ESC problem beeps not stoping!

Hi all ,

I have a problem with my plane when I startup I get beeps for long time with out arming the motor , I must restart always until it works and arm the motor .

I have

  • os motor 490 KV
  • Dualsky ESC 80 A
  • 5*6 li-ion battery 24V - 17 amp
  • PMU
  • frsky x9d.

could any one figure where is the problem ?
And how to solve it ?

Going to be Crazy :frowning:

Regards …