Originally Posted by
Sergei.a320
You must be joking when you write something like this about Airbus. DSC-34-NAV-10-30-20 explains what do SMF and DBUS mean

cannot attach image from FCOM.
OK thank you Sergei
I only have access to legacy and Sharklet FCOM, so can’t read that chapter with the description of SMF and DBUS
Anybody else who can post description of SMF and DBUS here or PM me ?