Siemens AC75 - Manual (Page 486)

AC75 AT Command Set
19.4 AT^SBC
s
AC75_ATC_V01.002 Page 486 of 569 10/30/06
Confidential / Released
19.4 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
provides URCs used to alert the user of undervoltage and overvoltage conditions before the
module switches off. The automatic shutdown caused by undervoltage or overvoltage 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 dereg-
ister 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 URCs do not need to activated by the TE. They will be output automatically when fault conditions occur.
• 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 AC75 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 AC75.
Syntax
Unsolicited Result Codes
URC 1
^SBC: Undervoltage
The message will be reported, for example, when the user attempts to set up a call while the voltage is close
to the critical limit and further power loss is caused during the transmit burst. When the external charging cir-
cuit includes an NTC connected to the BATT_TEMP pin, the URC appears several times before the module
switches off.
In applications which are not battery operated, i.e. where no NTC is connected to the BATT_TEMP pin, AC75
will present the undervoltage URC only once and will then switch off without sending any further messages.
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 USB MUX1 MUX2 MUX3 Charge
4
Last
SIEMENS - + + + + + + ± + -