Sbus rc receiver output and pixhawk rcin not working

I connected Sbus output in mc8re receiver to rcin input in pixhawk to make radio calibration through aground control but no any response.
Note: i not use sd card and not connected any components to pixhawk except rc receiver.

Two things come to mind immediately…,Is your SBUS signal inverted or regular?? Also be certain you are connecting the main S-BUS out (from your receiver) to the RCIN signal pin and not the S-BUS signal pin as this is an output only. Finally, confirm that you are using a compatible S-BUS receiver and be sure your radio is properly bound and mapped/mixed so it actually controls the appropriate channels. I hope this helps!