PullEventNotificationQueueCapacity Property (EasyUAClientCore)

Capacity of the event pull queue for event notifications.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<ValueRangeAttribute(0, 2147483647)>
Public Property PullEventNotificationQueueCapacity As Integer

'Usage
 
Dim instance As EasyUAClientCore
Dim value As Integer
 
instance.PullEventNotificationQueueCapacity = value
 
value = instance.PullEventNotificationQueueCapacity

[ValueRange(0, 2147483647)]
public int PullEventNotificationQueueCapacity {get; set;}

[ValueRange(0, 2147483647)]
public:
property int PullEventNotificationQueueCapacity {
   int get();
   void set (    int value);
}

Property Value

Valid values of this property are in the range from 0 to 2147483647 (Int32.MaxValue).

The default value of this property is 0.

Exceptions

Exception	Description
System.ArgumentOutOfRangeException	The value of an argument is outside the allowable range of values as defined by the invoked method. 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.

Exception

Description

System.ArgumentOutOfRangeException

The value of an argument is outside the allowable range of values as defined by the invoked method.

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.

Example

CSharp
VB.NET
Free Pascal
Object Pascal
PHP
Python

// This example shows how to subscribe to event notifications, pull events, and display each incoming event.
//
// 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;
using OpcLabs.EasyOpc.UA.AddressSpace.Standard;
using OpcLabs.EasyOpc.UA.OperationModel;

namespace UADocExamples.AlarmsAndConditions
{
    class PullEventNotification
    {
        public static void Main1()
        {
            // Define which server we will work with.
            UAEndpointDescriptor endpointDescriptor =
                "opc.tcp://opcua.demo-this.com:62544/Quickstarts/AlarmConditionServer";

            // Instantiate the client object.
            // In order to use event pull, you must set a non-zero queue capacity upfront.
            var client = new EasyUAClient { PullEventNotificationQueueCapacity = 1000 };

            Console.WriteLine("Subscribing...");
            client.SubscribeEvent(endpointDescriptor, UAObjectIds.Server, 1000);

            Console.WriteLine("Processing event notifications for 30 seconds...");
            int endTick = Environment.TickCount + 30 * 1000;
            do
            {
                EasyUAEventNotificationEventArgs eventArgs = client.PullEventNotification(2 * 1000);
                if (!(eventArgs is null))
                    // Handle the notification event.
                    Console.WriteLine(eventArgs);
            } while (Environment.TickCount < endTick);

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

            Console.WriteLine("Finished.");
        }

        // Example output (truncated):
        //Subscribing...
        //Processing event notifications for 30 seconds...
        //[] Success
        //[] Success; Refresh; RefreshInitiated
        //[] Success; Refresh; (10 field results) [EastTank] 100! "The dialog was activated" @9/10/2019 8:08:23 PM
        //[] Success; Refresh; (10 field results) [EastTank] 500! "The alarm was acknoweledged." @10/14/2019 4:00:13 PM
        //[] Success; Refresh; (10 field results) [EastTank] 100! "The alarm was acknoweledged." @11/9/2019 9:56:23 AM
        //[] Success; Refresh; (10 field results) [EastTank] 500! "The alarm was acknoweledged." @10/14/2019 4:00:17 PM
        //[] Success; Refresh; (10 field results) [EastTank] 100! "The alarm severity has increased." @9/10/2019 8:09:07 PM
        //[] Success; Refresh; (10 field results) [EastTank] 100! "The alarm severity has increased." @9/10/2019 8:10:09 PM
        //[] Success; Refresh; (10 field results) [NorthMotor] 100! "The dialog was activated" @9/10/2019 8:08:25 PM
        //[] Success; Refresh; (10 field results) [NorthMotor] 500! "The alarm was acknoweledged." @10/14/2019 4:00:02 PM
        //[] Success; Refresh; (10 field results) [NorthMotor] 500! "The alarm was acknoweledged." @10/14/2019 4:00:16 PM
        //[] Success; Refresh; (10 field results) [NorthMotor] 300! "The alarm severity has increased." @11/9/2019 10:29:42 AM
        //[] Success; Refresh; (10 field results) [NorthMotor] 100! "The alarm severity has increased." @9/10/2019 8:09:11 PM
        //[] Success; Refresh; (10 field results) [NorthMotor] 100! "The alarm severity has increased." @9/10/2019 8:10:19 PM
        //[] Success; Refresh; (10 field results) [WestTank] 100! "The dialog was activated" @9/10/2019 8:08:25 PM
        //[] Success; Refresh; (10 field results) [WestTank] 300! "The alarm was acknoweledged." @10/14/2019 4:00:12 PM
        //[] Success; Refresh; (10 field results) [WestTank] 300! "The alarm severity has increased." @11/9/2019 10:29:42 AM
        //[] Success; Refresh; (10 field results) [WestTank] 300! "The alarm was acknoweledged." @10/14/2019 4:00:04 PM
        //[] Success; Refresh; (10 field results) [WestTank] 100! "The alarm severity has increased." @9/10/2019 8:08:58 PM
        //[] Success; Refresh; (10 field results) [WestTank] 100! "The alarm severity has increased." @9/10/2019 8:09:48 PM
        //[] Success; Refresh; (10 field results) [SouthMotor] 100! "The dialog was activated" @9/10/2019 8:08:25 PM
        //[] Success; Refresh; (10 field results) [SouthMotor] 300! "The alarm severity has increased." @11/9/2019 10:29:42 AM
        //[] Success; Refresh; (10 field results) [SouthMotor] 700! "The alarm was acknoweledged." @10/14/2019 4:00:21 PM
        //[] Success; Refresh; (10 field results) [SouthMotor] 500! "The alarm was acknoweledged." @10/14/2019 4:00:03 PM
        //[] Success; Refresh; (10 field results) [SouthMotor] 100! "The alarm severity has increased." @9/10/2019 8:09:02 PM
        //[] Success; Refresh; (10 field results) [SouthMotor] 100! "The alarm severity has increased." @9/10/2019 8:09:59 PM
        //[] Success; Refresh; RefreshComplete
        //[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:43 AM
        //[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:43 AM
        //[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:44 AM
        //[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:44 AM
        //[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:45 AM
        //[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:45 AM
        //[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:46 AM
        //[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:46 AM
        //[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:47 AM
        //[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:47 AM
        //[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:48 AM
        //[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:48 AM
        //[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:49 AM
        //[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:49 AM
        //[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:50 AM
        //[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:50 AM
        //[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:51 AM
        //[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:51 AM
        //[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:52 AM
        //[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:52 AM
        //[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:53 AM
        //[] Success; (10 field results) [NorthMotor] 500! "The alarm severity has increased." @11/9/2019 10:29:53 AM
        //[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:53 AM
        //[] Success; (10 field results) [WestTank] 500! "The alarm severity has increased." @11/9/2019 10:29:53 AM
        //[] Success; (10 field results) [SouthMotor] 500! "The alarm severity has increased." @11/9/2019 10:29:53 AM
        //[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:54 AM
        //[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:54 AM
        //[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:55 AM
        //...
    }
}

' This example shows how to subscribe to event notifications, pull events, and display each incoming event.
'
' 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
Imports OpcLabs.EasyOpc.UA.AddressSpace.Standard
Imports OpcLabs.EasyOpc.UA.OperationModel

Namespace AlarmsAndConditions
    Friend Class PullEventNotification
        Public Shared Sub Main1()
            ' Instantiate the client object
            Dim client = New EasyUAClient()
            ' In order to use event pull, you must set a non-zero queue capacity upfront.
            client.PullEventNotificationQueueCapacity = 1000

            Console.WriteLine("Subscribing...")
            client.SubscribeEvent(
                "opc.tcp://opcua.demo-this.com:62544/Quickstarts/AlarmConditionServer",
                UAObjectIds.Server,
                1000)

            Console.WriteLine("Processing event notifications for 30 seconds...")
            Dim endTick As Integer = Environment.TickCount + 30 * 1000
            Do
                Dim eventArgs As EasyUAEventNotificationEventArgs = client.PullEventNotification(2 * 1000)
                If Not eventArgs Is Nothing Then
                    ' Handle the notification event
                    Console.WriteLine(eventArgs)
                End If
            Loop While Environment.TickCount < endTick
        End Sub
    End Class
End Namespace

// This example shows how to subscribe to event notifications, pull events, and display each incoming event.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
// 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.

class procedure PullEventNotification.Main;
var
  Client: EasyUAClient;
  EndTick: Cardinal;
  EventArgs: _EasyUAEventNotificationEventArgs;
begin
  // Instantiate the client object and hook events
  Client := CoEasyUAClient.Create;
  // In order to use event pull, you must set a non-zero queue capacity upfront.
  Client.PullEventNotificationQueueCapacity := 1000;

  WriteLn('Subscribing...');
  Client.SubscribeEvent(
    'opc.tcp://opcua.demo-this.com:62544/Quickstarts/AlarmConditionServer',
    'nsu=http://opcfoundation.org/UA/;i=2253',  // UAObjectIds.Server
    1000);

  WriteLn('Processing event notifications for 30 seconds...');
  EndTick := GetTickCount + 60*1000;
  while GetTickCount < EndTick do
  begin
    EventArgs := Client.PullEventNotification(2*1000);
    if EventArgs <> nil then
      // Handle the notification event
      WriteLn(EventArgs.ToString);
  end;

  WriteLn('Unsubscribing...');
  Client.UnsubscribeAllMonitoredItems;

  WriteLn('Finished.');
end;

// This example shows how to subscribe to event notifications, pull events, and display each incoming event.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
// OPC client and subscriber examples in Object Pascal (Delphi) on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-OP .
// 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.

class procedure PullEventNotification.Main;
var
  Client: OpcLabs_EasyOpcUA_TLB._EasyUAClient;
  EndTick: Cardinal;
  EventArgs: _EasyUAEventNotificationEventArgs;
begin
  // Instantiate the client object and hook events
  Client := CoEasyUAClient.Create;
  // In order to use event pull, you must set a non-zero queue capacity upfront.
  Client.PullEventNotificationQueueCapacity := 1000;

  WriteLn('Subscribing...');
  Client.SubscribeEvent(
    'opc.tcp://opcua.demo-this.com:62544/Quickstarts/AlarmConditionServer',
    'nsu=http://opcfoundation.org/UA/;i=2253',  // UAObjectIds.Server
    1000);

  WriteLn('Processing event notifications for 30 seconds...');
  EndTick := Ticks + 30*1000;
  while Ticks < EndTick do
  begin
    EventArgs := Client.PullEventNotification(2*1000);
    if EventArgs <> nil then
      // Handle the notification event
      WriteLn(EventArgs.ToString);
  end;

  WriteLn('Unsubscribing...');
  Client.UnsubscribeAllMonitoredItems;

  WriteLn('Finished.');
end;

// Example output (truncated):
//Subscribing...
//Processing event notifications for 30 seconds...
//[] Success
//[] Success; Refresh; RefreshInitiated
//[] Success; Refresh; (10 field results) [EastTank] 100! "The dialog was activated" @9/10/2019 8:08:23 PM
//[] Success; Refresh; (10 field results) [EastTank] 500! "The alarm was acknoweledged." @10/14/2019 4:00:13 PM
//[] Success; Refresh; (10 field results) [EastTank] 100! "The alarm was acknoweledged." @11/9/2019 9:56:23 AM
//[] Success; Refresh; (10 field results) [EastTank] 500! "The alarm was acknoweledged." @10/14/2019 4:00:17 PM
//[] Success; Refresh; (10 field results) [EastTank] 100! "The alarm severity has increased." @9/10/2019 8:09:07 PM
//[] Success; Refresh; (10 field results) [EastTank] 100! "The alarm severity has increased." @9/10/2019 8:10:09 PM
//[] Success; Refresh; (10 field results) [NorthMotor] 100! "The dialog was activated" @9/10/2019 8:08:25 PM
//[] Success; Refresh; (10 field results) [NorthMotor] 500! "The alarm was acknoweledged." @10/14/2019 4:00:02 PM
//[] Success; Refresh; (10 field results) [NorthMotor] 500! "The alarm was acknoweledged." @10/14/2019 4:00:16 PM
//[] Success; Refresh; (10 field results) [NorthMotor] 300! "The alarm severity has increased." @11/9/2019 10:29:42 AM
//[] Success; Refresh; (10 field results) [NorthMotor] 100! "The alarm severity has increased." @9/10/2019 8:09:11 PM
//[] Success; Refresh; (10 field results) [NorthMotor] 100! "The alarm severity has increased." @9/10/2019 8:10:19 PM
//[] Success; Refresh; (10 field results) [WestTank] 100! "The dialog was activated" @9/10/2019 8:08:25 PM
//[] Success; Refresh; (10 field results) [WestTank] 300! "The alarm was acknoweledged." @10/14/2019 4:00:12 PM
//[] Success; Refresh; (10 field results) [WestTank] 300! "The alarm severity has increased." @11/9/2019 10:29:42 AM
//[] Success; Refresh; (10 field results) [WestTank] 300! "The alarm was acknoweledged." @10/14/2019 4:00:04 PM
//[] Success; Refresh; (10 field results) [WestTank] 100! "The alarm severity has increased." @9/10/2019 8:08:58 PM
//[] Success; Refresh; (10 field results) [WestTank] 100! "The alarm severity has increased." @9/10/2019 8:09:48 PM
//[] Success; Refresh; (10 field results) [SouthMotor] 100! "The dialog was activated" @9/10/2019 8:08:25 PM
//[] Success; Refresh; (10 field results) [SouthMotor] 300! "The alarm severity has increased." @11/9/2019 10:29:42 AM
//[] Success; Refresh; (10 field results) [SouthMotor] 700! "The alarm was acknoweledged." @10/14/2019 4:00:21 PM
//[] Success; Refresh; (10 field results) [SouthMotor] 500! "The alarm was acknoweledged." @10/14/2019 4:00:03 PM
//[] Success; Refresh; (10 field results) [SouthMotor] 100! "The alarm severity has increased." @9/10/2019 8:09:02 PM
//[] Success; Refresh; (10 field results) [SouthMotor] 100! "The alarm severity has increased." @9/10/2019 8:09:59 PM
//[] Success; Refresh; RefreshComplete
//[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:43 AM
//[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:43 AM
//[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:44 AM
//[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:44 AM
//[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:45 AM
//[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:45 AM
//[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:46 AM
//[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:46 AM
//[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:47 AM
//[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:47 AM
//[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:48 AM
//[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:48 AM
//[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:49 AM
//[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:49 AM
//[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:50 AM
//[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:50 AM
//[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:51 AM
//[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:51 AM
//[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:52 AM
//[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:52 AM
//[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:53 AM
//[] Success; (10 field results) [NorthMotor] 500! "The alarm severity has increased." @11/9/2019 10:29:53 AM
//[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:53 AM
//[] Success; (10 field results) [WestTank] 500! "The alarm severity has increased." @11/9/2019 10:29:53 AM
//[] Success; (10 field results) [SouthMotor] 500! "The alarm severity has increased." @11/9/2019 10:29:53 AM
//[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:54 AM
//[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:54 AM
//[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:55 AM
//...

// This example shows how to subscribe to event notifications, pull events, and display each incoming event.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
// OPC client and subscriber examples in PHP on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-PHP .
// 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.


// Instantiate the client object and hook events
$Client = new COM("OpcLabs.EasyOpc.UA.EasyUAClient");
$Client->PullEventNotificationQueueCapacity = 1000;

printf("Subscribing...\n");
$Client->SubscribeEvent(
    "opc.tcp://opcua.demo-this.com:62544/Quickstarts/AlarmConditionServer",
    "nsu=http://opcfoundation.org/UA/;i=2253",  // UAObjectIds_Server
    1000);

printf("Processing event notifications for 30 seconds...\n");
$startTime = time(); 
do {
    $EventArgs = $Client->PullEventNotification(2*1000);
    if (!is_null($EventArgs)) {
        // Handle the notification event
        printf("%s\n", $EventArgs);
    }
} while (time() < $startTime + 30);

printf("Unsubscribing...\n");
$Client->UnsubscribeAllMonitoredItems;

printf("Waiting for 5 seconds...\n");
$startTime = time(); do { com_message_pump(1000); } while (time() < $startTime + 5);

// Example output (truncated):
//Subscribing...
//Processing event notifications for 30 seconds...
//[] Success
//[] Success; Refresh; RefreshInitiated
//[] Success; Refresh; (10 field results) [EastTank] 100! "The dialog was activated" @9/10/2019 8:08:23 PM
//[] Success; Refresh; (10 field results) [EastTank] 500! "The alarm was acknoweledged." @10/14/2019 4:00:13 PM
//[] Success; Refresh; (10 field results) [EastTank] 100! "The alarm was acknoweledged." @11/9/2019 9:56:23 AM
//[] Success; Refresh; (10 field results) [EastTank] 500! "The alarm was acknoweledged." @10/14/2019 4:00:17 PM
//[] Success; Refresh; (10 field results) [EastTank] 100! "The alarm severity has increased." @9/10/2019 8:09:07 PM
//[] Success; Refresh; (10 field results) [EastTank] 100! "The alarm severity has increased." @9/10/2019 8:10:09 PM
//[] Success; Refresh; (10 field results) [NorthMotor] 100! "The dialog was activated" @9/10/2019 8:08:25 PM
//[] Success; Refresh; (10 field results) [NorthMotor] 500! "The alarm was acknoweledged." @10/14/2019 4:00:02 PM
//[] Success; Refresh; (10 field results) [NorthMotor] 500! "The alarm was acknoweledged." @10/14/2019 4:00:16 PM
//[] Success; Refresh; (10 field results) [NorthMotor] 300! "The alarm severity has increased." @11/9/2019 10:29:42 AM
//[] Success; Refresh; (10 field results) [NorthMotor] 100! "The alarm severity has increased." @9/10/2019 8:09:11 PM
//[] Success; Refresh; (10 field results) [NorthMotor] 100! "The alarm severity has increased." @9/10/2019 8:10:19 PM
//[] Success; Refresh; (10 field results) [WestTank] 100! "The dialog was activated" @9/10/2019 8:08:25 PM
//[] Success; Refresh; (10 field results) [WestTank] 300! "The alarm was acknoweledged." @10/14/2019 4:00:12 PM
//[] Success; Refresh; (10 field results) [WestTank] 300! "The alarm severity has increased." @11/9/2019 10:29:42 AM
//[] Success; Refresh; (10 field results) [WestTank] 300! "The alarm was acknoweledged." @10/14/2019 4:00:04 PM
//[] Success; Refresh; (10 field results) [WestTank] 100! "The alarm severity has increased." @9/10/2019 8:08:58 PM
//[] Success; Refresh; (10 field results) [WestTank] 100! "The alarm severity has increased." @9/10/2019 8:09:48 PM
//[] Success; Refresh; (10 field results) [SouthMotor] 100! "The dialog was activated" @9/10/2019 8:08:25 PM
//[] Success; Refresh; (10 field results) [SouthMotor] 300! "The alarm severity has increased." @11/9/2019 10:29:42 AM
//[] Success; Refresh; (10 field results) [SouthMotor] 700! "The alarm was acknoweledged." @10/14/2019 4:00:21 PM
//[] Success; Refresh; (10 field results) [SouthMotor] 500! "The alarm was acknoweledged." @10/14/2019 4:00:03 PM
//[] Success; Refresh; (10 field results) [SouthMotor] 100! "The alarm severity has increased." @9/10/2019 8:09:02 PM
//[] Success; Refresh; (10 field results) [SouthMotor] 100! "The alarm severity has increased." @9/10/2019 8:09:59 PM
//[] Success; Refresh; RefreshComplete
//[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:43 AM
//[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:43 AM
//[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:44 AM
//[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:44 AM
//[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:45 AM
//[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:45 AM
//[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:46 AM
//[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:46 AM
//[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:47 AM
//[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:47 AM
//[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:48 AM
//[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:48 AM
//[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:49 AM
//[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:49 AM
//[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:50 AM
//[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:50 AM
//[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:51 AM
//[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:51 AM
//[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:52 AM
//[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:52 AM
//[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:53 AM
//[] Success; (10 field results) [NorthMotor] 500! "The alarm severity has increased." @11/9/2019 10:29:53 AM
//[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:53 AM
//[] Success; (10 field results) [WestTank] 500! "The alarm severity has increased." @11/9/2019 10:29:53 AM
//[] Success; (10 field results) [SouthMotor] 500! "The alarm severity has increased." @11/9/2019 10:29:53 AM
//[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:54 AM
//[] Success; (10 field results) [Internal] 500! "Events Raised" @11/9/2019 10:29:54 AM
//[] Success; (10 field results) [Internal] 500! "Raising Events" @11/9/2019 10:29:55 AM
//...

#  This example shows how to subscribe to event notifications, pull events, and display each incoming event.
#
# 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.AddressSpace.Standard import *
from OpcLabs.EasyOpc.UA.OperationModel import *


# Define which server we will work with.
endpointDescriptor = UAEndpointDescriptor('opc.tcp://opcua.demo-this.com:62544/Quickstarts/AlarmConditionServer')

# Instantiate the client object.
# In order to use event pull, you must set a non-zero queue capacity upfront.
client = EasyUAClient()
client.PullEventNotificationQueueCapacity = 1000

print('Subscribing...')
IEasyUAClientExtension.SubscribeEvent(
    client,
    endpointDescriptor,
    UANodeDescriptor(UAObjectIds.Server),
    1000)

print('Processing event notifications for 30 seconds...')
endTime = time.time() + 30
while time.time() < endTime:
    eventArgs = IEasyUAClientExtension.PullEventNotification(client, 2*1000)
    if eventArgs is not None:
        # Handle the notification event.
        print(eventArgs)

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

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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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.