Multiturn measurement value recording

Multiturn absolute value encoders can resolve the position of the rotor over several rotations.

Through a multiturn encoder, a coded position value is assigned to every angle position and every complete rotation. A zero setting or homing is only necessary at the first startup.
For the absolute position to remain known after several rotations, the rotations in the measurement system must continue to be counted after switch-off as well.
To record the rotations, multiturn rotary encoders use several code discs, which are internally connected through a gear.

At startup, the working range of the multiturn encoder must be selected so that modulo transition of the rotations is reliably avoided, which means the drive must not leave the permitted working range or it will lose its absolute reference.