Incremental Encoders — Which Sensor

Incremental encoders output a fixed number of pulses per revolution. Speed and direction can be read from the frequency and phase relation of the two channels A and B, while the absolute position has to come from a homing run after power-up.

HTL signals at 24 V are used in industrial conveyors, printing presses, and packaging machines. The higher signal level is robust against EMC noise on longer cable runs.

TTL versions at 5 V with RS-422 differential signals suit servo controls, positioning controllers, and control cards in machine tools.

Hollow-shaft versions with large bore are used as handwheels, spindle attachments, and on shafts where the shaft passes through the encoder.

Typical resolutions range from 100 to 10,000 pulses per revolution.

For hazardous areas there are ATEX versions, for harsh environments IP67 and IP68 versions with stainless-steel bearing housings.