QuickOPC User's Guide and Reference
EventNotification Event (IEasyUAClient)
Example 



OpcLabs.EasyOpcUA Assembly > OpcLabs.EasyOpc.UA Namespace > IEasyUAClient Interface : EventNotification Event
Raised for every event generated by a subscribed OPC monitored item.
Syntax
'Declaration
 
Event EventNotification As EasyUAEventNotificationEventHandler
'Usage
 
Dim instance As IEasyUAClient
Dim handler As EasyUAEventNotificationEventHandler
 
AddHandler instance.EventNotification, handler
event EasyUAEventNotificationEventHandler EventNotification
event EasyUAEventNotificationEventHandler^ EventNotification
Event Data

The event handler receives an argument of type EasyUAEventNotificationEventArgs containing data related to this event. The following EasyUAEventNotificationEventArgs properties provide information specific to this event.

PropertyDescription
Holds arguments that were used to subscribe to a monitored item in an OPC-UA server.  
Diagnostics information (such as warnings) assembled during the operation. (Inherited from OpcLabs.BaseLib.OperationModel.OperationEventArgs)
Count of diagnostic information elements assembled during the operation. (Inherited from OpcLabs.BaseLib.OperationModel.OperationEventArgs)
Textual summary of diagnostics information, one message per line. (Inherited from OpcLabs.BaseLib.OperationModel.OperationEventArgs)
Gets or sets the error ID of the error. (Inherited from OpcLabs.BaseLib.OperationModel.OperationEventArgs)
Gets or sets a message that describes the current exception. (Inherited from OpcLabs.BaseLib.OperationModel.OperationEventArgs)
The first line of the error message. (Inherited from OpcLabs.BaseLib.OperationModel.OperationEventArgs)
Event notification information.  
Gets the current exception. Contains null reference when no exception. (Inherited from OpcLabs.BaseLib.OperationModel.OperationEventArgs)
A normalized OpcLabs.BaseLib.OperationModel.OperationEventArgs.Diagnostics collection. (Inherited from OpcLabs.BaseLib.OperationModel.OperationEventArgs)
A normalized OpcLabs.BaseLib.OperationModel.OperationEventArgs.Exception object, or null if there was no error. (Inherited from OpcLabs.BaseLib.OperationModel.OperationEventArgs)
Denotes whether this notification was triggered by subscription refresh.  
When True, this notification denotes that the subscription refresh is complete.  
When True, this notification denotes that the subscription refresh has been initiated.  
Status information corresponding to the contents of the event arguments.  
Gets indication whether the operation has succeeded. (Inherited from OpcLabs.BaseLib.OperationModel.OperationEventArgs)
Example
// This example shows how to subscribe to event notifications 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
{
    partial class SubscribeEvent
    {
        public static void Overload1()
        {
            // Define which server we will work with.
            UAEndpointDescriptor endpointDescriptor =
                "opc.tcp://opcua.demo-this.com:62544/Quickstarts/AlarmConditionServer";

            // Instantiate the client object and hook events.
            var client = new EasyUAClient();
            client.EventNotification += client_EventNotification;

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

            Console.WriteLine("Processing event notifications for 30 seconds...");
            System.Threading.Thread.Sleep(30 * 1000);

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

            Console.WriteLine("Waiting for 5 seconds...");
            System.Threading.Thread.Sleep(5 * 1000);

            Console.WriteLine("Finished.");
        }

        static void client_EventNotification(object sender, EasyUAEventNotificationEventArgs e)
        {
            // Display the event.
            Console.WriteLine(e);
        }



        // Example output (truncated):
        //Subscribing...
        //Processing event notifications for 30 seconds...
        //[] Success
        //[] Success; Refresh; RefreshInitiated
        //[] Success; Refresh; [EastTank] 100! {DialogConditionType} "The dialog was activated" @9/9/2021 2:22:18 PM (10 fields)
        //[] Success; Refresh; [EastTank] 100! {ExclusiveDeviationAlarmType} "The alarm is active." @9/9/2021 4:19:37 PM (10 fields)
        //[] Success; Refresh; [EastTank] 500! {NonExclusiveLevelAlarmType} "The alarm severity has increased." @9/9/2021 4:19:35 PM (10 fields)
        //[] Success; Refresh; [EastTank] 900! {TripAlarmType} "The alarm severity has increased." @9/9/2021 4:19:29 PM (10 fields)
        //[] Success; Refresh; [EastTank] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:39:03 PM (10 fields)
        //[] Success; Refresh; [EastTank] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:40:03 PM (10 fields)
        //[] Success; Refresh; [NorthMotor] 100! {DialogConditionType} "The dialog was activated" @9/9/2021 2:22:18 PM (10 fields)
        //[] Success; Refresh; [NorthMotor] 500! {ExclusiveDeviationAlarmType} "The alarm severity has increased." @9/9/2021 4:19:35 PM (10 fields)
        //[] Success; Refresh; [NorthMotor] 900! {NonExclusiveLevelAlarmType} "The alarm severity has increased." @9/9/2021 4:19:29 PM (10 fields)
        //[] Success; Refresh; [NorthMotor] 100! {TripAlarmType} "The alarm is active." @9/9/2021 4:19:32 PM (10 fields)
        //[] Success; Refresh; [NorthMotor] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:39:08 PM (10 fields)
        //[] Success; Refresh; [NorthMotor] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:40:14 PM (10 fields)
        //[] Success; Refresh; [WestTank] 100! {DialogConditionType} "The dialog was activated" @9/9/2021 2:22:18 PM (10 fields)
        //[] Success; Refresh; [WestTank] 900! {ExclusiveDeviationAlarmType} "The alarm severity has increased." @9/9/2021 4:19:29 PM (10 fields)
        //[] Success; Refresh; [WestTank] 100! {NonExclusiveLevelAlarmType} "The alarm is active." @9/9/2021 4:19:32 PM (10 fields)
        //[] Success; Refresh; [WestTank] 100! {TripAlarmType} "The alarm is active." @9/9/2021 4:19:37 PM (10 fields)
        //[] Success; Refresh; [WestTank] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:38:55 PM (10 fields)
        //[] Success; Refresh; [WestTank] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:39:43 PM (10 fields)
        //[] Success; Refresh; [SouthMotor] 100! {DialogConditionType} "The dialog was activated" @9/9/2021 2:22:18 PM (10 fields)
        //[] Success; Refresh; [SouthMotor] 100! {ExclusiveDeviationAlarmType} "The alarm is active." @9/9/2021 4:19:32 PM (10 fields)
        //[] Success; Refresh; [SouthMotor] 100! {NonExclusiveLevelAlarmType} "The alarm is active." @9/9/2021 4:19:37 PM (10 fields)
        //[] Success; Refresh; [SouthMotor] 500! {TripAlarmType} "The alarm severity has increased." @9/9/2021 4:19:35 PM (10 fields)
        //[] Success; Refresh; [SouthMotor] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:39:51 PM (10 fields)
        //[] Success; Refresh; [SouthMotor] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:38:57 PM (10 fields)
        //[] Success; Refresh; RefreshComplete
        //[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:39 PM (10 fields)
        //[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:39 PM (10 fields)
        //[] Success; [EastTank] 100! {TripAlarmType} "The alarm was deactivated by the system." @9/9/2021 4:19:39 PM (10 fields)
        //[] Success; [NorthMotor] 100! {NonExclusiveLevelAlarmType} "The alarm was deactivated by the system." @9/9/2021 4:19:39 PM (10 fields)
        //[] Success; [WestTank] 100! {ExclusiveDeviationAlarmType} "The alarm was deactivated by the system." @9/9/2021 4:19:39 PM (10 fields)
        //[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:40 PM (10 fields)
        //[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:40 PM (10 fields)
        //[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:41 PM (10 fields)
        //[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:41 PM (10 fields)
        //[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:42 PM (10 fields)
        //[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:42 PM (10 fields)
        //[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:43 PM (10 fields)
        //[] Success; [NorthMotor] 300! {TripAlarmType} "The alarm severity has increased." @9/9/2021 4:19:43 PM (10 fields)
        //[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:43 PM (10 fields)
        //[] Success; [WestTank] 300! {NonExclusiveLevelAlarmType} "The alarm severity has increased." @9/9/2021 4:19:43 PM (10 fields)
        //[] Success; [SouthMotor] 300! {ExclusiveDeviationAlarmType} "The alarm severity has increased." @9/9/2021 4:19:43 PM (10 fields)
        //[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:44 PM (10 fields)
        //[] Success; [EastTank] 700! {NonExclusiveLevelAlarmType} "The alarm severity has increased." @9/9/2021 4:19:44 PM (10 fields)
        //[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:44 PM (10 fields)
        //[] Success; [NorthMotor] 700! {ExclusiveDeviationAlarmType} "The alarm severity has increased." @9/9/2021 4:19:44 PM (10 fields)
        //[] Success; [SouthMotor] 700! {TripAlarmType} "The alarm severity has increased." @9/9/2021 4:19:44 PM (10 fields)
        //[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:45 PM (10 fields)
        //[] Success; [EastTank] 300! {ExclusiveDeviationAlarmType} "The alarm severity has increased." @9/9/2021 4:19:45 PM (10 fields)
        //[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:45 PM (10 fields)
        //...
    }
}
# This example shows how to subscribe to event notifications and display each incoming event.

#requires -Version 5.1
using namespace OpcLabs.EasyOpc.UA
using namespace OpcLabs.EasyOpc.UA.AddressSpace
using namespace OpcLabs.EasyOpc.UA.AddressSpace.Standard

# The path below assumes that the current directory is [ProductDir]/Examples-NET/PowerShell/Windows .
Add-Type -Path "../../../Assemblies/net47/OpcLabs.EasyOpcUA.dll"

# Define which server we will work with.
[UAEndpointDescriptor]$endpointDescriptor = "opc.tcp://opcua.demo-this.com:62544/Quickstarts/AlarmConditionServer"

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

# Event notification handler
Register-ObjectEvent -InputObject $client -EventName EventNotification -Action { 
    # Display the event.
    Write-Host $EventArgs
}

Write-Host "Subscribing..."
[IEasyUAClientExtension]::SubscribeEvent($client, $endpointDescriptor, [UAObjectIds]::Server, 1000)

Write-Host "Processing event notifications for 30 seconds..."
$stopwatch =  [System.Diagnostics.Stopwatch]::StartNew() 
while ($stopwatch.Elapsed.TotalSeconds -lt 30) {    
    Start-Sleep -Seconds 1
}

Write-Host "Unsubscribing..."
$client.UnsubscribeAllMonitoredItems()

Write-Host "Waiting for 5 seconds..."
Start-Sleep -Seconds 5

Write-Host "Finished."


# Example output (truncated):
#Subscribing...
#Processing event notifications for 30 seconds...
#[] Success
#[] Success; Refresh; RefreshInitiated
#[] Success; Refresh; [EastTank] 100! {DialogConditionType} "The dialog was activated" @9/9/2021 2:22:18 PM (10 fields)
#[] Success; Refresh; [EastTank] 100! {ExclusiveDeviationAlarmType} "The alarm is active." @9/9/2021 4:19:37 PM (10 fields)
#[] Success; Refresh; [EastTank] 500! {NonExclusiveLevelAlarmType} "The alarm severity has increased." @9/9/2021 4:19:35 PM (10 fields)
#[] Success; Refresh; [EastTank] 900! {TripAlarmType} "The alarm severity has increased." @9/9/2021 4:19:29 PM (10 fields)
#[] Success; Refresh; [EastTank] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:39:03 PM (10 fields)
#[] Success; Refresh; [EastTank] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:40:03 PM (10 fields)
#[] Success; Refresh; [NorthMotor] 100! {DialogConditionType} "The dialog was activated" @9/9/2021 2:22:18 PM (10 fields)
#[] Success; Refresh; [NorthMotor] 500! {ExclusiveDeviationAlarmType} "The alarm severity has increased." @9/9/2021 4:19:35 PM (10 fields)
#[] Success; Refresh; [NorthMotor] 900! {NonExclusiveLevelAlarmType} "The alarm severity has increased." @9/9/2021 4:19:29 PM (10 fields)
#[] Success; Refresh; [NorthMotor] 100! {TripAlarmType} "The alarm is active." @9/9/2021 4:19:32 PM (10 fields)
#[] Success; Refresh; [NorthMotor] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:39:08 PM (10 fields)
#[] Success; Refresh; [NorthMotor] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:40:14 PM (10 fields)
#[] Success; Refresh; [WestTank] 100! {DialogConditionType} "The dialog was activated" @9/9/2021 2:22:18 PM (10 fields)
#[] Success; Refresh; [WestTank] 900! {ExclusiveDeviationAlarmType} "The alarm severity has increased." @9/9/2021 4:19:29 PM (10 fields)
#[] Success; Refresh; [WestTank] 100! {NonExclusiveLevelAlarmType} "The alarm is active." @9/9/2021 4:19:32 PM (10 fields)
#[] Success; Refresh; [WestTank] 100! {TripAlarmType} "The alarm is active." @9/9/2021 4:19:37 PM (10 fields)
#[] Success; Refresh; [WestTank] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:38:55 PM (10 fields)
#[] Success; Refresh; [WestTank] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:39:43 PM (10 fields)
#[] Success; Refresh; [SouthMotor] 100! {DialogConditionType} "The dialog was activated" @9/9/2021 2:22:18 PM (10 fields)
#[] Success; Refresh; [SouthMotor] 100! {ExclusiveDeviationAlarmType} "The alarm is active." @9/9/2021 4:19:32 PM (10 fields)
#[] Success; Refresh; [SouthMotor] 100! {NonExclusiveLevelAlarmType} "The alarm is active." @9/9/2021 4:19:37 PM (10 fields)
#[] Success; Refresh; [SouthMotor] 500! {TripAlarmType} "The alarm severity has increased." @9/9/2021 4:19:35 PM (10 fields)
#[] Success; Refresh; [SouthMotor] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:39:51 PM (10 fields)
#[] Success; Refresh; [SouthMotor] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:38:57 PM (10 fields)
#[] Success; Refresh; RefreshComplete
#[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:39 PM (10 fields)
#[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:39 PM (10 fields)
#[] Success; [EastTank] 100! {TripAlarmType} "The alarm was deactivated by the system." @9/9/2021 4:19:39 PM (10 fields)
#[] Success; [NorthMotor] 100! {NonExclusiveLevelAlarmType} "The alarm was deactivated by the system." @9/9/2021 4:19:39 PM (10 fields)
#[] Success; [WestTank] 100! {ExclusiveDeviationAlarmType} "The alarm was deactivated by the system." @9/9/2021 4:19:39 PM (10 fields)
#[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:40 PM (10 fields)
#[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:40 PM (10 fields)
#[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:41 PM (10 fields)
#[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:41 PM (10 fields)
#[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:42 PM (10 fields)
#[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:42 PM (10 fields)
#[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:43 PM (10 fields)
#[] Success; [NorthMotor] 300! {TripAlarmType} "The alarm severity has increased." @9/9/2021 4:19:43 PM (10 fields)
#[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:43 PM (10 fields)
#[] Success; [WestTank] 300! {NonExclusiveLevelAlarmType} "The alarm severity has increased." @9/9/2021 4:19:43 PM (10 fields)
#[] Success; [SouthMotor] 300! {ExclusiveDeviationAlarmType} "The alarm severity has increased." @9/9/2021 4:19:43 PM (10 fields)
#[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:44 PM (10 fields)
#[] Success; [EastTank] 700! {NonExclusiveLevelAlarmType} "The alarm severity has increased." @9/9/2021 4:19:44 PM (10 fields)
#[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:44 PM (10 fields)
#[] Success; [NorthMotor] 700! {ExclusiveDeviationAlarmType} "The alarm severity has increased." @9/9/2021 4:19:44 PM (10 fields)
#[] Success; [SouthMotor] 700! {TripAlarmType} "The alarm severity has increased." @9/9/2021 4:19:44 PM (10 fields)
#[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:45 PM (10 fields)
#[] Success; [EastTank] 300! {ExclusiveDeviationAlarmType} "The alarm severity has increased." @9/9/2021 4:19:45 PM (10 fields)
#[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:45 PM (10 fields)
#...
// This example shows how to subscribe to event notifications and display each
// incoming event.

type
  TClientEventHandlers2 = class
    procedure OnEventNotification(
      Sender: TObject;
      sender0: OleVariant;
      eventArgs: _EasyUAEventNotificationEventArgs);
  end;

procedure TClientEventHandlers2.OnEventNotification(
  Sender: TObject;
  sender0: OleVariant;
  eventArgs: _EasyUAEventNotificationEventArgs);
begin
  // Display the event
  WriteLn(eventArgs.ToString);
end;

class procedure SubscribeEvent.Main;
var
  Client: EasyUAClient;
  EvsClient: TEvsEasyUAClient;
  ClientEventHandlers2: TClientEventHandlers2;
begin
  // Instantiate the client object and hook events
  EvsClient := TEvsEasyUAClient.Create(nil);
  Client := EvsClient.ComServer;
  ClientEventHandlers2 := TClientEventHandlers2.Create;
  EvsClient.OnEventNotification := @ClientEventHandlers2.OnEventNotification;

  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...');
  PumpSleep(30*1000);

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

  WriteLn('Waiting for 5 seconds...');
  PumpSleep(5*1000);
end;
// This example shows how to subscribe to event notifications and display each incoming event.

type
  TClientEventHandlers18 = class
    procedure Client_EventNotification(
      ASender: TObject;
      sender: OleVariant;
      const eventArgs: _EasyUAEventNotificationEventArgs);
  end;

procedure TClientEventHandlers18.Client_EventNotification(
  ASender: TObject;
  sender: OleVariant;
  const eventArgs: _EasyUAEventNotificationEventArgs);
begin
  // Display the event
  if eventArgs.Succeeded then
    WriteLn(eventArgs.ToString)
  else
    WriteLn(Format('*** Failure: %s', [eventArgs.ErrorMessageBrief]));
end;

class procedure SubscribeEvent.Main;
const
  UAObjectIds_Server = 'nsu=http://opcfoundation.org/UA/;i=2253';
var
  Client: TEasyUAClient;
  ClientEventHandlers: TClientEventHandlers18;
  EndpointDescriptor: string;
begin
  EndpointDescriptor := 'opc.tcp://opcua.demo-this.com:62544/Quickstarts/AlarmConditionServer';

  // Instantiate the client object and hook events
  Client := TEasyUAClient.Create(nil);
  ClientEventHandlers := TClientEventHandlers18.Create;
  Client.OnEventNotification := ClientEventHandlers.Client_EventNotification;

  WriteLn('Subscribing...');
  Client.SubscribeEvent(EndpointDescriptor, UAObjectIds_Server, 1000);

  WriteLn('Processing event notifications for 30 seconds...');
  PumpSleep(30*1000);

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

  WriteLn('Waiting for 5 seconds...');
  Sleep(5*1000);

  WriteLn('Finished.');
  FreeAndNil(Client);
  FreeAndNil(ClientEventHandlers);

end;



// Example output (truncated):
//Subscribing...
//Processing event notifications for 30 seconds...
//[] Success
//[] Success; Refresh; RefreshInitiated
//[] Success; Refresh; [EastTank] 100! {DialogConditionType} "The dialog was activated" @9/9/2021 2:22:18 PM (10 fields)
//[] Success; Refresh; [EastTank] 100! {ExclusiveDeviationAlarmType} "The alarm is active." @9/9/2021 4:19:37 PM (10 fields)
//[] Success; Refresh; [EastTank] 500! {NonExclusiveLevelAlarmType} "The alarm severity has increased." @9/9/2021 4:19:35 PM (10 fields)
//[] Success; Refresh; [EastTank] 900! {TripAlarmType} "The alarm severity has increased." @9/9/2021 4:19:29 PM (10 fields)
//[] Success; Refresh; [EastTank] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:39:03 PM (10 fields)
//[] Success; Refresh; [EastTank] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:40:03 PM (10 fields)
//[] Success; Refresh; [NorthMotor] 100! {DialogConditionType} "The dialog was activated" @9/9/2021 2:22:18 PM (10 fields)
//[] Success; Refresh; [NorthMotor] 500! {ExclusiveDeviationAlarmType} "The alarm severity has increased." @9/9/2021 4:19:35 PM (10 fields)
//[] Success; Refresh; [NorthMotor] 900! {NonExclusiveLevelAlarmType} "The alarm severity has increased." @9/9/2021 4:19:29 PM (10 fields)
//[] Success; Refresh; [NorthMotor] 100! {TripAlarmType} "The alarm is active." @9/9/2021 4:19:32 PM (10 fields)
//[] Success; Refresh; [NorthMotor] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:39:08 PM (10 fields)
//[] Success; Refresh; [NorthMotor] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:40:14 PM (10 fields)
//[] Success; Refresh; [WestTank] 100! {DialogConditionType} "The dialog was activated" @9/9/2021 2:22:18 PM (10 fields)
//[] Success; Refresh; [WestTank] 900! {ExclusiveDeviationAlarmType} "The alarm severity has increased." @9/9/2021 4:19:29 PM (10 fields)
//[] Success; Refresh; [WestTank] 100! {NonExclusiveLevelAlarmType} "The alarm is active." @9/9/2021 4:19:32 PM (10 fields)
//[] Success; Refresh; [WestTank] 100! {TripAlarmType} "The alarm is active." @9/9/2021 4:19:37 PM (10 fields)
//[] Success; Refresh; [WestTank] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:38:55 PM (10 fields)
//[] Success; Refresh; [WestTank] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:39:43 PM (10 fields)
//[] Success; Refresh; [SouthMotor] 100! {DialogConditionType} "The dialog was activated" @9/9/2021 2:22:18 PM (10 fields)
//[] Success; Refresh; [SouthMotor] 100! {ExclusiveDeviationAlarmType} "The alarm is active." @9/9/2021 4:19:32 PM (10 fields)
//[] Success; Refresh; [SouthMotor] 100! {NonExclusiveLevelAlarmType} "The alarm is active." @9/9/2021 4:19:37 PM (10 fields)
//[] Success; Refresh; [SouthMotor] 500! {TripAlarmType} "The alarm severity has increased." @9/9/2021 4:19:35 PM (10 fields)
//[] Success; Refresh; [SouthMotor] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:39:51 PM (10 fields)
//[] Success; Refresh; [SouthMotor] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:38:57 PM (10 fields)
//[] Success; Refresh; RefreshComplete
//[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:39 PM (10 fields)
//[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:39 PM (10 fields)
//[] Success; [EastTank] 100! {TripAlarmType} "The alarm was deactivated by the system." @9/9/2021 4:19:39 PM (10 fields)
//[] Success; [NorthMotor] 100! {NonExclusiveLevelAlarmType} "The alarm was deactivated by the system." @9/9/2021 4:19:39 PM (10 fields)
//[] Success; [WestTank] 100! {ExclusiveDeviationAlarmType} "The alarm was deactivated by the system." @9/9/2021 4:19:39 PM (10 fields)
//[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:40 PM (10 fields)
//[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:40 PM (10 fields)
//[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:41 PM (10 fields)
//[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:41 PM (10 fields)
//[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:42 PM (10 fields)
//[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:42 PM (10 fields)
//[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:43 PM (10 fields)
//[] Success; [NorthMotor] 300! {TripAlarmType} "The alarm severity has increased." @9/9/2021 4:19:43 PM (10 fields)
//[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:43 PM (10 fields)
//[] Success; [WestTank] 300! {NonExclusiveLevelAlarmType} "The alarm severity has increased." @9/9/2021 4:19:43 PM (10 fields)
//[] Success; [SouthMotor] 300! {ExclusiveDeviationAlarmType} "The alarm severity has increased." @9/9/2021 4:19:43 PM (10 fields)
//[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:44 PM (10 fields)
//[] Success; [EastTank] 700! {NonExclusiveLevelAlarmType} "The alarm severity has increased." @9/9/2021 4:19:44 PM (10 fields)
//[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:44 PM (10 fields)
//[] Success; [NorthMotor] 700! {ExclusiveDeviationAlarmType} "The alarm severity has increased." @9/9/2021 4:19:44 PM (10 fields)
//[] Success; [SouthMotor] 700! {TripAlarmType} "The alarm severity has increased." @9/9/2021 4:19:44 PM (10 fields)
//[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:45 PM (10 fields)
//[] Success; [EastTank] 300! {ExclusiveDeviationAlarmType} "The alarm severity has increased." @9/9/2021 4:19:45 PM (10 fields)
//[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:45 PM (10 fields)
//...

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


class ClientEvents {
    function EventNotification($Sender, $E)
    {
        // Display the event
        if ($E->Succeeded) {
            printf("%s\n", $E);
        }
        else {
            printf(" *** Failure: %s\n", $E->ErrorMessageBrief);
        }
    }
}

const UAObjectIds_Server = "nsu=http://opcfoundation.org/UA/;i=2253";

$EndpointDescriptor = "opc.tcp://opcua.demo-this.com:62544/Quickstarts/AlarmConditionServer";

// Instantiate the client object and hook events
$Client = new COM("OpcLabs.EasyOpc.UA.EasyUAClient");
$ClientEvents = new ClientEvents();
com_event_sink($Client, $ClientEvents, "DEasyUAClientEvents");

printf("Subscribing...\n");
$Client->SubscribeEvent($EndpointDescriptor, UAObjectIds_Server, 1000);

printf("Processing event notifications for 30 seconds...\n");
$startTime = time(); do { com_message_pump(1000); } 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; [EastTank] 100! {DialogConditionType} "The dialog was activated" @9/9/2021 2:22:18 PM (10 fields)
//[] Success; Refresh; [EastTank] 100! {ExclusiveDeviationAlarmType} "The alarm is active." @9/9/2021 4:19:37 PM (10 fields)
//[] Success; Refresh; [EastTank] 500! {NonExclusiveLevelAlarmType} "The alarm severity has increased." @9/9/2021 4:19:35 PM (10 fields)
//[] Success; Refresh; [EastTank] 900! {TripAlarmType} "The alarm severity has increased." @9/9/2021 4:19:29 PM (10 fields)
//[] Success; Refresh; [EastTank] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:39:03 PM (10 fields)
//[] Success; Refresh; [EastTank] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:40:03 PM (10 fields)
//[] Success; Refresh; [NorthMotor] 100! {DialogConditionType} "The dialog was activated" @9/9/2021 2:22:18 PM (10 fields)
//[] Success; Refresh; [NorthMotor] 500! {ExclusiveDeviationAlarmType} "The alarm severity has increased." @9/9/2021 4:19:35 PM (10 fields)
//[] Success; Refresh; [NorthMotor] 900! {NonExclusiveLevelAlarmType} "The alarm severity has increased." @9/9/2021 4:19:29 PM (10 fields)
//[] Success; Refresh; [NorthMotor] 100! {TripAlarmType} "The alarm is active." @9/9/2021 4:19:32 PM (10 fields)
//[] Success; Refresh; [NorthMotor] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:39:08 PM (10 fields)
//[] Success; Refresh; [NorthMotor] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:40:14 PM (10 fields)
//[] Success; Refresh; [WestTank] 100! {DialogConditionType} "The dialog was activated" @9/9/2021 2:22:18 PM (10 fields)
//[] Success; Refresh; [WestTank] 900! {ExclusiveDeviationAlarmType} "The alarm severity has increased." @9/9/2021 4:19:29 PM (10 fields)
//[] Success; Refresh; [WestTank] 100! {NonExclusiveLevelAlarmType} "The alarm is active." @9/9/2021 4:19:32 PM (10 fields)
//[] Success; Refresh; [WestTank] 100! {TripAlarmType} "The alarm is active." @9/9/2021 4:19:37 PM (10 fields)
//[] Success; Refresh; [WestTank] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:38:55 PM (10 fields)
//[] Success; Refresh; [WestTank] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:39:43 PM (10 fields)
//[] Success; Refresh; [SouthMotor] 100! {DialogConditionType} "The dialog was activated" @9/9/2021 2:22:18 PM (10 fields)
//[] Success; Refresh; [SouthMotor] 100! {ExclusiveDeviationAlarmType} "The alarm is active." @9/9/2021 4:19:32 PM (10 fields)
//[] Success; Refresh; [SouthMotor] 100! {NonExclusiveLevelAlarmType} "The alarm is active." @9/9/2021 4:19:37 PM (10 fields)
//[] Success; Refresh; [SouthMotor] 500! {TripAlarmType} "The alarm severity has increased." @9/9/2021 4:19:35 PM (10 fields)
//[] Success; Refresh; [SouthMotor] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:39:51 PM (10 fields)
//[] Success; Refresh; [SouthMotor] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:38:57 PM (10 fields)
//[] Success; Refresh; RefreshComplete
//[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:39 PM (10 fields)
//[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:39 PM (10 fields)
//[] Success; [EastTank] 100! {TripAlarmType} "The alarm was deactivated by the system." @9/9/2021 4:19:39 PM (10 fields)
//[] Success; [NorthMotor] 100! {NonExclusiveLevelAlarmType} "The alarm was deactivated by the system." @9/9/2021 4:19:39 PM (10 fields)
//[] Success; [WestTank] 100! {ExclusiveDeviationAlarmType} "The alarm was deactivated by the system." @9/9/2021 4:19:39 PM (10 fields)
//[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:40 PM (10 fields)
//[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:40 PM (10 fields)
//[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:41 PM (10 fields)
//[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:41 PM (10 fields)
//[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:42 PM (10 fields)
//[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:42 PM (10 fields)
//[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:43 PM (10 fields)
//[] Success; [NorthMotor] 300! {TripAlarmType} "The alarm severity has increased." @9/9/2021 4:19:43 PM (10 fields)
//[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:43 PM (10 fields)
//[] Success; [WestTank] 300! {NonExclusiveLevelAlarmType} "The alarm severity has increased." @9/9/2021 4:19:43 PM (10 fields)
//[] Success; [SouthMotor] 300! {ExclusiveDeviationAlarmType} "The alarm severity has increased." @9/9/2021 4:19:43 PM (10 fields)
//[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:44 PM (10 fields)
//[] Success; [EastTank] 700! {NonExclusiveLevelAlarmType} "The alarm severity has increased." @9/9/2021 4:19:44 PM (10 fields)
//[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:44 PM (10 fields)
//[] Success; [NorthMotor] 700! {ExclusiveDeviationAlarmType} "The alarm severity has increased." @9/9/2021 4:19:44 PM (10 fields)
//[] Success; [SouthMotor] 700! {TripAlarmType} "The alarm severity has increased." @9/9/2021 4:19:44 PM (10 fields)
//[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:45 PM (10 fields)
//[] Success; [EastTank] 300! {ExclusiveDeviationAlarmType} "The alarm severity has increased." @9/9/2021 4:19:45 PM (10 fields)
//[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:45 PM (10 fields)
//...

' This example shows how to subscribe to event notifications and display each incoming event.

Imports OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.AddressSpace.Standard
Imports OpcLabs.EasyOpc.UA.OperationModel

Namespace UADocExamples.AlarmsAndConditions
    Friend Class SubscribeEvent
        Public Shared Sub Overload1()
            ' Instantiate the client object and hook events
            Dim client = New EasyUAClient()
            AddHandler client.EventNotification, AddressOf client_EventNotification

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

            Console.WriteLine("Processing event notifications for 10 seconds...")
            Threading.Thread.Sleep(10 * 1000)

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

            Console.WriteLine("Waiting for 5 seconds...")
            Threading.Thread.Sleep(5 * 1000)
        End Sub

        Private Shared Sub client_EventNotification(ByVal sender As Object, ByVal e As EasyUAEventNotificationEventArgs)
            ' Display the event
            Console.WriteLine(e)
        End Sub



        ' Example output (truncated):
        'Subscribing...
        'Processing event notifications for 30 seconds...
        '[] Success
        '[] Success; Refresh; RefreshInitiated
        '[] Success; Refresh; [EastTank] 100! {DialogConditionType} "The dialog was activated" @9/9/2021 2:22:18 PM (10 fields)
        '[] Success; Refresh; [EastTank] 100! {ExclusiveDeviationAlarmType} "The alarm is active." @9/9/2021 4:19:37 PM (10 fields)
        '[] Success; Refresh; [EastTank] 500! {NonExclusiveLevelAlarmType} "The alarm severity has increased." @9/9/2021 4:19:35 PM (10 fields)
        '[] Success; Refresh; [EastTank] 900! {TripAlarmType} "The alarm severity has increased." @9/9/2021 4:19:29 PM (10 fields)
        '[] Success; Refresh; [EastTank] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:39:03 PM (10 fields)
        '[] Success; Refresh; [EastTank] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:40:03 PM (10 fields)
        '[] Success; Refresh; [NorthMotor] 100! {DialogConditionType} "The dialog was activated" @9/9/2021 2:22:18 PM (10 fields)
        '[] Success; Refresh; [NorthMotor] 500! {ExclusiveDeviationAlarmType} "The alarm severity has increased." @9/9/2021 4:19:35 PM (10 fields)
        '[] Success; Refresh; [NorthMotor] 900! {NonExclusiveLevelAlarmType} "The alarm severity has increased." @9/9/2021 4:19:29 PM (10 fields)
        '[] Success; Refresh; [NorthMotor] 100! {TripAlarmType} "The alarm is active." @9/9/2021 4:19:32 PM (10 fields)
        '[] Success; Refresh; [NorthMotor] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:39:08 PM (10 fields)
        '[] Success; Refresh; [NorthMotor] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:40:14 PM (10 fields)
        '[] Success; Refresh; [WestTank] 100! {DialogConditionType} "The dialog was activated" @9/9/2021 2:22:18 PM (10 fields)
        '[] Success; Refresh; [WestTank] 900! {ExclusiveDeviationAlarmType} "The alarm severity has increased." @9/9/2021 4:19:29 PM (10 fields)
        '[] Success; Refresh; [WestTank] 100! {NonExclusiveLevelAlarmType} "The alarm is active." @9/9/2021 4:19:32 PM (10 fields)
        '[] Success; Refresh; [WestTank] 100! {TripAlarmType} "The alarm is active." @9/9/2021 4:19:37 PM (10 fields)
        '[] Success; Refresh; [WestTank] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:38:55 PM (10 fields)
        '[] Success; Refresh; [WestTank] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:39:43 PM (10 fields)
        '[] Success; Refresh; [SouthMotor] 100! {DialogConditionType} "The dialog was activated" @9/9/2021 2:22:18 PM (10 fields)
        '[] Success; Refresh; [SouthMotor] 100! {ExclusiveDeviationAlarmType} "The alarm is active." @9/9/2021 4:19:32 PM (10 fields)
        '[] Success; Refresh; [SouthMotor] 100! {NonExclusiveLevelAlarmType} "The alarm is active." @9/9/2021 4:19:37 PM (10 fields)
        '[] Success; Refresh; [SouthMotor] 500! {TripAlarmType} "The alarm severity has increased." @9/9/2021 4:19:35 PM (10 fields)
        '[] Success; Refresh; [SouthMotor] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:39:51 PM (10 fields)
        '[] Success; Refresh; [SouthMotor] 100! {TripAlarmType} "The alarm severity has increased." @9/9/2021 3:38:57 PM (10 fields)
        '[] Success; Refresh; RefreshComplete
        '[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:39 PM (10 fields)
        '[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:39 PM (10 fields)
        '[] Success; [EastTank] 100! {TripAlarmType} "The alarm was deactivated by the system." @9/9/2021 4:19:39 PM (10 fields)
        '[] Success; [NorthMotor] 100! {NonExclusiveLevelAlarmType} "The alarm was deactivated by the system." @9/9/2021 4:19:39 PM (10 fields)
        '[] Success; [WestTank] 100! {ExclusiveDeviationAlarmType} "The alarm was deactivated by the system." @9/9/2021 4:19:39 PM (10 fields)
        '[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:40 PM (10 fields)
        '[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:40 PM (10 fields)
        '[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:41 PM (10 fields)
        '[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:41 PM (10 fields)
        '[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:42 PM (10 fields)
        '[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:42 PM (10 fields)
        '[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:43 PM (10 fields)
        '[] Success; [NorthMotor] 300! {TripAlarmType} "The alarm severity has increased." @9/9/2021 4:19:43 PM (10 fields)
        '[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:43 PM (10 fields)
        '[] Success; [WestTank] 300! {NonExclusiveLevelAlarmType} "The alarm severity has increased." @9/9/2021 4:19:43 PM (10 fields)
        '[] Success; [SouthMotor] 300! {ExclusiveDeviationAlarmType} "The alarm severity has increased." @9/9/2021 4:19:43 PM (10 fields)
        '[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:44 PM (10 fields)
        '[] Success; [EastTank] 700! {NonExclusiveLevelAlarmType} "The alarm severity has increased." @9/9/2021 4:19:44 PM (10 fields)
        '[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:44 PM (10 fields)
        '[] Success; [NorthMotor] 700! {ExclusiveDeviationAlarmType} "The alarm severity has increased." @9/9/2021 4:19:44 PM (10 fields)
        '[] Success; [SouthMotor] 700! {TripAlarmType} "The alarm severity has increased." @9/9/2021 4:19:44 PM (10 fields)
        '[] Success; [Internal] 500! {SystemEventType} "Raising Events" @9/9/2021 4:19:45 PM (10 fields)
        '[] Success; [EastTank] 300! {ExclusiveDeviationAlarmType} "The alarm severity has increased." @9/9/2021 4:19:45 PM (10 fields)
        '[] Success; [Internal] 500! {AuditEventType} "Events Raised" @9/9/2021 4:19:45 PM (10 fields)
        '...

    End Class
End Namespace
// This example shows how to subscribe to multiple events.

using System;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.AddressSpace;
using OpcLabs.EasyOpc.UA.AddressSpace.Standard;
using OpcLabs.EasyOpc.UA.AlarmsAndConditions;
using OpcLabs.EasyOpc.UA.Filtering;
using OpcLabs.EasyOpc.UA.OperationModel;

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

            // Instantiate the client object and hook events.
            var client = new EasyUAClient();
            client.EventNotification += client_EventNotification;

            Console.WriteLine("Subscribing...");
            client.SubscribeMultipleMonitoredItems(new[]
                {
                    new EasyUAMonitoredItemArguments("firstState", 
                        endpointDescriptor, 
                        UAObjectIds.Server,
                        new UAMonitoringParameters(1000, new UAEventFilterBuilder(
                            UAFilterElements.GreaterThanOrEqual(UABaseEventObject.Operands.Severity, 500),
                            UABaseEventObject.AllFields)))
                        { AttributeId = UAAttributeId.EventNotifier },
                    new EasyUAMonitoredItemArguments("secondState",
                        endpointDescriptor, 
                        UAObjectIds.Server,
                        new UAMonitoringParameters(2000, new UAEventFilterBuilder(
                            UAFilterElements.Equals(
                                UABaseEventObject.Operands.SourceNode, 
                                new UANodeId("nsu=http://opcfoundation.org/Quickstarts/AlarmCondition ;ns=2;s=1:Metals/SouthMotor")),
                            UABaseEventObject.AllFields)))
                        { AttributeId = UAAttributeId.EventNotifier }
                });

            Console.WriteLine("Processing event notifications for 30 seconds...");
            System.Threading.Thread.Sleep(30 * 1000);

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

            Console.WriteLine("Waiting for 5 seconds...");
            System.Threading.Thread.Sleep(5 * 1000);

            Console.WriteLine("Finished.");
        }

        static void client_EventNotification(object sender, EasyUAEventNotificationEventArgs e)
        {
            // Display the event
            Console.WriteLine(e);
        }
        

        // Example output (truncated):
        //Subscribing...
        //Processing monitored item changed events for 30 seconds...
        //[firstState] Success
        //[secondState] Success
        //[firstState] Success; Refresh; RefreshInitiated
        //[firstState] Success; Refresh; (10 field results) [EastTank] 500! "The alarm was acknoweledged." @10/14/2019 4:00:13 PM
        //[firstState] Success; Refresh; (10 field results) [EastTank] 500! "The alarm was acknoweledged." @10/14/2019 4:00:17 PM
        //[firstState] Success; Refresh; (10 field results) [NorthMotor] 500! "The alarm was acknoweledged." @10/14/2019 4:00:02 PM
        //[firstState] Success; Refresh; (10 field results) [NorthMotor] 500! "The alarm was acknoweledged." @10/14/2019 4:00:16 PM
        //[firstState] Success; Refresh; (10 field results) [SouthMotor] 700! "The alarm was acknoweledged." @10/14/2019 4:00:21 PM
        //[firstState] Success; Refresh; (10 field results) [SouthMotor] 500! "The alarm was acknoweledged." @10/14/2019 4:00:03 PM
        //[firstState] Success; Refresh; RefreshComplete
        //[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:08 PM
        //[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:08 PM
        //[secondState] Success; Refresh; RefreshInitiated
        //[secondState] Success; Refresh; (10 field results) [SouthMotor] 100! "The dialog was activated" @9/10/2019 8:08:25 PM
        //[secondState] Success; Refresh; (10 field results) [SouthMotor] 100! "The alarm is active." @11/8/2019 7:48:07 PM
        //[secondState] Success; Refresh; (10 field results) [SouthMotor] 700! "The alarm was acknoweledged." @10/14/2019 4:00:21 PM
        //[secondState] Success; Refresh; (10 field results) [SouthMotor] 500! "The alarm was acknoweledged." @10/14/2019 4:00:03 PM
        //[secondState] Success; Refresh; (10 field results) [SouthMotor] 100! "The alarm severity has increased." @9/10/2019 8:09:02 PM
        //[secondState] Success; Refresh; (10 field results) [SouthMotor] 100! "The alarm severity has increased." @9/10/2019 8:09:59 PM
        //[secondState] Success; Refresh; RefreshComplete
        //[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:09 PM
        //[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:09 PM
        //[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:10 PM
        //[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:10 PM
        //[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:11 PM
        //[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:11 PM
        //[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:12 PM
        //[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:12 PM
        //[firstState] Success; (10 field results) [EastTank] 500! "The alarm severity has increased." @11/8/2019 7:48:13 PM
        //[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:13 PM
        //[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:13 PM
        //[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:14 PM
        //[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:14 PM
        //[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:15 PM
        //[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:15 PM
        //[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:16 PM
        //[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:16 PM
        //[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:17 PM
        //[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:17 PM
        //[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:18 PM
        //[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:18 PM
        //[secondState] Success; (10 field results) [SouthMotor] 300! "The alarm severity has increased." @11/8/2019 7:48:18 PM
        //...
    }
}
# This example shows how to subscribe to multiple events.

#requires -Version 5.1
using namespace OpcLabs.EasyOpc.UA
using namespace OpcLabs.EasyOpc.UA.AddressSpace
using namespace OpcLabs.EasyOpc.UA.AddressSpace.Standard
using namespace OpcLabs.EasyOpc.UA.AlarmsAndConditions
using namespace OpcLabs.EasyOpc.UA.Filtering
using namespace OpcLabs.EasyOpc.UA.OperationModel

# The path below assumes that the current directory is [ProductDir]/Examples-NET/PowerShell/Windows .
Add-Type -Path "../../../Assemblies/net47/OpcLabs.EasyOpcUA.dll"

# Define which server we will work with.
[UAEndpointDescriptor]$endpointDescriptor = "opc.tcp://opcua.demo-this.com:62544/Quickstarts/AlarmConditionServer"

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

# Event notification handler
Register-ObjectEvent -InputObject $client -EventName EventNotification -Action { 
    # Display the event.
    Write-Host $EventArgs
}

Write-Host "Subscribing..."
$client.SubscribeMultipleMonitoredItems(@(
        (New-Object EasyUAMonitoredItemArguments("firstState",
            $endpointDescriptor, 
            [UAObjectIds]::Server,
            (New-Object UAMonitoringParameters(1000, [UAEventFilter](New-Object UAEventFilterBuilder(
                [UAFilterElements]::GreaterThanOrEqual([UABaseEventObject+Operands]::Severity, 500),
                [UABaseEventObject]::AllFields))))) `
            -Property @{ AttributeId = [UAAttributeId]::EventNotifier }),
        (New-Object EasyUAMonitoredItemArguments("secondState",
            $endpointDescriptor, 
            [UAObjectIds]::Server,
            (New-Object UAMonitoringParameters(2000, [UAEventFilter](New-Object UAEventFilterBuilder(
                [UAFilterElements]::Equals(
                    [UABaseEventObject+Operands]::SourceNode, 
                    (New-Object UANodeId("nsu=http://opcfoundation.org/Quickstarts/AlarmCondition ;ns=2;s=1:Metals/SouthMotor"))),
                [UABaseEventObject]::AllFields))))) `
            -Property @{ AttributeId = [UAAttributeId]::EventNotifier })
    ))

Write-Host "Processing event notifications for 30 seconds..."
$stopwatch =  [System.Diagnostics.Stopwatch]::StartNew() 
while ($stopwatch.Elapsed.TotalSeconds -lt 30) {    
    Start-Sleep -Seconds 1
}

Write-Host "Unsubscribing..."
$client.UnsubscribeAllMonitoredItems()

Write-Host "Waiting for 5 seconds..."
Start-Sleep -Seconds 5

Write-Host "Finished."
      

# Example output (truncated):
#Subscribing...
#Processing monitored item changed events for 30 seconds...
#[firstState] Success
#[secondState] Success
#[firstState] Success; Refresh; RefreshInitiated
#[firstState] Success; Refresh; (10 field results) [EastTank] 500! "The alarm was acknoweledged." @10/14/2019 4:00:13 PM
#[firstState] Success; Refresh; (10 field results) [EastTank] 500! "The alarm was acknoweledged." @10/14/2019 4:00:17 PM
#[firstState] Success; Refresh; (10 field results) [NorthMotor] 500! "The alarm was acknoweledged." @10/14/2019 4:00:02 PM
#[firstState] Success; Refresh; (10 field results) [NorthMotor] 500! "The alarm was acknoweledged." @10/14/2019 4:00:16 PM
#[firstState] Success; Refresh; (10 field results) [SouthMotor] 700! "The alarm was acknoweledged." @10/14/2019 4:00:21 PM
#[firstState] Success; Refresh; (10 field results) [SouthMotor] 500! "The alarm was acknoweledged." @10/14/2019 4:00:03 PM
#[firstState] Success; Refresh; RefreshComplete
#[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:08 PM
#[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:08 PM
#[secondState] Success; Refresh; RefreshInitiated
#[secondState] Success; Refresh; (10 field results) [SouthMotor] 100! "The dialog was activated" @9/10/2019 8:08:25 PM
#[secondState] Success; Refresh; (10 field results) [SouthMotor] 100! "The alarm is active." @11/8/2019 7:48:07 PM
#[secondState] Success; Refresh; (10 field results) [SouthMotor] 700! "The alarm was acknoweledged." @10/14/2019 4:00:21 PM
#[secondState] Success; Refresh; (10 field results) [SouthMotor] 500! "The alarm was acknoweledged." @10/14/2019 4:00:03 PM
#[secondState] Success; Refresh; (10 field results) [SouthMotor] 100! "The alarm severity has increased." @9/10/2019 8:09:02 PM
#[secondState] Success; Refresh; (10 field results) [SouthMotor] 100! "The alarm severity has increased." @9/10/2019 8:09:59 PM
#[secondState] Success; Refresh; RefreshComplete
#[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:09 PM
#[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:09 PM
#[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:10 PM
#[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:10 PM
#[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:11 PM
#[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:11 PM
#[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:12 PM
#[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:12 PM
#[firstState] Success; (10 field results) [EastTank] 500! "The alarm severity has increased." @11/8/2019 7:48:13 PM
#[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:13 PM
#[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:13 PM
#[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:14 PM
#[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:14 PM
#[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:15 PM
#[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:15 PM
#[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:16 PM
#[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:16 PM
#[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:17 PM
#[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:17 PM
#[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:18 PM
#[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:18 PM
#[secondState] Success; (10 field results) [SouthMotor] 300! "The alarm severity has increased." @11/8/2019 7:48:18 PM
#...
// This example shows how to subscribe to multiple events.

type
  THelperMethods19 = class
    class function ObjectTypeIds_BaseEventType: _UANodeId; static;
    class function UAFilterElements_SimpleAttribute(TypeId: _UANodeId; simpleRelativeBrowsePathString: string): _UASimpleAttributeOperand; static;
    class function UABaseEventObject_Operands_NodeId: _UASimpleAttributeOperand; static;
    class function UABaseEventObject_Operands_EventId: _UASimpleAttributeOperand; static;
    class function UABaseEventObject_Operands_EventType: _UASimpleAttributeOperand; static;
    class function UABaseEventObject_Operands_SourceNode: _UASimpleAttributeOperand; static;
    class function UABaseEventObject_Operands_SourceName: _UASimpleAttributeOperand; static;
    class function UABaseEventObject_Operands_Time: _UASimpleAttributeOperand; static;
    class function UABaseEventObject_Operands_ReceiveTime: _UASimpleAttributeOperand; static;
    class function UABaseEventObject_Operands_LocalTime: _UASimpleAttributeOperand; static;
    class function UABaseEventObject_Operands_Message: _UASimpleAttributeOperand; static;
    class function UABaseEventObject_Operands_Severity: _UASimpleAttributeOperand; static;
    class function UABaseEventObject_AllFields: _UAAttributeFieldCollection; static;
  end;

type
  TClientEventHandlers19 = class
    procedure Client_EventNotification(
      ASender: TObject;
      sender: OleVariant;
      const eventArgs: _EasyUAEventNotificationEventArgs);
  end;

procedure TClientEventHandlers19.Client_EventNotification(
  ASender: TObject;
  sender: OleVariant;
  const eventArgs: _EasyUAEventNotificationEventArgs);
begin
  // Display the event
    WriteLn(eventArgs.ToString);
end;


class procedure SubscribeMultipleMonitoredItems.Events;
var
  Arguments: OleVariant;
  Client: TEasyUAClient;
  ClientEventHandlers: TClientEventHandlers19;
  EndpointDescriptor: string;
  EventFilter1, EventFilter2: _UAEventFilter;
  MonitoredItemArguments1, MonitoredItemArguments2: _EasyUAMonitoredItemArguments;
  MonitoringParameters1, MonitoringParameters2: _UAMonitoringParameters;
  Operand11, Operand21: _UASimpleAttributeOperand;
  Operand12, Operand22: _UALiteralOperand;
  ServerNodeId1, ServerNodeId2: _UANodeId;
  SourceNodeId: _UANodeId;
  WhereClause1, WhereClause2: _UAContentFilterElement;
begin
  EndpointDescriptor := 'opc.tcp://opcua.demo-this.com:62544/Quickstarts/AlarmConditionServer';

  // set MonitoredItemArguments1
  // Event filter: The severity is >= 500.
  Operand11 := THelperMethods19.UABaseEventObject_Operands_Severity;
  Operand12 := CoUALiteralOperand.Create;
  Operand12.Value := 500;
  WhereClause1 := CoUAContentFilterElement.Create;
  WhereClause1.FilterOperator := UAFilterOperator_GreaterThanOrEqual;
  WhereClause1.FilterOperands.Add(Operand11);
  WhereClause1.FilterOperands.Add(Operand12);

  EventFilter1 := CoUAEventFilter.Create;
  EventFilter1.SelectClauses := THelperMethods19.UABaseEventObject_AllFields;
  EventFilter1.WhereClause := WhereClause1;

  ServerNodeId1 := CoUANodeId.Create;
  ServerNodeId1.StandardName := 'Server';

  MonitoringParameters1 := CoUAMonitoringParameters.Create;
  MonitoringParameters1.EventFilter := EventFilter1;
  MonitoringParameters1.QueueSize := 1000;
  MonitoringParameters1.SamplingInterval := 1000;

  MonitoredItemArguments1 := CoEasyUAMonitoredItemArguments.Create;
  MonitoredItemArguments1.AttributeId := UAAttributeId_EventNotifier;
  MonitoredItemArguments1.EndpointDescriptor.UrlString := EndpointDescriptor;
  MonitoredItemArguments1.MonitoringParameters := MonitoringParameters1;
  MonitoredItemArguments1.NodeDescriptor.NodeId := ServerNodeId1;
  MonitoredItemArguments1.State := 'firstState';

  // set MonitoredItemArguments2
  // Event filter: The event comes from a specified source node.
  Operand21 := THelperMethods19.UABaseEventObject_Operands_SourceNode;
  SourceNodeId := CoUANodeId.Create;
  SourceNodeId.ExpandedText := 'nsu=http://opcfoundation.org/Quickstarts/AlarmCondition ;ns=2;s=1:Metals/SouthMotor';
  Operand22 := CoUALiteralOperand.Create;
  Operand22.Value := SourceNodeId;
  WhereClause2 := CoUAContentFilterElement.Create;
  WhereClause2.FilterOperator := UAFilterOperator_Equals;
  WhereClause2.FilterOperands.Add(Operand21);
  WhereClause2.FilterOperands.Add(Operand22);

  EventFilter2 := CoUAEventFilter.Create;
  EventFilter2.SelectClauses := THelperMethods19.UABaseEventObject_AllFields;
  EventFilter2.WhereClause := WhereClause2;

  ServerNodeId2 := CoUANodeId.Create;
  ServerNodeId2.StandardName := 'Server';

  MonitoringParameters2 := CoUAMonitoringParameters.Create;
  MonitoringParameters2.EventFilter := EventFilter2;
  MonitoringParameters2.QueueSize := 1000;
  MonitoringParameters2.SamplingInterval := 2000;

  MonitoredItemArguments2 := CoEasyUAMonitoredItemArguments.Create;
  MonitoredItemArguments2.AttributeId := UAAttributeId_EventNotifier;
  MonitoredItemArguments2.EndpointDescriptor.UrlString := EndpointDescriptor;
  MonitoredItemArguments2.MonitoringParameters := MonitoringParameters2;
  MonitoredItemArguments2.NodeDescriptor.NodeId := ServerNodeId2;
  MonitoredItemArguments2.State := 'secondState';


  // Instantiate the client object and hook events
  Client := TEasyUAClient.Create(nil);
  ClientEventHandlers := TClientEventHandlers19.Create;
  Client.OnEventNotification := ClientEventHandlers.Client_EventNotification;

  Arguments := VarArrayCreate([0, 1], varVariant);
  Arguments[0] := MonitoredItemArguments1;
  Arguments[1] := MonitoredItemArguments2;

  WriteLn('Subscribing...');
  Client.SubscribeMultipleMonitoredItems(Arguments);

  WriteLn('Processing monitored item changed events for 30 seconds...');
  PumpSleep(30*1000);

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

  WriteLn('Waiting for 5 seconds...');
  Sleep(5*1000);

  WriteLn('Finished.');
  VarClear(Arguments);
  FreeAndNil(Client);
  FreeAndNil(ClientEventHandlers);
end;

class function THelperMethods19.ObjectTypeIds_BaseEventType: _UANodeId;
  var NodeId: _UANodeId;
  begin
    NodeId := CoUANodeId.Create;
    NodeId.StandardName := 'BaseEventType';
    Result := NodeId;
  end;

class function THelperMethods19.UAFilterElements_SimpleAttribute(TypeId: _UANodeId; simpleRelativeBrowsePathString: string): _UASimpleAttributeOperand;
var
  BrowsePathParser: _UABrowsePathParser;
  Operand: _UASimpleAttributeOperand;
begin
  BrowsePathParser := CoUABrowsePathParser.Create;
  Operand := CoUASimpleAttributeOperand.Create;
  Operand.TypeId.NodeId := TypeId;
  Operand.QualifiedNames := BrowsePathParser.ParseRelative(simpleRelativeBrowsePathString).ToUAQualifiedNameCollection;
  Result := Operand;
end;

class function THelperMethods19.UABaseEventObject_Operands_NodeId: _UASimpleAttributeOperand;
var
  Operand: _UASimpleAttributeOperand;
begin
  Operand := CoUASimpleAttributeOperand.Create;
  Operand.TypeId.NodeId.StandardName := 'BaseEventType';
  Operand.AttributeId := UAAttributeId_NodeId;
  Result := Operand;
end;

class function THelperMethods19.UABaseEventObject_Operands_EventId: _UASimpleAttributeOperand;
begin
  Result := UAFilterElements_SimpleAttribute(ObjectTypeIds_BaseEventType, '/EventId');
end;

class function THelperMethods19.UABaseEventObject_Operands_EventType: _UASimpleAttributeOperand;
begin
  Result := UAFilterElements_SimpleAttribute(ObjectTypeIds_BaseEventType, '/EventType');
end;

class function THelperMethods19.UABaseEventObject_Operands_SourceNode: _UASimpleAttributeOperand;
begin
  Result := UAFilterElements_SimpleAttribute(ObjectTypeIds_BaseEventType, '/SourceNode');
end;

class function THelperMethods19.UABaseEventObject_Operands_SourceName: _UASimpleAttributeOperand;
begin
  Result := UAFilterElements_SimpleAttribute(ObjectTypeIds_BaseEventType, '/SourceName');
end;

class function THelperMethods19.UABaseEventObject_Operands_Time: _UASimpleAttributeOperand;
begin
  Result := UAFilterElements_SimpleAttribute(ObjectTypeIds_BaseEventType, '/Time');
end;

class function THelperMethods19.UABaseEventObject_Operands_ReceiveTime: _UASimpleAttributeOperand;
begin
  Result := UAFilterElements_SimpleAttribute(ObjectTypeIds_BaseEventType, '/ReceiveTime');
end;

class function THelperMethods19.UABaseEventObject_Operands_LocalTime: _UASimpleAttributeOperand;
begin
  Result := UAFilterElements_SimpleAttribute(ObjectTypeIds_BaseEventType, '/LocalTime');
end;

class function THelperMethods19.UABaseEventObject_Operands_Message: _UASimpleAttributeOperand;
begin
  Result := UAFilterElements_SimpleAttribute(ObjectTypeIds_BaseEventType, '/Message');
end;

class function THelperMethods19.UABaseEventObject_Operands_Severity: _UASimpleAttributeOperand;
begin
  Result := UAFilterElements_SimpleAttribute(ObjectTypeIds_BaseEventType, '/Severity');
end;

class function THelperMethods19.UABaseEventObject_AllFields: _UAAttributeFieldCollection;
var
  Fields: _UAAttributeFieldCollection;
begin
  Fields := CoUAAttributeFieldCollection.Create;
  Fields.Add(UABaseEventObject_Operands_NodeId.ToUAAttributeField);
  Fields.Add(UABaseEventObject_Operands_EventId.ToUAAttributeField);
  Fields.Add(UABaseEventObject_Operands_EventType.ToUAAttributeField);
  Fields.Add(UABaseEventObject_Operands_SourceNode.ToUAAttributeField);
  Fields.Add(UABaseEventObject_Operands_SourceName.ToUAAttributeField);
  Fields.Add(UABaseEventObject_Operands_Time.ToUAAttributeField);
  Fields.Add(UABaseEventObject_Operands_ReceiveTime.ToUAAttributeField);
  Fields.Add(UABaseEventObject_Operands_LocalTime.ToUAAttributeField);
  Fields.Add(UABaseEventObject_Operands_Message.ToUAAttributeField);
  Fields.Add(UABaseEventObject_Operands_Severity.ToUAAttributeField);

  Result := Fields;
end;
// This example shows how to subscribe to multiple events.

const UAAttributeId_NodeId = 1;
const UAAttributeId_EventNotifier = 12;

const UAFilterOperator_Equals = 1;
const UAFilterOperator_GreaterThanOrEqual = 5;

class ClientEvents {
    function EventNotification($Sender, $E)
    {
        // Display the event
        printf("%s\n", $E);
    }
}

$EndpointDescriptor = "opc.tcp://opcua.demo-this.com:62544/Quickstarts/AlarmConditionServer";

// set MonitoredItemArguments1
// Event filter: The severity is >= 500.
$Operand11 = UABaseEventObject_Operands_Severity();
$Operand12 = new COM("OpcLabs.EasyOpc.UA.Filtering.UALiteralOperand");
$Operand12->Value = 500;
$WhereClause1 = new COM("OpcLabs.EasyOpc.UA.Filtering.UAContentFilterElement");
$WhereClause1->FilterOperator = UAFilterOperator_GreaterThanOrEqual;
$WhereClause1->FilterOperands->Add($Operand11);
$WhereClause1->FilterOperands->Add($Operand12);

$EventFilter1 = new COM("OpcLabs.EasyOpc.UA.UAEventFilter");
$EventFilter1->SelectClauses = UABaseEventObject_AllFields();
$EventFilter1->WhereClause = $WhereClause1;

$ServerNodeId1 = new COM("OpcLabs.EasyOpc.UA.AddressSpace.UANodeId");
$ServerNodeId1->StandardName = "Server";

$MonitoringParameters1 = new COM("OpcLabs.EasyOpc.UA.UAMonitoringParameters");
$MonitoringParameters1->EventFilter = $EventFilter1;
$MonitoringParameters1->QueueSize = 1000;
$MonitoringParameters1->SamplingInterval = 1000;

$MonitoredItemArguments1 = new COM("OpcLabs.EasyOpc.UA.OperationModel.EasyUAMonitoredItemArguments");
$MonitoredItemArguments1->AttributeId = UAAttributeId_EventNotifier;
$MonitoredItemArguments1->EndpointDescriptor->UrlString = $EndpointDescriptor;
$MonitoredItemArguments1->MonitoringParameters = $MonitoringParameters1;
$MonitoredItemArguments1->NodeDescriptor->NodeId = $ServerNodeId1;
$MonitoredItemArguments1->State = "firstState";

// set MonitoredItemArguments2
// Event filter: The event comes from a specified source node.
$Operand21 = UABaseEventObject_Operands_SourceNode();
$SourceNodeId = new COM("OpcLabs.EasyOpc.UA.AddressSpace.UANodeId");
$SourceNodeId->ExpandedText = "nsu=http://opcfoundation.org/Quickstarts/AlarmCondition ;ns=2;s=1:Metals/SouthMotor";
$Operand22 = new COM("OpcLabs.EasyOpc.UA.Filtering.UALiteralOperand");
$Operand22->Value = $SourceNodeId;
$WhereClause2 = new COM("OpcLabs.EasyOpc.UA.Filtering.UAContentFilterElement");
$WhereClause2->FilterOperator = UAFilterOperator_Equals;
$WhereClause2->FilterOperands->Add($Operand21);
$WhereClause2->FilterOperands->Add($Operand22);

$EventFilter2 = new COM("OpcLabs.EasyOpc.UA.UAEventFilter");
$EventFilter2->SelectClauses = UABaseEventObject_AllFields();
$EventFilter2->WhereClause = $WhereClause2;

$ServerNodeId2 = new COM("OpcLabs.EasyOpc.UA.AddressSpace.UANodeId");
$ServerNodeId2->StandardName = "Server";

$MonitoringParameters2 = new COM("OpcLabs.EasyOpc.UA.UAMonitoringParameters");
$MonitoringParameters2->EventFilter = $EventFilter2;
$MonitoringParameters2->QueueSize = 1000;
$MonitoringParameters2->SamplingInterval = 2000;

$MonitoredItemArguments2 = new COM("OpcLabs.EasyOpc.UA.OperationModel.EasyUAMonitoredItemArguments");
$MonitoredItemArguments2->AttributeId = UAAttributeId_EventNotifier;
$MonitoredItemArguments2->EndpointDescriptor->UrlString = $EndpointDescriptor;
$MonitoredItemArguments2->MonitoringParameters = $MonitoringParameters2;
$MonitoredItemArguments2->NodeDescriptor->NodeId = $ServerNodeId2;
$MonitoredItemArguments2->State = "secondState";

// Instantiate the client object and hook events
$Client = new COM("OpcLabs.EasyOpc.UA.EasyUAClient");
$ClientEvents = new ClientEvents();
com_event_sink($Client, $ClientEvents, "DEasyUAClientEvents");

$arguments[0] = $MonitoredItemArguments1;
$arguments[1] = $MonitoredItemArguments2;

printf("Subscribing...\n");
$Client->SubscribeMultipleMonitoredItems($arguments);

printf("Processing monitored item changed events for 30 seconds...\n");
$startTime = time(); do { com_message_pump(1000); } 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);


function ObjectTypeIds_BaseEventType() {
    $NodeId = new COM("OpcLabs.EasyOpc.UA.AddressSpace.UANodeId");
    $NodeId->StandardName = "BaseEventType";
    return $NodeId;
}

function UAFilterElements_SimpleAttribute($TypeId, $simpleRelativeBrowsePathString) {
  $BrowsePathParser = new COM("OpcLabs.EasyOpc.UA.Navigation.Parsing.UABrowsePathParser");
  $Operand = new COM("OpcLabs.EasyOpc.UA.Filtering.UASimpleAttributeOperand");
  $Operand->TypeId->NodeId = $TypeId;
  $Operand->QualifiedNames = $BrowsePathParser->ParseRelative($simpleRelativeBrowsePathString)->ToUAQualifiedNameCollection;
  return $Operand;
}

function UABaseEventObject_Operands_NodeId() {
    $Operand = new COM("OpcLabs.EasyOpc.UA.Filtering.UASimpleAttributeOperand");
    $Operand->TypeId->NodeId->StandardName = "BaseEventType";
    $Operand->AttributeId = UAAttributeId_NodeId;
    return $Operand;
}

function UABaseEventObject_Operands_EventId() {
  return UAFilterElements_SimpleAttribute(ObjectTypeIds_BaseEventType(), "/EventId");
}

function UABaseEventObject_Operands_EventType() {
  return UAFilterElements_SimpleAttribute(ObjectTypeIds_BaseEventType(), "/EventType");
}

function UABaseEventObject_Operands_SourceNode() {
  return UAFilterElements_SimpleAttribute(ObjectTypeIds_BaseEventType(), "/SourceNode");
}

function UABaseEventObject_Operands_SourceName() {
  return UAFilterElements_SimpleAttribute(ObjectTypeIds_BaseEventType(), "/SourceName");
}

function UABaseEventObject_Operands_Time() {
  return UAFilterElements_SimpleAttribute(ObjectTypeIds_BaseEventType(), "/Time");
}

function UABaseEventObject_Operands_ReceiveTime() {
  return UAFilterElements_SimpleAttribute(ObjectTypeIds_BaseEventType(), "/ReceiveTime");
}

function UABaseEventObject_Operands_LocalTime() {
  return UAFilterElements_SimpleAttribute(ObjectTypeIds_BaseEventType(), "/LocalTime");
}

function UABaseEventObject_Operands_Message() {
  return UAFilterElements_SimpleAttribute(ObjectTypeIds_BaseEventType(), "/Message");
}

function UABaseEventObject_Operands_Severity() {
  return UAFilterElements_SimpleAttribute(ObjectTypeIds_BaseEventType(), "/Severity");
}


function UABaseEventObject_AllFields() {
    $Fields = new COM("OpcLabs.EasyOpc.UA.UAAttributeFieldCollection");
    $Fields->Add(UABaseEventObject_Operands_NodeId()->ToUAAttributeField);
    $Fields->Add(UABaseEventObject_Operands_EventId()->ToUAAttributeField);
    $Fields->Add(UABaseEventObject_Operands_EventType()->ToUAAttributeField);
    $Fields->Add(UABaseEventObject_Operands_SourceNode()->ToUAAttributeField);
    $Fields->Add(UABaseEventObject_Operands_SourceName()->ToUAAttributeField);
    $Fields->Add(UABaseEventObject_Operands_Time()->ToUAAttributeField);
    $Fields->Add(UABaseEventObject_Operands_ReceiveTime()->ToUAAttributeField);
    $Fields->Add(UABaseEventObject_Operands_LocalTime()->ToUAAttributeField);
    $Fields->Add(UABaseEventObject_Operands_Message()->ToUAAttributeField);
    $Fields->Add(UABaseEventObject_Operands_Severity()->ToUAAttributeField);

    return $Fields;
}

// Example output (truncated):
//Subscribing...
//Processing monitored item changed events for 30 seconds...
//[firstState] Success
//[secondState] Success
//[firstState] Success; Refresh; RefreshInitiated
//[firstState] Success; Refresh; (10 field results) [EastTank] 500! "The alarm was acknoweledged." @10/14/2019 4:00:13 PM
//[firstState] Success; Refresh; (10 field results) [EastTank] 500! "The alarm was acknoweledged." @10/14/2019 4:00:17 PM
//[firstState] Success; Refresh; (10 field results) [NorthMotor] 500! "The alarm was acknoweledged." @10/14/2019 4:00:02 PM
//[firstState] Success; Refresh; (10 field results) [NorthMotor] 500! "The alarm was acknoweledged." @10/14/2019 4:00:16 PM
//[firstState] Success; Refresh; (10 field results) [SouthMotor] 700! "The alarm was acknoweledged." @10/14/2019 4:00:21 PM
//[firstState] Success; Refresh; (10 field results) [SouthMotor] 500! "The alarm was acknoweledged." @10/14/2019 4:00:03 PM
//[firstState] Success; Refresh; RefreshComplete
//[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:08 PM
//[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:08 PM
//[secondState] Success; Refresh; RefreshInitiated
//[secondState] Success; Refresh; (10 field results) [SouthMotor] 100! "The dialog was activated" @9/10/2019 8:08:25 PM
//[secondState] Success; Refresh; (10 field results) [SouthMotor] 100! "The alarm is active." @11/8/2019 7:48:07 PM
//[secondState] Success; Refresh; (10 field results) [SouthMotor] 700! "The alarm was acknoweledged." @10/14/2019 4:00:21 PM
//[secondState] Success; Refresh; (10 field results) [SouthMotor] 500! "The alarm was acknoweledged." @10/14/2019 4:00:03 PM
//[secondState] Success; Refresh; (10 field results) [SouthMotor] 100! "The alarm severity has increased." @9/10/2019 8:09:02 PM
//[secondState] Success; Refresh; (10 field results) [SouthMotor] 100! "The alarm severity has increased." @9/10/2019 8:09:59 PM
//[secondState] Success; Refresh; RefreshComplete
//[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:09 PM
//[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:09 PM
//[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:10 PM
//[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:10 PM
//[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:11 PM
//[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:11 PM
//[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:12 PM
//[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:12 PM
//[firstState] Success; (10 field results) [EastTank] 500! "The alarm severity has increased." @11/8/2019 7:48:13 PM
//[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:13 PM
//[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:13 PM
//[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:14 PM
//[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:14 PM
//[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:15 PM
//[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:15 PM
//[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:16 PM
//[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:16 PM
//[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:17 PM
//[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:17 PM
//[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:18 PM
//[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:18 PM
//[secondState] Success; (10 field results) [SouthMotor] 300! "The alarm severity has increased." @11/8/2019 7:48:18 PM
//...

' This example shows how to subscribe to multiple events.

Imports OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.AddressSpace
Imports OpcLabs.EasyOpc.UA.AddressSpace.Standard
Imports OpcLabs.EasyOpc.UA.AlarmsAndConditions
Imports OpcLabs.EasyOpc.UA.Filtering
Imports OpcLabs.EasyOpc.UA.OperationModel

Namespace UADocExamples.AlarmsAndConditions
    Partial Friend Class SubscribeMultipleMonitoredItems
        Public Shared Sub Events()

            ' Instantiate the client object and hook events
            Dim client = New EasyUAClient()
            AddHandler client.EventNotification, AddressOf client_EventNotification

            Console.WriteLine("Subscribing...")

            client.SubscribeMultipleMonitoredItems(New EasyUAMonitoredItemArguments() _
                { _
                    New EasyUAMonitoredItemArguments("firstState", _
                        "opc.tcp://opcua.demo-this.com:62544/Quickstarts/AlarmConditionServer", _
                        UAObjectIds.Server, _
                        New UAMonitoringParameters(1000, New UAEventFilterBuilder( _
                            UAFilterElements.GreaterThanOrEqual(UABaseEventObject.Operands.Severity, 500), _
                            UABaseEventObject.AllFields))) _
                        With {.AttributeId = UAAttributeId.EventNotifier}, _
                    New EasyUAMonitoredItemArguments("secondState", _
                        "opc.tcp://opcua.demo-this.com:62544/Quickstarts/AlarmConditionServer", _
                        UAObjectIds.Server, _
                        New UAMonitoringParameters(2000, New UAEventFilterBuilder( _
                            UAFilterElements.Equals( _
                                UABaseEventObject.Operands.SourceNode, _
                                New UANodeId("nsu=http://opcfoundation.org/Quickstarts/AlarmCondition ;ns=2;s=1:Metals/SouthMotor")), _
                            UABaseEventObject.AllFields))) _
                        With {.AttributeId = UAAttributeId.EventNotifier} _
                } _
             )

            Console.WriteLine("Processing event notifications for 30 seconds...")
            Threading.Thread.Sleep(30 * 1000)

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

            Console.WriteLine("Waiting for 5 seconds...")
            Threading.Thread.Sleep(5 * 1000)
        End Sub

        Private Shared Sub client_EventNotification(ByVal sender As Object, ByVal e As EasyUAEventNotificationEventArgs)
            ' Display the event
            Console.WriteLine(e)
        End Sub
    End Class
End Namespace
Rem This example shows how to subscribe to multiple events.

Option Explicit

Const UAAttributeId_NodeId = 1
Const UAAttributeId_EventNotifier = 12

Const UAFilterOperator_Equals = 1
Const UAFilterOperator_GreaterThanOrEqual = 5

Dim endpointDescriptor
endpointDescriptor = "opc.tcp://opcua.demo-this.com:62544/Quickstarts/AlarmConditionServer"

' Instantiate the client object and hook events
Dim Client: Set Client = CreateObject("OpcLabs.EasyOpc.UA.EasyUAClient")
WScript.ConnectObject Client, "Client_"

Dim arguments(1)
Set arguments(0) = CreateMonitoredItemArguments1
Set arguments(1) = CreateMonitoredItemArguments2

WScript.Echo "Subscribing..."
Client.SubscribeMultipleMonitoredItems arguments

WScript.Echo "Processing monitored item changed events for 30 seconds..."
WScript.Sleep 30 * 1000

WScript.Echo "Unsubscribing..."
Client.UnsubscribeAllMonitoredItems

WScript.Echo "Waiting for 5 seconds..."
WScript.Sleep 5 * 1000



Function ObjectTypeIds_BaseEventType
    Dim NodeId: Set NodeId = CreateObject("OpcLabs.EasyOpc.UA.AddressSpace.UANodeId")
    NodeId.StandardName = "BaseEventType"
    Set ObjectTypeIds_BaseEventType = NodeId
End Function

Function UAFilterElements_SimpleAttribute(TypeId, simpleRelativeBrowsePathString)
    Dim BrowsePathParser: Set BrowsePathParser = CreateObject("OpcLabs.EasyOpc.UA.Navigation.Parsing.UABrowsePathParser")
    Dim Operand: Set Operand = CreateObject("OpcLabs.EasyOpc.UA.Filtering.UASimpleAttributeOperand")
    Set Operand.TypeId.NodeId = TypeId
    Set Operand.QualifiedNames = BrowsePathParser.ParseRelative(simpleRelativeBrowsePathString).ToUAQualifiedNameCollection
    Set UAFilterElements_SimpleAttribute = Operand
End Function

Function UABaseEventObject_Operands_NodeId
    Dim Operand: Set Operand = CreateObject("OpcLabs.EasyOpc.UA.Filtering.UASimpleAttributeOperand")
    Operand.TypeId.NodeId.StandardName = "BaseEventType"
    Operand.AttributeId = UAAttributeId_NodeId
    Set UABaseEventObject_Operands_NodeId = Operand
End Function

Function UABaseEventObject_Operands_EventId
    Set UABaseEventObject_Operands_EventId = UAFilterElements_SimpleAttribute(ObjectTypeIds_BaseEventType, "/EventId")
End Function

Function UABaseEventObject_Operands_EventType
    Set UABaseEventObject_Operands_EventType = UAFilterElements_SimpleAttribute(ObjectTypeIds_BaseEventType, "/EventType")
End Function

Function UABaseEventObject_Operands_SourceNode
    Set UABaseEventObject_Operands_SourceNode = UAFilterElements_SimpleAttribute(ObjectTypeIds_BaseEventType, "/SourceNode")
End Function

Function UABaseEventObject_Operands_SourceName
    Set UABaseEventObject_Operands_SourceName = UAFilterElements_SimpleAttribute(ObjectTypeIds_BaseEventType, "/SourceName")
End Function

Function UABaseEventObject_Operands_Time
    Set UABaseEventObject_Operands_Time = UAFilterElements_SimpleAttribute(ObjectTypeIds_BaseEventType, "/Time")
End Function

Function UABaseEventObject_Operands_ReceiveTime
    Set UABaseEventObject_Operands_ReceiveTime = UAFilterElements_SimpleAttribute(ObjectTypeIds_BaseEventType, "/ReceiveTime")
End Function

Function UABaseEventObject_Operands_LocalTime
    Set UABaseEventObject_Operands_LocalTime = UAFilterElements_SimpleAttribute(ObjectTypeIds_BaseEventType, "/LocalTime")
End Function

Function UABaseEventObject_Operands_Message
    Set UABaseEventObject_Operands_Message = UAFilterElements_SimpleAttribute(ObjectTypeIds_BaseEventType, "/Message")
End Function

Function UABaseEventObject_Operands_Severity
    Set UABaseEventObject_Operands_Severity = UAFilterElements_SimpleAttribute(ObjectTypeIds_BaseEventType, "/Severity")
End Function

Function UABaseEventObject_AllFields
    Dim Fields: Set Fields = CreateObject("OpcLabs.EasyOpc.UA.UAAttributeFieldCollection")

    Fields.Add UABaseEventObject_Operands_NodeId.ToUAAttributeField

    Fields.Add UABaseEventObject_Operands_EventId.ToUAAttributeField
    Fields.Add UABaseEventObject_Operands_EventType.ToUAAttributeField
    Fields.Add UABaseEventObject_Operands_SourceNode.ToUAAttributeField
    Fields.Add UABaseEventObject_Operands_SourceName.ToUAAttributeField
    Fields.Add UABaseEventObject_Operands_Time.ToUAAttributeField
    Fields.Add UABaseEventObject_Operands_ReceiveTime.ToUAAttributeField
    Fields.Add UABaseEventObject_Operands_LocalTime.ToUAAttributeField
    Fields.Add UABaseEventObject_Operands_Message.ToUAAttributeField
    Fields.Add UABaseEventObject_Operands_Severity.ToUAAttributeField

    Set UABaseEventObject_AllFields = Fields
End Function

Function CreateMonitoredItemArguments1
    ' Event filter: The severity is >= 500.
    Dim Operand1: Set Operand1 = UABaseEventObject_Operands_Severity
    Dim Operand2: Set Operand2 = CreateObject("OpcLabs.EasyOpc.UA.Filtering.UALiteralOperand")
    Operand2.Value = 500
    Dim WhereClause: Set WhereClause = CreateObject("OpcLabs.EasyOpc.UA.Filtering.UAContentFilterElement")
    WhereClause.FilterOperator = UAFilterOperator_GreaterThanOrEqual
    WhereClause.FilterOperands.Add Operand1
    WhereClause.FilterOperands.Add Operand2

    Dim EventFilter: Set EventFilter = CreateObject("OpcLabs.EasyOpc.UA.UAEventFilter")
    Set EventFilter.SelectClauses = UABaseEventObject_AllFields
    Set EventFilter.WhereClause = WhereClause

    Dim ServerNodeId: Set ServerNodeId = CreateObject("OpcLabs.EasyOpc.UA.AddressSpace.UANodeId")
    ServerNodeId.StandardName = "Server"

    Dim MonitoringParameters: Set MonitoringParameters = CreateObject("OpcLabs.EasyOpc.UA.UAMonitoringParameters")
    Set MonitoringParameters.EventFilter = EventFilter
    MonitoringParameters.QueueSize = 1000
    MonitoringParameters.SamplingInterval = 1000

    Dim MonitoredItemArguments: Set MonitoredItemArguments = CreateObject("OpcLabs.EasyOpc.UA.OperationModel.EasyUAMonitoredItemArguments")
    MonitoredItemArguments.AttributeId = UAAttributeId_EventNotifier
    MonitoredItemArguments.EndpointDescriptor.UrlString = endpointDescriptor
    Set MonitoredItemArguments.MonitoringParameters = MonitoringParameters
    Set MonitoredItemArguments.NodeDescriptor.NodeId = ServerNodeId
    MonitoredItemArguments.State = "firstState"

    Set CreateMonitoredItemArguments1 = MonitoredItemArguments
End Function

Function CreateMonitoredItemArguments2
    ' Event filter: The event comes from a specified source node.
    Dim Operand1: Set Operand1 = UABaseEventObject_Operands_SourceNode
    Dim SourceNodeId: Set SourceNodeId = CreateObject("OpcLabs.EasyOpc.UA.AddressSpace.UANodeId")
    SourceNodeId.ExpandedText = "nsu=http://opcfoundation.org/Quickstarts/AlarmCondition ;ns=2;s=1:Metals/SouthMotor"
    Dim Operand2: Set Operand2 = CreateObject("OpcLabs.EasyOpc.UA.Filtering.UALiteralOperand")
    Set Operand2.Value = SourceNodeId
    Dim WhereClause: Set WhereClause = CreateObject("OpcLabs.EasyOpc.UA.Filtering.UAContentFilterElement")
    WhereClause.FilterOperator = UAFilterOperator_Equals
    WhereClause.FilterOperands.Add Operand1
    WhereClause.FilterOperands.Add Operand2

    Dim EventFilter: Set EventFilter = CreateObject("OpcLabs.EasyOpc.UA.UAEventFilter")
    Set EventFilter.SelectClauses = UABaseEventObject_AllFields
    Set EventFilter.WhereClause = WhereClause

    Dim ServerNodeId: Set ServerNodeId = CreateObject("OpcLabs.EasyOpc.UA.AddressSpace.UANodeId")
    ServerNodeId.StandardName = "Server"

    Dim MonitoringParameters: Set MonitoringParameters = CreateObject("OpcLabs.EasyOpc.UA.UAMonitoringParameters")
    Set MonitoringParameters.EventFilter = EventFilter
    MonitoringParameters.QueueSize = 1000
    MonitoringParameters.SamplingInterval = 2000

    Dim MonitoredItemArguments: Set MonitoredItemArguments = CreateObject("OpcLabs.EasyOpc.UA.OperationModel.EasyUAMonitoredItemArguments")
    MonitoredItemArguments.AttributeId = UAAttributeId_EventNotifier
    MonitoredItemArguments.EndpointDescriptor.UrlString = endpointDescriptor
    Set MonitoredItemArguments.MonitoringParameters = MonitoringParameters
    Set MonitoredItemArguments.NodeDescriptor.NodeId = ServerNodeId
    MonitoredItemArguments.State = "secondState"

    Set CreateMonitoredItemArguments2 = MonitoredItemArguments
End Function

Sub Client_EventNotification(Sender, e)
    ' Display the event
    WScript.Echo e
End Sub



' Example output (truncated):
'Subscribing...
'Processing monitored item changed events for 30 seconds...
'[firstState] Success
'[secondState] Success
'[firstState] Success; Refresh; RefreshInitiated
'[firstState] Success; Refresh; (10 field results) [EastTank] 500! "The alarm was acknoweledged." @10/14/2019 4:00:13 PM
'[firstState] Success; Refresh; (10 field results) [EastTank] 500! "The alarm was acknoweledged." @10/14/2019 4:00:17 PM
'[firstState] Success; Refresh; (10 field results) [NorthMotor] 500! "The alarm was acknoweledged." @10/14/2019 4:00:02 PM
'[firstState] Success; Refresh; (10 field results) [NorthMotor] 500! "The alarm was acknoweledged." @10/14/2019 4:00:16 PM
'[firstState] Success; Refresh; (10 field results) [SouthMotor] 700! "The alarm was acknoweledged." @10/14/2019 4:00:21 PM
'[firstState] Success; Refresh; (10 field results) [SouthMotor] 500! "The alarm was acknoweledged." @10/14/2019 4:00:03 PM
'[firstState] Success; Refresh; RefreshComplete
'[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:08 PM
'[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:08 PM
'[secondState] Success; Refresh; RefreshInitiated
'[secondState] Success; Refresh; (10 field results) [SouthMotor] 100! "The dialog was activated" @9/10/2019 8:08:25 PM
'[secondState] Success; Refresh; (10 field results) [SouthMotor] 100! "The alarm is active." @11/8/2019 7:48:07 PM
'[secondState] Success; Refresh; (10 field results) [SouthMotor] 700! "The alarm was acknoweledged." @10/14/2019 4:00:21 PM
'[secondState] Success; Refresh; (10 field results) [SouthMotor] 500! "The alarm was acknoweledged." @10/14/2019 4:00:03 PM
'[secondState] Success; Refresh; (10 field results) [SouthMotor] 100! "The alarm severity has increased." @9/10/2019 8:09:02 PM
'[secondState] Success; Refresh; (10 field results) [SouthMotor] 100! "The alarm severity has increased." @9/10/2019 8:09:59 PM
'[secondState] Success; Refresh; RefreshComplete
'[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:09 PM
'[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:09 PM
'[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:10 PM
'[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:10 PM
'[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:11 PM
'[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:11 PM
'[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:12 PM
'[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:12 PM
'[firstState] Success; (10 field results) [EastTank] 500! "The alarm severity has increased." @11/8/2019 7:48:13 PM
'[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:13 PM
'[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:13 PM
'[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:14 PM
'[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:14 PM
'[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:15 PM
'[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:15 PM
'[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:16 PM
'[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:16 PM
'[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:17 PM
'[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:17 PM
'[firstState] Success; (10 field results) [Internal] 500! "Raising Events" @11/8/2019 7:48:18 PM
'[firstState] Success; (10 field results) [Internal] 500! "Events Raised" @11/8/2019 7:48:18 PM
'[secondState] Success; (10 field results) [SouthMotor] 300! "The alarm severity has increased." @11/8/2019 7:48:18 PM
'...
Requirements

Target Platforms: .NET Framework: Windows 10, Windows Server 2012, Windows Server 2016; .NET Core, .NET 5: Linux, macOS, Microsoft Windows

See Also