DynamicSymbol.ValueChanged Event

C#

public event EventHandler<ValueChangedArgs> ValueChanged

VB

Public Event ValueChanged As EventHandler(Of ValueChangedArgs)

Value

Type: System.EventHandler.ValueChangedArgs.

Implements

IValueSymbol.ValueChanged

Use Dynamic Notifications

using System;
using System.Diagnostics;
using System.Threading;
using TwinCAT;
using TwinCAT.Ads;
using TwinCAT.Ads.TypeSystem;
using TwinCAT.Ads.ValueAccess;
using TwinCAT.TypeSystem;
using TwinCAT.TypeSystem.Generic;

namespace Sample
{
    class SymbolBrowserV2Notifications
    {
    /// <summary>
    /// Defines the entry point of the application.
    /// </summary>
    /// <param name="args">The arguments.</param>
    static void Main(string[] args)
    {
        // Parse the Command Line Parameters.
        AmsAddress address = ArgParser.Parse(args);

        #region DEFAULTNOTIFICATON_SAMPLE

        // Create AdsClient object
        using (TcAdsClient client = new TcAdsClient())
        {
        // No automatic Synchronization (necessary for Console applications without message loop)
        client.Synchronize = false;

        // Connect to client
        client.Connect(address);

        // Usage of 'dynamic' type/symbol loader
        SymbolLoaderSettings settings = new SymbolLoaderSettings(SymbolsLoadMode.DynamicTree, ValueAccessMode.IndexGroupOffsetPreferred);
        IAdsSymbolLoader dynLoader = (IAdsSymbolLoader)SymbolLoaderFactory.Create(client, settings);

        // Set the DefaultNotification Properties
        dynLoader.DefaultNotificationSettings = new NotificationSettings(AdsTransMode.ClientOnChange, 200, 2000);

        // Determine the symbols
        dynamic dynamicSymbols = ((IDynamicSymbolLoader)dynLoader).SymbolsDynamic;

        // Task 1 Symbol (build in symbol)
        dynamic task1Symbol = dynamicSymbols.TwinCAT_SystemInfoVarList._TaskInfo[1];

        // CycleCount Symbol
        dynamic cycleCountSymbol = task1Symbol.CycleCount;

        // Override Notification Setting for Cycle Count Symbol
        cycleCountSymbol.NotificationSettings = new NotificationSettings(AdsTransMode.OnChange, 250, 0);

        // Register Dynamic Value Changed event.
        cycleCountSymbol.ValueChanged += new EventHandler<ValueChangedArgs>(cycleCount_ValueChanged);
#endregion
        // Sleep main thread to receive notifications
        Thread.Sleep(10000); 
#region DEFAULTNOTIFICATON_SAMPLE
        }
#endregion
        Console.WriteLine("CycleCount Changed events received: {0}", _cycleCountEvents);
        Console.WriteLine("");
        Console.WriteLine("Press [Enter] for leave:");
        Console.ReadLine();
    }

    /// <summary>
    /// The cycle count event counter
    /// </summary>
    static int _cycleCountEvents = 0;

    /// <summary>
    /// Handler function for CycleCount changed events.
    /// </summary>
    /// <param name="sender">Event sender.</param>
    /// <param name="args">Event arguments.</param>
    static void cycleCount_ValueChanged(object sender, ValueChangedArgs args)
    {
        Interlocked.Increment(ref _cycleCountEvents);

        // Use Value as dynamic (type safe: UINT)  object.
        dynamic val = args.Value;
        uint intVal = val;

        DateTime changedTime = args.UtcRtime.ToLocalTime(); // Convert UTC to local time
        Console.WriteLine("CycleCount changed to: {0}, TimeStamp: {1}", intVal, changedTime.ToString("HH:mm:ss:fff"));
    }
    }
}

Reference

DynamicSymbol Class

TwinCAT.TypeSystem Namespace