Connectivity Software User's Guide and Reference
UADiscoveryElement Class
Members  Example 



OpcLabs.EasyOpcUAPrimitives Assembly > OpcLabs.EasyOpc.UA.Discovery Namespace : UADiscoveryElement Class
Contains information gathered about an OPC application (typically, an OPC-UA server) or an endpoint.
Object Model
UADiscoveryElement ClassStringCollection ClassUAEndpointSelectionPolicy ClassStringCollection ClassStringSet ClassIPkiCertificate Interface
Syntax
'Declaration
 
<CLSCompliantAttribute(True)>
<ComDefaultInterfaceAttribute(OpcLabs.EasyOpc.UA.Discovery.ComTypes._UADiscoveryElement)>
<ComVisibleAttribute(True)>
<FacetAttribute("OpcLabs.EasyOpc.UA.Forms.Implementation.UADiscoveryElementContent, OpcLabs.EasyOpcForms, Version=5.84.192.1, Culture=neutral, PublicKeyToken=6faddca41dacb409", 
   OpcLabs.BaseLib.Media.IContent, 
   "{A1DB0591-3E22-43A2-A072-2B76C04BE0C0}")>
<GuidAttribute("0CE96037-6560-4EF7-9879-66FE2F65A7C8")>
<TypeConverterAttribute(System.ComponentModel.ExpandableObjectConverter)>
<ValueControlAttribute("OpcLabs.EasyOpc.UA.Forms.Implementation.UAApplicationElementControl, OpcLabs.EasyOpcForms, Version=5.84.192.1, Culture=neutral, PublicKeyToken=6faddca41dacb409", CanChangeReadWrite=True)>
<SerializableAttribute()>
Public NotInheritable Class UADiscoveryElement 
   Inherits UAApplicationElement
   Implements LINQPad.ICustomMemberProvider, OpcLabs.BaseLib.ComTypes._Info, OpcLabs.BaseLib.ComTypes._Object2, OpcLabs.EasyOpc.UA.Discovery.ComTypes._UAApplicationElement, OpcLabs.EasyOpc.UA.Discovery.ComTypes._UADiscoveryElement, IUAReadOnlyApplicationElement, IUAReadOnlyDiscoveryElement, System.ICloneable, System.Runtime.Serialization.ISerializable, System.Xml.Serialization.IXmlSerializable 
'Usage
 
Dim instance As UADiscoveryElement
[CLSCompliant(true)]
[ComDefaultInterface(OpcLabs.EasyOpc.UA.Discovery.ComTypes._UADiscoveryElement)]
[ComVisible(true)]
[Facet("OpcLabs.EasyOpc.UA.Forms.Implementation.UADiscoveryElementContent, OpcLabs.EasyOpcForms, Version=5.84.192.1, Culture=neutral, PublicKeyToken=6faddca41dacb409", 
   OpcLabs.BaseLib.Media.IContent, 
   "{A1DB0591-3E22-43A2-A072-2B76C04BE0C0}")]
[Guid("0CE96037-6560-4EF7-9879-66FE2F65A7C8")]
[TypeConverter(System.ComponentModel.ExpandableObjectConverter)]
[ValueControl("OpcLabs.EasyOpc.UA.Forms.Implementation.UAApplicationElementControl, OpcLabs.EasyOpcForms, Version=5.84.192.1, Culture=neutral, PublicKeyToken=6faddca41dacb409", CanChangeReadWrite=true)]
[Serializable()]
public sealed class UADiscoveryElement : UAApplicationElement, LINQPad.ICustomMemberProvider, OpcLabs.BaseLib.ComTypes._Info, OpcLabs.BaseLib.ComTypes._Object2, OpcLabs.EasyOpc.UA.Discovery.ComTypes._UAApplicationElement, OpcLabs.EasyOpc.UA.Discovery.ComTypes._UADiscoveryElement, IUAReadOnlyApplicationElement, IUAReadOnlyDiscoveryElement, System.ICloneable, System.Runtime.Serialization.ISerializable, System.Xml.Serialization.IXmlSerializable  
[CLSCompliant(true)]
[ComDefaultInterface(OpcLabs.EasyOpc.UA.Discovery.ComTypes._UADiscoveryElement)]
[ComVisible(true)]
[Facet("OpcLabs.EasyOpc.UA.Forms.Implementation.UADiscoveryElementContent, OpcLabs.EasyOpcForms, Version=5.84.192.1, Culture=neutral, PublicKeyToken=6faddca41dacb409", 
   OpcLabs.BaseLib.Media.IContent, 
   "{A1DB0591-3E22-43A2-A072-2B76C04BE0C0}")]
[Guid("0CE96037-6560-4EF7-9879-66FE2F65A7C8")]
[TypeConverter(System.ComponentModel.ExpandableObjectConverter)]
[ValueControl("OpcLabs.EasyOpc.UA.Forms.Implementation.UAApplicationElementControl, OpcLabs.EasyOpcForms, Version=5.84.192.1, Culture=neutral, PublicKeyToken=6faddca41dacb409", CanChangeReadWrite=true)]
[Serializable()]
public ref class UADiscoveryElement sealed : public UAApplicationElement, LINQPad.ICustomMemberProvider, OpcLabs.BaseLib.ComTypes._Info, OpcLabs.BaseLib.ComTypes._Object2, OpcLabs.EasyOpc.UA.Discovery.ComTypes._UAApplicationElement, OpcLabs.EasyOpc.UA.Discovery.ComTypes._UADiscoveryElement, IUAReadOnlyApplicationElement, IUAReadOnlyDiscoveryElement, System.ICloneable, System.Runtime.Serialization.ISerializable, System.Xml.Serialization.IXmlSerializable  
Remarks

This object is filled in and returned e.g. when you discover the OPC servers.

There are implicit conversions from this type to:

Example
// This example shows how to obtain application URLs of all OPC Unified Architecture servers on a given machine.
//
// Find all latest examples here: https://www.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
// OPC client and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-CSharp .
// Missing some example? Ask us for it on our Online Forums, https://forum.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 OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.Discovery;
using OpcLabs.EasyOpc.UA.OperationModel;

namespace UADocExamples._EasyUAClient
{
    class DiscoverLocalServers
    {
        public static void Overload1()
        {
            // Instantiate the client object.
            var client = new EasyUAClient();

            // Obtain collection of server elements.
            UADiscoveryElementCollection discoveryElementCollection;
            try
            {
                discoveryElementCollection = client.DiscoverLocalServers("opcua.demo-this.com");
            }
            catch (UAException uaException)
            {
                Console.WriteLine($"*** Failure: {uaException.GetBaseException().Message}");
                return;
            }

            // Display results.
            foreach (UADiscoveryElement discoveryElement in discoveryElementCollection)
                Console.WriteLine($"discoveryElementCollection[\"{discoveryElement.DiscoveryUriString}\"].ApplicationUriString: {discoveryElement.ApplicationUriString}");

            
            // Example output:
            //
            //discoveryElementCollection["opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"].ApplicationUriString: urn: DEMO - 5:UA Sample Server
            //discoveryElementCollection["http://opcua.demo-this.com:51211/UA/SampleServer"].ApplicationUriString: urn: DEMO - 5:UA Sample Server
            //discoveryElementCollection["https://opcua.demo-this.com:51212/UA/SampleServer/"].ApplicationUriString: urn: DEMO - 5:UA Sample Server
            //discoveryElementCollection["http://opcua.demo-this.com:62543/Quickstarts/AlarmConditionServer"].ApplicationUriString: urn: opcua.demo - this.com:Quickstart Alarm Condition Server
            //discoveryElementCollection["opc.tcp://opcua.demo-this.com:62544/Quickstarts/AlarmConditionServer"].ApplicationUriString: urn: opcua.demo - this.com:Quickstart Alarm Condition Server
        }
    }
}
# This example shows how to obtain application URLs of all OPC Unified Architecture servers on a given machine.
#
# Find all latest examples here: https://www.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
# OPC client and subscriber examples in PowerShell on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-PowerShell .
# Missing some example? Ask us for it on our Online Forums, https://forum.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.EasyOpc.UA
using namespace OpcLabs.EasyOpc.UA.Discovery
using namespace OpcLabs.EasyOpc.UA.OperationModel

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

# Instantiate the client object.
$client = New-Object EasyUAClient

# Obtain collection of server elements.
try {
    $discoveryElementCollection = [IEasyUAClientExtension]::DiscoverLocalServers($client, "opcua.demo-this.com")
}
catch [UAException] {
    Write-Host "*** Failure: $($PSItem.Exception.GetBaseException().Message)"
    return
}

# Display results.
foreach ($discoveryElement in $discoveryElementCollection) {
    Write-Host "discoveryElementCollection[`"$($discoveryElement.DiscoveryUriString)`"].ApplicationUriString: $($discoveryElement.ApplicationUriString)"
}


# Example output:
#
#discoveryElementCollection["opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"].ApplicationUriString: urn:DEMO-5:UA Sample Server
#discoveryElementCollection["http://opcua.demo-this.com:51211/UA/SampleServer"].ApplicationUriString: urn:DEMO-5:UA Sample Server
#discoveryElementCollection["https://opcua.demo-this.com:51212/UA/SampleServer/"].ApplicationUriString: urn:DEMO-5:UA Sample Server
#discoveryElementCollection["http://opcua.demo-this.com:62543/Quickstarts/AlarmConditionServer"].ApplicationUriString: urn:opcua.demo-this.com:Quickstart Alarm Condition Server
#discoveryElementCollection["opc.tcp://opcua.demo-this.com:62544/Quickstarts/AlarmConditionServer"].ApplicationUriString: urn:opcua.demo-this.com:Quickstart Alarm Condition Server
' This example shows how to obtain application URLs of all OPC Unified Architecture servers on a given machine.
'
' Find all latest examples here: https://www.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
' OPC client and subscriber examples in VB.NET on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-VBNET .
' Missing some example? Ask us for it on our Online Forums, https://forum.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
Imports OpcLabs.EasyOpc.UA.Discovery
Imports OpcLabs.EasyOpc.UA.OperationModel

Namespace Global.UADocExamples._EasyUAClient
    Friend Class DiscoverLocalServers
        Public Shared Sub Overload1()
            ' Instantiate the client object
            Dim client = New EasyUAClient()

            ' Obtain collection of server elements
            Dim discoveryElementCollection As UADiscoveryElementCollection
            Try
                discoveryElementCollection = client.DiscoverLocalServers("opcua.demo-this.com")
            Catch uaException As UAException
                Console.WriteLine("*** Failure: {0}", uaException.GetBaseException.Message)
                Exit Sub
            End Try

            ' Display results
            For Each discoveryElement As UADiscoveryElement In discoveryElementCollection
                Console.WriteLine("discoveryElementCollection[""{0}""].ApplicationUriString: {1}", _
                                  discoveryElement.DiscoveryUriString, discoveryElement.ApplicationUriString)
            Next discoveryElement

            ' Example output:
            'discoveryElementCollection["opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"].ApplicationUriString: urn:Test-PC:UA Sample Server
            'discoveryElementCollection["http://opcua.demo-this.com:51211/UA/SampleServer"].ApplicationUriString: urn:Test-PC:UA Sample Server
        End Sub
    End Class
End Namespace
# This example shows how to obtain application URLs of all OPC Unified Architecture servers on the specified host.
#
# Find all latest examples here: https://www.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
# OPC client and subscriber examples in Python on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-Python .
# Missing some example? Ask us for it on our Online Forums, https://forum.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 .NET namespaces.
from OpcLabs.EasyOpc.UA import *
from OpcLabs.EasyOpc.UA.OperationModel import *


# Instantiate the client object.
client = EasyUAClient()

# Obtain collection of server elements.
try:
    discoveryElementCollection = IEasyUAClientExtension.DiscoverLocalServers(client, 'opcua.demo-this.com')
except UAException as uaException:
    print('*** Failure: ' + uaException.GetBaseException().Message)
    exit()

# Display results.
for discoveryElement in discoveryElementCollection:
    print('DiscoveryElementCollection["', discoveryElement.DiscoveryUriString, '"].ApplicationUriString: ', 
          discoveryElement.ApplicationUriString, sep='')
// This example shows how to obtain application URLs of all OPC Unified Architecture servers, using specified discovery URI
// strings.
//
// Find all latest examples here: https://www.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
// OPC client and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-CSharp .
// Missing some example? Ask us for it on our Online Forums, https://forum.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 OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.Discovery;
using OpcLabs.EasyOpc.UA.OperationModel;

namespace UADocExamples._EasyUAClient
{
    class FindLocalApplications
    {
        public static void Main1()
        {

            string[] discoveryUriStrings =
            {
                "opc.tcp://opcua.demo-this.com:4840/UADiscovery",
                "http://opcua.demo-this.com/UADiscovery/Default.svc",
                "http://opcua.demo-this.com:52601/UADiscovery"
            };

            // Instantiate the client object.
            var client = new EasyUAClient();

            // Obtain collection of application elements.
            UADiscoveryElementCollection discoveryElementCollection;
            try
            {
                discoveryElementCollection = client.FindLocalApplications(discoveryUriStrings, UAApplicationTypes.Server);
            }
            catch (UAException uaException)
            {
                Console.WriteLine($"*** Failure: {uaException.GetBaseException().Message}");
                return;
            }

            // Display results.
            foreach (UADiscoveryElement discoveryElement in discoveryElementCollection)
                Console.WriteLine($"discoveryElementCollection[\"{discoveryElement.DiscoveryUriString}\"].ApplicationUriString: {discoveryElement.ApplicationUriString}");


            // Example output:
            //discoveryElementCollection["http://opcua.demo-this.com:62543/Quickstarts/AlarmConditionServer"].ApplicationUriString: urn:opcua.demo-this.com:Quickstart Alarm Condition Server
            //discoveryElementCollection["opc.tcp://opcua.demo-this.com:62544/Quickstarts/AlarmConditionServer"].ApplicationUriString: urn:opcua.demo-this.com:Quickstart Alarm Condition Server
            //discoveryElementCollection["opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"].ApplicationUriString: urn:opcua.demo-this.com:UA Sample Server
            //discoveryElementCollection["http://opcua.demo-this.com:51211/UA/SampleServer"].ApplicationUriString: urn:opcua.demo-this.com:UA Sample Server
            //discoveryElementCollection["https://opcua.demo-this.com:51212/UA/SampleServer/"].ApplicationUriString: urn:opcua.demo-this.com:UA Sample Server
            //discoveryElementCollection["opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"].ApplicationUriString: urn:Test-PC:UA Sample Server
        }
    }
}
# This example shows how to obtain application URLs of all OPC Unified Architecture servers, using specified discovery URI
# strings.
#
# Find all latest examples here: https://www.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
# OPC client and subscriber examples in PowerShell on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-PowerShell .
# Missing some example? Ask us for it on our Online Forums, https://forum.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.EasyOpc.UA
using namespace OpcLabs.EasyOpc.UA.Discovery
using namespace OpcLabs.EasyOpc.UA.OperationModel

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

$discoveryUriStrings = @(
    "opc.tcp://opcua.demo-this.com:4840/UADiscovery",
    "http://opcua.demo-this.com/UADiscovery/Default.svc",
    "http://opcua.demo-this.com:52601/UADiscovery")

# Instantiate the client object.
$client = New-Object EasyUAClient

# Obtain collection of application elements.
try {
    $discoveryElementCollection = [IEasyUAClientExtension]::FindLocalApplications($client, 
        $discoveryUriStrings, [UAApplicationTypes]::Server)
}
catch [UAException] {
    Write-Host "*** Failure: $($PSItem.Exception.GetBaseException().Message)"
    return
}

# Display results.
foreach ($discoveryElement in $discoveryElementCollection) {
    Write-Host "discoveryElementCollection[`"$($discoveryElement.DiscoveryUriString)`"].ApplicationUriString: $($discoveryElement.ApplicationUriString)"
}


# Example output:
#
#discoveryElementCollection["http://opcua.demo-this.com:62543/Quickstarts/AlarmConditionServer"].ApplicationUriString: urn:opcua.demo-this.com:Quickstart Alarm Condition Server
#discoveryElementCollection["opc.tcp://opcua.demo-this.com:62544/Quickstarts/AlarmConditionServer"].ApplicationUriString: urn:opcua.demo-this.com:Quickstart Alarm Condition Server
#discoveryElementCollection["opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"].ApplicationUriString: urn:opcua.demo-this.com:UA Sample Server
#discoveryElementCollection["http://opcua.demo-this.com:51211/UA/SampleServer"].ApplicationUriString: urn:opcua.demo-this.com:UA Sample Server
#discoveryElementCollection["https://opcua.demo-this.com:51212/UA/SampleServer/"].ApplicationUriString: urn:opcua.demo-this.com:UA Sample Server
#discoveryElementCollection["opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"].ApplicationUriString: urn:Test-PC:UA Sample Server
' This example shows how to obtain application URLs of all OPC Unified Architecture servers, using specified discovery URI strings.
'
' Find all latest examples here: https://www.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
' OPC client and subscriber examples in VB.NET on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-VBNET .
' Missing some example? Ask us for it on our Online Forums, https://forum.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
Imports OpcLabs.EasyOpc.UA.Discovery
Imports OpcLabs.EasyOpc.UA.OperationModel

Namespace Global.UADocExamples._EasyUAClient
    Friend Class FindLocalApplications
        Public Shared Sub Main1()
            Dim discoveryUriStrings() As String =
            { _
                "opc.tcp://opcua.demo-this.com:4840/UADiscovery", _
                "http://opcua.demo-this.com/UADiscovery/Default.svc", _
                "http://opcua.demo-this.com:52601/UADiscovery" _
            }

            ' Instantiate the client object
            Dim client = New EasyUAClient()

            ' Obtain collection of application elements
            Dim discoveryElementCollection As UADiscoveryElementCollection
            Try
                discoveryElementCollection = client.FindLocalApplications(discoveryUriStrings, UAApplicationTypes.Server)
            Catch uaException As UAException
                Console.WriteLine("*** Failure: {0}", uaException.GetBaseException.Message)
                Exit Sub
            End Try

            ' Display results
            For Each discoveryElement As UADiscoveryElement In discoveryElementCollection
                Console.WriteLine("discoveryElementCollection[""{0}""].ApplicationUriString: {1}", _
                    discoveryElement.DiscoveryUriString, discoveryElement.ApplicationUriString)
            Next discoveryElement

            ' Example output:
            'discoveryElementCollection["http://opcua.demo-this.com:62543/Quickstarts/AlarmConditionServer"].ApplicationUriString: urn:opcua.demo-this.com:Quickstart Alarm Condition Server
            'discoveryElementCollection["opc.tcp://opcua.demo-this.com:62544/Quickstarts/AlarmConditionServer"].ApplicationUriString: urn:opcua.demo-this.com:Quickstart Alarm Condition Server
            'discoveryElementCollection["opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"].ApplicationUriString: urn:opcua.demo-this.com:UA Sample Server
            'discoveryElementCollection["http://opcua.demo-this.com:51211/UA/SampleServer"].ApplicationUriString: urn:opcua.demo-this.com:UA Sample Server
            'discoveryElementCollection["https://opcua.demo-this.com:51212/UA/SampleServer/"].ApplicationUriString: urn:opcua.demo-this.com:UA Sample Server
            'discoveryElementCollection["opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"].ApplicationUriString: urn:Test-PC:UA Sample Server
        End Sub
    End Class
End Namespace
// This example shows how to obtain application URLs of all OPC Unified Architecture servers, using specified discovery URI strings.
//
// Find all latest examples here: https://www.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
// OPC client and subscriber examples in Object Pascal (Delphi) on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-OP .
// Missing some example? Ask us for it on our Online Forums, https://forum.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.

class procedure FindLocalApplications.Main;
const
  UAApplicationTypes_Server = 1;
var
  Client: OpcLabs_EasyOpcUACore_TLB._EasyUAClient;
  Count: Cardinal;
  Element: OleVariant;
  DiscoveryElement: _UADiscoveryElement;
  DiscoveryElementEnumerator: IEnumVariant;
  DiscoveryElements: _UADiscoveryElementCollection;
  DiscoveryUriStrings: OleVariant;
begin
  DiscoveryUriStrings := VarArrayCreate([0, 2], varVariant);
  DiscoveryUriStrings[0] := 'opc.tcp://opcua.demo-this.com:4840/UADiscovery';
  DiscoveryUriStrings[1] := 'http://opcua.demo-this.com/UADiscovery/Default.svc';
  DiscoveryUriStrings[2] := 'http://opcua.demo-this.com:52601/UADiscovery';

  // Instantiate the client object
  Client := CoEasyUAClient.Create;

  // Obtain collection of application elements
  try
    DiscoveryElements := Client.FindLocalApplications(DiscoveryUriStrings, UAApplicationTypes_Server);
  except
    on E: EOleException do
    begin
      WriteLn(Format('*** Failure: %s', [E.GetBaseException.Message]));
      Exit;
    end;
  end;

  // Display results
  DiscoveryElementEnumerator := DiscoveryElements.GetEnumerator;
  while (DiscoveryElementEnumerator.Next(1, Element, Count) = S_OK) do
  begin
    DiscoveryElement := IUnknown(Element) as _UADiscoveryElement;
    WriteLn(
      'DiscoveryElements["',
      DiscoveryElement.DiscoveryUriString,
      '".ApplicationUriString: ',
      DiscoveryElement.ApplicationUriString);
  end;

  VarClear(DiscoveryUriStrings);
end;
REM This example shows how to obtain application URLs of all OPC Unified Architecture servers, using specified discovery URI strings.
REM
REM Find all latest examples here: https://www.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
REM OPC client and subscriber examples in Visual Basic on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-VB .
REM Missing some example? Ask us for it on our Online Forums, https://forum.opclabs.com/forum/index ! You do not have to own
REM a commercial license in order to use Online Forums, and we reply to every post.

Public Sub FindLocalApplications_Main_Command_Click()
    OutputText = ""
    
    Dim DiscoveryUriStrings(2)
    DiscoveryUriStrings(0) = "opc.tcp://opcua.demo-this.com:4840/UADiscovery"
    DiscoveryUriStrings(1) = "http://opcua.demo-this.com/UADiscovery/Default.svc"
    DiscoveryUriStrings(2) = "http://opcua.demo-this.com:52601/UADiscovery"

    ' Instantiate the client object
    Dim Client As New EasyUAClient

    ' Obtain collection of application elements
    On Error Resume Next
    Dim DiscoveryElementCollection As UADiscoveryElementCollection
    Set DiscoveryElementCollection = Client.FindLocalApplications(DiscoveryUriStrings, UAApplicationTypes_Server)
    If Err.Number <> 0 Then
        OutputText = OutputText & "*** Failure: " & Err.Source & ": " & Err.Description & vbCrLf
        Exit Sub
    End If
    On Error GoTo 0
    
    ' Display results
    Dim DiscoveryElement As UADiscoveryElement: For Each DiscoveryElement In DiscoveryElementCollection
        OutputText = OutputText & "DiscoveryElementCollection[""" & DiscoveryElement.DiscoveryUriString & """].ApplicationUriString: " & _
            DiscoveryElement.applicationUriString & vbCrLf
    Next
End Sub
# This example shows how to obtain application URLs of all OPC Unified Architecture servers, using specified discovery
# URI strings.
#
# Find all latest examples here: https://www.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
# OPC client and subscriber examples in Python on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-Python .
# Missing some example? Ask us for it on our Online Forums, https://forum.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 .NET namespaces.
from OpcLabs.EasyOpc.UA import *
from OpcLabs.EasyOpc.UA.Discovery import *
from OpcLabs.EasyOpc.UA.OperationModel import *


discoveryUriStrings = [
    'opc.tcp://opcua.demo-this.com:4840/UADiscovery',
    'http://opcua.demo-this.com/UADiscovery/Default.svc',
    'http://opcua.demo-this.com:52601/UADiscovery'
]

# Instantiate the client object.
client = EasyUAClient()

# Obtain collection of application elements.
try:
    discoveryElementCollection = IEasyUAClientExtension.FindLocalApplications(client,
        discoveryUriStrings, UAApplicationTypes.Server)
except UAException as uaException:
    print('*** Failure: ' + uaException.GetBaseException().Message)
    exit()

# Display results.
for discoveryElement in discoveryElementCollection:
    print('DiscoveryElementCollection["', discoveryElement.DiscoveryUriString, '"].ApplicationUriString: ',
          discoveryElement.ApplicationUriString, sep='')
// This example shows how to obtain information about OPC UA servers available on the network.
// The result is flat, i.e. each discovery URL is returned in separate element, with possible repetition of the servers.
//
// Find all latest examples here: https://www.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
// OPC client and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-CSharp .
// Missing some example? Ask us for it on our Online Forums, https://forum.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 OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.Discovery;
using OpcLabs.EasyOpc.UA.OperationModel;

namespace UADocExamples._EasyUAClient
{
    partial class DiscoverNetworkServers
    {
        public static void Main1()
        {
            // Instantiate the client object.
            var client = new EasyUAClient();

            // Obtain collection of application elements.
            UADiscoveryElementCollection discoveryElementCollection;
            try
            {
                discoveryElementCollection = client.DiscoverNetworkServers("opcua.demo-this.com");
            }
            catch (UAException uaException)
            {
                Console.WriteLine($"*** Failure: {uaException.GetBaseException().Message}");
                return;
            }

            // Display results.
            foreach (UADiscoveryElement discoveryElement in discoveryElementCollection)
            {
                Console.WriteLine();
                Console.WriteLine($"Server name: {discoveryElement.ServerName}");
                Console.WriteLine($"Discovery URI string: {discoveryElement.DiscoveryUriString}");
                Console.WriteLine($"Server capabilities: {discoveryElement.ServerCapabilities}");
                Console.WriteLine($"Application URI string: {discoveryElement.ApplicationUriString}");
                Console.WriteLine($"Product URI string: {discoveryElement.ProductUriString}");
            }
        }
    }
}
# This example shows how to obtain information about OPC UA servers available on the network.
# The result is flat, i.e. each discovery URL is returned in separate element, with possible repetition of the servers.
#
# Find all latest examples here: https://www.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
# OPC client and subscriber examples in PowerShell on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-PowerShell .
# Missing some example? Ask us for it on our Online Forums, https://forum.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.EasyOpc.UA
using namespace OpcLabs.EasyOpc.UA.Discovery
using namespace OpcLabs.EasyOpc.UA.OperationModel

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

# Instantiate the client object.
$client = New-Object EasyUAClient

# Obtain collection of application elements.
try {
    $discoveryElementCollection = [IEasyUAClientExtension]::DiscoverNetworkServers($client, "opcua.demo-this.com")
}
catch [UAException] {
    Write-Host "*** Failure: $($PSItem.Exception.GetBaseException().Message)"
    return
}

# Display results.
foreach ($discoveryElement in $discoveryElementCollection) {
    Write-Host
    Write-Host "Server name: $($discoveryElement.ServerName)"
    Write-Host "Discovery URI string: $($discoveryElement.DiscoveryUriString)"
    Write-Host "Server capabilities: $($discoveryElement.ServerCapabilities)"
    Write-Host "Application URI string: $($discoveryElement.ApplicationUriString)"
    Write-Host "Product URI string: $($discoveryElement.ProductUriString)"
}
' This example shows how to obtain information about OPC UA servers available on the network.
' The result is flat, i.e. each discovery URL is returned in separate element, with possible repetition of the servers.
'
' Find all latest examples here: https://www.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
' OPC client and subscriber examples in VB.NET on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-VBNET .
' Missing some example? Ask us for it on our Online Forums, https://forum.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
Imports OpcLabs.EasyOpc.UA.Discovery
Imports OpcLabs.EasyOpc.UA.OperationModel

Namespace Global.UADocExamples._EasyUAClient
    Partial Friend Class DiscoverNetworkServers
        Public Shared Sub Main1()
            ' Instantiate the client object
            Dim client = New EasyUAClient()

            ' Obtain collection of application elements
            Dim discoveryElementCollection As UADiscoveryElementCollection
            Try
                discoveryElementCollection = client.DiscoverNetworkServers("opcua.demo-this.com")
            Catch uaException As UAException
                Console.WriteLine("*** Failure: {0}", uaException.GetBaseException.Message)
                Exit Sub
            End Try

            ' Display results
            For Each discoveryElement As UADiscoveryElement In discoveryElementCollection
                Console.WriteLine()
                Console.WriteLine("Server name: {0}", discoveryElement.ServerName)
                Console.WriteLine("Discovery URI string: {0}", discoveryElement.DiscoveryUriString)
                Console.WriteLine("Server capabilities: {0}", discoveryElement.ServerCapabilities)
                Console.WriteLine("Application URI string: {0}", discoveryElement.ApplicationUriString)
                Console.WriteLine("Product URI string: {0}", discoveryElement.ProductUriString)
            Next discoveryElement
        End Sub
    End Class
End Namespace
// This example shows how to obtain information about OPC UA servers available on the network.
//
// Find all latest examples here: https://www.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
// OPC client and subscriber examples in Object Pascal (Delphi) on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-OP .
// Missing some example? Ask us for it on our Online Forums, https://forum.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.

class procedure DiscoverNetworkServers.Main;
var
  Client: OpcLabs_EasyOpcUACore_TLB._EasyUAClient;
  Count: Cardinal;
  Element: OleVariant;
  DiscoveryElement: _UADiscoveryElement;
  DiscoveryElementEnumerator: IEnumVariant;
  DiscoveryElements: _UADiscoveryElementCollection;
begin
  // Instantiate the client object
  Client := CoEasyUAClient.Create;

  // Obtain collection of application elements
  try
    DiscoveryElements := Client.DiscoverNetworkServers(Unassigned, 'opcua.demo-this.com');
  except
    on E: EOleException do
    begin
      WriteLn(Format('*** Failure: %s', [E.GetBaseException.Message]));
      Exit;
    end;
  end;

  // Display results
  DiscoveryElementEnumerator := DiscoveryElements.GetEnumerator;
  while (DiscoveryElementEnumerator.Next(1, Element, Count) = S_OK) do
  begin
    DiscoveryElement := IUnknown(Element) as _UADiscoveryElement;
    WriteLn;
    WriteLn('Server name: ', DiscoveryElement.ServerName);
    WriteLn('Discovery URI string: ', DiscoveryElement.DiscoveryUriString);
    WriteLn('Server capabilities: ', DiscoveryElement.ServerCapabilities.ToString);
  end;
end;
REM This example shows how to obtain information about OPC UA servers available on the network.
REM
REM Find all latest examples here: https://www.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
REM OPC client and subscriber examples in Visual Basic on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-VB .
REM Missing some example? Ask us for it on our Online Forums, https://forum.opclabs.com/forum/index ! You do not have to own
REM a commercial license in order to use Online Forums, and we reply to every post.

Public Sub DiscoverNetworkServers_Main_Command_Click()
    OutputText = ""

    ' Instantiate the client object
    Dim Client As New EasyUAClient

    ' Obtain collection of application elements
    On Error Resume Next
    Dim DiscoveryElementCollection As UADiscoveryElementCollection
    Set DiscoveryElementCollection = Client.DiscoverNetworkServers(Nothing, "opcua.demo-this.com")
    If Err.Number <> 0 Then
        OutputText = OutputText & "*** Failure: " & Err.Source & ": " & Err.Description & vbCrLf
        Exit Sub
    End If
    On Error GoTo 0
    
    ' Display results
    Dim DiscoveryElement As UADiscoveryElement: For Each DiscoveryElement In DiscoveryElementCollection
        OutputText = OutputText & vbCrLf
        OutputText = OutputText & "Server name: " & DiscoveryElement.ServerName & vbCrLf
        OutputText = OutputText & "Discovery URI string: " & DiscoveryElement.DiscoveryUriString & vbCrLf
        OutputText = OutputText & "Server capabilities: " & DiscoveryElement.serverCapabilities.ToString & vbCrLf
    Next
End Sub
# This example shows how to obtain information about OPC UA servers available on the network.
# The result is flat, i.e. each discovery URL is returned in separate element, with possible repetition of the servers.
#
# Find all latest examples here: https://www.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
# OPC client and subscriber examples in Python on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-Python .
# Missing some example? Ask us for it on our Online Forums, https://forum.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 .NET namespaces.
from OpcLabs.EasyOpc.UA import *
from OpcLabs.EasyOpc.UA.Discovery import *
from OpcLabs.EasyOpc.UA.OperationModel import *


# Instantiate the client object.
client = EasyUAClient()

# Obtain collection of application elements.
try:
    discoveryElementCollection = IEasyUAClientExtension.DiscoverNetworkServers(client, 'opcua.demo-this.com')
except UAException as uaException:
    print('*** Failure: ' + uaException.GetBaseException().Message)
    exit()

# Display results.
for discoveryElement in discoveryElementCollection:
    print()
    print('Server name: ', discoveryElement.ServerName, sep='')
    print('Discovery URI string: ', discoveryElement.DiscoveryUriString, sep='')
    print('Server capabilities: ', discoveryElement.ServerCapabilities, sep='')
    print('Application URI string: ', discoveryElement.ApplicationUriString, sep='')
    print('Product URI string: ', discoveryElement.ProductUriString, sep='')

print()
print('Finished.')
// This example shows how to obtain information about OPC UA servers available on the network.
// The result is hierarchical, i.e. each server is returned in one element, and the element contains all its discovery URLs.
//
// Find all latest examples here: https://www.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
// OPC client and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-CSharp .
// Missing some example? Ask us for it on our Online Forums, https://forum.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 OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.Discovery;
using OpcLabs.EasyOpc.UA.OperationModel;

namespace UADocExamples._EasyUAClient
{
    partial class DiscoverNetworkServers
    {
        public static void Hierarchical()
        {
            // Instantiate the client object
            var client = new EasyUAClient();

            // Obtain collection of application elements
            UADiscoveryElementCollection discoveryElementCollection;
            try
            {
                discoveryElementCollection = client.DiscoverNetworkServers("opcua.demo-this.com", flat:false);
            }
            catch (UAException uaException)
            {
                Console.WriteLine("*** Failure: {0}", uaException.GetBaseException().Message);
                return;
            }

            // Display results
            foreach (UADiscoveryElement discoveryElement in discoveryElementCollection)
            {
                Console.WriteLine();
                Console.WriteLine("Server name: {0}", discoveryElement.ServerName);
                Console.WriteLine("Discovery URI strings:");
                foreach (string discoveryUriString in discoveryElement.DiscoveryUriStrings)
                    Console.WriteLine("  {0}", discoveryUriString);
                Console.WriteLine("Server capabilities: {0}", discoveryElement.ServerCapabilities);
            }
        }
    }
}
' This example shows how to obtain information about OPC UA servers available on the network.
' The result is hierarchical, i.e. each server is returned in one element, and the element contains all its discovery URLs.
'
' Find all latest examples here: https://www.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
' OPC client and subscriber examples in VB.NET on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-VBNET .
' Missing some example? Ask us for it on our Online Forums, https://forum.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
Imports OpcLabs.EasyOpc.UA.Discovery
Imports OpcLabs.EasyOpc.UA.OperationModel

Namespace Global.UADocExamples._EasyUAClient
    Partial Friend Class DiscoverNetworkServers
        Public Shared Sub Hierarchical()
            ' Instantiate the client object
            Dim client = New EasyUAClient()

            ' Obtain collection of application elements
            Dim discoveryElementCollection As UADiscoveryElementCollection
            Try
                discoveryElementCollection = client.DiscoverNetworkServers("opcua.demo-this.com", flat:=False)
            Catch uaException As UAException
                Console.WriteLine("*** Failure: {0}", uaException.GetBaseException.Message)
                Exit Sub
            End Try

            ' Display results
            For Each discoveryElement As UADiscoveryElement In discoveryElementCollection
                Console.WriteLine()
                Console.WriteLine("Server name: {0}", discoveryElement.ServerName)
                Console.WriteLine("Discovery URI strings:")
                For Each discoveryUriString As String In discoveryElement.DiscoveryUriStrings
                    Console.WriteLine("  {0}", discoveryUriString)
                Next discoveryUriString
                Console.WriteLine("Server capabilities: {0}", discoveryElement.ServerCapabilities)
            Next discoveryElement
        End Sub
    End Class
End Namespace
# This example shows how to obtain information about OPC UA servers available on the network.
# The result is hierarchical, i.e. each server is returned in one element, and the element contains all its discovery
# URLs.
#
# Find all latest examples here: https://www.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
# OPC client and subscriber examples in Python on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-Python .
# Missing some example? Ask us for it on our Online Forums, https://forum.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 .NET namespaces.
from OpcLabs.EasyOpc.UA import *
from OpcLabs.EasyOpc.UA.Discovery import *
from OpcLabs.EasyOpc.UA.OperationModel import *


# Instantiate the client object.
client = EasyUAClient()

# Obtain collection of application elements.
try:
    discoveryElementCollection = IEasyUAClientExtension.DiscoverNetworkServers(client,
        'opcua.demo-this.com',
        False) # flat=False
except UAException as uaException:
    print('*** Failure: ' + uaException.GetBaseException().Message)
    exit()

# Display results.
for discoveryElement in discoveryElementCollection:
    print()
    print('Server name: ', discoveryElement.ServerName, sep='')
    print('Discovery URI strings:')
    for discoveryUriString in discoveryElement.DiscoveryUriStrings:
        print('  ', discoveryUriString, sep='')
    print('Server capabilities: ', discoveryElement.ServerCapabilities, sep='')

print()
print('Finished.')
Inheritance Hierarchy

System.Object
   OpcLabs.BaseLib.Object2
      OpcLabs.BaseLib.Info
         OpcLabs.EasyOpc.UA.Discovery.UAApplicationElement
            OpcLabs.EasyOpc.UA.Discovery.UADiscoveryElement

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