Specifications

TC35i AT Command Set
Confidential / Released
TC35i_ATC_V01.05 Page 193 of 278 04.08.2003
Unsolicited result
codes
Undervoltage and overvoltage conditions will be reported by unsolicited result
codes. The URCs need not be activated by the user, but will be output automati-
cally when fault conditions occur. For further details regarding automatic shut-
down and voltage ratings please refer to [1].
^SBC: Undervoltage
The URC will be indicated, for example, when you attempt to make a call while
the voltage is close to the critical limit and further power loss is caused during the
transmit burst. To remind you that the battery needs to be charged soon, the URC
appears several times in a minute before the module switches off. If the voltage
drops quickly down to a value which is 50mV below the minimum threshold only
one URC will be presented.
^SBC: Overvoltage warning
This URC is an alarm indicator displayed when the supply voltage approaches its
maximum level. The URC appears only once.
^SBC: Overvoltage shutdown
This URC will be reported when the voltage exceeds the maximum level specified
in [1]. It appears only once before the module starts to perform an orderly shut-
down.
In applications powered from Li-Ion batteries the incorporated protection circuit
typically prevents overcharging, thus eliminating the risk of overvoltage condi-
tions. Yet, in case of charging errors, for example caused by a bad battery or due
to the absence of a battery protection circuit, the module’s overvoltage shutdown
function will take effect to avoid overcharging.
The automatic shutdown procedure caused by undervoltage or overvoltage is
equivalent to the power-down initiated with the AT^SMSO command, i.e. TC35i
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.
Reference
Siemens
Note
· If Multiplex mode is active, any virtual channel can be used to enter the write
command and to specify <current>. An unsolicited result code appears simul-
taneously on all three channels.
· The URC "^SYSSTART CHARGE-ONLY MODE" is indicated automatically
when the engine enters this mode (except when autobauding is active).
Table 16: Summary of AT commands available in Charge-only and Alarm mode
AT command Use
AT+CALA Set alarm time
AT+CCLK Set date and time of RTC
AT^SBC Monitor charging process, specify power consumption of application
AT^SCTM Query temperature of GSM engine, enable or disable URCs
AT^SMSO Power down GSM engine