Sierra Wireless AIRPRIME WISMO218 - Manual (Page 27)

WA_DEV_W218_PTS_002 Rev 006 April 29, 2010 27
Product Technical Specification &
Customer Design Guidelines Interfaces
3.3. Power Consumption
3.3.1. Various Operating Modes
There are various kinds of operating modes for the AirPrime WISMO218 as defined in the table
below.
Table 3: AirPrime WISMO218 Operating Modes
Mode Description
OFF Mode
When VBATT power is supplied to the AirPrime WISMO218 but has not yet been
powered ON.
Alarm Mode
When alarm clock is set for the AirPrime WISMO218 with ALL of the following
conditions:
 before time is up
 with AT + CPOF having been entered from a computer that is connected to the
AirPrime WISMO218
 with the ON/~OFF signal being left open (remains at HIGH level)
Idle Mode
When the AirPrime WISMO218 has a location update with a live network but with no
GSM/GPRS connection, while the UART interface is in sleep mode. Refer to
Note 1 .
Connected Mode The AirPrime WISMO218 has GSM voice codec connection with a live network.
Transfer Mode The AirPrime WISMO218 has GPRS data transfer connection with a live network.
Note 1 : There are two different methods to enter sleep mode through the AT command setting, AT + PSSLEEP, as
described below:
 AT + PSSLEEP = 0
 The entry of sleep mode is controlled by the level of DTR signal and the firmware.
 When DTR (viewed from the embedded module side) is of LOW voltage level, the
AirPrime WISMO218 will never enter sleep mode.
 When DTR (viewed from the embedded module side) is of HIGH voltage level, the
AirPrime WISMO218 will enter sleep mode. To wake the AirPrime WISMO218 up, it is
necessary to toggle the DTR (viewed from the embedded module side) from HIGH to
LOW voltage level.
 This method should be applied if the application needs to forbid the entry of sleep mode.
 AT + PSSLEEP = 1
 For this method, the entry of sleep mode is controlled just by the firmware.
 When the AirPrime WISMO218 has had no activities for a certain period of time, it will
enter sleep mode automatically, regardless of the DTR level.
 Any ASCII character on the UART can wake the AirPrime WISMO218 up. Note that due
to the wake-up mechanism of the AirPrime WISMO218, it is recommended to have at
least 10ms latency time after the wake-up character before sending AT commands to the
embedded module.
For details of the AT + PSSLEEP command, please refer to document [2] AirPrime WISMO218 AT
Commands Manual.
Note that the power consumption level will vary depending on the operating mode used.