Available with Analog Sin/Cos , Digital SSi , Digital AqB+I outputs, these rotary encoders feature up to 20 Bit Resolution (with 12 bit A/D) and. What is a quadrature encoder? A quadrature encoder is an incremental encoder with 2 out-of-phase output channels used in many general automation. An incremental encoder is a linear or rotary electromechanical device that has two output. A rotary encoder, also called a shaft encoder, is an electro-mechanical device that converts the angular position or motion of a shaft or axle to analog or digital output signals. Quadrature encoder channel A B code track on disk. Our Incremental Optical Encoders produce digital output related to the position of a rotating shaft, providing feedback elements in closed-loop control systems.