Fanuc 9900 parameter series is a critical, often "hidden" set of configuration values used by Fanuc CNC controls (including the 16i, 18i, 21i, and 0i series) to enable or disable optional software features
Mistakes happen. Here is the recovery path: fanuc 9900 parameter list
If you change a standard parameter incorrectly, you might get an alarm or a crash. If you change a 9900 parameter incorrectly, you can instantly , make the screen go blank, or wipe out critical system options. Because these parameters configure the core hardware communication, the control may not even know how to boot up properly if they are altered. Fanuc 9900 parameter series is a critical, often