Nrf9160 Network (LTE-M) issue on custom board

[JackFitton]

Hello,

I am currently having an issue with my custom board.

I am getting CEREG 4. it is difficult to tell from the documentation if this is:

4 – Subscribe unsolicited result codes +CEREG: <stat>[,[<tac>],[<ci>],[<AcT>][,,[,[<Active-Time>],[<Periodic-TAU-ext>]]]]

or

4 – Unknown (for example, out of Evolved Terrestrial Radio Access Network (E-UTRAN) coverage)

I have ran the same program on the nRF9160DK and it runs perfectly and connects. I have tried running the AT client but as the J-link is over RTT rather than serial I cant find a way to send AT commands to the chip - is this possible?

It is also possible it is my matching network. Is there a way for me to test this besides using a VNA?

Board files:

Thank you in advance

Edit:

Running modem firmware 1.3.6

SDK 2.5.0

Chip: SICA-B1A-R

[Achim Kraus]

> I am getting CEREG 4. it is difficult to tell from the documentation if this is:

You need to distinguish between a response to the read command and a "notification/unsolicited result codes".

With the set and read command you configure and check, which data is contained in an "notification/unsolicited result codes". Such a notification is reported by the modem on it's own without using a read command.

The documentation itself mentions then "For the notification syntax parameters, see Read command."

AFAIK, that is only half true. That documentation for the read contains a  <n>, which is only contained in the response to the read command. It indicates the subscribed information level there. The "notification/unsolicited result codes" itself then doesn't contain the <n> and starts with <stat>. That patter is used quite often, I guess therefore the author didn't pay too much attention to it.

Maybe a candidate for a small improvement ;-).

[Charlie]

Hi Achim and Jack,

Thanks for your report. I agree with the improvement proposal and will share with our modem team.

Best regards,
Charlie

[JackFitton]

Thank you Charlie

Jack