SARA R410 instability when connected with weak signal to AT&T

[genosensor]

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SARA R410M loses USB connection to RPi

I am developing a smart agriculture application on a Raspberry Pi 3 B+ (Buster). For cellular comms I use a Nova SARA-R410M-02B modems with a Hologram SIM card. Also part of the application is an XBee RF radio that receives sensor data from the field. Both devices use serial IO via the Pi USB ports. My application is written in Ruby and uses the Serialport gem for serial communications. I set up a udev rule that creates a symlink called ttyNOVA for the Nova modem and ttyXBEE for the SBee ra…