SARA-R42 - Application note
UBX-20050829 - R02
EFS backup & restore
Page 49 of 58
C1-Public
•
The device goes into the non-signaling mode and is unable to exit with
AT+UTEST=0
and
+CFUN
cannot change its state from a value of 5. This non-signaling state can be checked and detected
with the
+CFUN
read command, where the device would return a value of 5.
Restore is only intended for the above situations.
Example on using
+CGSN
AT
command to detect lost IMEI
Command
Response
Description
AT+CGSN
+CME ERROR: memory failure
Error result code indicates lost IMEI
using +CGSN AT command.
With the possibility of a restore event, to detect when the module boot-up is complete and AT
interface is available here are following options:
•
Loop AT until the "OK" final result code is issued
o
Example: send AT every one second until the OK final result code is received
•
Enable and monitor the GPIO pin with
“Module status indication” functionality via the
+UGPIOC
AT
command
•
Enable and monitor the greeting message via the
+CGST
AT command
13.1.3
Creating backup after flashing FW update with delta package
If a FW build with the Backup & Restore feature is being updated via FOTA / uFOTA with a delta
package, then after the successful update a restore is triggered autonomously by the module itself.
13.1.4
EasyFlash, backup and SMS storage
If a FW build with the Backup & Restore feature is being flashed onto a module via EasyFlash, after a
successful FW update when the device boots up, then the host is required to:
•
define a new EFS backup through the
+UBKUPDATA
AT command;
•
set the preferred SMS message storage with
+CPMS
AT command just once after flashing. This
step is required if the host application should use SMS. If it does not intend to use SMS, then this
step can be ignored. Even if the host intends to use the
+CPMS
factory-programmed setting, the
storage setting still needs to be set.
