Isolated Property (EasyUAClientCore)

Specifies that you wish that the EasyUAClientCore object instance works with an "isolated" connection to the OPC-UA server, i.e. one that is not shared with other instances.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<DefaultValueAttribute(False)>
Public Property Isolated As Boolean

'Usage
 
Dim instance As EasyUAClientCore
Dim value As Boolean
 
instance.Isolated = value
 
value = instance.Isolated

[DefaultValue(false)]
public bool Isolated {get; set;}

[DefaultValue(false)]
public:
property bool Isolated {
   bool get();
   void set (    bool value);
}

Remarks

This method or property does not throw any exceptions, aside from execution exceptions such as System.Threading.ThreadAbortException or System.OutOfMemoryException.

Example

// This example shows how to create and use two isolated client objects, resulting in two separate connections to the target
// OPC UA server.

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

namespace UADocExamples._EasyUAClient
{
    class Isolated
    {
        public static void Main1()
        {
            UAEndpointDescriptor endpointDescriptor =
                "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer";
            // or "http://opcua.demo-this.com:51211/UA/SampleServer" (currently not supported)
            // or "https://opcua.demo-this.com:51212/UA/SampleServer/"

            // Instantiate the client objects and make them isolated
            var client1 = new EasyUAClient { Isolated = true };
            var client2 = new EasyUAClient { Isolated = true };

            // The callback is a local method the displays the value
            void DataChangeCallback(object sender, EasyUADataChangeNotificationEventArgs eventArgs)
            {
                Debug.Assert(!(eventArgs is null));

                Console.Write($"[{eventArgs.Arguments.State}] ");
                if (eventArgs.Succeeded)
                {
                    Debug.Assert(!(eventArgs.AttributeData is null));
                    Console.WriteLine(eventArgs.AttributeData.ToString());
                }
                else
                    Console.WriteLine("*** Failure: {0}", eventArgs.ErrorMessageBrief);
            }

            Console.WriteLine("Subscribing...");
            client1.SubscribeDataChange(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10853", 1000, 
                DataChangeCallback, state: 1);
            client2.SubscribeDataChange(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10853", 1000,
                DataChangeCallback, state: 2);

            Console.WriteLine("Processing data change events for 10 seconds...");
            System.Threading.Thread.Sleep(10 * 1000);

            Console.WriteLine("Unsubscribing...");
            client1.UnsubscribeAllMonitoredItems();
            client2.UnsubscribeAllMonitoredItems();

            Console.WriteLine("Waiting for 2 seconds...");
            System.Threading.Thread.Sleep(2 * 1000);
        }
    }
}

# This example shows how to create and use two isolated client objects, resulting in two separate connections to the
# target OPC UA server.

# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc
import time

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


# The callback is a regular method the displays the value.
def dataChangeCallback(sender, eventArgs):
    print('[', eventArgs.Arguments.State, '] ', sep='', end='')
    if eventArgs.Succeeded:
        assert eventArgs.AttributeData is not None
        print('Value: ', eventArgs.AttributeData.Value, sep='')
    else:
        print('*** Failure: ', eventArgs.ErrorMessageBrief, sep='')


endpointDescriptor = UAEndpointDescriptor('opc.tcp://opcua.demo-this.com:51210/UA/SampleServer')
# or 'http://opcua.demo-this.com:51211/UA/SampleServer' (currently not supported)
# or 'https://opcua.demo-this.com:51212/UA/SampleServer/'

# Instantiate the client objects and make them isolated.
client1 = EasyUAClient()
client1.Isolated = True
client2 = EasyUAClient()
client2.Isolated = True

print('Subscribing...')
IEasyUAClientExtension.SubscribeDataChange(client1,
    endpointDescriptor,
    UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10853'),
    1000,
    EasyUADataChangeNotificationEventHandler(dataChangeCallback),
    1)  # state
IEasyUAClientExtension.SubscribeDataChange(client2,
    endpointDescriptor,
    UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10853'),
    1000,
    EasyUADataChangeNotificationEventHandler(dataChangeCallback),
    2)  # state

print('Processing data change events for 10 seconds...')
time.sleep(10)

print('Unsubscribing...')
client1.UnsubscribeAllMonitoredItems()
client2.UnsubscribeAllMonitoredItems()

print('Waiting for 2 seconds...')
time.sleep(2)

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

Reference

EasyUAClientCore Class
EasyUAClientCore Members

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