Notification Method (DEasyAEClientEvents)

Raised for every OPC event subscribed to by the SubscribeEvents method. This method can be called whether this is a refresh or standard event notification.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<DispIdAttribute(1002)>
Sub Notification( _
   ByVal sender0 As Object, _
   ByVal eventArgs As EasyAENotificationEventArgs _
)

'Usage
 
Dim instance As DEasyAEClientEvents
Dim sender0 As Object
Dim eventArgs As EasyAENotificationEventArgs
 
instance.Notification(sender0, eventArgs)

[DispId(1002)]
void Notification( 
   object sender0,
   EasyAENotificationEventArgs eventArgs
)

[DispId(1002)]
void Notification( 
   Object^ sender0,
   EasyAENotificationEventArgs^ eventArgs
)

Parameters

sender0
eventArgs

Example

.NET

COM

.NET

CSharp
PowerShell
Python
VB.NET

// This example shows how to subscribe to events and display the event message with each notification. It also shows how to 
// unsubscribe afterwards.

using System;
using System.Threading;
using OpcLabs.EasyOpc.AlarmsAndEvents;
using OpcLabs.EasyOpc.AlarmsAndEvents.OperationModel;

namespace DocExamples.AlarmsAndEvents._EasyAEClient
{
    partial class SubscribeEvents
    {
        public static void Main1()
        {
            // Instantiate the client object.
            using (var client = new EasyAEClient())
            {
                var eventHandler = new EasyAENotificationEventHandler(client_Notification);
                client.Notification += eventHandler;

                int handle = client.SubscribeEvents("", "OPCLabs.KitEventServer.2", 1000);

                Console.WriteLine("Processing event notifications for 1 minute...");
                Thread.Sleep(60 * 1000);

                client.UnsubscribeEvents(handle);
            }
        }

        // Notification event handler
        static void client_Notification(object sender, EasyAENotificationEventArgs e)
        {
            if (!e.Succeeded)
            {
                Console.WriteLine("*** Failure: {0}", e.ErrorMessageBrief);
                return;
            }
            if (!(e.EventData is null))
                Console.WriteLine(e.EventData.Message);
        }
    }
}

# This example shows how to subscribe to events and display the event message with each notification. It also shows how to 
# unsubscribe afterwards.

#requires -Version 5.1
using namespace OpcLabs.EasyOpc.AlarmsAndEvents

# The path below assumes that the current directory is [ProductDir]/Examples-NET/PowerShell/Windows .
Add-Type -Path "../../../Components/Opclabs.QuickOpc/net472/OpcLabs.EasyOpcClassicCore.dll"
Add-Type -Path "../../../Components/Opclabs.QuickOpc/net472/OpcLabs.EasyOpcClassic.dll"
Add-Type -Path "../../../Components/Opclabs.QuickOpc/net472/OpcLabs.EasyOpcClassicComponents.dll"

# Instantiate the client object.
$client = New-Object EasyAEClient

# Notification event handler
Register-ObjectEvent -InputObject $client -EventName Notification -Action { 
    if (-not $EventArgs.Succeeded) {
        Write-Host "*** Failure: $($EventArgs.ErrorMessageBrief)"
        #return
    }
    if ($EventArgs.EventData -ne $null) {
        Write-Host $EventArgs.EventData.Message
    }
}

Write-Host "Subscribing events..."
$handle = [IEasyAEClientExtension]::SubscribeEvents($client, "", "OPCLabs.KitEventServer.2", 1000)

Write-Host "Processing event notifications for 1 minute..."
$stopwatch =  [System.Diagnostics.Stopwatch]::StartNew() 
while ($stopwatch.Elapsed.TotalSeconds -lt 60) {    
    Start-Sleep -Seconds 1
}

Write-Host "Unsubscribing events..."
$client.UnsubscribeEvents($handle)

Write-Host "Finished."

# This example shows how to subscribe to events and display the event message with each notification. It also shows how
# to unsubscribe afterwards.

# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc
import time

# Import .NET namespaces.
from OpcLabs.EasyOpc import *
from OpcLabs.EasyOpc.AlarmsAndEvents import *


# Notification event handler
def notification(sender, e):
    if not e.Succeeded:
        print('*** Failure: ', e.ErrorMessageBrief, sep='')
        return
    else:
        if e.EventData is not None:
            print(e.EventData.Message)


# Instantiate the client object
client = EasyAEClient()

client.Notification += notification

print('Subscribing events...')
handle = IEasyAEClientExtension.SubscribeEvents(client, '', 'OPCLabs.KitEventServer.2', 1000)

print('Processing event notifications for 1 minute...')
time.sleep(60)

print('Unsubscribing events...')
client.UnsubscribeAllEvents()

client.Notification -= notification

print('Finished.')

' This example shows how to subscribe to events and display the event message with each notification. It also shows how to 
' unsubscribe afterwards.

Imports System.Threading
Imports OpcLabs.EasyOpc.AlarmsAndEvents
Imports OpcLabs.EasyOpc.AlarmsAndEvents.OperationModel

Namespace AlarmsAndEvents._EasyAEClient
    Partial Friend Class SubscribeEvents
        Public Shared Sub Main1()
            Using client = New EasyAEClient()
                Dim eventHandler = New EasyAENotificationEventHandler(AddressOf client_Notification)
                AddHandler client.Notification, eventHandler

                Dim handle As Integer = client.SubscribeEvents("", "OPCLabs.KitEventServer.2", 1000)

                Console.WriteLine("Processing event notifications for 1 minute...")
                Thread.Sleep(60 * 1000)

                client.UnsubscribeEvents(handle)
            End Using
        End Sub

        ' Notification event handler
        Private Shared Sub client_Notification(ByVal sender As Object, ByVal e As EasyAENotificationEventArgs)
            If Not e.Succeeded Then
                Console.WriteLine("*** Failure: {0}", e.ErrorMessageBrief)
                Exit Sub
            End If
            If e.EventData IsNot Nothing Then
                Console.WriteLine(e.EventData.Message)
            End If
        End Sub
    End Class
End Namespace

PHP
Visual Basic (VB 6.0)

// This example shows how to subscribe to events and display the event message with each notification. It also shows how to
// unsubscribe afterwards.

class DEasyEAClientEvents {
    function Notification($Sender, $E)
    {
        if (!($E->Succeeded))
        {
            printf("*** Failure: %s\n", $E->ErrorMessageBrief);
            Exit();
        }

        if (!is_null($E->EventData))
        {
            print $E->EventData->Message;
            print "\n";
        }
    }
}

$ServerDescriptor = new COM("OpcLabs.EasyOpc.ServerDescriptor");
$ServerDescriptor->ServerClass = "OPCLabs.KitEventServer.2";

$Client = new COM("OpcLabs.EasyOpc.AlarmsAndEvents.EasyAEClient");
$Events = new DEasyEAClientEvents();
com_event_sink($Client, $Events, "DEasyEAClientEvents");

print "Subscribing events...\n";
$SubscriptionParameters = new COM("OpcLabs.EasyOpc.AlarmsAndEvents.AESubscriptionParameters");
$SubscriptionParameters->NotificationRate = 1000;
$handle = $Client->SubscribeEvents($ServerDescriptor, $SubscriptionParameters, TRUE, NULL);

print "Processing event notifications for 1 minute...\n";
$startTime = time(); do { com_message_pump(1000); } while (time() < $startTime + 60);

print "Unsubscribing events...\n";
$Client->UnsubscribeEvents($handle);

print "Finished.\n";

Rem This example shows how to subscribe to events and display the event message with each notification. It also shows how to
Rem unsubscribe afterwards.

Private Sub SubscribeEvents_Main_Command_Click()
    OutputText = ""
    
    Dim serverDescriptor As New serverDescriptor
    serverDescriptor.ServerClass = "OPCLabs.KitEventServer.2"
    
    ' Instantiate the client object and hook events
    Set Client1 = New EasyAEClient
    
    OutputText = OutputText & "Subscribing..." & vbCrLf
    Dim subscriptionParameters As New AESubscriptionParameters
    subscriptionParameters.notificationRate = 1000
    Dim handle
    Dim state
    handle = Client1.SubscribeEvents(serverDescriptor, subscriptionParameters, True, state)

    OutputText = OutputText & "Processing event notifications for 1 minute..." & vbCrLf
    Pause 60000

    OutputText = OutputText & "Unsubscribing events..." & vbCrLf
    Client1.UnsubscribeEvents handle

    OutputText = OutputText & "Waiting for 5 seconds..." & vbCrLf
    Pause 5000

    OutputText = OutputText & "Finished." & vbCrLf

    Set Client1 = Nothing
End Sub

Private Sub Client1_OnNotification(ByVal sender As Variant, ByVal eventArgs As EasyAENotificationEventArgs)
    If Not eventArgs.Succeeded Then
        OutputText = OutputText & eventArgs.ErrorMessageBrief & vbCrLf
        Exit Sub
    End If
    If Not eventArgs.EventData Is Nothing Then
        OutputText = OutputText & eventArgs.EventData.Message & vbCrLf
    End If
End Sub

CSharp
VB.NET

// This example shows how to work with Software Tolbox TOP Server 5 Alarms and Events.
// Use simdemo_WithA&E.opf configuration file and write a value above 1000 to Channel1.Device1.Tag1 or Channel1.Device1.Tag2.

using System;
using System.Diagnostics;
using System.Threading;
using OpcLabs.EasyOpc.AlarmsAndEvents;
using OpcLabs.EasyOpc.AlarmsAndEvents.AddressSpace;
using OpcLabs.EasyOpc.AlarmsAndEvents.OperationModel;
using OpcLabs.EasyOpc.OperationModel;

namespace DocExamples.AlarmsAndEvents.SWToolbox
{
    class TOPServer_AE
    {
        public static void Main1()
        {
            // Instantiate the client object.
            var client = new EasyAEClient();

            // Browse for some areas and sources

            AENodeElementCollection areaElements;
            try
            {
                areaElements = client.BrowseAreas("", "SWToolbox.TOPServer_AE.V5", "");
            }
            catch (OpcException opcException)
            {
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message);
                return;
            }

            foreach (AENodeElement areaElement in areaElements)
            {
                Debug.Assert(!(areaElement is null));
                Debug.Assert(!(areaElement.QualifiedName is null));

                Console.WriteLine("areaElements[\"{0}\"]:", areaElement.Name);
                Console.WriteLine("    .QualifiedName: {0}", areaElement.QualifiedName);

                AENodeElementCollection sourceElements =
                    client.BrowseSources("", "SWToolbox.TOPServer_AE.V5", areaElement.QualifiedName);
                foreach (AENodeElement sourceElement in sourceElements)
                {
                    Debug.Assert(sourceElement != null);

                    Console.WriteLine("    sourceElements[\"{0}\"]:", sourceElement.Name);
                    Console.WriteLine("        .QualifiedName: {0}", sourceElement.QualifiedName);
                }
            }

            // Query for event categories

            AECategoryElementCollection categoryElements;
            try
            {
                categoryElements = client.QueryEventCategories("", "SWToolbox.TOPServer_AE.V5");
            }
            catch (OpcException opcException)
            {
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message);
                return;
            }

            foreach (AECategoryElement categoryElement in categoryElements)
            {
                Debug.Assert(categoryElement != null);
                Console.WriteLine("CategoryElements[\"{0}\"].Description: {1}", categoryElement.CategoryId,
                                  categoryElement.Description);
            }

            // Subscribe to events, wait, and unsubscribe

            var eventHandler = new EasyAENotificationEventHandler(client_Notification);
            client.Notification += eventHandler;

            int handle = client.SubscribeEvents("", "SWToolbox.TOPServer_AE.V5", 1000);

            Console.WriteLine("Processing event notifications for 1 minute...");
            Thread.Sleep(60 * 1000);

            client.UnsubscribeEvents(handle);
        }

        // Notification event handler
        static void client_Notification(object sender, EasyAENotificationEventArgs e)
        {
            if (!(e.Exception is null)) Console.WriteLine("e.Exception.Message: {0}", e.Exception.Message);
            if (!(e.Exception is null)) Console.WriteLine("e.Exception.Source: {0}", e.Exception.Source);
            Console.WriteLine("e.Refresh: {0}", e.Refresh);
            Console.WriteLine("e.RefreshComplete: {0}", e.RefreshComplete);
            if (!(e.EventData is null)) Console.WriteLine("e.EventData.QualifiedSourceName: {0}", e.EventData.QualifiedSourceName);
            if (!(e.EventData is null)) Console.WriteLine("e.EventData.Time: {0}", e.EventData.Time);
            if (!(e.EventData is null)) Console.WriteLine("e.EventData.Message: {0}", e.EventData.Message);
            if (!(e.EventData is null)) Console.WriteLine("e.EventData.EventType: {0}", e.EventData.EventType);
            if (!(e.EventData is null)) Console.WriteLine("e.EventData.CategoryId: {0}", e.EventData.CategoryId);
            if (!(e.EventData is null)) Console.WriteLine("e.EventData.Severity: {0}", e.EventData.Severity);
            if (!(e.EventData is null)) Console.WriteLine("e.EventData.ConditionName: {0}", e.EventData.ConditionName);
            if (!(e.EventData is null)) Console.WriteLine("e.EventData.SubconditionName: {0}", e.EventData.SubconditionName);
            if (!(e.EventData is null)) Console.WriteLine("e.EventData.Enabled: {0}", e.EventData.Enabled);
            if (!(e.EventData is null)) Console.WriteLine("e.EventData.Active: {0}", e.EventData.Active);
            if (!(e.EventData is null)) Console.WriteLine("e.EventData.Acknowledged: {0}", e.EventData.Acknowledged);
            if (!(e.EventData is null)) Console.WriteLine("e.EventData.Quality: {0}", e.EventData.Quality);
            if (!(e.EventData is null)) Console.WriteLine("e.EventData.AcknowledgeRequired: {0}", e.EventData.AcknowledgeRequired);
            if (!(e.EventData is null)) Console.WriteLine("e.EventData.ActiveTime: {0}", e.EventData.ActiveTime);
        }
    }
}

' This example shows how to work with Software Tolbox TOP Server 5 Alarms and Events.
' Use simdemo_WithA&E.opf configuration file and write a value above 1000 to Channel1.Device1.Tag1 or Channel1.Device1.Tag2.

Imports System.Threading
Imports OpcLabs.EasyOpc.AlarmsAndEvents
Imports OpcLabs.EasyOpc.AlarmsAndEvents.AddressSpace
Imports OpcLabs.EasyOpc.AlarmsAndEvents.OperationModel
Imports OpcLabs.EasyOpc.OperationModel

Namespace AlarmsAndEvents.SWToolbox

    Friend Class TOPServer_AE
        Public Shared Sub Main1()
            Dim client = New EasyAEClient()

            ' Browse for some areas and sources

            Dim areaElements As AENodeElementCollection
            Try
                areaElements = client.BrowseAreas("", "SWToolbox.TOPServer_AE.V5", "")
            Catch opcException As OpcException
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message)
                Exit Sub
            End Try

            For Each areaElement As AENodeElement In areaElements
                Debug.Assert(areaElement IsNot Nothing)
                Debug.Assert(areaElement.QualifiedName IsNot Nothing)

                Console.WriteLine("areaElements[""{0}""]:", areaElement.Name)
                Console.WriteLine("    .QualifiedName: {0}", areaElement.QualifiedName)

                Dim sourceElements As AENodeElementCollection = client.BrowseSources("", "SWToolbox.TOPServer_AE.V5", areaElement.QualifiedName)
                For Each sourceElement As AENodeElement In sourceElements
                    Debug.Assert(sourceElement IsNot Nothing)

                    Console.WriteLine("    sourceElements[""{0}""]:", sourceElement.Name)
                    Console.WriteLine("        .QualifiedName: {0}", sourceElement.QualifiedName)
                Next sourceElement
            Next areaElement

            ' Query for event categories

            Dim categoryElements As AECategoryElementCollection
            Try
                categoryElements = client.QueryEventCategories("", "SWToolbox.TOPServer_AE.V5")
            Catch opcException As OpcException
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message)
                Exit Sub
            End Try

            For Each categoryElement As AECategoryElement In categoryElements
                Debug.Assert(categoryElement IsNot Nothing)
                Console.WriteLine("CategoryElements[""{0}""].Description: {1}", categoryElement.CategoryId, categoryElement.Description)
            Next categoryElement

            ' Subscribe to events, wait, and unsubscribe

            Dim eventHandler = New EasyAENotificationEventHandler(AddressOf client_Notification)
            AddHandler client.Notification, eventHandler

            Dim handle As Integer = client.SubscribeEvents("", "SWToolbox.TOPServer_AE.V5", 1000)

            Console.WriteLine("Processing event notifications for 1 minute...")
            Thread.Sleep(60 * 1000)

            client.UnsubscribeEvents(handle)
        End Sub

        ' Notification event handler
        Private Shared Sub client_Notification(ByVal sender As Object, ByVal e As EasyAENotificationEventArgs)
            If e.Exception IsNot Nothing Then
                Console.WriteLine("e.Exception.Message: {0}", e.Exception.Message)
            End If
            If e.Exception IsNot Nothing Then
                Console.WriteLine("e.Exception.Source: {0}", e.Exception.Source)
            End If
            Console.WriteLine("e.Refresh: {0}", e.Refresh)
            Console.WriteLine("e.RefreshComplete: {0}", e.RefreshComplete)
            If e.EventData IsNot Nothing Then
                Console.WriteLine("e.EventData.QualifiedSourceName: {0}", e.EventData.QualifiedSourceName)
            End If
            If e.EventData IsNot Nothing Then
                Console.WriteLine("e.EventData.Time: {0}", e.EventData.Time)
            End If
            If e.EventData IsNot Nothing Then
                Console.WriteLine("e.EventData.Message: {0}", e.EventData.Message)
            End If
            If e.EventData IsNot Nothing Then
                Console.WriteLine("e.EventData.EventType: {0}", e.EventData.EventType)
            End If
            If e.EventData IsNot Nothing Then
                Console.WriteLine("e.EventData.CategoryId: {0}", e.EventData.CategoryId)
            End If
            If e.EventData IsNot Nothing Then
                Console.WriteLine("e.EventData.Severity: {0}", e.EventData.Severity)
            End If
            If e.EventData IsNot Nothing Then
                Console.WriteLine("e.EventData.ConditionName: {0}", e.EventData.ConditionName)
            End If
            If e.EventData IsNot Nothing Then
                Console.WriteLine("e.EventData.SubconditionName: {0}", e.EventData.SubconditionName)
            End If
            If e.EventData IsNot Nothing Then
                Console.WriteLine("e.EventData.Enabled: {0}", e.EventData.Enabled)
            End If
            If e.EventData IsNot Nothing Then
                Console.WriteLine("e.EventData.Active: {0}", e.EventData.Active)
            End If
            If e.EventData IsNot Nothing Then
                Console.WriteLine("e.EventData.Acknowledged: {0}", e.EventData.Acknowledged)
            End If
            If e.EventData IsNot Nothing Then
                Console.WriteLine("e.EventData.Quality: {0}", e.EventData.Quality)
            End If
            If e.EventData IsNot Nothing Then
                Console.WriteLine("e.EventData.AcknowledgeRequired: {0}", e.EventData.AcknowledgeRequired)
            End If
            If e.EventData IsNot Nothing Then
                Console.WriteLine("e.EventData.ActiveTime: {0}", e.EventData.ActiveTime)
            End If
        End Sub
    End Class

End Namespace

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

DEasyAEClientEvents Interface
DEasyAEClientEvents Members

Send Documentation Feedback. Resources: Knowledge Base. Technical support: Online Forums, FAQ.