User's Manual

HE920 Hardware User Guide
1vv0301014 Rev.9 – 2014-01-23
Reproduction forbidden without written authorization from Telit Communications S.p.A. - All Rights
Reserved. Page 27 of 84
4.3. Turning OFF the HE920
Turning off the device can be done in two ways:
 by software command (see HE920 Software User Guide)
 by Hardware shutdown(pad ON_OFF*)
When the device is shut down by software command or by hardware shutdown(pad
ON_OFF*), it issues to the network a detach request that informs the network that the device
will not be reachable any more.
TIP:
To check if the device has powered off, hardware line PWRMON must be monitored. When
PWRMON goes low it can be considered the device has powered off.
NOTE:
In order to avoid a back powering effect it is recommended to avoid having any HIGH logic
level signal applied to the digital pins of the module when is powered OFF or during an
ON/OFF transition.