SerialPort COMport = new SerialPort("COM5", 19200);
            List<string> ReceivedData = new List<string>();
            COMport.ReadTimeout = 5000; //Setting ReadTimeout =3500 ms or 3.5 seconds
            COMport.Open();
            if (COMport.IsOpen)
            {
                for (int i = 0; i < 5000; i++)
                {

                    ReceivedData.Add(COMport.ReadLine());
                    if (ReceivedData.Count == 5)
                    {
                        break;
                    }

                }
                COMport.Close();                                  // Close the Port

            }
            else
            {
                MessageBox.Show("Unable to Write to COM port ");
                COMport.Close();                                  // Close the Port
            }
            for (int n = 0; n < ReceivedData.Count; n++)
            {
                String text = "txtTemp"+(n+1);
                TextBox tv = this.Controls.Find(text, true).FirstOrDefault() as TextBox;
                tv.Text=ReceivedData[n];
            }