Tyco iSTAR eX Installation And Configuration Manual page 55

Backup and Restore
iSTAR eX detects the presence of the PMB by polling it on the SPI bus. If the
PMB is missing, for example, because the dealer removed iSTAR eX from its
enclosure for testing, or the customer has a generator and does not expect to
lose power, iSTAR eX displays a "WARNING" - "No Power Board" message on
the LCD.
The warning message displays periodically for as long as the PMB is not
present. However, event triggered backups can still occur without the PMB.
iSTAR eX Installation and Configuration Guide 1–35