Software House iSTAR Edge, Installation & Quick Start Manual, Page: 16 / 26

Power - Batteries - Backup
16
Onboard backup
batteries
iSTAR Edge uses four onboard AA batteries to power backup to flash on loss of main input
power. These batteries must be non-rechargeable Alkaline batteries, specifically:

AA

Alkaline

2.5 Amp hour

Button top
Backup When power (input voltage) drops too low to support full operation, power usage is reduced
as much as possible, processes are stopped and data is written into flash. Processes remain
stopped until the input voltage returns to a normal operating range. At that point, iSTAR
Edge reboots and reloads data from flash to RAM and starts processing again.
The only input that controls the initiation of iSTAR Edge’s power-fail backup process is iSTAR
Edge's own onboard measurement of incoming power voltage. iSTAR Edge measures external
power voltage every 1/10 of a second. When external power voltage moves outside of normal
operating voltage (10.2 V to 14.4 V for nominal 12 V operation, or below 20.4 V for nominal 24
V operation), iSTAR Edge will initiate the backup process.
When the backup process starts iSTAR Edge will:

Cut power to as many non-critical devices as possible, including:
• LEDs
• LCD backlight
• Wiegand readers
• AUX power ports
•
WET relays
• Relay coils are de-energized, i.e. relays revert to normal state - NO contacts open and NC
contacts close.

Set the following devices to low power or shutdown mode
• Ethernet circuit
• Serial transceivers

Stop all processes

Write data in RAM to flash.

iSTAR Edge issues an activity report indicating a backup is beginning.

As with iSTAR Classic and iSTAR eX, the backup process will finish even if power returns
during the backup process.
When the backup completes, iSTAR Edge will check whether power voltage has returned to
normal operating range. If the voltage is within the normal range, iSTAR Edge will reboot.
As with iSTAR Classic, iSTAR Pro and iSTAR eX, data can only be restored if the clock is valid
when the iSTAR boots. Otherwise, the firmware would not be able to make valid access
control decisions. As with iSTAR Pro, iSTAR Classic and iSTAR eX, if the clock is not valid on
reboot the iSTAR will not restore any data, and will in fact invalidate all data, including
activity history.