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



OpcLabs.EasyOpcUA Assembly > OpcLabs.EasyOpc.UA.PubSub Namespace : UAPublisherId Class
A unique identifier for a publisher within a message oriented middleware.
Object Model
UAPublisherId ClassUAPublisherId Class
Syntax
'Declaration
 
<ComDefaultInterfaceAttribute(OpcLabs.EasyOpc.UA.PubSub.ComTypes._UAPublisherId)>
<ComVisibleAttribute(True)>
<GuidAttribute("E4ECD2E2-4E6A-4158-8FA1-4E9C6DAB5318")>
<TypeConverterAttribute(OpcLabs.EasyOpc.UA.PubSub.Implementation.UAPublisherIdConverter)>
<ValueControlAttribute("OpcLabs.EasyOpc.UA.Forms.Internal.PubSub.UAPublisherIdControl, OpcLabs.EasyOpcForms, Version=5.80.82.1, Culture=neutral, PublicKeyToken=6faddca41dacb409")>
<CLSCompliantAttribute(True)>
<SerializableAttribute()>
Public NotInheritable Class UAPublisherId 
   Inherits OpcLabs.BaseLib.Info
   Implements LINQPad.ICustomMemberProvider, OpcLabs.BaseLib.ComTypes._Info, OpcLabs.BaseLib.ComTypes._Object2, OpcLabs.EasyOpc.UA.PubSub.ComTypes._UAPublisherId, System.ICloneable, System.IComparable(Of UAPublisherId), System.Runtime.Serialization.ISerializable, System.Xml.Serialization.IXmlSerializable 
'Usage
 
Dim instance As UAPublisherId
[ComDefaultInterface(OpcLabs.EasyOpc.UA.PubSub.ComTypes._UAPublisherId)]
[ComVisible(true)]
[Guid("E4ECD2E2-4E6A-4158-8FA1-4E9C6DAB5318")]
[TypeConverter(OpcLabs.EasyOpc.UA.PubSub.Implementation.UAPublisherIdConverter)]
[ValueControl("OpcLabs.EasyOpc.UA.Forms.Internal.PubSub.UAPublisherIdControl, OpcLabs.EasyOpcForms, Version=5.80.82.1, Culture=neutral, PublicKeyToken=6faddca41dacb409")]
[CLSCompliant(true)]
[Serializable()]
public sealed class UAPublisherId : OpcLabs.BaseLib.Info, LINQPad.ICustomMemberProvider, OpcLabs.BaseLib.ComTypes._Info, OpcLabs.BaseLib.ComTypes._Object2, OpcLabs.EasyOpc.UA.PubSub.ComTypes._UAPublisherId, System.ICloneable, System.IComparable<UAPublisherId>, System.Runtime.Serialization.ISerializable, System.Xml.Serialization.IXmlSerializable  
[ComDefaultInterface(OpcLabs.EasyOpc.UA.PubSub.ComTypes._UAPublisherId)]
[ComVisible(true)]
[Guid("E4ECD2E2-4E6A-4158-8FA1-4E9C6DAB5318")]
[TypeConverter(OpcLabs.EasyOpc.UA.PubSub.Implementation.UAPublisherIdConverter)]
[ValueControl("OpcLabs.EasyOpc.UA.Forms.Internal.PubSub.UAPublisherIdControl, OpcLabs.EasyOpcForms, Version=5.80.82.1, Culture=neutral, PublicKeyToken=6faddca41dacb409")]
[CLSCompliant(true)]
[Serializable()]
public ref class UAPublisherId sealed : public OpcLabs.BaseLib.Info, LINQPad.ICustomMemberProvider, OpcLabs.BaseLib.ComTypes._Info, OpcLabs.BaseLib.ComTypes._Object2, OpcLabs.EasyOpc.UA.PubSub.ComTypes._UAPublisherId, System.ICloneable, System.IComparable<UAPublisherId>, System.Runtime.Serialization.ISerializable, System.Xml.Serialization.IXmlSerializable  
Remarks

The published Id can be included in sent network message for identification or filtering.

External value is a CLS-compliant value used e.g. when accessing the publisher ID over OpcLabs.EasyOpc.UA.IEasyUAClient. It is System.Byte, System.Int32, System.Int64, System.Decimal, System.String, or null.

Internal value is used in the OPC-UA PubSub specification, not CLS-compliant. It is System.Byte, System.UInt16, System.UInt32, System.UInt64, System.String, or null.

It is intentional that there is no way to directly construct a numerical UAPublisherId without having to somehow explicitly state the desired type. This design attempts to prevent unwanted creation of publisher Ids with wrong type.

 

This article describes the physical identifiers used in OPC UA PubSub communication. For a distinction between physical and logical identifiers, see Identifying information in OPC UA PubSub.

Network Address and Resource Address

Network address is an abstract concept used to represent the basic information needed to make a PubSub connection to the message oriented middleware. In OPC Studio products, it represented by the NetworkAddress Class. The network address specifies a network interface used for the communication, with its InterfaceName Property. This is an empty string if you want to leave the choice of the network interface up to the component, or a non-empty string specifying the name of the network interface on the computer where the component runs.

Resource address is a concrete derivation of network address, in which the network address information is represented by a resource string - essentially, a URL string. Currently, all network addresses used in OPC UA PubSub are resource addresses. In OPC Studio, resource address is represented by the ResourceAddress Class. The actual URL information is stored in its ResourceDescriptor Property.

URL schemes and syntaxes

The URL schemes and syntaxes for OPC UA PubSub are described in OPC specifications. For datagram-oriented transports, the ones currently supported by core OPC Studio are:

With UDP, both IPv4 and IPv6 addresses are supported.

OPC Studio components support Enhanced Host Name Resolution in OPC UA PubSub URLs. This allows you to conveniently and reliably use some pre-defined host names as shortcuts for IP and MAC addresses with the above URL schemes, such as "ip6-allrouters" or "eth-broadcast".

OPC Data Client will, by default, use MQTT protocol with any of the URL schemes below:

The details of the URL syntax are then left on the concrete MQTT communication package used (see MQTT communication packages). Some communication packages define useful extensions to the URL syntax, which are described with each communication package. The basic syntax options, described in the OPC UA PubSub specification, are supported by every communication package (as long as the corresponding scheme is supported at all), i.e.:

Publisher Id

The publisher Id is a unique identifier for a publisher with the message-oriented middleware. A publisher can use a publisher Id of one of these types:

Publisher Ids are only equal if both their type and their value are equal. For example, a UInt16 publisher Id with value 31 is different from UInt32 publisher Id with the same value. You therefore need to be careful when specifying the publisher Ids, and with numerical Ids, pay attention to their precise type. Also, a String publisher Id is different from any numerical publisher Id, even if it carries a string representation of the same numerical value (such as a string "31", in our example).

In OPC Studio, the publisher Id is represented by the UAPublisherId Class, and the types of publisher Ids are expressed by the UAPublisherIdType Enumeration. The easiest way to create a publisher Id is to use one of the static CreateXXXX methods, defined on the class:

In a Message Filtering (OPC UA PubSub), you can also use a publisher Id with type None. This specifies that no filtering on publisher Ids should be performed.

Writer Group Id

The writer group Id is an unsigned 16-bit integer that identifies the writer group. It is unique across writer groups for a publisher Id. Writer groups can only have non-zero Ids, but a zero writer group Id may be used in a Message Filtering (OPC UA PubSub) to specify that no filtering on writer group Ids should be performed.

Dataset Writer Id

The dataset writer Id identifies the dataset writer in the writer group. It is an unsigned 16-bit integer that is unique across all dataset writers for a publisher Id. Dataset writers can only have non-zero Ids, but a zero dataset writer Id may be used in a Message Filtering (OPC UA PubSub) to specify that no filtering on dataset writer Ids should be performed.

Field Name and Field Index

Each dataset consists of a collection of dataset fields. Each field has a unique name within a dataset. Some message mappings (such as JSON) transfer the field names in the dataset message, others (such as UADP) do not, and they rely on the order of fields, which then must be the same as in the dataset metadata.

When OPC Studio components deliver information to you, it preferably uses field names, but it resorts to field indexes when the field names are not available. When you need to specify a dataset field to OPC Studio components, you can use either form (name or index). Normally, we recommend using field names and not field indexes, but an exception must be made in case when message mapping such as UADP is sued, and metadata (as a source of field names) is not available).

Dataset Metadata (OPC UA PubSub) can be provided through OPC UA PubSub logical resolution, or you can supply it manually (from the code).

Physical identifier with topic tree

When OPC UA PubSub Topic Tree is used, writer group name and dataset writer name become physical identifiers.

 

 

Example

.NET

COM

// This example shows how to subscribe to all dataset messages with specific publisher Id, 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 PublisherId()
        {
            // 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 arguments for subscribing to the dataset, where the filter is (unsigned 64-bit) publisher Id 31.
            var subscribeDataSetArguments = new UASubscribeDataSetArguments(
                pubSubConnectionDescriptor, UAPublisherId.CreateUInt64(31));

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

            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_PublisherId(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; Event; publisher=(UInt64)31, writer=51, fields: 4
        //[#0, True {System.Boolean}; Good]
        //[#1, 1237 {System.Int32}; Good]
        //[#2, 2514 {System.Int32}; Good]
        //[#3, 10/1/2019 9:03:59 AM {System.DateTime}; Good]
        //
        //Dataset data: Good; Data; publisher=(UInt64)31, writer=1, fields: 4
        //[#0, False {System.Boolean}; Good]
        //[#1, 1239 {System.Int32}; Good]
        //[#2, 2703 {System.Int32}; Good]
        //[#3, 10/1/2019 9:04:01 AM {System.DateTime}; Good]
        //
        //Dataset data: Good; Data; publisher=(UInt64)31, writer=4, fields: 16
        //[#0, False {System.Boolean}; Good]
        //[#1, 215 {System.Byte}; Good]
        //[#2, 1239 {System.Int16}; Good]
        //[#3, 1239 {System.Int32}; Good]
        //[#4, 1239 {System.Int64}; Good]
        //[#5, 87 {System.Int16}; Good]
        //[#6, 1239 {System.Int32}; Good]
        //[#7, 1239 {System.Int64}; Good]
        //[#8, 1239 {System.Decimal}; Good]
        //[#9, 1239 {System.Single}; Good]
        //[#10, 1239 {System.Double}; Good]
        //[#11, Romeo {System.String}; Good]
        //[#12, [20] {175, 186, 248, 246, 215, ...} {System.Byte[]}; Good]
        //[#13, d4492ca8-35c8-4b98-8edf-6ffa5ca041ca {System.Guid}; Good]
        //[#14, 10/1/2019 9:04:01 AM {System.DateTime}; Good]
        //[#15, [10] {1239, 1240, 1241, 1242, 1243, ...} {System.Int64[]}; Good]
        //
        //Dataset data: Good; Data; publisher=(UInt64)31, writer=1, fields: 4
        //[#2, 2722 {System.Int32}; Good]
        //[#3, 10/1/2019 9:04:01 AM {System.DateTime}; Good]
        //[#0, False {System.Boolean}; Good]
        //[#1, 1239 {System.Int32}; Good]
        //
        //Dataset data: Good; Data; publisher=(UInt64)31, writer=3, fields: 100
        //[#0, 39 {System.Int64}; Good]
        //[#1, 139 {System.Int64}; Good]
        //[#2, 239 {System.Int64}; Good]
        //[#3, 339 {System.Int64}; Good]
        //[#4, 439 {System.Int64}; Good]
        //[#5, 539 {System.Int64}; Good]
        //[#6, 639 {System.Int64}; Good]
        //[#7, 739 {System.Int64}; Good]
        //[#8, 839 {System.Int64}; Good]
        //[#9, 939 {System.Int64}; Good]
        //[#10, 1039 {System.Int64}; Good]
        //...
    }
}
# This example shows how to subscribe to all dataset messages with specific publisher Id, 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.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 arguments for subscribing to the dataset, where the filter is (unsigned 64-bit) publisher Id 31.
subscribeDataSetArguments = UASubscribeDataSetArguments(
    pubSubConnectionDescriptor,
    UASubscribeDataSetFilter(UAPublisherId.CreateUInt64(Decimal(31))))

# 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 with specific publisher Id, 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
    Partial Friend Class SubscribeDataSet
        Public Shared Sub PublisherId()

            ' 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 arguments for subscribing to the dataset, where the filter is (unsigned 64-bit) publisher Id 31.
            Dim subscribeDataSetArguments = New UASubscribeDataSetArguments(
                pubSubConnectionDescriptor, UAPublisherId.CreateUInt64(31))

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

            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_PublisherId(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; Event; publisher=(UInt64)31, writer=51, fields: 4
    '[#0, True {System.Boolean}; Good]
    '[#1, 1237 {System.Int32}; Good]
    '[#2, 2514 {System.Int32}; Good]
    '[#3, 10/1/2019 9:03:59 AM {System.DateTime}; Good]
    '
    'Dataset data: Good; Data; publisher=(UInt64)31, writer=1, fields: 4
    '[#0, False {System.Boolean}; Good]
    '[#1, 1239 {System.Int32}; Good]
    '[#2, 2703 {System.Int32}; Good]
    '[#3, 10/1/2019 9:04:01 AM {System.DateTime}; Good]
    '
    'Dataset data: Good; Data; publisher=(UInt64)31, writer=4, fields: 16
    '[#0, False {System.Boolean}; Good]
    '[#1, 215 {System.Byte}; Good]
    '[#2, 1239 {System.Int16}; Good]
    '[#3, 1239 {System.Int32}; Good]
    '[#4, 1239 {System.Int64}; Good]
    '[#5, 87 {System.Int16}; Good]
    '[#6, 1239 {System.Int32}; Good]
    '[#7, 1239 {System.Int64}; Good]
    '[#8, 1239 {System.Decimal}; Good]
    '[#9, 1239 {System.Single}; Good]
    '[#10, 1239 {System.Double}; Good]
    '[#11, Romeo {System.String}; Good]
    '[#12, [20] {175, 186, 248, 246, 215, ...} {System.Byte[]}; Good]
    '[#13, d4492ca8-35c8-4b98-8edf-6ffa5ca041ca {System.Guid}; Good]
    '[#14, 10/1/2019 9:04:01 AM {System.DateTime}; Good]
    '[#15, [10] {1239, 1240, 1241, 1242, 1243, ...} {System.Int64[]}; Good]
    '
    'Dataset data: Good; Data; publisher=(UInt64)31, writer=1, fields: 4
    '[#2, 2722 {System.Int32}; Good]
    '[#3, 10/1/2019 9:04:01 AM {System.DateTime}; Good]
    '[#0, False {System.Boolean}; Good]
    '[#1, 1239 {System.Int32}; Good]
    '
    'Dataset data: Good; Data; publisher=(UInt64)31, writer=3, fields: 100
    '[#0, 39 {System.Int64}; Good]
    '[#1, 139 {System.Int64}; Good]
    '[#2, 239 {System.Int64}; Good]
    '[#3, 339 {System.Int64}; Good]
    '[#4, 439 {System.Int64}; Good]
    '[#5, 539 {System.Int64}; Good]
    '[#6, 639 {System.Int64}; Good]
    '[#7, 739 {System.Int64}; Good]
    '[#8, 839 {System.Int64}; Good]
    '[#9, 939 {System.Int64}; Good]
    '[#10, 1039 {System.Int64}; Good]
    '...

End Namespace
// This example shows how to subscribe to all dataset messages with specific publisher Id, 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
  TSubscriberEventHandlers80 = class
    procedure OnDataSetMessage(
      ASender: TObject;
      sender: OleVariant;
      const eventArgs: _EasyUADataSetMessageEventArgs);
  end;

class procedure SubscribeDataSet.PublisherId;
var
  ConnectionDescriptor: _UAPubSubConnectionDescriptor;
  SubscribeDataSetArguments: _EasyUASubscribeDataSetArguments;
  Subscriber: TEasyUASubscriber;
  SubscriberEventHandlers: TSubscriberEventHandlers80;
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 arguments for subscribing to the dataset, where the filter is (unsigned 64-bit) publisher Id 31.
  SubscribeDataSetArguments.DataSetSubscriptionDescriptor.Filter.PublisherId.SetIdentifier(UAPublisherIdType_UInt64, 31);

  // Instantiate the subscriber object and hook events.
  Subscriber := TEasyUASubscriber.Create(nil);
  SubscriberEventHandlers := TSubscriberEventHandlers80.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 TSubscriberEventHandlers80.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; Event; publisher=(UInt64)31, writer=51, fields: 4
//[#0, True {System.Boolean}; Good]
//[#1, 1237 {System.Int32}; Good]
//[#2, 2514 {System.Int32}; Good]
//[#3, 10/1/2019 9:03:59 AM {System.DateTime}; Good]
//
//Dataset data: Good; Data; publisher=(UInt64)31, writer=1, fields: 4
//[#0, False {System.Boolean}; Good]
//[#1, 1239 {System.Int32}; Good]
//[#2, 2703 {System.Int32}; Good]
//[#3, 10/1/2019 9:04:01 AM {System.DateTime}; Good]
//
//Dataset data: Good; Data; publisher=(UInt64)31, writer=4, fields: 16
//[#0, False {System.Boolean}; Good]
//[#1, 215 {System.Byte}; Good]
//[#2, 1239 {System.Int16}; Good]
//[#3, 1239 {System.Int32}; Good]
//[#4, 1239 {System.Int64}; Good]
//[#5, 87 {System.Int16}; Good]
//[#6, 1239 {System.Int32}; Good]
//[#7, 1239 {System.Int64}; Good]
//[#8, 1239 {System.Decimal}; Good]
//[#9, 1239 {System.Single}; Good]
//[#10, 1239 {System.Double}; Good]
//[#11, Romeo {System.String}; Good]
//[#12, [20] {175, 186, 248, 246, 215, ...} {System.Byte[]}; Good]
//[#13, d4492ca8-35c8-4b98-8edf-6ffa5ca041ca {System.Guid}; Good]
//[#14, 10/1/2019 9:04:01 AM {System.DateTime}; Good]
//[#15, [10] {1239, 1240, 1241, 1242, 1243, ...} {System.Int64[]}; Good]
//
//Dataset data: Good; Data; publisher=(UInt64)31, writer=1, fields: 4
//[#2, 2722 {System.Int32}; Good]
//[#3, 10/1/2019 9:04:01 AM {System.DateTime}; Good]
//[#0, False {System.Boolean}; Good]
//[#1, 1239 {System.Int32}; Good]
//
//Dataset data: Good; Data; publisher=(UInt64)31, writer=3, fields: 100
//[#0, 39 {System.Int64}; Good]
//[#1, 139 {System.Int64}; Good]
//[#2, 239 {System.Int64}; Good]
//[#3, 339 {System.Int64}; Good]
//[#4, 439 {System.Int64}; Good]
//[#5, 539 {System.Int64}; Good]
//[#6, 639 {System.Int64}; Good]
//[#7, 739 {System.Int64}; Good]
//[#8, 839 {System.Int64}; Good]
//[#9, 939 {System.Int64}; Good]
//[#10, 1039 {System.Int64}; Good]
//...
Rem This example shows how to subscribe to all dataset messages with specific publisher Id, on an OPC-UA PubSub connection
Rem 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

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 arguments for subscribing to the dataset, where the filter is (unsigned 64-bit) publisher Id 31.
SubscribeDataSetArguments.DataSetSubscriptionDescriptor.Filter.PublisherId.SetIdentifier UAPublisherIdType_UInt64, 31

' 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; Event; publisher=(UInt64)31, writer=51, fields: 4
'[#0, True {System.Boolean}; Good]
'[#1, 1237 {System.Int32}; Good]
'[#2, 2514 {System.Int32}; Good]
'[#3, 10/1/2019 9:03:59 AM {System.DateTime}; Good]
'
'Dataset data: Good; Data; publisher=(UInt64)31, writer=1, fields: 4
'[#0, False {System.Boolean}; Good]
'[#1, 1239 {System.Int32}; Good]
'[#2, 2703 {System.Int32}; Good]
'[#3, 10/1/2019 9:04:01 AM {System.DateTime}; Good]
'
'Dataset data: Good; Data; publisher=(UInt64)31, writer=4, fields: 16
'[#0, False {System.Boolean}; Good]
'[#1, 215 {System.Byte}; Good]
'[#2, 1239 {System.Int16}; Good]
'[#3, 1239 {System.Int32}; Good]
'[#4, 1239 {System.Int64}; Good]
'[#5, 87 {System.Int16}; Good]
'[#6, 1239 {System.Int32}; Good]
'[#7, 1239 {System.Int64}; Good]
'[#8, 1239 {System.Decimal}; Good]
'[#9, 1239 {System.Single}; Good]
'[#10, 1239 {System.Double}; Good]
'[#11, Romeo {System.String}; Good]
'[#12, [20] {175, 186, 248, 246, 215, ...} {System.Byte[]}; Good]
'[#13, d4492ca8-35c8-4b98-8edf-6ffa5ca041ca {System.Guid}; Good]
'[#14, 10/1/2019 9:04:01 AM {System.DateTime}; Good]
'[#15, [10] {1239, 1240, 1241, 1242, 1243, ...} {System.Int64[]}; Good]
'
'Dataset data: Good; Data; publisher=(UInt64)31, writer=1, fields: 4
'[#2, 2722 {System.Int32}; Good]
'[#3, 10/1/2019 9:04:01 AM {System.DateTime}; Good]
'[#0, False {System.Boolean}; Good]
'[#1, 1239 {System.Int32}; Good]
'
'Dataset data: Good; Data; publisher=(UInt64)31, writer=3, fields: 100
'[#0, 39 {System.Int64}; Good]
'[#1, 139 {System.Int64}; Good]
'[#2, 239 {System.Int64}; Good]
'[#3, 339 {System.Int64}; Good]
'[#4, 439 {System.Int64}; Good]
'[#5, 539 {System.Int64}; Good]
'[#6, 639 {System.Int64}; Good]
'[#7, 739 {System.Int64}; Good]
'[#8, 839 {System.Int64}; Good]
'[#9, 939 {System.Int64}; Good]
'[#10, 1039 {System.Int64}; Good]
'...
REM This example shows how to subscribe to all dataset messages with specific publisher Id, on an OPC-UA PubSub connection
REM 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 Subscriber5 As EasyUASubscriber

Private Sub EasyUASubscriber_SubscribeDataSet_PublisherId_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 arguments for subscribing to the dataset, where the filter is (unsigned 64-bit) publisher Id 31.
    Call subscribeDataSetArguments.dataSetSubscriptionDescriptor.Filter.PublisherId.SetIdentifier(UAPublisherIdType_UInt64, 31)
    
    ' Instantiate the subscriber object and hook events.
    Set Subscriber5 = New EasyUASubscriber
    
    OutputText = OutputText & "Subscribing..." & vbCrLf
    Call Subscriber5.SubscribeDataSet(subscribeDataSetArguments)

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

    OutputText = OutputText & "Unsubscribing..." & vbCrLf
    Subscriber5.UnsubscribeAllDataSets

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

    Set Subscriber5 = Nothing

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

Private Sub Subscriber5_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
    ' Example output:
    '
    'Subscribing...
    'Processing dataset message events for 20 seconds...
    '
    'Dataset data: Good; Event; publisher=(UInt64)31, writer=51, fields: 4
    '[#0, True {System.Boolean}; Good]
    '[#1, 1237 {System.Int32}; Good]
    '[#2, 2514 {System.Int32}; Good]
    '[#3, 10/1/2019 9:03:59 AM {System.DateTime}; Good]
    '
    'Dataset data: Good; Data; publisher=(UInt64)31, writer=1, fields: 4
    '[#0, False {System.Boolean}; Good]
    '[#1, 1239 {System.Int32}; Good]
    '[#2, 2703 {System.Int32}; Good]
    '[#3, 10/1/2019 9:04:01 AM {System.DateTime}; Good]
    '
    'Dataset data: Good; Data; publisher=(UInt64)31, writer=4, fields: 16
    '[#0, False {System.Boolean}; Good]
    '[#1, 215 {System.Byte}; Good]
    '[#2, 1239 {System.Int16}; Good]
    '[#3, 1239 {System.Int32}; Good]
    '[#4, 1239 {System.Int64}; Good]
    '[#5, 87 {System.Int16}; Good]
    '[#6, 1239 {System.Int32}; Good]
    '[#7, 1239 {System.Int64}; Good]
    '[#8, 1239 {System.Decimal}; Good]
    '[#9, 1239 {System.Single}; Good]
    '[#10, 1239 {System.Double}; Good]
    '[#11, Romeo {System.String}; Good]
    '[#12, [20] {175, 186, 248, 246, 215, ...} {System.Byte[]}; Good]
    '[#13, d4492ca8-35c8-4b98-8edf-6ffa5ca041ca {System.Guid}; Good]
    '[#14, 10/1/2019 9:04:01 AM {System.DateTime}; Good]
    '[#15, [10] {1239, 1240, 1241, 1242, 1243, ...} {System.Int64[]}; Good]
    '
    'Dataset data: Good; Data; publisher=(UInt64)31, writer=1, fields: 4
    '[#2, 2722 {System.Int32}; Good]
    '[#3, 10/1/2019 9:04:01 AM {System.DateTime}; Good]
    '[#0, False {System.Boolean}; Good]
    '[#1, 1239 {System.Int32}; Good]
    '
    'Dataset data: Good; Data; publisher=(UInt64)31, writer=3, fields: 100
    '[#0, 39 {System.Int64}; Good]
    '[#1, 139 {System.Int64}; Good]
    '[#2, 239 {System.Int64}; Good]
    '[#3, 339 {System.Int64}; Good]
    '[#4, 439 {System.Int64}; Good]
    '[#5, 539 {System.Int64}; Good]
    '[#6, 639 {System.Int64}; Good]
    '[#7, 739 {System.Int64}; Good]
    '[#8, 839 {System.Int64}; Good]
    '[#9, 939 {System.Int64}; Good]
    '[#10, 1039 {System.Int64}; Good]
    '...
End Sub
Inheritance Hierarchy

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

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