For maintenance engineers and integrators, understanding why WN57 triggers requires a look at the PMC (Programmable Machine Controller) ladder logic.
Check the physical knobs on the operator panel. Turn the and Spindle Speed Override switches back to exactly 100% . Ensure Rapid Traverse is set to normal operating limits. Step 2: Deactivate Setup Modes
The rapid override buttons or switches ( ) are engaged, slowing down movements.
After making the change, restart the machine to allow the PMC to load the new configuration. The PMC alarm should disappear upon restart. fanuc wn57 override function is active
To remove the WN57 warning, you must disable the override function in the PMC parameter settings. Here are the common methods, ordered from simplest to most technical. Method 1: Changing the PMC Parameter Screen (Recommended) Go to the or PMC screen on your Fanuc controller. Navigate to the PMCPRM (PMC Parameter) screen. Find the option for "Override" or "Force".
Look up the feedrate override signals ( for bits *OV0 to *OV7 ). A broken wire or failed rotary switch contact can send a continuous override signal to the control, even if the physical knob points to 100%. Summary for Operators
When any of these functions are in an "active" state, the CNC is technically not in pure Memory or MDI operation. The WN57 warning appears when you attempt to change modes (e.g., from EDIT to MEM) or start a program while one of these overrides is still engaged. Ensure Rapid Traverse is set to normal operating limits
If the message persists, it means the PMC still thinks a condition is being overridden. A maintenance technician may need to look at the CNC diagnostic screens (PMC -> PMCDGN -> STATUS) to identify which input is forcing the override, often listed under specific diagnostic addresses.
Verify if a stuck physical switch is continuously sending a 0V or 24V signal to the I/O module. Step 4: Clear the Buffer via MDI Mode Switch the machine mode to .
Understanding the "Fanuc WN57 Override Function is Active" Message: Causes, Implications, and Resolution Strategies The PMC alarm should disappear upon restart
: 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.
In many systems, this function is tied to a specific keep relay. Setting K906.0 to "0" will often immediately deactivate the override function and clear the WN57 message.