PPR (Pulses Per Revolution) determines the encoder’s resolution, which is defined as the number of square wave pulses per 360 degree rotation of the encoder. Additionally, PPR is defined as the number of low to high transitions per channel per revolution. Occasionally, an encoder’s resolution is specified as CPR (Counts Per Revolution), which is simply the number of quadrature state changes per revolution, CPR= 4 X PPR. Detents are useful in providing feedback to the user by “clicking” into place as the shaft is rotated. Detents are specified as the number of clicks per 360 degree rotation. The push switch feature simply provides another user input signal. It is often used to select the function to be manipulated by turning the encoder knob.