Question

I have a fleet of remote IoT devices running RUT240's with a Jetson NX plugged into LAN. The Jetson conserves power by switching the RUT on every 10-60 minutes to upload some files and then switches the RUT back off. Recently I have started seeing some of these devices get stuck offline for a few hours at a time where the RUT gets switched on but never gets an internet connection. My code will eventually hit a timer after being offline for too long and power cycle the RUT, where it usually then comes back online.

To debug this I first want to confirm that the RUT is indeed powered on during those offline times, and that there's not just an error in my wiring that is failing to properly power the RUT. When I look at the event logs from one of those RUT's, I don't see any events during the hours of offline time, and then the first event that I see is "Mobile data connected (internal modem)" once the RUT is power cycled and gets internet again after a few hours offline.

What's the best place for me to look further down within the OS to find a log stream that will show me each time the RUT has booted?

Perhaps I should be setting these RUTs up with a ping reboot, but first I'd like to work out why the connection is sometimes failing.

Answer 1

Hello,

Unless configured to be saved to flash memory, device logs are lost after each reboot.

The mobile connection process, together with other logs, can be viewed via command line with commands logread && logread -f.

If your SIM can send/receive SMS, you can enquire device state by sending a status SMS to the device. You can find more details on SMS commands here.

I would also suggest to configure automatic modem reboot in Services -> Auto reboot section, when data connection fails. That might help to restore connection before the power cycling.

In terms of mobile connection, I would advice to check if the router has a good enough signal quality. 

Also, are you using automatically selected APN or a custom value?

Best regards,

Comments

Thanks ZygimantasBliu,

We are using the default by leaving auto-APN switched on. Note that this is with the global version of the RUT240 (EG25) although I'm not sure if that's relevant here.

I will turn on the automatic ping reboots, however I still want to investigate how/why these modems are sometimes remaining offline when I switch them on. Where can I turn on the device logs that you mentioned? I'd like to configure them to record at least the last 24hrs of data, and show me each time the RUT was switched on.

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Change configuration in System -> Administration -> Ttroubleshoot -> Logging settings section.