AcknowledgeCondition(String,String,String,String,DateTime,Int64) Method

Acknowledges a condition in the Event Server. Uses computer name and server class for specifying the OPC server. Use default acknowledger ID and an empty comment.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<ComVisibleAttribute(False)>
Public Overloads Sub AcknowledgeCondition( _
   ByVal machineName As String, _
   ByVal serverClass As String, _
   ByVal qualifiedSourceName As String, _
   ByVal conditionName As String, _
   ByVal activeTime As Date, _
   ByVal cookie As Long _
)

'Usage
 
Dim instance As EasyAEClientCore
Dim machineName As String
Dim serverClass As String
Dim qualifiedSourceName As String
Dim conditionName As String
Dim activeTime As Date
Dim cookie As Long
 
instance.AcknowledgeCondition(machineName, serverClass, qualifiedSourceName, conditionName, activeTime, cookie)

[ComVisible(false)]
public void AcknowledgeCondition( 
   string machineName,
   string serverClass,
   string qualifiedSourceName,
   string conditionName,
   DateTime activeTime,
   long cookie
)

[ComVisible(false)]
public:
void AcknowledgeCondition( 
   String^ machineName,
   String^ serverClass,
   String^ qualifiedSourceName,
   String^ conditionName,
   DateTime activeTime,
   int64 cookie
)

Parameters

machineName

Name of the machine. Determines the computer on which the OPC server is located. It may be an empty string, in which case the OPC server is assumed to exist on the local computer or at the computer specified for it by DCOM configuration.

The value represents a UNC or DNS computer name. Any string can be passed to this parameter (i.e. will not cause System.ArgumentException), but not all values make sense and will work when an operation using them is attempted. IPv6 addresses are normally enclosed between '[' and ']'.

The value of this parameter cannot be null (Nothing in Visual Basic).

serverClass

Contains ProgID of the OPC server.

The value of this parameter cannot be null (Nothing in Visual Basic).

qualifiedSourceName

Fully qualified source name. Identifies the source of the condition that is being acknowledged, e.g. FIC101.

The value of this parameter cannot be null (Nothing in Visual Basic).

conditionName

A condition name, identifying the condition that is being acknowledged. Condition Names are unique within the scope of the event server. Examples of Condition Names might be "LevelAlarm" or "Deviation".

The value of this parameter cannot be null (Nothing in Visual Basic).

activeTime

An active time corresponding to the Source and Condition Name pair. This parameter uniquely identifies a specific transition of the condition to the active state or into a different sub-condition and is the same as the AEConditionState.SubconditionActiveTime condition attribute. Active Times are passed to the client in the event notification. If the condition has become active again or transitioned into a different sub-condition at a later time, this acknowledgment will be ignored.

cookie

A server supplied "cookie" corresponding to the Source and Condition Name pair that in addition to the Active Time uniquely identifies a specific event notification. Cookies are passed to the client in the event notification. The client is responsible for returning the same cookie parameter, received in the event notification, back to the server in the condition acknowledgment.

Exceptions

Exception Description

Exception	Description
System.ArgumentNullException	A `null` reference (`Nothing` in Visual Basic) is passed to a method that does not accept it as a valid argument. This is a usage error, i.e. it will never occur (the exception will not be thrown) in a correctly written program. Your code should not catch this exception.
System.ArgumentOutOfRangeException	The value of an argument is outside the allowable range of values as defined by the invoked method. This is a usage error, i.e. it will never occur (the exception will not be thrown) in a correctly written program. Your code should not catch this exception.
OpcLabs.EasyOpc.OperationModel.OpcException	The OPC "Classic" (or OPC XML-DA) operation has failed. This operation exception in uniformly used to allow common handling of various kinds of errors. The System.Exception.InnerException always contains information about the actual error cause. This is an operation error that depends on factors external to your program, and thus cannot be always avoided. Your code must handle it appropriately.

System.ArgumentNullException

A null reference (Nothing in Visual Basic) is passed to a method that does not accept it as a valid argument.

This is a usage error, i.e. it will never occur (the exception will not be thrown) in a correctly written program. Your code should not catch this exception.

System.ArgumentOutOfRangeException

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

This is a usage error, i.e. it will never occur (the exception will not be thrown) in a correctly written program. Your code should not catch this exception.

OpcLabs.EasyOpc.OperationModel.OpcException

The OPC "Classic" (or OPC XML-DA) operation has failed. This operation exception in uniformly used to allow common handling of various kinds of errors. The System.Exception.InnerException always contains information about the actual error cause.

This is an operation error that depends on factors external to your program, and thus cannot be always avoided. Your code must handle it appropriately.

Example

CSharp
VB.NET
Python

// This example shows how to acknowledge an event condition in the OPC server.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
// OPC client and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-CSharp .
// Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
// a commercial license in order to use Online Forums, and we reply to every post.

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

namespace DocExamples.AlarmsAndEvents._EasyAEClient
{
    class AcknowledgeCondition
    {
        // Instantiate the OPC-A&E client object.
        static readonly EasyAEClient AEClient = new EasyAEClient();

        // Instantiate the OPC-DA client object.
        static readonly EasyDAClient DAClient = new EasyDAClient();

        static volatile bool _done;

        public static void Main1()
        {
            var eventHandler = new EasyAENotificationEventHandler(AEClient_Notification);
            AEClient.Notification += eventHandler;

            Console.WriteLine("Processing event notifications for 1 minute...");
            var subscriptionFilter = new AESubscriptionFilter
            {
                Sources = new AENodeDescriptor[] { "Simulation.ConditionState1" }
            };
            int handle = AEClient.SubscribeEvents("", "OPCLabs.KitEventServer.2", 1000, null, subscriptionFilter);

            // Give the refresh operation time to complete
            Thread.Sleep(5 * 1000);

            // Trigger an acknowledgeable event
            try
            {
                DAClient.WriteItemValue("", "OPCLabs.KitServer.2", "SimulateEvents.ConditionState1.Activate", true);
            }
            catch (OpcException opcException)
            {
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message);
                return;
            }

            _done = false;
            DateTime endTime = DateTime.Now + new TimeSpan(0, 0, 5);
            while ((!_done) && (DateTime.Now < endTime))
                Thread.Sleep(1000);

            // Give some time to also receive the acknowledgement notification
            Thread.Sleep(5 * 1000);

            AEClient.UnsubscribeEvents(handle);
            AEClient.Notification -= eventHandler;
        }

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

            Console.WriteLine("Refresh: {0}", e.Refresh);
            Console.WriteLine("RefreshComplete: {0}", e.RefreshComplete);
            AEEventData eventData = e.EventData;
            if (!(eventData is null))
            {
                Console.WriteLine("Event.QualifiedSourceName: {0}", eventData.QualifiedSourceName);
                Console.WriteLine("Event.Message: {0}", eventData.Message);
                Console.WriteLine("Event.Active: {0}", eventData.Active);
                Console.WriteLine("Event.Acknowledged: {0}", eventData.Acknowledged);
                Console.WriteLine("Event.AcknowledgeRequired: {0}", eventData.AcknowledgeRequired);

                if (eventData.AcknowledgeRequired)
                {
                    Console.WriteLine(">>>>> ACKNOWLEDGING THIS EVENT");
                    try
                    {
                        AEClient.AcknowledgeCondition("", "OPCLabs.KitEventServer.2", "Simulation.ConditionState1", "Simulated",
                            eventData.ActiveTime, eventData.Cookie);
                    }
                    catch (OpcException opcException)
                    {
                        Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message);
                        return;
                    }
                    Console.WriteLine(">>>>> EVENT ACKNOWLEDGED");
                    _done = true;
                }
            }
        }
    }
}

' This example shows how to acknowledge an event condition in the OPC server.
'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
' OPC client and subscriber examples in VB.NET on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-VBNET .
' Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
' a commercial license in order to use Online Forums, and we reply to every post.

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

Namespace AlarmsAndEvents._EasyAEClient

    Friend Class AcknowledgeCondition
        _
        Private Shared ReadOnly AEClient As New EasyAEClient()
        _
        Private Shared ReadOnly DAClient As New EasyDAClient()

        Private Shared _done As Boolean ' volatile

        Public Shared Sub Main1()
            Dim eventHandler = New EasyAENotificationEventHandler(AddressOf AEClient_Notification)
            AddHandler AEClient.Notification, eventHandler

            Console.WriteLine("Processing event notifications for 1 minute...")
            Dim subscriptionFilter As New AESubscriptionFilter
            subscriptionFilter.Sources = New AENodeDescriptor() {"Simulation.ConditionState1"}
            Dim handle As Integer = AEClient.SubscribeEvents("", "OPCLabs.KitEventServer.2", 1000, Nothing, subscriptionFilter)

            ' Give the refresh operation time to complete
            Thread.Sleep(5 * 1000)

            ' Trigger an acknowledgeable event
            Try
                DAClient.WriteItemValue("", "OPCLabs.KitServer.2", "SimulateEvents.ConditionState1.Activate", True)
            Catch opcException As OpcException
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message)
                Exit Sub
            End Try

            _done = False
            Dim endTime As Date = Date.Now + New TimeSpan(0, 0, 5)
            Do While ((Not _done)) AndAlso (Date.Now < endTime)
                Thread.Sleep(1000)
            Loop

            ' Give some time to also receive the acknowledgement notification
            Thread.Sleep(5 * 1000)

            AEClient.UnsubscribeEvents(handle)
            RemoveHandler AEClient.Notification, eventHandler
        End Sub

        ' Notification event handler
        Private Shared Sub AEClient_Notification(ByVal sender As Object, ByVal e As EasyAENotificationEventArgs)
            Console.WriteLine()
            If Not e.Succeeded Then
                Console.WriteLine("*** Failure: {0}", e.ErrorMessageBrief)
                Exit Sub
            End If

            Console.WriteLine("Refresh: {0}", e.Refresh)
            Console.WriteLine("RefreshComplete: {0}", e.RefreshComplete)
            If e.EventData IsNot Nothing Then
                Dim eventData As AEEventData = e.EventData
                Console.WriteLine("EventData.QualifiedSourceName: {0}", eventData.QualifiedSourceName)
                Console.WriteLine("EventData.Message: {0}", eventData.Message)
                Console.WriteLine("EventData.Active: {0}", eventData.Active)
                Console.WriteLine("EventData.Acknowledged: {0}", eventData.Acknowledged)
                Console.WriteLine("EventData.AcknowledgeRequired: {0}", eventData.AcknowledgeRequired)

                If eventData.AcknowledgeRequired Then
                    Console.WriteLine(">>>>> ACKNOWLEDGING THIS EVENT")
                    Try
                        AEClient.AcknowledgeCondition("", "OPCLabs.KitEventServer.2", "Simulation.ConditionState1", "Simulated", eventData.ActiveTime, eventData.Cookie)
                    Catch opcException As OpcException
                        Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message)
                        Exit Sub
                    End Try
                    Console.WriteLine(">>>>> EVENT ACKNOWLEDGED")
                    _done = True
                End If
            End If
        End Sub
    End Class
End Namespace

# This example shows how to acknowledge an event condition in the OPC server.
#
# Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
# OPC client and subscriber examples in Python on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-Python .
# Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
# a commercial license in order to use Online Forums, and we reply to every post.
# The QuickOPC package is needed. Install it using "pip install opclabs_quickopc".
import opclabs_quickopc
import time

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


# Notification event handler
def notification(sender, e):
    global aeClient
    global done

    if not e.Succeeded:
        print('*** Failure: ', e.ErrorMessageBrief, sep='')
        return
    print('Refresh: ', e.Refresh, sep='')
    print('RefreshComplete: ', e.RefreshComplete, sep='')
    eventData = e.EventData
    if eventData is not None:
        print('EventData.QualifiedSourceName: ', eventData.QualifiedSourceName, sep='')
        print('EventData.Message: ', eventData.Message, sep='')
        print('EventData.Active: ', eventData.Active, sep='')
        print('EventData.ActiveTime: ', eventData.ActiveTime, sep='')
        print('EventData.ActiveTimeTicks: ', eventData.ActiveTimeTicks, sep='')
        print('EventData.Acknowledged: ', eventData.Acknowledged, sep='')
        print('EventData.AcknowledgeRequired: ', eventData.AcknowledgeRequired, sep='')
        print('EventData.Cookie: ', eventData.Cookie, sep='')
        if eventData.AcknowledgeRequired:
            print('>>>>> ACKNOWLEDGING THIS EVENT')
            try:
                IEasyAEClientExtension.AcknowledgeCondition(aeClient,
                                                            '', 'OPCLabs.KitEventServer.2',
                                                            'Simulation.ConditionState1', 'Simulated',
                                                            eventData.ActiveTimeTicks, eventData.Cookie,
                                                            'Myself')  # acknowledgerId
                # The precise ActiveTime is important for event acknowledgement in OPC A&E. Python.NET, however,
                # represents .NET DateTime to Python 'datetime' object, possibly losing precision. For this reason,
                # use AEEventData.ActiveTimeTicks (as above), and not AEEventData.ActiveTime.
                # aeClient.AcknowledgeCondition('', 'OPCLabs.KitEventServer.2',
                #                               'Simulation.ConditionState1', 'Simulated',
                #                               eventData.ActiveTime, eventData.Cookie)
            except OpcException as opcException:
                print('*** Failure: ' + opcException.GetBaseException().Message)
                done = True
                return
            print('>>>>> EVENT ACKNOWLEDGED')
            done = True


# Instantiate the OPC-A&E client object.
aeClient = EasyAEClient()

# Instantiate the OPC-DA client object.
daClient = EasyDAClient()

#
aeClient.Notification += notification

print('Processing event notifications for 1 minute...')
subscriptionFilter = AESubscriptionFilter()
subscriptionFilter.Sources = [AENodeDescriptor('Simulation.ConditionState1')]
handle = IEasyAEClientExtension.SubscribeEvents(aeClient, '', 'OPCLabs.KitEventServer.2', 1000, None,
                                                subscriptionFilter)

# Give the refresh operation time to complete.
time.sleep(5)

# Trigger an acknowledgeable event.
done = False
try:
    IEasyDAClientExtension.WriteItemValue(daClient, '', 'OPCLabs.KitServer.2',
                                          'SimulateEvents.ConditionState1.Activate', True)
except OpcException as opcException:
    print('*** Failure: ' + opcException.GetBaseException().Message)
    exit()

endTime = time.time() + 60
while (not done) and (time.time() < endTime):
    time.sleep(1)

# Give some time to also receive the acknowledgement notification.
time.sleep(5)

aeClient.UnsubscribeAllEvents()
aeClient.Notification -= notification

print('Finished.')

Requirements

Target Platforms: .NET Framework: Windows 10 (selected versions), Windows 11 (selected versions), Windows Server 2016, Windows Server 2022; .NET: Linux, macOS, Microsoft Windows

Reference

EasyAEClientCore Class
EasyAEClientCore Members
Overload List

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