Isolated Property (_EasyUAClient)

Specifies that you wish that the OpcLabs.EasyOpc.UA.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
 
Property Isolated As Boolean

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

bool Isolated {get; set;}

property bool Isolated {
   bool get();
   void set (    bool value);
}

Property Value

The default value of this property is False.

Remarks

The getter method of this property is pure, i.e. it does not have observable side effects.

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.

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

Example

CSharp
VB.NET
Python

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

                string displayPrefix = $"[{eventArgs.Arguments.State}]";
                if (eventArgs.Succeeded)
                {
                    Debug.Assert(!(eventArgs.AttributeData is null));
                    Console.WriteLine($"{displayPrefix} {eventArgs.AttributeData}");
                }
                else
                    Console.WriteLine($"{displayPrefix} *** Failure: {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.
'
' 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 System.Windows.Forms.AxHost
Imports OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.OperationModel

Namespace _EasyUAClient
    Partial Class Isolated
        Public Shared Sub Main1()

            ' Define which server we will work with.
            Dim endpointDescriptor As 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
            Dim client1 = New EasyUAClient() With {.Isolated = True}
            Dim client2 = New EasyUAClient() With {.Isolated = True}

            ' The callback is a local method the displays the value
            Dim dataChangeCallback = Sub(ByVal sender As Object, ByVal eventArgs As EasyUADataChangeNotificationEventArgs)
                                         Debug.Assert(eventArgs IsNot Nothing)

                                         Dim displayPrefix As String = $"[{eventArgs.Arguments.State}]"
                                         If eventArgs.Succeeded Then
                                             Debug.Assert(eventArgs.AttributeData IsNot Nothing)
                                             Console.WriteLine($"{displayPrefix} {eventArgs.AttributeData}")
                                         Else
                                             Console.WriteLine($"{displayPrefix} *** Failure: {eventArgs.ErrorMessageBrief}")
                                         End If
                                     End Sub

            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...")
            Threading.Thread.Sleep(10 * 1000)

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

            Console.WriteLine("Waiting for 2 seconds...")
            Threading.Thread.Sleep(2 * 1000)
        End Sub
    End Class
End Namespace

# This example shows how to create and use two isolated client objects, resulting in two separate connections to the
# target OPC UA server.
#
# 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 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):
    displayPrefix = '[{}]'.format(eventArgs.Arguments.State)
    if eventArgs.Succeeded:
        assert eventArgs.AttributeData is not None
        print(displayPrefix + ' Value: ' + '{}'.format(eventArgs.AttributeData.Value) + '\n', end='')
    else:
        print(displayPrefix + ' *** Failure: ' + eventArgs.ErrorMessageBrief + '\n', end='')


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

_EasyUAClient Interface
_EasyUAClient Members

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Missing some example? Ask us for it on our Online Forums! You do not have to own a commercial license in order to use Online Forums, and we reply to every post.