Fanuc Wn57 Override Function Is Active

A: Check for a stuck physical switch (internal contact failure). Use the FANUC diagnostic screen (DIAGNOSIS → PMC → SIGNAL) to see if G104.0 (MLK) reads "1" even when the switch is off. This indicates a hardware failure in the I/O unit.

. This bit typically controls whether the override function is enabled. Why This Happens

The FANUC WN57 alarm is not a cause for immediate panic but a sign that the machine is currently in a special engineering state not intended for production. Understanding this alarm, its purpose, and how to resolve it provides valuable insight into the interaction between your FANUC CNC and its internal logic control.

Example 1 — First-piece slowdown

You need to unlock writing permissions for Keep Relays. Set PROGRAMMER ENABLE to YES in the PMC configuration settings. This is a "supervisor mode" that unlocks advanced functions.

: Illegal Override Function Setting (too many PMC paths active).

: It indicates that an override setting—such as Feedrate Override, Spindle Override, or Rapid Traverse Override—is currently engaged or forced. fanuc wn57 override function is active

To clear the WN57 message and return the PMC to its normal state, you must disable the override effective setting in the system parameters. Method 1: Via the PMC Parameter Screen Navigate to the screen on your FANUC controller. Select the [PMCPRM] (PMC Parameter) softkey. Look for the [SETTING] or [OVERRIDE] tab.

The message "WN57 override function is active" indicates that one or more feedrate or spindle override functions are currently enabled on a FANUC CNC control. This is a status/notification describing that the machine will not run at the programmed nominal feed or spindle speed because operator overrides are modifying those values in real time.

If your CNC mill or lathe is paired with a FANUC robot or a gantry loader, they must share workspace coordinates safely. When the robot enters the machine envelope to load a raw blank or unload a finished part, the CNC activates an override function. This ensures the machine axes cannot move at high speeds—or move at all—while the robot is inside. If the handshake signal gets stuck, WN57 remains on the screen. 2. Manual Interlock or Setup Mode (Door Open Override) A: Check for a stuck physical switch (internal

To help pinpoint exactly why this warning is showing up on your control, could you tell me:

It is incredibly useful for troubleshooting sensor issues, bypass safety interlocks momentarily, or testing logic during commissioning.