The HS22 series of hollow shaft incremental encoder offers application advantages over conventional optical encoders. Designed for ease of installation to a servo motor, the encoder's flexible coupling fits over the driven motor shaft to provide an accurate, backlash-free method of attachment. This integral flex mount eliminates the need for couplings, sprockets, or gearing and provides for a 20-degree angular adjustment. Through-shaft or blind-shaft configurations of the HS22 are available. Standard outputs for both configurations include A and B in quadrature with index and optical commutation signals for brushless motor control.