private void SendClicked(object sender, RoutedEventArgs e)
        {
            if (serialLayer.serialPort.IsOpen)
            {
                int len = ASCIITextBox.Text.Length;
                if (len > 0)
                {
                    byte[] data = new byte[len];
                    string msg  = ASCIITextBox.Text;
                    for (int i = 0; i < len; ++i)
                    {
                        data[i] = (byte)msg[i];
                    }

                    CommandEnum cmd = CommandEnum.DL_DATA_REQUEST;
                    if ((bool)PHYRadioButton.IsChecked)
                    {
                        cmd = CommandEnum.PHY_DATA_REQUEST;
                    }

                    ModulationEnum mod = ModulationEnum.B_PSK;
                    if ((bool)QPSKRadioButton.IsChecked)
                    {
                        mod = ModulationEnum.Q_PSK;
                    }
                    else if ((bool)EIGHTPSKRadioButton.IsChecked)
                    {
                        mod = ModulationEnum.EIGHT_PSK;
                    }
                    else if ((bool)BPSKPNARadioButton.IsChecked)
                    {
                        mod = ModulationEnum.BPSK_WITH_PNA;
                    }

                    serialLayer.SendDataRequest(cmd, mod, (bool)FECCheckBox.IsChecked, data);
                }
            }
        }