Installed Examples - Client Console

The example below logs OPC Data Access item changes into an XML file.

The main program:

C#
VB.NET

// Logs OPC Data Access item changes into an XML file.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
// OPC client and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-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.Diagnostics;
using System.Xml;
using System.Xml.Serialization;
using OpcLabs.BaseLib.Runtime.InteropServices;
using OpcLabs.EasyOpc.DataAccess;
using OpcLabs.EasyOpc.DataAccess.OperationModel;

namespace XmlLogger
{
    class Program
    {
        static void Main()
        {
            ComManagement.Instance.AssureSecurityInitialization();

            Console.WriteLine("Starting up...");
            var xmlSerializer = new XmlSerializer(typeof(EasyDAItemChangedEventArgs));
            var xmlWriter = XmlWriter.Create("OpcData.xml", new XmlWriterSettings
                                        {
                                            Indent = true,
                                            CloseOutput = true
                                        });
            // The root element can have any name you need, but the name below also allows reading the log back as .NET array
            xmlWriter.WriteStartElement("ArrayOfEasyDAItemChangedEventArgs");

            Console.WriteLine("Logging data for 30 seconds...");
            int handle = EasyDAClient.SharedInstance.SubscribeItem("", "OPCLabs.KitServer.2", 
                "Simulation.Incrementing (1 s)", 100,
               (_, eventArgs) =>
                   {
                       Debug.Assert(!(eventArgs is null));
                       Console.Write(".");
                       xmlSerializer.Serialize(xmlWriter, eventArgs);
                   });
            System.Threading.Thread.Sleep(30 * 1000);

            Console.WriteLine();
            Console.WriteLine("Shutting down...");
            EasyDAClient.SharedInstance.UnsubscribeItem(handle);
            xmlWriter.WriteEndElement();    // not really necessary - XmlWriter would write the end tag for us anyway
            xmlWriter.Close();

            Console.WriteLine("Finished.");
        }
    }
}

' Logs OPC Data Access item changes into an XML file.
'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
' OPC client and subscriber examples in VB.NET on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-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.Xml
Imports System.Xml.Serialization
Imports OpcLabs.BaseLib.Runtime.InteropServices
Imports OpcLabs.EasyOpc.DataAccess
Imports OpcLabs.EasyOpc.DataAccess.OperationModel

Namespace Global.XmlLogger
    Friend Class Program
        Shared WithEvents _client As New EasyDAClient
        Shared ReadOnly XmlSerializer As New XmlSerializer(GetType(EasyDAItemChangedEventArgs))
        Shared _xmlWriter As XmlWriter

        <MTAThread> ' needed for COM security initialization to succeed
        Shared Sub Main()
            ComManagement.Instance.AssureSecurityInitialization()

            Console.WriteLine("Starting up...")
            _xmlWriter = XmlWriter.Create("OpcData.xml", New XmlWriterSettings With {.Indent = True, .CloseOutput = True})
            ' The root element can have any name you need, but the name below also allows reading the log back as .NET array
            _xmlWriter.WriteStartElement("ArrayOfEasyDAItemChangedEventArgs")

            Console.WriteLine("Logging data for 30 seconds...")
            Dim handle As Integer = _client.SubscribeItem(
                "",
                "OPCLabs.KitServer.2",
                "Simulation.Incrementing (1 s)",
                100)
            Threading.Thread.Sleep(30 * 1000)

            Console.WriteLine()
            Console.WriteLine("Shutting down...")
            _client.UnsubscribeItem(handle)
            _xmlWriter.WriteEndElement() ' not really necessary - XmlWriter would write the end tag for us anyway
            _xmlWriter.Close()

            Console.WriteLine("Finished.")
        End Sub

        Private Shared Sub ItemChanged(ByVal sender As Object, ByVal eventArgs As EasyDAItemChangedEventArgs) Handles _client.ItemChanged
            Debug.Assert(eventArgs IsNot Nothing)
            Console.Write(".")
            XmlSerializer.Serialize(_xmlWriter, eventArgs)
        End Sub
    End Class
End Namespace

Examples - OPC Client

QuickOPC

Examples - Client OPC Data Access