A bus error occurred on the FANUC–BUS connecting each option board.
This alarm indicates that a fault occurred during the exchange of data
between the base printed–circuit board and an option board.
This alarm is also issued if an error occurs during the exchange of data
between the base printed–circuit board and the PMC control circuit.
Replace the installed option boards, one at a time.
Replace the back panel.
Replace the CPU card on the base printed–circuit board.
Replace the base printed–circuit board.
If alarm 972 is issued, indicating on the screen that an F–BUS error
occurred on an option board, replace the option board on which the
F–BUS error occurred.
Screen display example
972 NMI OCCURRED IN OTHER MODULE
974 FĆBUS ERROR <SUB
Causes and actions
D Replacing the option
D Replacing the back panel
D Replacing the CPU card
D Replacing the base
D F–BUS error on an