The write command sets an alarm time in the ME. When the alarm is timed out and executed the ME returns an
Unsolicited Result Code (URC) and the alarm time is reset to "00/01/01,00:00:00".
The alarm can adopt two functions, depending on whether or not you switch the GSM engine off after setting the
alarm:
• Reminder message: You can use the alarm function to generate reminder messages. For this purpose, set

the alarm as described below and do not switch off or power down the ME. When executed the message
comes as an Unsolicited Result Code.

• Alarm mode: You can use the alarm function to restart the ME when powered down. For this purpose, set the

alarm as described below. Then power down the ME by entering the

AT^SMSO

command. When the alarm

time is reached, the ME will wake up to Alarm mode. To prevent the ME from unintentionally logging into the
GSM network, Alarm mode provides restricted operation. Upon wake-up, the ME indicates an Unsolicited
Result Code which reads: ^SYSSTART ALARM MODE. A limited number of AT commands is available dur-
ing Alarm mode, for details see Table

"List of AT Commands Available in Alarm and Charge-only Mode>"

The ME remains deregistered from the GSM network. If you want the ME to return to full operation (normal
operating mode) it is necessary to drive the ignition line (IGT pin of application interface) to ground. If your
ME is battery powered note that the battery can be charged while the ME stays in Alarm mode. For details
please refer to

[2]

Parameter Description

Format is "yy/MM/dd,hh:mm:ss", where characters indicate year (two last digits), month, day, hour, minutes. E.g.
6th of May 2004, 22:10:00 hours equals to "04/05/06,22:10:00" (see also

AT+CCLK

). Note: if

<time>

equals

current date and time or is set to an earlier date, TA returns +CME ERROR: 21.

Integer type value indicating the array index of the alarm.
The ME allows to set only one alarm at a time. Therefore, the list of supported alarm events indicated by the test
command

AT+CALA

=? is

<n>

=0. If a second alarm time is set, the previous alarm will be deleted. Therefore, the

read command

AT+CALA

? will always return

<n>

=0. This is also true if individual settings are made on ASC0

and ASC1 or the various Multiplexer channels, for details see notes below.

<time>

(str)