Appendix: SAPIP-Cell-LTE Message Explanations
CPU RESET, V535 (LTE NOSLEEP)
CPU (central processor unit) Power-on message with the firmware version number (535) and options (LTE
NOSLEEP). Possible options are
LTE -
4G LTE network
NOSLEEP - Digi module never goes to sleep
Wait for power up…
The CPU is waiting for the LTE module to acknowledge that it has powered up. A response is sent only if the
module was previously powered down or reset.
No response
No response was seen from the module after the maximum wait time (which may vary).
CTS HI OR OPEN
The Clear-To-Send line is high (not asserted) and so the LTE module is present and working or the mod-
ule is removed from the board.
Wake up…
The CPU is waking up the LTE module
SLEEP_RQ LO
The CPU is commanding the LTE module to wake up
CTS LO (OK)
The Clear-To-Send line is asserted which means the module is present and working
Wait 2 min for LTE connect…
The CPU is waiting up to 2 minutes for status == 2 (cell tower connect)
Got M status = 2
The cell connection is good
Got M status = 14
The LTE data network is good
+++
The CPU is commanding the LTE module into AT (transparent) mode for some commands
OK
The CPU received an OK response
