '[#5, 585 {System.Int64}; Good]
        '[#6, 685 {System.Int64}; Good]
        '[#7, 785 {System.Int64}; Good]
        '[#8, 885 {System.Int64}; Good]
        '[#9, 985 {System.Int64}; Good]
        '[#10, 1085 {System.Int64}; Good]
        '...
    End Class
End Namespace
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