I have esc beeping once every second which I understand it is not receiving a signal for pixhawk cube orange. If i plug the esc into a normal spektrum receiver the esc works fine. In mission planner the throttle in the radio calibraion has a low of 1100 and high of 1920, and this matches the flame 60a esc specs i have. I am using normal pwm output. can anyone help me sort this problem?