Flash Read-Only Memory (Flash ROM) 
Flash Read-Only Memory (Flash ROM) is the non-volatile, permanent memory of the 
PXC Compact, which stores the operating system, the APOGEE firmware, and the 
language files. A limited amount of secondary storage is provided in Electrically 
Erasable Programmable Read-Only Memory (EEPROM) for the field panel address or 
name, communication speeds, and other set-up parameters. In the event of a power 
surge, a power loss, or failure of the battery backup, the Flash ROM and EEPROM 
contents stay intact. 
PXC Compact Flash ROM size cannot be upgraded in the field. 
Compressed ROM 
The PXC Compact has a large amount of high performance RAM. To allow for future 
features and to provide high system performance, the APOGEE firmware is stored in 
ROM in a compressed state; it is de-compressed into RAM on system power-up. As a 
result, the entire onboard RAM is not available for the point database, the PPCL 
program, and trend data. 
Auto-Restore and Database Backup to Flash 
APOGEE Firmware Revision 2.8.4/3.1 and later supports Auto-Restore and Database 
Backup to Flash. 
●  Database Backup to Flash allows the user to manually save a copy of the 
database in flash memory of the controller. 
●  The field panel may be configured to automatically restore the database from flash 
memory after a coldstart. 
–  When auto-restore is enabled, a coldstart does not result in the same downtime 
as with earlier revisions of APOGEE Firmware. Because there is no waiting on 
a full download from the backup system, the database is restored from flash so 
quickly that there is little to no downtime. However, the accumulated trend data 
is deleted from memory. 
–  Database restoration from flash is disabled by default. 
–  When FLN Mode is selected for the PXC Compact or UEC, database 
restoration from flash is automatically enabled. 
–  When P1 Mode is selected for the PXC Compact, database restoration from 
flash is automatically enabled and 128K of memory is reserved for ISB files. 
●  The field panel may be configured to automatically restore the database from flash 
memory after a coldstart. 
–  When auto-restore is enabled, a coldstart does not result in the same downtime 
as with earlier revisions of APOGEE firmware. Because there is no waiting on a 
full download from the backup system, the database is restored from flash so 
quickly that there is little to no downtime. However, the accumulated trend data 
is deleted from memory. 
–  Database restoration from flash is disabled by default. 
For procedures on using Auto-Restore and Database Backup to Flash, see the 
APOGEE P2 ALN Field Panel User's Manual (125-3019) or the APOGEE BACnet ALN 
Field Panel User's Manual (125-3020).