SessionTimeoutDebug Property (UAClientSessionParameters)

A session timeout used when a debugger is attached (in milliseconds).

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<DefaultValueAttribute(600000)>
<UnitAttribute("ms")>
Public Property SessionTimeoutDebug As Integer

'Usage
 
Dim instance As UAClientSessionParameters
Dim value As Integer
 
instance.SessionTimeoutDebug = value
 
value = instance.SessionTimeoutDebug

[DefaultValue(600000)]
[Unit("ms")]
public int SessionTimeoutDebug {get; set;}

[DefaultValue(600000)]
[Unit("ms")]
public:
property int SessionTimeoutDebug {
   int get();
   void set (    int value);
}

Remarks

This parameter controls the same behavior as the SessionTimeout parameter, but the component uses it when the program is being debugged in the debugger. The default value is quite long, significantly longer than that of the SessionTimeout parameter. This allows the developer to reasonably debug the OPC UA program using e.g. breakpoints. Without prolonging the session timeout, "pausing" the program in the debugger (which means that communication is stopped temporarily) would cause the OPC UA server to detect the session as "broken", resulting in a disconnection of the OPC UA communication. With the long session timeouts, the OPC UA server will allow the client not to communicate permanently, giving the developer a chance to use breakpoints and pause the program as needed.

Note that the actual session timeout that will be used is negotiated between the OPC UA client and OPC UA server. The value of this parameters is only a "request" from the client side, and can be revised by the server - the server has the final word.

In order to obtain or modify this parameter, in the default state (when OpcLabs.EasyOpc.UA.EasyUAClientCore.Isolated equals to false), access UAClientAdaptableParameters.SessionParameters property of static OpcLabs.EasyOpc.UA.EasyUAClientCore.AdaptableParameters. If you have set OpcLabs.EasyOpc.UA.EasyUAClientCore.Isolated to true, you need to access UAClientAdaptableParameters.SessionParameters property of OpcLabs.EasyOpc.UA.EasyUAClientCore.IsolatedParameters.

Example

// This example shows how to set fairly short OPC UA timeouts (failures can thus occur).

using System;
using OpcLabs.EasyOpc.UA;

namespace UADocExamples._UAClientSessionParameters
{
    class Timeouts
    {
        public static void Isolated()
        {
            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 object and set timeouts
            var client = new EasyUAClient
            {
                Isolated = true,
                IsolatedParameters =
                {
                    SessionParameters =
                    {
                        EndpointSelectionTimeout = 1500,
                        SessionConnectTimeout = 3000,
                        SessionTimeout = 3000,
                        SessionTimeoutDebug = 3000
                    }
                }
            };

            Console.WriteLine("Subscribing...");
            // The callback is a lambda expression the displays the value
            client.SubscribeDataChange(endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10853", 1000,
                (sender, eventArgs) =>
                {
                    if (eventArgs.Succeeded)
                        Console.WriteLine("Value: {0}", eventArgs.AttributeData.Value);
                    else
                        Console.WriteLine("*** Failure: {0}", eventArgs.ErrorMessageBrief);
                });

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

            Console.WriteLine("Unsubscribing...");
            client.UnsubscribeAllMonitoredItems();

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

# This example shows how to set fairly short OPC UA timeouts (failures can thus occur).

# 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 *


def dataChangeNotification(sender, eventArgs):
    # Display value.
    if eventArgs.Succeeded:
        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 object and set timeouts.
client = EasyUAClient()
client.Isolated = True
client.IsolatedParameters.SessionParameters.EndpointSelectionTimeout = 1500
client.IsolatedParameters.SessionParameters.SessionConnectTimeout = 3000
client.IsolatedParameters.SessionParameters.SessionTimeout = 3000
client.IsolatedParameters.SessionParameters.SessionTimeoutDebug = 3000

print('Subscribing...')
IEasyUAClientExtension.SubscribeDataChange(client,
    endpointDescriptor,
    UANodeDescriptor('nsu=http://test.org/UA/Data/ ;i=10853'),
    1000,
    EasyUADataChangeNotificationEventHandler(dataChangeNotification))

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

print('Unsubscribing...')
client.UnsubscribeAllMonitoredItems()

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

print('Finished.')

CSharp

// Shows an OPC UA data change observable with specified timeouts.

using OpcLabs.EasyOpc.UA.Reactive;
using System;
using System.Threading;
using OpcLabs.EasyOpc.UA;

namespace ReactiveDocExamples
{
    namespace _UADataChangeNotificationObservable
    {
        partial class Subscribe
        {
            public static void Timeouts()
            {
                // Define which server we will work with.
                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/"

                Console.WriteLine("Creating observable...");
                UADataChangeNotificationObservable<float> observable =
                    UADataChangeNotificationObservable.Create<float>(
                        endpointDescriptor, "nsu=http://test.org/UA/Data/ ;i=10853", 1000);
                // Set fairly short timeouts (failure can thus occur).
                observable.ClientSelector.Isolated = true;
                observable.ClientSelector.IsolatedParameters.SessionParameters.EndpointSelectionTimeout = 1500;
                observable.ClientSelector.IsolatedParameters.SessionParameters.SessionConnectTimeout = 3000;
                observable.ClientSelector.IsolatedParameters.SessionParameters.SessionTimeout = 3000;
                observable.ClientSelector.IsolatedParameters.SessionParameters.SessionTimeoutDebug = 3000;

                Console.WriteLine("Subscribing...");
                using (observable.Subscribe(e => Console.WriteLine(
                    (e.Exception is null) ? e.AttributeData.ToString() : e.Exception.GetBaseException().ToString())))
                {
                    Console.WriteLine("Waiting for 10 seconds...");
                    Thread.Sleep(10*1000);

                    Console.WriteLine("Unsubscribing...");
                }

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

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

UAClientSessionParameters Class
UAClientSessionParameters Members
KeepAliveIntervalDebug Property
SessionTimeout Property

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