Fanuc Wn57 Override Function Is Active ^new^ Jun 2026

In CNC machining, precise control over axis movements and spindle speeds determines part quality and operator safety. FANUC CNC systems use specialized alerts to communicate when the machine departs from normal execution states. One such specific warning is the alert.

Resolving the WN57 message depends entirely on whether it is an intentional operator choice or an unexpected system state.

Identifies builder-specific logic blocks causing the warning.

Set a default program header to force overrides to 100% at start: fanuc wn57 override function is active

If the feedrate or rapid override is set below 100%, the machine moves slower than programmed. This increases total cycle time and lowers production efficiency. 2. Risk to Surface Finish and Tool Life

When the machine is rebooted, the system performs a self-check (a "watchdog" process). If it detects that the parameters governing the feed rate generation or servo loop gains have been compromised, it may trigger the WN57 state. The system recognizes that the logic governing movement is unreliable, and consequently, it activates the override function to inhibit normal operation. Therefore, the WN57 message is often a precursor or companion to low-voltage alarms or parity errors on the servo drives.

| Item | Detail | |------|--------| | | Warning message number (varies slightly by FANUC model) | | 57 | Specific alarm/warning code | | Override function active | The CNC is using a non-standard override (e.g., rapid traverse override, feed override beyond normal limits, or special parameter-enabled override) | In CNC machining, precise control over axis movements

Locate the , Spindle Override , and Rapid Override controls on the main panel.

This function is typically used by technicians and builders during machine commissioning or ladder logic debugging to manually force or "override" PMC signals. When active, it can prevent the PMC program from operating normally, which is why the control displays this warning message. Why the WN57 Message Appears

The "WN57 Override Function is Active" message is a generated by the FANUC PMC (Programmable Machine Controller) [1]. Resolving the WN57 message depends entirely on whether

To find the exact cause, you must look at what the PLC is telling the CNC. Press the key on the FANUC MDI panel. Press the PMC softkey, then select STATUS or SIGNAL .

If the dials are at 100% but the screen shows otherwise, check the digital inputs: Press the key, then select the PMC softkey.