Cell network scan

Firmware
1

Hi,

I have several notecards in the same place that connect using Cat-M1 and suddenly one of them has changed to GSM.

  • Will this notecard eventually do a new scan and switch back to Cat-M1?
  • What would be the conditions for a notecard to do a new scan?
  • What could the host processor do to force the notecard to do a new scan?

Thank you

2

Hi @Alec,

In which country you are located? I ask because only a few countries have both M1 and GSM as options, so this is a curious issue you’ve run into!

Otherwise, to answer your question, your Notecard will stay on its existing RAT until there is a failure, then it will try another scan. You can also perform a card.restart to restart the Notecard and have it perform a new scan.

Thanks,
Rob

3

Hi @RobLauer,

The notecards are in Canada.

Is there a way to force a restart with a command from the notehub directly to the notecard without programming the host MCU to scan an inbound queue and perform the restart command?

Thank you.

4

Hi @Alec,

There is no such command available, but it’s an interesting idea so I’ll be letting our product team know about your interest.

Rob

5

Another option that just occurred to us is to use the card.wireless API to force the Notecard to use M1. For instance:

{
  "req": "card.wireless",
  "mode": "m"
}
6

Hi,

I thought about forcing the mode but, in fact, I only want to use the most efficient “RAT” without preventing communication if, for some reason, M1 is not available.

In my design, I have wired the notecard reset pin to a GPIO of the MCU. What would be the differences between a hard reset and the command card.restart?

Thanks

7

Hi @Alec,

A card.restart is preferred over a hard reset as it flushes all in-memory buffers before restarting (this includes configuration data, modem data usage counters, new notes, etc). All of that would be lost with a hard reset.

If you reset the Notecard with a soft or hard reset, the first sync after booting will transfer much more data than a typical sync, as we try to ensure that we are in sync with the Notehub and we re-authenticate over TLS. Therefore, we really don’t recommend heading down this path if you foresee resetting on a regular basis.

Are you looking at the RAT property in _session.qo or _env.dbs? If it’s the latter, the data in that event can be stale and not 100% up to date.

Thanks,
Rob

8

Hi @RobLauer,

I’m looking at the _session.qo.

Thank you for the info.