The 1520-0201-03 is an encoder module designed by Allen-Bradley, a Rockwell Automation company. It is a four-in-one encoder amplifier module designed to control velocity and position of various motor types. It combines a four-digit encoder input with ability to detect direction and speed of a motor, provide electrical isolation between the encoder and the motor, and support for both open-loop and closed-loop control. The module includes both a single-ended output and differential output for motor speed and direction, as well as programmable deadband capabilities, automatic detection of motor type, and a built-in diagnostic display. It can be used in applications including robotics, automated manufacturing, and machine vision.