By default the unit comes as a DCSBIOS device. If you are not familiar with DCSBIOS please check out the following link
https://dcs-bios.readthedocs.io/en/latest/installation.html
If you wish to have this unit as a HID device, this can be achieved by flicking UHF to the UPPER position, then turning the INS one left position past Zero, then and flicking the UHF toggle all the way to the LOWER position in one Push.
The unit will flash and then function as a USB HID Joystick Controller. Please note, this may not appear in Game Controllers, but this will work perfectly fine for any game and will require mapping to be done in most games.
If you wish to switch back to DCSBIOS Mode this can be achieved by flicking UHF to the LOWER position, then turning the MDS LVT one left position past Zero, then and flicking the UHF toggle all the way to the UPPER position in one Push.
The unit will flash and then function through DCSBIOS.