an encoder is a very important sensor for control motor positioning and many industrial & machine design for precise control and measurements system. an encoder is two types absolute encoder and incremental encoder. absolute encoder used for retention its last data but in rotary incremental, not retention is used. absolute encoder is costly than a rotary encoder. wiring connection is the same in both encoder A-B-C-PHASE FOR INPUT COMMAND VDC(POWER SUPPLY TO ENCODER 5-24V DC).