Re above query, I should have mentioned that the mount and DSLR camera have direct 5v power by way of adapters power , ie not getting power as such for operation from the asiair. TheEAF and Guidescope get power from the asiair. Am using a Nikon D7500 camera, and a HEQ5 mount. So the USB facility on the asiair has EAF, Guide camera, lead from mount to asiair for control and camera, a total of 4.