The conventional and common way to connect a receiver and servos is to connect the each servo to the designated receiver output channel depending on the role of each servo installed on the aircraft/vehicle (aileron, throttle, etc.).
With this method, as the number of servos increases, the number of wires and weight also increases, so the wires around the channel output of the receiver become crowded and difficult to arrange neatly, and the size of the receiver has to be bigger. In addition, the mass of the wire results in increase of the total weight of the aircraft.
The S.BUS system was devised to eliminate these inconveniences. It supplies control data for all channels to all servos. Each servo is programmed in advance to determine which channel of control data it receives among all channels. By doing this, multiple servos and the receiver can be connected by simply connecting one control signal line, and each servo is connected by distributing the signal through a dedicated hub or relay box.
S.BUS is a monodirectional communication system for sending control data from the receiver to the servos, but S.BUS2 is a two-way communication system that not only control the servos but also sending data from the telemetry sensor connected to the signal line back to the receiver.By combining S.BUS2 with a controller equipped with a wireless two-way communication function such as FASSTest/T-FHSS, information such as the battery voltage, motor rotation speed, and temperature of the aircraft/car can be monitored on the controller’s screen.
Please note that if devices other than S.BUS2 compatible devices (including “S.BUS” servos) are connected to the S.BUS2 controlled line, the S.BUS2 devices will not operate properly.Therefore, connect only S.BUS2 compatible devices to the S.BUS2 system.
S.BUS/S.BUS2 is also employed in some drones and industrial apparatus besides hobby RC devices. Please do not connect devices that do not indicate the S.BUS/S.BUS2 logo as this may cause operational issues.