Encoder

This sensor can detect the speed and position of the drive.
Encoders are broadly classified into "incremental encoders" and "absolute encoders."
The type that detects the rotational position (angle) of a shaft is called a rotary encoder, and the type that detects a linear position (displacement) is called a linear encoder (linear scale). Servo motors are equipped with encoders which are used not only to detect the actual movement of the drive unit, but also to control it closer to the command.

Absolute Encoder

This encoder is capable of detecting the absolute position within 1 revolution of the motor, and outputs the absolute position of the rotation angle.
Normally, multiple rotation information is transferred to the servo amplifier when the power is turned on, and then output to the present position data.

Incremental Encoder

An encoder that can detect the amount of rotation, rotation speed, and rotation direction of a motor, and outputs pulses for each change in rotation angle.
Normally, the detected waveform is output as it is, so the present position is lost in the event of a blackout.