Fanuc Wn57 Override Function Is Active 🆓 🚀

After making the change, restart the machine to allow the PMC to load the new configuration. The PMC alarm should disappear upon restart.

What are you currently using (e.g., 0i-F, 31i-B)?

Has anyone else encountered the WN57 alarm while rigid tapping? Share your experience below! 👇

Some high-end FANUC models (31i-A, 31i-B) feature – a mode allowing the operator to manually jog an axis during an automatic cycle using the MPG (handwheel). If the operator exits this mode without canceling the interrupt or if the program expects synchronized axes, WN57 appears as a safety warning.

Look at your Operator’s Panel.

Include override function activation in maintenance logs.

While the alarm should be addressed, it indicates a configuration state rather than a hardware fault. The resolution is typically straightforward through parameter modification.

In the FANUC control ecosystem, "WN" prefixes generally denote warnings or operator messages rather than critical system faults (which usually carry an "ALM" prefix).

A very specific topic!

这是最通用、操作界面最友好的方法。

The warning is a helpful diagnostic indicator designed to keep processes predictable. In most everyday scenarios, it requires nothing more than turning a physical dial back to its standard 100% position or ensuring a safety door is completely sealed. By systematically verifying the physical switches, checking interlock states, and inspecting PMC inputs, maintenance technicians can quickly eliminate this alert and keep production running at maximum efficiency. To help isolate the issue further, please share:

On FANUC i-Series controls (such as the 31i, 0i-F, or older 16i/18i models), is an acronym-based system warning code. WN stands for Warning.

Locate the rotary switch and turn it precisely to 100% . fanuc wn57 override function is active

Before turning off the override, ensure that any forced signals were not masking a physical fault or sensor failure, as the machine will immediately return to following the actual physical inputs.

Whether you are a machine operator, maintenance technician, or machine builder, respecting the purpose and limitations of the override function is crucial for safe and reliable machine operation. As FANUC officially states, disable the override function before shipping the machine—and by extension, before returning any machine to normal production after debugging activities.

If a manual intervention occurs mid-cycle—such as pausing execution via Feed Hold or switching the machine into Single Block mode while an override parameter is processing in the background—the ladder logic may flag the state as WN57 until the cycle resumes normally. Step-by-Step Troubleshooting and Resolution