Could not send AT command, error: -8

RE: Could not send AT command, error: -8

Simon — Mon, 13 Jul 2020 09:33:21 GMT

That is strange. Could you try to update the modem firmware to the latest and see if you're still experiencing this. Download the modem firmware from here.

Best regards,

Simon

RE: Could not send AT command, error: -8

Remco — Thu, 09 Jul 2020 07:51:47 GMT

I have flashed the 'at_client' firmware back again. 'AT+CFUN?' works -> '+CFUN: 0'.
"AT+CFUN=1' does not: -> 'ERROR'
'AT+CFUN=4' crashes the controller. i get no reply and no further commands work until i press the reset button.

I think this has always been the case, but i didnt notice the error before, since uploading the certificates worked.

May be the board is defect? it is revision 0.9.0, fresh from Farnell.

RE: Could not send AT command, error: -8

Simon — Tue, 07 Jul 2020 15:50:42 GMT

This line: "Could not send AT command, error: -8" implies that ncs\v1.3.0\nrf\lib\lte_link_control\lte_lc.c-->lte_lc_system_mode_set() fails. Thus the call to XSYSTEMMODE fails. Check out the information about this command in the infocenter:

"Note: Only one supported LTE mode allowed at a time. This command is allowed only before activating the modem using the CFUN=1 command. If the mode needs to be changed, the modem must first be set to flight mode using the CFUN=4 command."

Could you try to set the modem to flight mode first and see if that resolves your issues?

Best regards,

Simon

RE: Could not send AT command, error: -8

Simon — Mon, 06 Jul 2020 23:47:54 GMT

Currently, a huge portion of the support team (including many of the experts on nRF9160) is on summer vacation, and you may experience delayed answers. My apologies for that.

I will try to provide you with an answer within this week.

Best regards,

Simon