I have a system where there is usb slave device that is in a rotating structure behind a slipring. I need to pass the signal through the slipring (we only have 4 "wires") and onto a computer. Due to the long distance and noisy environment I'd like to convert the usb signal to rs232 or 485 but my understanding is that usb to rs232 dongles do not work on slave devices.
Does anyone have an idea as to how to do this? There are usb to cat5 but I only have four conductors.