ABB FreeLance AC800F fieldbus module FI810F/FI820F/FI830F/FI840F ABB FreeLance AC800F Overview The ABB AC800F controller supports four fieldbus modules, which are CAN module FI810F, serial interface module FI820F, FrofiBUS module FI830F, and FF/HSE module FI840F. The bus type is optional according to the control requirements. ABB AC800F controller is designed in 4 slots F1 to F4