Answer:
An SSI encoder is a type of absolute encoder that uses the Synchronous Serial Interface (SSI) protocol to transmit position data in digital form. Unlike incremental encoders, which provide relative position changes, SSI encoders deliver a unique digital value for each shaft position, ensuring accurate and repeatable absolute position feedback even after power loss.
The encoder works by sending position data synchronously with the clock signal provided by the controller (PLC, motion controller, or drive). This communication is noise-resistant, reliable, and suited for long-distance transmission, making SSI encoders widely used in industrial automation, CNC machinery, elevators, robotics, and motion control systems.
Main functions of SSI encoders include:
Providing absolute position feedback for precise motion control
Eliminating the need for homing on startup
Ensuring reliable communication over long cable lengths
Supporting multi-turn and single-turn position measurement
