RC TX RX Protocols

When it comes to radio receiver (RX) and transmitter (TX) protocols, confusing acronyms are often used: PWM, PPM, SBUS, DSMX etc.

These radio protocols can be confusing to beginners. We will try to explain the basics and differences of these radio communication protocols. We will also have a look at some of the technology, and see how it makes flying more reliable and safer.

These radio communication protocols used in drones, RC planes/wings quadcopters and other radio controlled multirotors can be divided into two groups:

  • RX Protocols (communication between RX and FC), and
  • TX Protocols (communication between TX and RX)

Some of the RX protocols are universal across different brands of RF equipment, but some can be exclusive to certain brands. Some of them include the following:

  • PWM (universal)
  • PPM (universal)
  • PCM (universal)
  • SBUS (Futaba, Frsky)
  • IBUS (Flysky)
  • XBUS (JR)
  • MSP (Multiwii)
  • SUMD (Graupner)
  • SUMH (Graupner)
  • CRSF – Crossfire (TBS)
  • FPort (Frsky)

While TX protocols are mostly different between brands. Some brands might offer multiple different protocols depends on the pairing radio receiver. Some of them include:

  • D8 (Frsky)
  • D16 (Frsky)
  • LR12 (Frsky)
  • DSM (Spektrum)
  • DSM2 (Spektrum)
  • DSMX (Spektrum)
  • AFHDS (Flysky)
  • AFHDS 2A (Flysky)
  • A-FHSS (Hitec)
  • FASST (Futaba)
  • Hi-Sky (Deviation)