I have a board with a Teensy 4.0 that is placed too far to be accessed by a USB connection, moreover, it must be electrically insulated from any computer, because it is placed at high voltage. I am currently accessing this board through an optical fibre connection by 2 serial TX, RX signals, that I use to send and receive data from the Teensy 4.0. My question is: is it possible to program the Teensy 4.0 through this kind of optical fibre connection? Or, is there any serial connection, different from USB, that I could use to program the Teensy 4.0 through optical fibres?