Pixhawk esc problem

hi

we have
-pixhawk
-arduplane 3.1.1
-hobbywing platinium hv 100A esc
we have tested esc directly with receiver and it worked as expected
but when we want to connect everything to pixhawk , esc start beeping which means abnormal throttle signal according to esc manual.
how can i solve this problem?
is it timing problem?
or what is the cause of problem?

thanks…

Hi,
This forum is for the PX4 flight stack. Please ask on the ardupilot forum.