Specifications

TC35 / TC37 Hardware Interface Description

TC35_37_HD_02_V03.10 - Released Page 33 of 92 21.12.2001

3.3.2 Power saving

Intended for power saving, the SLEEP mode reduces the functionality of the module to a

minimum and, thus, minimizes the current consumption to the lowest level. To activate

SLEEP mode use the AT command

AT+CFUN=0.

While SLEEP mode is effective, the serial interface is not responding. The module shortly

wakes up to respond to a paging request from the base station and immediately returns to

the power saving mode.

The first wake-up event fully activates the module, enables the serial interface and

terminates power saving. See following chapter for wake-ups.

3.3.3 Wake up GSM engine

The following table summarizes the options of waking up the GSM engine from SLEEP or

Power Down mode. See also Table 10 for further information.

Table 7: Wake-up events

GSM engine is registered to GSM network

How to wake up From SLEEP mode

Ignition line No

RTS (falling edge) Yes

Unsolicited Result Code (URC) Yes

Incoming call Yes

Incoming SMS depending on mode selected by AT+CNMI:

AT+CNMI=0,0 (= default, no indication upon receipt of SMS)

AT+CNMI=1,1 (= displays URC upon receipt of SMS)

Yes

RTC alarm Yes

GSM engine is detached from GSM network

How to wake up From Power Down mode

Ignition line Yes (see Chapter 3.3.1.1)

RTS (falling edge) No

Unsolicited Result Code No

Incoming call No

RTC alarm Yes, but only wake-up into Alarm

mode (see Chapter 3.3.1.4)

Connecting charger to POWER lines Yes, but only wake-up into Charge-

only mode (see Chapter 3.2.2.3)