Fanuc Wn57 Override Function Is Active Instant

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  fanuc wn57 override function is active

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 The WN57 (also written as W057 ) is

2. Most common causes

✅ Rapid traverse override set to 100% when parameter has flagged that as “override active”
✅ Feed override knob set above 100% (if parameter enabled)
✅ Manual handle override (jog/handle multiplier in effect)
✅ Programmed override via PMC or G-code (e.g., G10.6 or G10.9 on some controls)
✅ Dry run + feed override combination tripping a builder-defined warning
✅ Machine builder’s custom PMC logic activates WN57 when any override ≠ 100%

Step 2 – Reset the control

• Press RESET once (sometimes clears warning)
• If not cleared → cycle Emergency Stop (push in E-stop, then release)
• If still present → power off/on control (not always required)

Scenario 4: Auxiliary Function Lock Active

If M-Function Lock, S-Function Lock (Spindle speed), or T-Function Lock (Tool change) is active, the control is in a state of "partial operation." Attempting to run a program that requires these functions will trigger the warning because the override function overrides the standard program flow.

Scenario 2: The Block Search Aftermath

After performing a Block Search (mid-program start), the operator may not complete the "distance-to-go" cancellation. The controller remains in an “Override” state (a type of position deviation allowance) until the cycle start is pressed again. Attempting to edit or reset the sequence prematurely triggers WN57.

Part 5: Common Misconceptions & Myths About WN57

Myth 1: “WN57 means my FANUC control has corrupted software.” Step 2 – Reset the control

• Fact: No. It is a purely logical state warning. Your control is fine.

Myth 2: “I can clear WN57 by pressing RESET + CAN together.”

• Fact: This does nothing for WN57. RESET clears program execution errors (PS alarms), not override warnings.

Myth 3: “Power cycling always fixes it.”

• Fact: While power cycling clears the state, it is a crude solution. Worse, if the physical Dry Run switch is still ON, WN57 will reappear immediately after reboot.

Myth 4: “The machine is safe to run if I ignore WN57.”

• Fact: You cannot ignore it; the machine will not run. But even if you could, running with active overrides (like Machine Lock) would cause a catastrophic crash.

Scenario 1: The Toggle Trap (Most Common)

An operator turns on Machine Lock or Dry Run to test a program quickly. After testing, they switch from MEM mode to EDIT mode to correct a line of code. When they try to switch back to MEM mode and press CYCLE START, the controller refuses and displays WN57. Why? Because the override switches are still physically ON.