N_Tesla:
Many thanks, it's working now.I have one more little question : there's always a delay of 1-2 seconds between the order and the execution by the servo. I reduced the delays in the code but it makes little difference. Is there a way to fix this ?
Not sure. It should be so fast as to appear instantaneous. Does DH and DL for the XBee on the potentiometer end equal SH and SL for the XBee on the servo end?