You have to buy motherboard with as many usb ports and aux usb also when building i use Leo Bodnar usb board where u can setup 6 axes and 32 knobs par board this will use only one usb on the motherboard. In fsuipc you can adress for example 7005 brake settings and added with, /1 or,/2 up to i believe, /12 so 12 settings for loran or rotary switch and uses only one or two inputs.