Add RC_Channels::set_override

I add button on Mission Planner FlightData page for control gimbal camera ch9
and call function like this…

MainV2.comPort.SendRCOverride((byte)MainV2.comPort.sysidcurrent, (byte)MainV2.comPort.compidcurrent, 0, 0, 0, 0, 0, 0, 0, 1494, 982, 982, 982, 1494, 1494, 1494, 1494, 1494);

and I modify ardupilot code set_override function on RC_Channels.cpp, RC_Channel.cpp, and RC_Channel.h. for rc_channel 9.

but I receive return value 257 instead of 982 on mission planner when I click the button I added
If i send value 2006 , it return 257 too…

what’s the problem and How can I add rc channel override function ?

I think I gave my best answer in the other (duplicate) thread…