Re: USB sends a signal that cause my program to restart

void loop()

{ 

  power_on_off(pin13, timer);

  if (Serial.available())

  {

    clear_usb_buffers();

    Serial.readBytes(raw_usb_command_received, raw_usb_command_lenght);

    Serial.readBytes(raw_usb_command_received, raw_usb_command_lenght);  

    //Disables serial communication, allowing the RX and TX pins to be used for general input and output

    Serial.end();  

    parse_raw_usb_command_received2(raw_usb_command_received);

    switch (usb_command_received[start_state_position]) {

      case '5':

        print2strings("EXECUTING", "STATE");                     

        delay(18000);                                        

        power_off_on(pin_to_SUT, 1000);

        print2strings("SHORT CIRCUIT", "SENT");

        break;     

      case '6':

        print2strings("EXECUTING", "STATE");      

        delay(18000);    

        power_on_off(pin_to_ACM, 5000);

        print2strings("SHORT CIRCUIT", "SENT TO A/C MOD");

        power_off_on(pin_to_SUT, 1000);

        print2strings("SHORT CIRCUIT", "SENT");      

        break;

      default:

          print2strings("ERROR USB DATA", " ");

          break;

    }

    print2strings("WAITING2 USB","DATA...");

  }else {

  }

  Serial.begin(9600);

}