or the Fanuc 11M Configuration Document for serial port wiring and handshake settings. Fanuc 10M-11M Communications Parameters - Squarespace
While you need the full list, these "master" parameters are the most commonly corrupted or changed. Have these written down on a piece of tape inside your electrical cabinet.
These parameters set the maximum spindle speeds for different gear ranges. According to CNCMakers , you can modify these directly to limit RPM.