While this notification is typically a status warning rather than a critical system fault, it directly impacts cycle times, automated operations, and machine efficiency. What is the FANUC WN57 Alert?
This indicates that a function within the machine’s PLC ladder (designed by the machine tool builder, not necessarily FANUC itself) is currently bypassing the standard operation logic.
Restrict access to PMC parameter modifications to qualified personnel only. fanuc wn57 override function is active
It is a reminder to the operator to be cautious, as standard constraints may not be active. How to Clear "WN57 Override Function is Active"
Include override function activation in maintenance logs. While this notification is typically a status warning
Because WN57 is an "active" status rather than a failure, it can usually be resolved by toggling the function off through the CNC’s internal settings or by modifying a specific Keep Relay ( -address). Method 1: Using the PMC Parameter Screen Navigate to the on your FANUC controller. Select [PMC SET] or [PMC PARAM] . Look for the Setting or Override sub-menu.
This function allows maintenance technicians or machine tool builders to "force" PMC signals (inputs/outputs) to a specific state, overriding their actual physical input. This is used for debugging and testing the ladder program. Restrict access to PMC parameter modifications to qualified
💡 : To find the exact trigger, go to the PMC Maintenance screen and search for the address associated with Message WN57 . This will show you the exact ladder rung and the inputs required to satisfy the condition. Reference Documentation
[Identify the Override] ──> [Normalize Switches] ──> [Toggle G-Codes/Modes] ──> [Check PMC Diagnostics] Step 1: Normalize Physical Override Switches
According to the FANUC programming manual, the override function also requires the setting of "OVERRIDE ENABLE" in the setting parameters. The official recommendation states: "CAUTION Set this setting to NO(0) before shipment of the machine. If this setting is left as YES(1), the operator may stop execution of the ladder program by mistake".
Because WN57 is categorized as a warning, it usually a running program automatically. However, leaving it unaddressed causes several operational bottlenecks: