Operating Modes - SIM Tech SIM900D HD Manual

SIM900D Hardware Design
PWM O PWM Output

3.2 Operating Modes

The table below briefly summarizes the various operating modes referred to in the following chapters.
Table6: Overview of operating modes
Mode Function
Normal GSM/GPRS
operation SLEEP
GSM IDLE
GSM TALK
GPRS
STANDBY
GPRS DATA
POWER Normal shutdown by sending the "AT+CPOWD=1" command or using the PWRKEY. The
DOWN power management ASIC disconnects the power supply from the baseband part of the
module, and only the power supply for the RTC is remained. Software is not active. The
serial port is not accessible. Operating voltage (connected to VBAT) remains applied.
Minimum Use the "AT+CFUN" command can set the module to a minimum functionality mode
functionality without remove the power supply. In this case, the RF part of the module will not work or the
mode (without SIM card will not be accessible, or both RF part and SIM card will be closed, and the serial
remove power port is still accessible. The power consumption in this case is very low.
supply)
Charge-only Charge-only mode means: charging when power down. In this mode, the module can not be
SIM900D_HD_V1.02
VOHmin= 2.7V
VOLmax=0.1V
VOHmax= 3V
VOLmin= 0V
Module will automatically go into SLEEP mode if DTR is set to high level
and there is no on air and no hardware interrupt (such as GPIO interrupt or
data on serial port).
In this case, the current consumption of module will reduce to the minimal
level.
In SLEEP mode, the module can still receive paging message and SMS
from the system normally.
Software is active. Module has registered to the GSM network, and the
module is ready to send and receive.
Connection between two subscribers is in progress. In this case, the power
consumption depends on network settings such as DTX off/on,
FR/EFR/HR, hopping sequences, antenna.
Module is ready for GPRS data transfer, but no data is currently sent or
received. In this case, power consumption depends on network settings and
GPRS configuration.
There is GPRS data transfer (PPP or TCP or UDP) in progress. In this case,
power consumption is related with network settings (e.g. power control
level), uplink / downlink data rates and GPRS configuration (e.g. used
multi-slot settings).
21
If unused keep
open
09.04.2010