Flashed wrong firmware to a MGS1600 GY sensor - now not working anymore

Dear All,

I have used the DFU loader to flash the file MGSW1600-Firmware-Update-v30-090618 into a MGS1600GY unit - over USB connection. Now the device TD led is blinking red at 1Hz and it is not detected as a COM port or in the DFU utility. How can I recover it to a working state?

Should I connect over DSUB pins 3 and 2 (RS232 RX/TX) ? According to the manual : Serial communication will not work with microcomputers equipped with TTL-levels serial ports. What does this mean exactly?

Regards,
Cezar