Serial Receiver Protocols Supported PPM Receiver Futaba S.Bus (compatible with FrSky SBus, JETI SBus, RadioLink SBus and WFLY WBus) Spektrum DSM2/X 1024 Satellite (Remote) Receiver Spektrum DSM2/X 2048 Satellite (Remote) Receiver Spektrum SRXL Multiplex SRXL / JR XBUS Mode B Graupner SUMD FlySky iBus JETI EXBus Standard PWM Receiver Connection When using a standard PWM receiver, A3 Super 4 has 7 input channels in which at least one channel should be connected to the receiver in Aileron (A), Elevator (E) and Rudder (R), or the gyro will enter the receiver timeout mode (Red Slow Flashing). [Serial RX/M] is used for flight mode switching, use a 3-position switch of the transmitter to switch the flight mode during flight. [G] is used for remote master gain control, a slide lever or a switch of the transmitter can be used to tune or change the master gain during flight. Connect the ESC or the throttle servo to the receiver directly without passing through the gyro.