How do I fix and clear Mazak alarm 257?

Check the milling spindle tool unclamping sensor. If the alarm is not released, contact the nearest Mazak Technical Center or Technology Center. Clearing procedure: Fix cause → press RESET.

ALARMSMazatrol Assistant

CRITICALAlarm code

257

TOOL UNCLAMP SENSOR MALFUNCTION

Q: What does Mazak alarm 257 mean?

Mazak alarm 257 is "TOOL UNCLAMP SENSOR MALFUNCTION". The milling spindle tool unclamping sensor has not turned on within 5 seconds after the issue of a milling spindle tool unclamp command. Error type: Machine (PLC) — machine failure. Machine state: Feed hold — feed stopped, machine ready.

What it means

The milling spindle tool unclamping sensor has not turned on within 5 seconds after the issue of a milling spindle tool unclamp command.

What to do

1Check the milling spindle tool unclamping sensor.
2If the alarm is not released, contact the nearest Mazak Technical Center or Technology Center.

Codebook — decoded

FError typeMachine (PLC) — machine failure

KStop statusFeed hold — feed stopped, machine ready

OClearingFix cause → press RESET

Still faulted after these steps? Do not restart under load — ask the Mazatrol assistant.

Still stuck? Ask the Mazatrol assistant →