Timeouts

For discussion on various OPC Data Client timeout settings for OPC UA, see the QuickOPC-UA Timeout Settings article (in Knowledge Base).

Example

.NET

C#
VB.NET

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

Namespace _UAClientSessionParameters
    Partial Friend Class Timeouts
        Public Shared Sub Isolated()

            ' 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 object and set timeouts
            Dim client = New EasyUAClient() With
                {
                    .Isolated = True,
                    .IsolatedParameters = New Engine.EasyUAClientAdaptableParameters() With
                        {
                            .SessionParameters = New Engine.UASmartClientSessionParameters() With
                                {
                                    .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,
                Sub(sender, eventArgs)
                    If eventArgs.Succeeded Then
                        Console.WriteLine("Value: {0}", eventArgs.AttributeData.Value)
                    Else
                        Console.WriteLine("*** Failure: {0}", eventArgs.ErrorMessageBrief)
                    End If
                End Sub)

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

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

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

Python

Python (.NET)

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


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.')

Server Diagnostics

The DiagnosticsMasks property on the SessionParameters allows the developer to specify the types of vendor-specific diagnostics to be returned by the OPC-UA server in the responses. The information from the server responses is then made available in the Diagnostics collection of OperationResult and EasyDataChangeNotificationEventArgs objects.

Knowledge Base

QuickOPC-UA Timeout Settings