Sony FCB-ER8550 Technical Manual page 20

Update procedure (USB)
HOST
CMD_GET_STATE
ERR_OK (CURSTAT_PRE_INIT)
CMD_INIT
ERR_OKP
CMD_CHK_GUARD
ERR_OK (STAT_OK)
CMD_QUERY_VERSION
ERR_OK
CMD_SWITCH_MODE
ERR_OK (STAT_OK)
Error occurrence patterns
The update (UART) error patterns are as follows.
UART update-error 1
Different versions
FCB
Reboot
HOST
VISCA
xmodem
error occurs
H/W RePower
VISCA
0
HOST
CMD_GET_STATE
ERR_OK (CURSTAT_PRE_SWITCTMODE)
CMD_CHK_GUARD
ERR_OK (STAT_OK)
CMD_WRITE_FIRM
ERR_OK (STAT_BUSY)
CMD_WRITE_FIRM
ERR_OK (STAT_BUSY)
CMD_WRITE_FIRM
ERR_OK (STAT_OK)
CMD_COMPLETE
FCB
Reboot
ready
Error
Reboot
FCB
Reboot
updater mode
different versions
application mode