C#

port = new SerialPort(MyParam._COM, Brate, Parity.None, 8, StopBits.One); //COM7
port.DataReceived += new System.IO.Ports.SerialDataReceivedEventHandler(Recepcion);
private SerialPort port;
string Recibidos;

 private void Recepcion(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
        {
            try
            {
                Recibidos = "";
                Application.DoEvents();
                System.Threading.Thread.Sleep(122);
                Recibidos += port.ReadExisting();
                this.Invoke(new EventHandler(Actualizar));
            }
            catch { }

 string text;
 decimal dTEXT;
        private void Actualizar(object s, EventArgs e)
        {
            text = Recibidos.Trim();
            lblMSG.Text = text;
      }