Finds all registrations for this application URI in the GDS.
Syntax
Parameters
- gdsEndpointDescriptor
- The endpoint of OPC UA Global Discovery Server (GDS).
Return Value
Returns a dictionary of
OpcLabs.EasyOpc.UA.Discovery.UAApplicationElement objects with application registration information, keyed by a
OpcLabs.EasyOpc.UA.AddressSpace.UANodeId which is the application ID identifying the registration in the GDS.
Exceptions
Exception | Description |
System.ArgumentNullException |
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. |
OpcLabs.EasyOpc.UA.OperationModel.UAException |
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. |
Example
.NET
COM
// Shows how to find all application's registrations in the GDS.
// In order to be able to find the registration, run the example for the RegisterToGds method first.
using System;
using System.Collections.Generic;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.AddressSpace;
using OpcLabs.EasyOpc.UA.Application;
using OpcLabs.EasyOpc.UA.Application.Extensions;
using OpcLabs.EasyOpc.UA.Discovery;
using OpcLabs.EasyOpc.UA.Extensions;
using OpcLabs.EasyOpc.UA.OperationModel;
namespace UADocExamples.Application._IEasyUAClientServerApplication
{
class FindGdsRegistrations
{
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);
// Find all application's registrations in the GDS.
IReadOnlyDictionary<UANodeId, UAApplicationElement> applicationElementDictionary;
try
{
applicationElementDictionary = application.FindGdsRegistrations(gdsEndpointDescriptor);
}
catch (UAException uaException)
{
Console.WriteLine("*** Failure: {0}", uaException.GetBaseException().Message);
return;
}
// Display results
foreach (KeyValuePair<UANodeId, UAApplicationElement> pair in applicationElementDictionary)
{
Console.WriteLine();
Console.WriteLine("Application ID: {0}", pair.Key);
UAApplicationElement applicationElement = pair.Value;
Console.WriteLine("Application element: {0}", applicationElement);
Console.WriteLine(" Application URI string: {0}", applicationElement.ApplicationUriString);
Console.WriteLine(" Discovery URI strings: {0}", applicationElement.DiscoveryUriStrings);
Console.WriteLine(" Product URI string: {0}", applicationElement.ProductUriString);
}
}
}
}
# Shows how to find all application's registrations in the GDS.
# In order to be able to find the registration, run the example for the RegisterToGds method first.
# 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.Application import *
from OpcLabs.EasyOpc.UA.Application.Extensions import *
from OpcLabs.EasyOpc.UA.Extensions import *
from OpcLabs.EasyOpc.UA.OperationModel import *
# Define which GDS we will work with.
gdsEndpointDescriptor = UAEndpointDescriptor('opc.tcp://opcua.demo-this.com:58810/GlobalDiscoveryServer')
gdsEndpointDescriptor = UAEndpointDescriptorExtension.WithUserNameIdentity(gdsEndpointDescriptor,
'appadmin', 'demo')
# Obtain the application interface.
application = EasyUAApplication.Instance
# Display which application we are about to work with.
applicationElement = IEasyUAClientServerApplicationExtension.GetApplicationElement(application)
print('Application URI string: ', applicationElement.ApplicationUriString, sep='')
# Find all application's registrations in the GDS.
try:
applicationElementDictionary = application.FindGdsRegistrations(gdsEndpointDescriptor)
except UAException as uaException:
print('*** Failure: ' + uaException.GetBaseException().Message)
exit()
# Display results.
for pair in applicationElementDictionary:
print()
print('Application ID: ', pair.Key, sep='')
applicationElement = pair.Value
print('Application element: ', applicationElement, sep='')
print(' Application URI string: ', applicationElement.ApplicationUriString, sep='')
print(' Discovery URI strings: ', applicationElement.DiscoveryUriStrings, sep='')
print(' Product URI string: ', applicationElement.ProductUriString, sep='')
print()
print('Finished.')
' Shows how to find all application's registrations in the GDS.
Imports OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.AddressSpace
Imports OpcLabs.EasyOpc.UA.Application
Imports OpcLabs.EasyOpc.UA.Application.Extensions
Imports OpcLabs.EasyOpc.UA.Discovery
Imports OpcLabs.EasyOpc.UA.Extensions
Imports OpcLabs.EasyOpc.UA.OperationModel
Namespace Application._IEasyUAClientServerApplication
Friend Class FindGdsRegistrations
Public Shared Sub Main1()
' Define which GDS we will work with.
Dim gdsEndpointDescriptor As UAEndpointDescriptor =
New UAEndpointDescriptor("opc.tcp://opcua.demo-this.com:58810/GlobalDiscoveryServer") _
.WithUserNameIdentity("appadmin", "demo")
' Obtain the application interface.
Dim application As EasyUAApplication = EasyUAApplication.Instance
' Display which application we are about to work with.
Console.WriteLine("Application URI string: {0}",
application.GetApplicationElement().ApplicationUriString)
' Find all application's registrations in the GDS.
Dim applicationElementDictionary As IReadOnlyDictionary(Of UANodeId, UAApplicationElement)
Try
applicationElementDictionary = application.FindGdsRegistrations(gdsEndpointDescriptor)
Catch uaException As UAException
Console.WriteLine("*** Failure: {0}", uaException.GetBaseException.Message)
Exit Sub
End Try
' Display results
For Each pair In applicationElementDictionary
Console.WriteLine()
Console.WriteLine("Application ID: {0}", pair.Key)
Dim applicationElement = pair.Value
Console.WriteLine("Application element: {0}", applicationElement)
Console.WriteLine(" Application URI string: {0}", applicationElement.ApplicationUriString)
Console.WriteLine(" Discovery URI strings: {0}", applicationElement.DiscoveryUriStrings)
Console.WriteLine(" Product URI string: {0}", applicationElement.ProductUriString)
Next pair
End Sub
End Class
End Namespace
// Shows how to find all application's registrations in the GDS.
class procedure FindGdsRegistrations.Main;
var
Application: TEasyUAApplication;
ApplicationElement: _UAApplicationElement;
ApplicationElementDictionary: _UANodeIdUAApplicationElementReadOnlyDictionary;
ApplicationId: _UANodeId;
Count: Cardinal;
Element: OleVariant;
Enumerator: IEnumVARIANT;
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);
// Find all application's registrations in the GDS.
try
ApplicationElementDictionary := Application.FindGdsRegistrations(GdsEndpointDescriptor);
except
on E: EOleException do
begin
WriteLn(Format('*** Failure: %s', [E.GetBaseException.Message]));
end;
end;
// Display results
Enumerator := ApplicationElementDictionary.GetEnumerator;
while (Enumerator.Next(1, Element, Count) = S_OK) do
begin
WriteLn;
ApplicationId := IUnknown(Element.Key) as _UANodeId;
WriteLn('Application ID: ', ApplicationId.ToString);
ApplicationElement := IUnknown(Element.Value) as _UAApplicationElement;
WriteLn(' Application URI string: ', ApplicationElement.ApplicationUriString);
WriteLn(' Discovery URI string: ', ApplicationElement.DiscoveryUriString);
WriteLn(' Product URI string: ', ApplicationElement.ProductUriString);
end;
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