QuickOPC User's Guide and Reference
UpdateGdsRegistration Method (_EasyUAApplication)
Example 



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OpcLabs.EasyOpcUA Assembly > OpcLabs.EasyOpc.UA.Application.ComTypes Namespace > _EasyUAApplication Interface : UpdateGdsRegistration Method
The endpoint of OPC UA Global Discovery Server (GDS).
Updates an application registration in the GDS, keeping its application ID. A new registration is created if the application is not yet registered in the GDS. Preexisting registrations with the same application URI are removed.
Syntax
'Declaration
 
<NotNullAttribute()>
Function UpdateGdsRegistration( _
   ByVal gdsEndpointDescriptor As Object _
) As UANodeId
 
'Usage
 
Dim instance As _EasyUAApplication
Dim gdsEndpointDescriptor As Object
Dim value As UANodeId
 
value = instance.UpdateGdsRegistration(gdsEndpointDescriptor)

Parameters

gdsEndpointDescriptor
The endpoint of OPC UA Global Discovery Server (GDS).

Return Value

Returns the preexisting (if available) or new application ID.
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

The difference between the RegisterToGds and UpdateGdsRegistration methods is that the RegisterToGds method always obtains a new application ID, whereas the UpdateGdsRegistration method attempts to reuse the existing application ID, if known. Neither of these methods requires the GDS registration be in any particular state for it to succeed, and both methods assure that after a successful execution, there is one and only one registration in the given GDS for this application.

The identity of the application itself is carried by its application URI, as given by the OpcLabs.EasyOpc.UA.Discovery.UAApplicationElement.ApplicationUriString returned by the OpcLabs.EasyOpc.UA.Application.Extensions.IEasyUAClientServerApplicationExtension.GetApplicationElement. Methods on this interface that manipulate or inspect the GDS registration use the application URI to identify the registration records belonging to this application.

Example

.NET

COM

// Shows how to update an application registration in the GDS, keeping its application ID if possible.

using System;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.AddressSpace;
using OpcLabs.EasyOpc.UA.Application;
using OpcLabs.EasyOpc.UA.Application.Extensions;
using OpcLabs.EasyOpc.UA.Extensions;
using OpcLabs.EasyOpc.UA.OperationModel;

namespace UADocExamples.Application._IEasyUAClientServerApplication
{
    class UpdateGdsRegistration
    {
        public static void Main1()
        {
            // Define which GDS we will work with.
            UAEndpointDescriptor gdsEndpointDescriptor =
                ((UAEndpointDescriptor)"opc.tcp://opcua.demo-this.com:58810/GlobalDiscoveryServer")
                .WithUserNameIdentity("appadmin", "demo");

            // Obtain the application interface.
            EasyUAApplication application = EasyUAApplication.Instance;

            // Display which application we are about to work with.
            Console.WriteLine("Application URI string: {0}",
                application.GetApplicationElement().ApplicationUriString);

            // Update an application registration in the GDS, keeping its application ID if possible.
            UANodeId applicationId;
            try
            {
                applicationId = application.UpdateGdsRegistration(gdsEndpointDescriptor);
            }
            catch (UAException uaException)
            {
                Console.WriteLine("*** Failure: {0}", uaException.GetBaseException().Message);
                return;
            }

            // Display results
            Console.WriteLine("Application ID: {0}", applicationId);
        }
    }
}
// Shows how to update an application registration in the GDS, keeping its application ID if possible.

class procedure UpdateGdsRegistration.Main;
var
  Application: TEasyUAApplication;
  ApplicationId: _UANodeId;
  GdsEndpointDescriptor: _UAEndpointDescriptor;
begin
  // Define which GDS we will work with.
  GdsEndpointDescriptor := CoUAEndpointDescriptor.Create;
  GdsEndpointDescriptor.UrlString := 'opc.tcp://opcua.demo-this.com:58810/GlobalDiscoveryServer';
  GdsEndpointDescriptor.UserIdentity.UserNameTokenInfo.UserName := 'appadmin';
  GdsEndpointDescriptor.UserIdentity.UserNameTokenInfo.Password := 'demo';

  // Obtain the application interface.
  Application := TEasyUAApplication.Create(nil);

  // Display which application we are about to work with.
  WriteLn('Application URI string: ', Application.GetApplicationElement.ApplicationUriString);

  // Update an application registration in the GDS, keeping its application ID if possible.
  try
    ApplicationId := Application.UpdateGdsRegistration(gdsEndpointDescriptor);
  except
    on E: EOleException do
    begin
      WriteLn(Format('*** Failure: %s', [E.GetBaseException.Message]));
    end;
  end;

  // Display results
  WriteLn('Application ID: ', ApplicationId.ToString);
end;
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