Using Pixhawk4 & Redbrick ESCs. Escs will not run motors or program

ESC Wont run the motor or program. I get 10 short musical tones with a 6 second pause then a repeat of the 10 musical tones, this repeats over and over. I am useing 4 ESCs all 4 respond in the same manor. Thanks for any help you can give me. Dave