OPC Studio User's Guide and Reference
BrowseCertificateGroups Method (_EasyUACertificateManagementClient)
Example 



OpcLabs.EasyOpcUA Assembly > OpcLabs.EasyOpc.UA.Gds.ComTypes Namespace > _EasyUACertificateManagementClient Interface : BrowseCertificateGroups Method
Endpoint descriptor. Identifies the OPC-UA server. The server must be a Global Directory Server (GDS).

Because the OpcLabs.EasyOpc.UA.UAEndpointDescriptor has implicit conversions from System.String and System.Uri, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use a string (representing the endpoint URL, or a so-called OPC UA endpoint descriptor string), or a System.Uri object, in place of this parameter, and the corresponding endpoint descriptor will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can use the OpcLabs.EasyOpc.UA.UAEndpointDescriptor.FromString or OpcLabs.EasyOpc.UA.UAEndpointDescriptor.FromUri static method instead.

Also, because the OpcLabs.EasyOpc.UA.Discovery.UAApplicationElement and OpcLabs.EasyOpc.UA.Discovery.UADiscoveryElement have an implicit conversion to OpcLabs.EasyOpc.UA.UAEndpointDescriptor, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use a OpcLabs.EasyOpc.UA.Discovery.UAApplicationElement or OpcLabs.EasyOpc.UA.Discovery.UADiscoveryElement (results from OPC UA discovery) in place of this parameter, and the corresponding endpoint descriptor will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can convert a (non-null) OpcLabs.EasyOpc.UA.Discovery.UAApplicationElement or OpcLabs.EasyOpc.UA.Discovery.UADiscoveryElement to OpcLabs.EasyOpc.UA.UAEndpointDescriptor using the ToUAEndpointDescriptor or ToUAEndpointDescriptor method instead.

If you are using OPC Wizard (for server development), an implicit conversion from OpcLabs.EasyOpc.UA.EasyUAServerCore can be used in the same way to simply pass the server object in place of this parameter, which will use its OpcLabs.EasyOpc.UA.EasyUAServerCore.EffectiveServerDescriptor property for the connection.

The value of this parameter cannot be null (Nothing in Visual Basic).

Browses the certificate groups available in the Certificate Management information model.
Syntax
'Declaration
 
<NotNullAttribute()>
Function BrowseCertificateGroups( _
   ByVal gdsEndpointDescriptor As Object _
) As UACertificateGroupElementCollection
'Usage
 
Dim instance As _EasyUACertificateManagementClient
Dim gdsEndpointDescriptor As Object
Dim value As UACertificateGroupElementCollection
 
value = instance.BrowseCertificateGroups(gdsEndpointDescriptor)
[NotNull()]
UACertificateGroupElementCollection BrowseCertificateGroups( 
   object gdsEndpointDescriptor
)
[NotNull()]
UACertificateGroupElementCollection^ BrowseCertificateGroups( 
   Object^ gdsEndpointDescriptor
) 

Parameters

gdsEndpointDescriptor
Endpoint descriptor. Identifies the OPC-UA server. The server must be a Global Directory Server (GDS).

Because the OpcLabs.EasyOpc.UA.UAEndpointDescriptor has implicit conversions from System.String and System.Uri, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use a string (representing the endpoint URL, or a so-called OPC UA endpoint descriptor string), or a System.Uri object, in place of this parameter, and the corresponding endpoint descriptor will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can use the OpcLabs.EasyOpc.UA.UAEndpointDescriptor.FromString or OpcLabs.EasyOpc.UA.UAEndpointDescriptor.FromUri static method instead.

Also, because the OpcLabs.EasyOpc.UA.Discovery.UAApplicationElement and OpcLabs.EasyOpc.UA.Discovery.UADiscoveryElement have an implicit conversion to OpcLabs.EasyOpc.UA.UAEndpointDescriptor, in languages that support implicit conversion operators (such as C# or VB.NET), you can simply use a OpcLabs.EasyOpc.UA.Discovery.UAApplicationElement or OpcLabs.EasyOpc.UA.Discovery.UADiscoveryElement (results from OPC UA discovery) in place of this parameter, and the corresponding endpoint descriptor will be constructed automatically. When the implicit conversion operators are not supported (such as with Python.NET), you can convert a (non-null) OpcLabs.EasyOpc.UA.Discovery.UAApplicationElement or OpcLabs.EasyOpc.UA.Discovery.UADiscoveryElement to OpcLabs.EasyOpc.UA.UAEndpointDescriptor using the ToUAEndpointDescriptor or ToUAEndpointDescriptor method instead.

If you are using OPC Wizard (for server development), an implicit conversion from OpcLabs.EasyOpc.UA.EasyUAServerCore can be used in the same way to simply pass the server object in place of this parameter, which will use its OpcLabs.EasyOpc.UA.EasyUAServerCore.EffectiveServerDescriptor property for the connection.

The value of this parameter cannot be null (Nothing in Visual Basic).

Return Value

The method returns a certificate group element collection, which contains OpcLabs.EasyOpc.UA.Gds.UACertificateGroupElement values. Each element contains information about a particular certificate group found.

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

The individual elements of the returned value are never null (Nothing in Visual Basic).

Exceptions
ExceptionDescription

A null reference (Nothing in Visual Basic) is passed to a method that does not accept it as a valid argument.

This is a usage error, i.e. it will never occur (the exception will not be thrown) in a correctly written program. Your code should not catch this exception.

The OPC UA operation has failed. This operation exception in uniformly used to allow common handling of various kinds of errors. The System.Exception.InnerException always contains information about the actual error cause.

This is an operation error that depends on factors external to your program, and thus cannot be always avoided. Your code must handle it appropriately.

Remarks

This member or type is for use from COM. It is not meant to be used from .NET or Python. Refer to the corresponding .NET member or type instead, if you are developing in .NET or Python.

Example
// Shows how to browse and display the certificate groups available in the Certificate Manager.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
// OPC client and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-CSharp .
// Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
// a commercial license in order to use Online Forums, and we reply to every post.

using System;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.Gds;
using OpcLabs.EasyOpc.UA.OperationModel;

namespace UADocExamples.Gds._EasyUACertificateManagementClient
{
    class BrowseCertificateGroups
    {
        public static void Main1()
        {
            // Define which GDS we will work with.
            UAEndpointDescriptor gdsEndpointDescriptor = "opc.tcp://opcua.demo-this.com:58810/GlobalDiscoveryServer";

            // Instantiate the certificate management client object.
            var certificateManagementClient = new EasyUACertificateManagementClient();

            // Browse the certificate groups available in the GDS.
            UACertificateGroupElementCollection certificateGroupElementCollection;
            try
            {
                certificateGroupElementCollection = certificateManagementClient.BrowseCertificateGroups(gdsEndpointDescriptor);
            }
            catch (UAException uaException)
            {
                Console.WriteLine("*** Failure: {0}", uaException.GetBaseException().Message);
                return;
            }

            // Display results
            foreach (UACertificateGroupElement certificateGroupElement in certificateGroupElementCollection)
            {
                Console.WriteLine(certificateGroupElement);
            }
        }
    }
}
' Shows how to browse and display the certificate groups available in the Certificate Manager.
'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
' OPC client and subscriber examples in VB.NET on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-VBNET .
' Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
' a commercial license in order to use Online Forums, and we reply to every post.

Imports OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.Discovery
Imports OpcLabs.EasyOpc.UA.Gds
Imports OpcLabs.EasyOpc.UA.OperationModel

Namespace Gds._EasyUACertificateManagementClient
    Friend Class BrowseCertificateGroups
        Public Shared Sub Main1()
            ' Define which GDS we will work with.
            Dim gdsEndpointDescriptor As UAEndpointDescriptor = "opc.tcp://opcua.demo-this.com:58810/GlobalDiscoveryServer"

            ' Instantiate the certificate management client object
            Dim certificateManagementClient = New EasyUACertificateManagementClient()

            ' Browse the certificate groups available in the GDS.
            Dim certificateGroupElementCollection As UACertificateGroupElementCollection
            Try
                certificateGroupElementCollection = certificateManagementClient.BrowseCertificateGroups(gdsEndpointDescriptor)
            Catch uaException As UAException
                Console.WriteLine("*** Failure: {0}", uaException.GetBaseException.Message)
                Exit Sub
            End Try

            ' Display results
            For Each certificateGroupElement As UACertificateGroupElement In certificateGroupElementCollection
                Console.WriteLine(certificateGroupElement)
            Next certificateGroupElement
        End Sub
    End Class
End Namespace
# Shows how to browse and display the certificate groups available in the Certificate Manager.
#
# Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
# OPC client and subscriber examples in Python on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-Python .
# Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
# a commercial license in order to use Online Forums, and we reply to every post.
# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc

# Import .NET namespaces.
from OpcLabs.EasyOpc.UA import *
from OpcLabs.EasyOpc.UA.Gds import *
from OpcLabs.EasyOpc.UA.OperationModel import *


# Define which GDS we will work with.
gdsEndpointDescriptor = UAEndpointDescriptor('opc.tcp://opcua.demo-this.com:58810/GlobalDiscoveryServer')

# Instantiate the certificate management client object.
certificateManagementClient = EasyUACertificateManagementClient()

# Browse the certificate groups available in the GDS.
try:
    certificateGroupElementCollection = certificateManagementClient.BrowseCertificateGroups(gdsEndpointDescriptor)
except UAException as uaException:
    print('*** Failure: ' + uaException.GetBaseException().Message)
    exit()

# Display results.
for certificateGroupElement in certificateGroupElementCollection:
    print(certificateGroupElement)

print()
print('Finished.')
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