PullEventNotificationQueueCapacity Property (EasyUAClient)

Capacity of the event pull queue for event notifications.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<DefaultValueAttribute(0)>
Public Property PullEventNotificationQueueCapacity As Integer

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

[DefaultValue(0)]
public int PullEventNotificationQueueCapacity {get; set;}

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

Remarks

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

Example

CSharp
Free Pascal
Object Pascal
PHP
VB.NET

// This example shows how to subscribe to event notifications, pull events, and display each incoming event.

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.

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.

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.


// 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.

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

Requirements

Target Platforms: .NET Framework: Windows 10 (selected versions), Windows 11 (selected versions), Windows Server 2012 R2, Windows Server 2016; .NET: Linux, macOS, Microsoft Windows

Reference

EasyUAClient Class
EasyUAClient Members

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