OPC Studio User's Guide and Reference
Examples - OPC Alarms&Events - Retrieve attribute values
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.NET

// This example shows how to subscribe to events with specified event attributes, and obtain the attribute values in event 
// notifications.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

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

namespace DocExamples.AlarmsAndEvents._EasyAENotificationEventArgs
{
    class AttributeValues
    {
        public static void Main1()
        {
            // Instantiate the OPC-A&E client object.
            var aeClient = new EasyAEClient();

            // Instantiate the OPC-DA client object.
            var daClient = new EasyDAClient();

            var eventHandler = new EasyAENotificationEventHandler(aeClient_Notification);
            aeClient.Notification += eventHandler;

            // Inactivate the event condition (we will later activate it and receive the notification)
            daClient.WriteItemValue("", "OPCLabs.KitServer.2", "SimulateEvents.ConditionState1.Inactivate", true);

            var subscriptionFilter = new AESubscriptionFilter
            {
                Sources = new AENodeDescriptor[] { "Simulation.ConditionState1" }
            };

            // Prepare a dictionary holding requested event attributes for each event category
            // The event category IDs and event attribute IDs are hard-coded here, but can be obtained from the OPC 
            // server by querying as well.
            var returnedAttributesByCategory = new AEAttributeSetDictionary
            {
                [0x00ECFF02] = new long[] {0x00EB0003, 0x00EB0008}
            };

            Console.WriteLine("Subscribing to events...");
            int handle = aeClient.SubscribeEvents("", "OPCLabs.KitEventServer.2", 1000, null, subscriptionFilter,
                returnedAttributesByCategory);

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

            // Trigger an event carrying specified attributes (activate the condition)
            try
            {
                daClient.WriteItemValue("", "OPCLabs.KitServer.2",
                    "SimulateEvents.ConditionState1.AttributeValues.15400963", 123456);
                daClient.WriteItemValue("", "OPCLabs.KitServer.2",
                    "SimulateEvents.ConditionState1.AttributeValues.15400968", "Some string value");
                daClient.WriteItemValue("", "OPCLabs.KitServer.2", "SimulateEvents.ConditionState1.Activate", true);
            }
            catch (OpcException opcException)
            {
                Console.WriteLine("*** Failure: {0}", opcException.GetBaseException().Message);
                return;
            }

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

            aeClient.UnsubscribeEvents(handle);
        }

        // Notification event handler
        static void aeClient_Notification(object sender, EasyAENotificationEventArgs e)
        {
            if (!e.Succeeded)
            {
                Console.WriteLine("*** Failure: {0}", e.ErrorMessageBrief);
                return;
            }
            if (!e.Refresh && (!(e.EventData is null)))
            {
                // Display all received event attribute IDs and their corresponding values
                Console.WriteLine("Event attribute count: {0}", e.EventData.AttributeValues.Count);
                foreach (KeyValuePair<long, object> pair in e.EventData.AttributeValues)
                    Console.WriteLine("    {0}: {1}", pair.Key, pair.Value);
            }
        }
    }
}

.NET

Rem This example subscribe to events, and displays rich information available with each event notification. 
Rem
Rem Find all latest examples here : https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

Option Explicit

Dim ServerDescriptor: Set ServerDescriptor = CreateObject("OpcLabs.EasyOpc.ServerDescriptor")
ServerDescriptor.ServerClass = "OPCLabs.KitEventServer.2"

Dim Client: Set Client = CreateObject("OpcLabs.EasyOpc.AlarmsAndEvents.EasyAEClient")
WScript.ConnectObject Client, "Client_"

WScript.Echo "Subscribing..."
Dim SubscriptionParameters: Set SubscriptionParameters = CreateObject("OpcLabs.EasyOpc.AlarmsAndEvents.AESubscriptionParameters")
SubscriptionParameters.NotificationRate = 1000
Dim handle: handle = Client.SubscribeEvents(ServerDescriptor, SubscriptionParameters, True, Nothing)

WScript.Echo "Processing event notifications for 1 minute..."
WScript.Sleep 60*1000

Client.UnsubscribeEvents handle



Rem Notification event handler
Sub Client_Notification(Sender, e)
    On Error Resume Next
    WScript.Echo
    WScript.Echo "e.Exception.Message: " & e.Exception.Message
    WScript.Echo "e.Exception.Source: " & e.Exception.Source
    WScript.Echo "e.Exception.ErrorCode: " & e.Exception.ErrorCode
    WScript.Echo "e.Arguments.State: " & e.Arguments.State
    WScript.Echo "e.Arguments.ServerDescriptor.MachineName: " & e.Arguments.ServerDescriptor.MachineName
    WScript.Echo "e.Arguments.ServerDescriptor.ServerClass: " & e.Arguments.ServerDescriptor.ServerClass
    WScript.Echo "e.Arguments.SubscriptionParameters.Active: " & e.Arguments.SubscriptionParameters.Active
    WScript.Echo "e.Arguments.SubscriptionParameters.NotificationRate: " & e.Arguments.SubscriptionParameters.NotificationRate
    Rem IMPROVE: Display Arguments.SubscriptionParameters.Filter details
    WScript.Echo "e.Arguments.SubscriptionParameters.Filter: " & e.Arguments.SubscriptionParameters.Filter  
    Rem IMPROVE: Display Arguments.SubscriptionParameters.ReturnedAttributesByCategory details
    WScript.Echo "e.Arguments.SubscriptionParameters.ReturnedAttributesByCategory: " & e.Arguments.SubscriptionParameters.ReturnedAttributesByCategory
    WScript.Echo "e.Refresh: " & e.Refresh
    WScript.Echo "e.RefreshComplete: " & e.RefreshComplete
    WScript.Echo "e.EnabledChanged: " & e.EnabledChanged 
    WScript.Echo "e.ActiveChanged: " & e.ActiveChanged 
    WScript.Echo "e.AcknowledgedChanged: " & e.AcknowledgedChanged 
    WScript.Echo "e.QualityChanged: " & e.QualityChanged  
    WScript.Echo "e.SeverityChanged: " & e.SeverityChanged 
    WScript.Echo "e.SubconditionChanged: " & e.SubconditionChanged 
    WScript.Echo "e.MessageChanged: " & e.MessageChanged
    WScript.Echo "e.AttributeChanged: " & e.AttributeChanged 
    WScript.Echo "e.EventData.QualifiedSourceName: " & e.EventData.QualifiedSourceName 
    WScript.Echo "e.EventData.Time: " & e.EventData.Time
    WScript.Echo "e.EventData.TimeLocal: " & e.EventData.TimeLocal
    WScript.Echo "e.EventData.Message: " & e.EventData.Message
    WScript.Echo "e.EventData.EventType: " & e.EventData.EventType 
    WScript.Echo "e.EventData.CategoryId: " & e.EventData.CategoryId 
    WScript.Echo "e.EventData.Severity: " & e.EventData.Severity 
    Rem IMPROVE: Display EventData.AttributeValues details
    WScript.Echo "e.EventData.AttributeValues: " & e.EventData.AttributeValues 
    WScript.Echo "e.EventData.ConditionName: " & e.EventData.ConditionName 
    WScript.Echo "e.EventData.SubconditionName: " & e.EventData.SubconditionName 
    WScript.Echo "e.EventData.Enabled: " & e.EventData.Enabled 
    WScript.Echo "e.EventData.Active: " & e.EventData.Active 
    WScript.Echo "e.EventData.Acknowledged: " & e.EventData.Acknowledged 
    WScript.Echo "e.EventData.Quality: " & e.EventData.Quality 
    WScript.Echo "e.EventData.AcknowledgeRequired: " & e.EventData.AcknowledgeRequired 
    WScript.Echo "e.EventData.ActiveTime: " & e.EventData.ActiveTime
    WScript.Echo "e.EventData.ActiveTimeLocal: " & e.EventData.ActiveTimeLocal
    WScript.Echo "e.EventData.Cookie: " & e.EventData.Cookie 
    WScript.Echo "e.EventData.ActorId: " & e.EventData.ActorId 
End Sub

 

See Also

Conceptual

Examples - OPC UA Alarms&Conditions