MC55_ATC_V04.00 Page 430 of 475 3/17/06
Confidential / Released
18.3 AT^SBC Battery Charge Control
The functions of the AT^SBC differ depending on whether or not a battery is present.
• General functions:
The AT^SBC write command enables the presentation of URCs alerting the user of undervoltage conditions
before the module switches off. The automatic shutdown caused by undervoltage is equivalent to the power-
down initiated with the AT^SMSO command, i.e. ME logs off from the network and the software enters a secure
state avoiding loss of data. When the module is in IDLE mode it takes typically one minute to deregister from
the network and to switch off. For further details regarding automatic shutdown and voltage ratings please
refer to the Hardware Interface Description [2].
The AT^SBC read command displays the average current consumption of the module and, if specified, of the
external application.
• Functions available with battery connected:
The AT^SBC read command can be used to query the status of the battery and the charger.
The AT^SBC write command is important for entering the current consumption of the external application via
<current>. It should be noted that the charge control supported by MC55 works only if the requirements
described in the Hardware Interface Description [2] are met (battery type Lithium-Ion or Lithium Polymer,
presence of an NTC and protection circuit etc.) and if <current> is correctly specified. If the battery does
not incorporate an NTC, or the battery and the NTC are not compliant with the specified requirements the
battery cannot be detected by MC55.
Syntax
Unsolicited Result Code
Test Command
AT^SBC=?
Response(s)
^SBC:(list of supported <bcs>s), (list of supported <bcl>s), (list of supported <mpc>s)
OK
Read Command
AT^SBC?
Response(s)
^SBC: <bcs>, <bcl>, <mpc>
OK
ERROR
+CME ERROR: <err>
Write Command
AT^SBC=<current>
Response(s)
OK
ERROR
+CME ERROR: <err>
Reference(s) PIN ASC0 ASC1 MUX1 MUX2 MUX3 Charge Last
SIEMENS ! % % % % % § % !