DS 12

Hello, please i need help ...
after connecting the REX7 the Rsat2 and the new 900NG in the CBOX 220 with DS12 transmitter it seems that everything works but I realized that the servos are not smooth but they move in jerks, what happens that I don't understand?

Hi, i found the problem.
I connected the REX7 and RSAT2 receivers in EX BUS mode in the CB220 and the 900 NG back up in the CB220 in EX BUS mode and this is not good, the port of the 900 in the CBOX must be in receiving mode and not in EXBUS, I hope I have explained myself