Hello,
If I try to repeatedly connect and then disconnect from the LTE-M network with an nRF9160 (I'm using the Actinius Icarus v2 board), I observe that the first 30 (approx) connection attempts are successful, after which the modem gets stuck in searching mode in future attempts. I think the issue is related to the modem firmware and not the network provider because the connection attempts succeed again if I reset the board altogether.
The following are the sequences of AT commands I used. I suspected the modem reset loop restriction but this should have triggered after the first 5 connection attempts already. Besides, I am always deinitialising the modem with AT+CFUN=0 before attempting another connection, so ideally, the reset loop should not trigger at all.
Device info:
AT%HWVERSION %HWVERSION: nRF9160 SICA B1A OK AT+CGMR mfw_nrf9160_1.2.3 OK
Successful connection followed by modem power off:
AT%XSYSTEMMODE=1,0,1,0 OK AT+CEREG=5 OK AT+CSCON=1 OK AT+CFUN=0 OK AT+CMEE=1 OK AT+CNEC=24 OK AT+CPSMS=1,,,"00110000","01000001" OK AT+CEDRXS=2,4,"1001" OK AT+CEREG=5 OK AT+CSCON=1 OK AT+CFUN=21 OK +CEREG: 2,"63A9","01A93900",7,0,0,"11100000","11100000" +CSCON: 1 +CNEC_ESM: 50,0 +CEREG: 5,"63A9","01A93900",7,,,"00100110","00110000" +CEDRXP: 4,"1001","1001","0001" +CSCON: 0 AT+CFUN=0 +CSCON: 1 +CEREG: 0,"63A9","01A93900",7,0,0,"11100000","11100000" +CSCON: 0 OK
Failed connection followed by modem power off:
AT%XSYSTEMMODE=1,0,1,0 OK AT+CEREG=5 OK AT+CSCON=1 OK AT+CFUN=0 OK AT+CMEE=1 OK AT+CNEC=24 OK AT+CPSMS=1,,,"00110000","01000001" OK AT+CEDRXS=2,4,"1001" OK AT+CEREG=5 OK AT+CSCON=1 OK AT+CFUN=21 OK +CEREG: 2,"63A9","01A93900",7,0,0,"11100000","11100000" AT+CFUN=0 +CEREG: 0,"63A9","01A93900",7,0,0,"11100000","11100000" OK
In the case for failed connection attempt, I do not receive any notifications after +CEREG: 2 (searching for network).