S42/Central Software User Guide
1VV0301318 Rev. 3
– 2018-08-31
Reproduction forbidden without written authorization from Telit Communications S.p.A.- All Rights Reserved.
Page 57 of 66
9.
System OFF Mode
The S42/Central supports the possibility to set the module into low power mode
during the time the module is not used with the AT+SYSTEMOFF command.
The S42/Central will restart on activity at the GPIO input lines UART-RTS#, IUR-
IN# or GPIO[4].
The host controller can use the IOA pin (GPIO[8]) to monitor the system status. Please also
verify the configuration of the AT+IOACFG parameter.
It is also possible to monitor the UART flow control line UART-RTS#.
9.1.
Using System OFF Mode for Terminal I/O
The following example will list the communication between the host controller and the
S42/Central using the integrated Terminal I/O profile.
To set the S42/Central into the low power mode the host controller needs to send the
AT+SYSTEMOFF command.
The S42/Central will respond “OK” before changing into low power mode.
To activate the S42/Central from low power mode the host controller needs to
activate one of the following GPIO lines: UART-RTS#, IUR-IN#, GPIO[4]
The module detects the GPIO change and starts the firmware.
After the firmware is started the host can continue the UART communication.
An incoming call is reported with RING and CONNECT.
