All alarm codes
ALARM 22

Feedback System Malfunction (1, 0, &0043)

Feedback system fault on the affected axis — encoder, feedback cable, or drive feedback path is failing.

Controls
Mazatrol 640T
Machine series
Mazak lathes on M640T

Causes

  1. Feedback system fault on the affected axis — encoder, feedback cable, or drive feedback path is failing.

    • Fabian Achavalyoutube
      If you have 22 Feedback System Malfunction ( 1, 0, &0043), by configuring the machine in semi-closed loop you would be able to test the axis without being attached to the m[achine]

How to clear it

  1. 1

    Reconfigure the X-axis to semi-closed loop mode so you can run and diagnose the axis without the external feedback path active — isolates whether the fault is in the motor/drive or in the linear scale/encoder.

Confidence: medium · Single video naming code + alarm string + diagnostic method; resolution depends on what the semi-closed test reveals.

First sourced: 5/21/2026