Digi XBee 3 Cellular LTE-M, User Manual, Page: 142 / 331

Power saving features and design recommendations Power Saving Mode (PSM)
Digi XBee® 3 Cellular LTE-M/NB-IoT Global Smart Modem User Guide 142
monitor ATAI to detect the PSM "dormant" state ( AI = 0x2C), because this state will not cause these
activities to error out.
Note In firmware versions ending in *16 and earlier, sending an SMS did not wake the cellular
component.
Mobile-terminated activity
While the cellular component is in the PSM "dormant" state, the device is not reachable over the
network, and mobile-terminated traffic such as SMS or IP connections will not trigger it to wake up.
Additional activities
Additional activities which will trigger the cellular component to wake up from PSM include:
n
Creating a TCP or TLS connection. This includes the connection implicitly created when using
transparent mode or TX IPv4 API frames, as well as explicit connections like a
Socket Connect
API frame , or calling
connect(...)
on a MicroPython socket or using a MicroPython library
which does so.
n
Creating a TCP "listener" socket.
n
Sending a UDP datagram.
n
Binding a UDP socket to a specific port.
n
Performing a DNS lookup request using ATLA , or
socket.getaddrinfo(...)
in
MicroPython.
n
Using MicroPython to upload datapoints to Digi Remote Manager.
XBee 3 cellular device features that periodically wake up the cellular component
Features of the XBee 3 Cellular device which will automatically wake up the cellular component on a
periodic basis include:
n
Digi Remote Manager status checks. See the DF command to control the interval of these
checks.
n
Upload of health metrics to Digi Remote Manager. See the HM and HF commands.
XBee 3 cellular device features that continually wake up the cellular component
Features of the XBee 3 Cellular device that continually wake up the cellular component do not take
advantage of power savings and should not be used in combination with PSM.
Features that continually wake up the cellular component include:
n
Persistent TCP connection to Digi Remote Manager (if bit 0 of MO is set).
n
Using a server/listening socket in transparent mode or API mode (if C0 is not 0 and AP is 0, 1 or
2).
XBee sleep features (Pin Sleep or Cyclic Sleep) and the PSM feature
You can use XBee sleep features (such as Pin Sleep or Cyclic Sleep) when the PSM feature is enabled.
The sections below explain how they work together.
n
XBee sleep features (such as Pin Sleep or Cyclic Sleep) do not immediately put the cellular
component into its PSM state. When PSM is enabled, during XBee sleep the cellular component
continues to be powered so that it can manage the PSM active and tracking area timers and