SumSymbolRead Class

Inheritance Hierarchy

System.Object
  SumCommandWrapper.SumReadWrite.
    SumSymbolCommand.SumReadWrite.
      SumSymbolReadBase
        TwinCAT.Ads.SumCommand.SumSymbolRead
Namespace:  TwinCAT.Ads.SumCommand
Assembly:  TwinCAT.Ads (in TwinCAT.Ads.dll) Version: 6.0.328+39e3229

C#

public class SumSymbolRead : SumSymbolReadBase, 
    ISumRead, ISumCommand, ISumRead2<ISymbol>

The SumSymbolRead type exposes the following members.

Methods

Extension Methods

Remarks

The SumSymbolRead implements symbolic read access with automatic (dynamic) value marshalling. The advantage of the symbolic access is (in contrast to the handle access classes SumHandleRead,SumHandleWrite) that all type information is available when using this ADS Sum Command. The disadvantage is, that the Symbolic information must be loaded beforehand, see examples. The SumSymbolWrite defaults to an InstancPath/SymbolName read (ValueByName).

Usage of SumSymbolRead/SumSymbolWrite with AdsSession

/// <summary>
/// Defines the entry point of the application.
/// </summary>
/// <param name="args">The arguments.</param>
static async void Main(string[] args)
{
    Console.WriteLine("");
    Console.WriteLine("Press [Enter] for start:");
    Console.ReadLine();

    // Parse the command-line arguments
    AmsAddress address = ArgParser.Parse(args);

    CancellationTokenSource cancelSource = new CancellationTokenSource();
    CancellationToken cancel = cancelSource.Token;

    using (AdsSession session = new AdsSession(address))
    {
    // Connect to the device target.
    AdsConnection connection = (AdsConnection)session.Connect();

    // Load symbolic information
    var resultSymbols = await session.SymbolServer.GetSymbolsAsync(cancel);
    resultSymbols.ThrowOnError();

    ISymbolCollection<ISymbol> symbols = resultSymbols.Symbols;

    ISymbol bVar1 = symbols["GVL.bVar1"];
    ISymbol bVar2 = symbols["GVL.bVar2"];
    ISymbol projectName = symbols["TwinCAT_SystemInfoVarList._AppInfo.ProjectName"];

    SymbolCollection coll = new SymbolCollection() {bVar1, bVar2, projectName};

    // Sum Command Read
    SumSymbolRead readCommand = new SumSymbolRead(connection,coll);
    var resultReadValues = await readCommand.ReadAsync(cancel);

    if (resultReadValues.Succeeded)
    {
        object[] values = resultReadValues.Values;

        for (int i = 0; i < coll.Count; i++)
        {
        Console.WriteLine("Symbol: {0} (Value: {1}, Type: {2})", coll[i].InstancePath, values[i].ToString(), values[i].GetType().Name);
        }
    }
    // Sum Command Write

    SumSymbolWrite writeCommand = new SumSymbolWrite(connection,coll);
    object[] writeValues = new object[] {true, (short) 42, "MyNewProjectName"};

    var resultWrite = await writeCommand.WriteAsync(writeValues,cancel);
    }

    Console.WriteLine("");
    Console.WriteLine("Press [Enter] for leave:");
    Console.ReadLine();
}

Usage of SumSymbolRead/SumSymbolWrite with AdsClient

/// <summary>
/// Defines the entry point of the application.
/// </summary>
/// <param name="args">The arguments.</param>
static async void Main(string[] args)
{
    Console.WriteLine("");
    Console.WriteLine("Press [Enter] for start:");
    Console.ReadLine();

    CancellationTokenSource cancelSource = new CancellationTokenSource();
    CancellationToken cancel = cancelSource.Token;

    // Parse the command-line arguments
    AmsAddress address = ArgParser.Parse(args);

    using (AdsClient client = new AdsClient())
    {
    // Connect the AdsClient to the device target.
    client.Connect(address);

    // Load symbolic information
    ISymbolLoader loader = SymbolLoaderFactory.Create(client, SymbolLoaderSettings.Default);
    var resultReadSymbols = await loader.GetSymbolsAsync(cancel);

    resultReadSymbols.ThrowOnError();

    ISymbolCollection<ISymbol> allSymbols = resultReadSymbols.Symbols;

    ISymbol bVar1 = allSymbols["GVL.bVar1"];
    ISymbol bVar2 = allSymbols["GVL.iCount"];
    ISymbol projectName = allSymbols["TwinCAT_SystemInfoVarList._AppInfo.ProjectName"];

    SymbolCollection symbols = new SymbolCollection() {bVar1, bVar2, projectName};

    // Sum Command Read
    SumSymbolRead readCommand = new SumSymbolRead(client,symbols);
    var resultSumRead = await readCommand.ReadAsync(cancel);

    if (resultSumRead.Succeeded)
    {
        object[] values = resultSumRead.Values;

        for (int i = 0; i < symbols.Count; i++)
        {
        Console.WriteLine("Symbol: {0} (Value: {1}, Type: {2})", symbols[i].InstancePath, values[i].ToString(), values[i].GetType().Name);
        }

        // Sum Command Write
        SumSymbolWrite writeCommand = new SumSymbolWrite(client, symbols);
        object[] writeValues = new object[] { true, (short)42, "MyNewProjectName" };

        var resultSumWrite = await writeCommand.WriteAsync(writeValues, cancel);
    }
    }

    Console.WriteLine("");
    Console.WriteLine("Press [Enter] for leave:");
    Console.ReadLine();
}

Reference

TwinCAT.Ads.SumCommand Namespace

TwinCAT.Ads.SumCommand.ISumCommand

TwinCAT.Ads.SumCommand.SumAnyTypeRead

TwinCAT.Ads.SumCommand.SumSymbolWrite