PPM stands for Pulse Position Modulation.
There are several data encoding/decoding systems on the market today. The older one is PPM. That's just the way the data is encoded/decoded, since the RF carrier is often FM modulated on all systems.
The PPM encoding system consists of a data frame containing a synchronising pulse followed by a number of shorter pulses equal to the number of channels. The frame duration is about 20mS, which means the data is being send at a frequency of about 50Hz.
The transmitter encoder circuit reads each control potentiometer's value and switch's position sequentially, converting each value to a pulse width. The width of each pulse corresponds to the respective Servo position. A control in neutral position gives a pulse of 1.5mS and in the end position may be either 1 or 2mS depending on which way the control has been moved.
There are several data encoding/decoding systems on the market today. The older one is PPM. That's just the way the data is encoded/decoded, since the RF carrier is often FM modulated on all systems.
The PPM encoding system consists of a data frame containing a synchronising pulse followed by a number of shorter pulses equal to the number of channels. The frame duration is about 20mS, which means the data is being send at a frequency of about 50Hz.
The transmitter encoder circuit reads each control potentiometer's value and switch's position sequentially, converting each value to a pulse width. The width of each pulse corresponds to the respective Servo position. A control in neutral position gives a pulse of 1.5mS and in the end position may be either 1 or 2mS depending on which way the control has been moved.
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