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Design recommendations
SIM cards
Digi XBee® 3 Cellular LTE-M/NB-IoT Global Smart Modem User Guide
121
You can verify the state of the device using the
. After you issue the
SD
command and a
response has been returned (either
OK
or
ERROR
), issue the
AI
command. If the shutdown was
successful,
2D
is returned.
Sleep feature
The recommended approach is to use one of the available sleep configurations such as the
) or sleeping through MicroPython (
). When the module has gone to
sleep and the
is low, power may safely be removed.
1. Initiate sleep: Assert SLEEP_RQ
2. Wait for sleep state to be entered: SLEEP pin (pin 13) low.
3. Power off the device.
Airplane mode
Change the XBee configuration to use Airplane mode (
). This puts the XBee into a safe state for
shutdown.
1. Set
AM
=1.
2. Apply configuration change.
3. Wait 30 seconds to allow time for shutdown to occur.
4. Power off the device.
SIM cards
n
For best performance, use a SIM card with gold-plated contacts.
n
Because vibrations in your application environment may cause unexpected SIM card failures
due to fretting between the SIM card and the card holder, Digi strongly recommends that you
apply a thin layer of dielectric grease to the SIM contacts prior to installing the SIM cards.