I asked:
I'm trying to get a 6310i to work with DLR-3P cable. It works fine in
FBUS mode (6510 driver, dlr3p connection), but not in AT/serial mode.
I've learnt that the phone is originally in AT mode, and with a specific
command the communication mode is changed to FBUS; but also that there
is no known way to move back to AT communication, other than power
cycling the phone. Is this correct? If yes, perhaps power cycling the
phone and then trying AT commands as the very first thing might help
(the phone is currently out of my reach).