Q: Is WN57 the same as EMG (Emergency Stop)? A: No. EMG is a hard stop (red alarm). WN57 is a soft warning (white/yellow message).
Q: Can I disable WN57 permanently? A: Yes, by modifying the PMC message table, but this is extremely dangerous and voids safety certifications. Never do this on a production machine.
Q: Does WN57 appear on FANUC 0i-Mate? A: Yes. The 0i-Mate series (common on lathes and mills) exhibits WN57 identically for Dry Run and Machine Lock functions.
Q: My machine shows WN57 but all switches are off. What now? 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 article is for informational purposes. Always consult your specific FANUC CNC manual and machine tool builder’s documentation before performing maintenance or altering operational procedures.
The WN57 OVERRIDE FUNCTION IS ACTIVE message is a specific PMC (Programmable Machine Control) alarm found on FANUC CNC systems . It indicates that the Override Function—a debugging tool used to manually force PMC signals—is currently enabled .
While this function is active, the PMC may not operate according to its standard programmed logic because signals are being "overridden" for testing purposes. It is generally recommended to disable this function once debugging is complete to ensure normal machine operation . How to Resolve WN57
You can deactivate this function using one of the following methods: Via PMC Parameters: Navigate to the PMC Parameter setting screen. Locate the Override Function (倍率功能) option.
Move the cursor to the "Valid" (有效) setting and change it to "No" or "Invalid" . Using Keep Relays:
Directly change the keep relay address K906.0 to 0. Setting this bit to 0 disables the override function and should clear the WN57 alarm after a system restart .
Note: Since WN (Warning) alarms are often informational, the machine might still run, but specific safety or logic interlocks handled by the PMC could be bypassed by the active override. 【报警】FANUC PMC"WN57 OVERRIDE FUNCTION IS ACTIVE"
This Fanuc message indicates that a customized Override Function (WN57)
is currently active within the PMC (Programmable Machine Control)
, typically used to modify feedrates, rapid traversals, or spindle speeds specifically for authorized machine operations. Overview of Fanuc WN57 Override
Usually mapped to custom PLC/PMC logic to lock, limit, or force a specific override percentage, overriding the standard operator panel knobs. Operation: fanuc wn57 override function is active
When active, the feedrate or speed is dictated by the PMC logic rather than the physical operator panel dial. Where to Check: (PMC Maintenance) screens for the specific status of WN57. Potential Reasons for Activation Custom PMC Function:
A custom PMC function is currently running, often configured in the Robodrill or similar PMC-controlled machinery. Manual Intervention: Manual intervention occurred during an automatic cycle. System Macro Settings: System macro variable
may have been utilized to disable or set overrides programmatically. What to Do If Unintended Check Diagnostics: DIAGNOSTICS screen and look at status for (W-address 57) to determine if it is (Active) or (Inactive). Toggle Switch/Menu: Use the custom operator panel or softkey to disable the specific override function.
Press the [Reset] button to clear temporary custom PMC overrides.
For more tailored information, please verify if this is on a FANUC ROBODRILL OPERATOR'S MANUAL or a similar specialized machine.
FANUC Robodrill Operator's Manual | PDF | Direct Current - Scribd
Title: Understanding FANUC WN57: "Override Function is Active"
Body:
If you are running a FANUC-controlled CNC machine and have encountered the WN57 alarm or status message stating "Override Function is Active," don’t panic.
This is not a critical machine failure, but rather a protective notification. Here is a breakdown of what it means, why it appears, and how to resolve it.
If you performed a block search:
✅ 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%
If you want, I can tailor this write-up for a specific FANUC series (e.g., 0i, 16i/18i, 21i) or draft a short diagnostic checklist formatted for printing.
(Invoking related search terms tool.)
Understanding the FANUC WN57 Override Function Active Message
The message "WN57 OVERRIDE FUNCTION IS ACTIVE" is a PMC (Programmable Machine Control) alarm commonly found on FANUC CNC systems. Unlike standard system alarms that indicate hardware failures, this message signifies that a specific PMC debugging tool—the Override Function—has been enabled.
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 "Override Function" allows an operator or technician to force a signal in the PMC ladder to a specific state (ON or OFF), regardless of the actual logic or physical input. This is useful for:
Testing Interlocks: Checking if a tool changer will move even if a specific sensor isn't triggered.
Debugging Logic: Isolating specific parts of the PMC ladder to see how the rest of the program reacts.
Temporary Bypasses: Allowing the machine to function temporarily while waiting for a replacement sensor.
If you see the WN57 message during normal production, it means this "force" mode was left on, which may cause the machine to ignore safety interlocks or standard operating conditions. How to Deactivate the WN57 Override
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 [PMC] screen on your FANUC controller. Select the [PMCPRM] (PMC Parameter) softkey. Look for the [SETTING] or [OVERRIDE] tab.
Find the field labeled "OVERRIDE EFFECTIVE" (or similar terminology). Move the cursor to this option and set it to "NO" or "0".
The WN57 message should disappear from the alarm screen immediately. Method 2: Via Keep Relay (K-Address)
On many FANUC models, this function is directly tied to a specific Keep Relay. Locate Keep Relay K906.0. Change the bit value from 1 (Active) to 0 (Inactive). Restart the system if necessary to clear the message. Precautions
Because the override function can bypass critical safety logic, it should only be used by qualified maintenance personnel. Always ensure that all "forced" signals are released before returning the machine to automatic production mode to avoid mechanical crashes or operator injury. 【报警】FANUC PMC"WN57 OVERRIDE FUNCTION IS ACTIVE"
Here’s a useful, practical review of the "FANUC WN57 Override Function is Active" message, written for CNC operators and setup personnel. Q: Is WN57 the same as EMG (Emergency Stop)
What it is:
The WN57 alarm (or status message) on a FANUC CNC control indicates that an override function is currently enabled – typically a rapid traverse override, feed rate override, or a dry run override. Unlike many alarms, WN57 is generally an informational message, not a critical error. The machine will continue to run, but with altered motion parameters.
When it appears:
Key implications:
Useful tips for operators:
Pros of having this message:
Cons / annoyances:
Final verdict:
A useful safety reminder, not a problem. Treat it as a “heads-up” that the machine is not running exactly as programmed. Always check it before running production.
If you need help disabling a specific override or understanding a custom ladder message related to WN57, let me know your FANUC control model (e.g., 0i-MF, 31i, 18i).
On newer FANUC i-Series (Series 0i-F, 31i-B5), overrides can be triggered via soft keys:
If step 1–3 fail, the machine builder’s PLC is holding WN57 active.
Machine: FANUC Robodrill α-D21MiB (31i-B control) Problem: Operator runs a warm-up program. Then turns on Dry Run to test a new engraving cycle. After testing, he edits the engraving program (Z-depth correction). He switches back to MEM and presses CYCLE START. Result: Alarm WN57 appears. Machine does nothing.
Troubleshooting:
Lesson Learned: On many FANUC 31i models, the CYCLE START button itself serves as the confirmation to exit "override active" state after the physical switch is turned off. Do not just reset – attempt cycle start.