Hi
I'm having an intermittent connectivity issue with the nRF9161 where after days of operation the device loses cellular registration and fails to reconnect.
[15:03:19.297,973] <err> lte_lc: Could not get registration status, error: -1 [15:03:19.307,800] <err> lte_lc: Failed to get current registration status [15:03:19.317,413] <err> lte_lc: Invalid functional mode: 6 [15:03:19.345,184] <err> lte_lc: Failed to set functional mode. Please check XSYSTEMMODE.
The zerphyr console commands to change the modem state also fail to execute
uart:~$ lte normal [15:03:45.151,367] <err> lte_lc: Failed to subscribe to CEREG notifications, error: -1 [15:03:45.159,973] <err> lte_lc: Failed to enable notifications, error: -14 Error: lte_lc_normal() returned -14 [15:03:49.638,336] <err> modem_info: Could not get temperature, error: -1 uart:~$ lte offline [15:03:53.521,789] <err> lte_lc: Failed to set functional mode. Please check XSYSTEMMODE. Error: lte_lc_offline() returned -14 uart:~$ lte power_off [15:04:04.026,519] <err> lte_lc: Failed to set functional mode. Please check XSYSTEMMODE. Error: lte_lc_power_off() returned -14
Software: nrf-sdk v2.6.1 (zephyr v3.5.99-ncs1-1-4-g768b62536ea6)
Hardware: Custom PCBA with nRF9161
Network: Telstra (Australia)
The application is running a LwM2M client with LTE PSM disabled. After power cycling the nrf91 the software can register with the network without issue.
Because this is an intermittent issue, I have been unable to capture a modem trace of a device in this state yet.
I have also not discovered a way to reproduce the issue, it occurs randomly across the test devices we currently have deployed after days, sometimes weeks, of normal operation.
Also, interestingly the software cannot read the modem temperature when in this state:
[15:03:49.638,336] <err> modem_info: Could not get temperature, error: -1
