AT_CLIENT connects but SERIAL_LTE_MODEM does not connect to network

[GerryB]

Is there a reason that AT_CLIENT example always works for LTE but SERIAL_LTE_MODEM only works the first time, and then trying again it never connects to the LTE ?  Typing AT+CFUN=1 on both to get things started.  IDE is 1.7.0 with no modifications to the code.

[Albrecht Markus Schellenberger]

Hello Gerry,

GerryB said:

yes that is correct.  Same everything

The thing is: reject cause 17 is a network failure, which I have a hard time to see that it is caused by the device.

2021-10-04T20:28:37.391Z DEBUG modem << +CEREG: 2,"2D83","01D1860A",7,0,17,"11100000","11100000"
2021-10-04T20:28:39.057Z DEBUG modem << +CEREG: 2,"2D83","01D11B0A",7,0,17,"11100000","11100000"

Cause #17 – Network failure

This EMM cause is sent to the UE if the MME cannot service an UE generated request because of PLMN failures.

And generally, network related operations are handled by the modem firmware and that should be independent of the application running it, so this should not have anything to do with the Serial LTE modem application.

On the other hand, it is interesting that you constantly are able to reproduce this behaviour. Could you upgrade to mfw 1.3.0 and check if that makes any difference? And do you have the possibility to try a different SIM card as well, maybe?

Thanks and regards,

Markus

[GerryB]

I upgraded the firmware to 1.3.0 and now neither example works.  In the LTE Link Monitor software in the upper right corner the LTE box jus blinks from red to yellow and back.  I keep asking it the status with AT+CFUN? but nothing connects now.  Is this a modem firmware problem then?  Other than the occasional %CESQ update in light blue in the terminal, there is no other light blue text which I used to have with the old modem firmware

[Didrik Rokhaug]

Hi,

Markus is currently on vacation, so I have taken over this ticket.

What board are you using? A nRF91DK, Thingy:91 or a custom one?

Have you tried to re-program the applications?

Could you share the logs?

Best regards,

Didrik

[GerryB]

Hi Didrik.  In this case we are using the "Feather" board also known as CIrcuit Dojo Feather.

Tried reprogramming both the AT-Client and then the LTE Serial Modem Applications.  

Tried again just now and, to my surprise, everything is working, including the LTE Serial Modem.  :)   Well Im not sure what happened between yesterday and today but it is all good now