Fanuc Wn57 Override Function Is Active -

WN57 on FANUC CNC controls indicates that the machine is running with an active feed override or rapid override function tied to a safety or watchdog feature that modulates axis motion. It’s commonly seen as a displayed override status (often in the MPG/MDI or alarm/message area) when the control has detected a condition where commanded motion has been limited or overridden by the system. The exact behavior and causes vary by FANUC series and machine OEM implementation.

The WN57 message indicates that an Override Function (such as Feedrate Override, Spindle Override, or Rapid Traverse Override) is currently active while a specific prohibited operation (like a threading cycle or rigid tapping) is being attempted.

In simpler terms: The CNC is telling you, “I cannot run this cycle because someone has turned a knob (override) that I am not allowed to ignore right now.”

Some high-end FANUC models (31i-A, 31i-B) feature Handle Interrupt – a mode allowing the operator to manually jog an axis during an automatic cycle using the MPG (handwheel). If the operator exits this mode without canceling the interrupt or if the program expects synchronized axes, WN57 appears as a safety warning.

FANUC alarms are categorized by prefixes:

WN57 specifically belongs to a family of safety and interlock warnings. It translates to: “The control is currently in a state where manual or automatic override functions are engaged, preventing the requested action.” fanuc wn57 override function is active

If you are writing a macro and want to check if an operator has left an override active, you can use system variables:

However, WN57 is typically a built-in safety feature for FANUC Series 0i, 16i, 18i, 21i, and 31i controls.

Final Verdict: Check your override knobs. Set them all to 100%. The machine will then proceed.

Has anyone else encountered the WN57 alarm while rigid tapping? Share your experience below! 👇

#FANUC #CNC #Machining #Troubleshooting #WN57 #OverrideFunction WN57 on FANUC CNC controls indicates that the

The WN57 (also written as W057) is a status message on FANUC Robodrill and CNC systems indicating that the Override Function is currently active. 

While it may appear as a warning, this "Override Function" is a helpful feature designed for safety and process verification during machine setup or program testing.  Key Benefits of the Override Function 

Safe Program Verification: It allows you to run a program at a reduced speed—often significantly lower than the programmed feedrate—to ensure there are no collisions or errors before running at full production speed.

Variable Speed Control: You can manually adjust the feedrate (Feedrate Override) or rapid traverse (Rapid Override) percentages using the dials or buttons on the control panel.

Tool Protection: By slowing down the motion during the first run of a new tool or part, you can stop the machine quickly if the tool path looks incorrect.  Why You See the WN57 Message  WN57 specifically belongs to a family of safety

The message typically appears when the system detects that the Override Select or a related custom PMC (Programmable Machine Control) function has been engaged. 

Diagnostic Tip: If you want to disable this feature to run at 100% speed, ensure all override dials are set to 100% and any "Dry Run" or "Override" toggle switches are turned off.

System Variables: In some cases, advanced users can control or disable these overrides through system variables like #3004 or $GENOV_ENB to prevent accidental speed changes during production. 

If you'd like to know the specific parameter number to disable this warning or how to lock the override at 100% for production, just let me know!  Four Ways to Control FANUC Robots' Speed Override