Can't establish NB-IOT connection although M1 connection is working

[Frog]

I'm developing with a Thingy:91; here (New Zealand) we have both M1 and NB-IOT but in some locations where the product will go there's only NB-IOT so I'd like to verify the NB-IOT functionality.

I've loaded up the AT command binaries and I'm running Link Monitor to send AT commands manually.  What I've found is that the 9160 will always establish an M1 connection unless I disable M1 connectivity altogether with AT%XSYSTEMMODE=0,1,0,0.  When I disable M1, however the modem fails to establish an NB-IOT connection.  I've tried this with different SIMs from different carriers.  A specialist at one carrier (Spark) has confirmed that the SIMs are compatible with NB-IOT and that NB-IOT coverage is available in my local cell.

Can you suggest anything that I can try?

Here are some logs from Link Monitor:

Fullscreen modem log for NB-IOT connection attempts.txt Download

// First attempt, NB-IOT mode
2022-10-03T02:03:06.502Z DEBUG modem >> at+cfun=4
2022-10-03T02:03:06.534Z DEBUG modem << %CESQ: 255,0,255,0
2022-10-03T02:03:06.543Z DEBUG modem << +CEREG: 0
2022-10-03T02:03:06.551Z DEBUG modem << %XSIM: 0
2022-10-03T02:03:06.556Z DEBUG modem << OK
2022-10-03T02:03:12.327Z DEBUG modem >> at%xsystemmode=0,1,0,0
2022-10-03T02:03:12.355Z DEBUG modem << OK
2022-10-03T02:03:21.818Z DEBUG modem >> at+cfun=1
2022-10-03T02:03:21.855Z DEBUG modem << OK
2022-10-03T02:03:22.725Z DEBUG modem << %XSIM: 1
2022-10-03T02:03:22.759Z DEBUG modem >> AT+CPIN?
2022-10-03T02:03:22.793Z DEBUG modem << +CPIN: READY
2022-10-03T02:03:22.797Z DEBUG modem << OK
2022-10-03T02:03:22.806Z DEBUG modem >> AT+CPINR="SIM PIN"
2022-10-03T02:03:22.848Z DEBUG modem << +CPINR: "SIM PIN",3
2022-10-03T02:03:22.854Z DEBUG modem << OK
2022-10-03T02:03:22.862Z DEBUG modem >> AT+CIMI
2022-10-03T02:03:22.908Z DEBUG modem << 530058721172935
2022-10-03T02:03:22.911Z DEBUG modem << OK
2022-10-03T02:03:22.917Z INFO IMSIdentity: 530058721172935
2022-10-03T02:04:44.454Z DEBUG modem << %CESQ: 65,3,24,3
2022-10-03T02:04:44.483Z DEBUG modem << +CEREG: 2
2022-10-03T02:04:52.970Z DEBUG modem << %CESQ: 68,3,18,2
2022-10-03T02:18:21.928Z DEBUG modem << %CESQ: 73,3,17,2
2022-10-03T02:24:26.162Z DEBUG modem >> AT+CFUN?
2022-10-03T02:24:26.216Z DEBUG modem << +CFUN: 1
2022-10-03T02:24:26.227Z DEBUG modem << OK
2022-10-03T02:24:26.270Z DEBUG modem >> AT+CGSN=1
2022-10-03T02:24:26.280Z DEBUG modem << +CGSN: "351358811472304"
2022-10-03T02:24:26.282Z DEBUG modem << OK
2022-10-03T02:24:26.285Z DEBUG modem >> AT+CGMI
2022-10-03T02:24:26.348Z DEBUG modem << Nordic Semiconductor ASA
2022-10-03T02:24:26.358Z DEBUG modem << OK
2022-10-03T02:24:26.405Z DEBUG modem >> AT+CGMM
2022-10-03T02:24:26.448Z DEBUG modem << nRF9160-SICA
2022-10-03T02:24:26.451Z DEBUG modem << OK
2022-10-03T02:24:26.485Z DEBUG modem >> AT+CGMR
2022-10-03T02:24:26.520Z DEBUG modem << mfw_nrf9160_1.3.1
2022-10-03T02:24:26.524Z DEBUG modem << OK
2022-10-03T02:24:26.527Z INFO Nordic Semiconductor ASA nRF9160-SICA [mfw_nrf9160_1.3.1] SerNr: 351358811472304
2022-10-03T02:24:26.529Z DEBUG modem >> AT+CEMODE?
2022-10-03T02:24:26.566Z DEBUG modem << +CEMODE: 0
2022-10-03T02:24:26.571Z DEBUG modem << OK
2022-10-03T02:24:26.607Z DEBUG modem >> AT%XCBAND=?
2022-10-03T02:24:26.641Z DEBUG modem << %XCBAND: (1,2,3,4,5,8,12,13,17,19,20,25,26,28,66)
2022-10-03T02:24:26.646Z DEBUG modem << OK
2022-10-03T02:24:26.682Z DEBUG modem >> AT+CMEE?
2022-10-03T02:24:26.717Z DEBUG modem << +CMEE: 1
2022-10-03T02:24:26.722Z DEBUG modem << OK
2022-10-03T02:24:26.756Z DEBUG modem >> AT+CNEC?
2022-10-03T02:24:26.821Z DEBUG modem << +CNEC: 24
2022-10-03T02:24:26.824Z DEBUG modem << OK
2022-10-03T02:24:26.829Z DEBUG modem >> AT+CGEREP?
2022-10-03T02:24:26.857Z DEBUG modem << +CGEREP: 1,0
2022-10-03T02:24:26.863Z DEBUG modem << OK
2022-10-03T02:24:26.867Z DEBUG modem >> AT+CIND=1,1,1
2022-10-03T02:24:26.900Z DEBUG modem << OK
2022-10-03T02:24:26.938Z DEBUG modem >> AT+CEREG=5
2022-10-03T02:24:26.972Z DEBUG modem << OK
2022-10-03T02:24:26.978Z DEBUG modem >> AT+CEREG?
2022-10-03T02:24:27.014Z DEBUG modem << +CEREG: 5,2
2022-10-03T02:24:27.052Z DEBUG modem << OK
2022-10-03T02:24:27.063Z DEBUG modem >> AT%CESQ=1
2022-10-03T02:24:27.097Z DEBUG modem << OK
2022-10-03T02:24:27.101Z DEBUG modem >> AT+CESQ
2022-10-03T02:24:27.111Z DEBUG modem << +CESQ: 99,99,255,255,18,71
2022-10-03T02:24:27.114Z DEBUG modem << OK
2022-10-03T02:24:27.148Z DEBUG modem >> AT%XSIM=1
2022-10-03T02:24:27.183Z DEBUG modem << OK
2022-10-03T02:24:27.221Z DEBUG modem >> AT%XSIM?
2022-10-03T02:24:27.256Z DEBUG modem << %XSIM: 1
2022-10-03T02:24:27.260Z DEBUG modem << OK
2022-10-03T02:24:27.269Z DEBUG modem >> AT+CPIN?
2022-10-03T02:24:27.307Z DEBUG modem << +CPIN: READY
2022-10-03T02:24:27.313Z DEBUG modem << OK
2022-10-03T02:24:27.349Z DEBUG modem >> AT+CPINR="SIM PIN"
2022-10-03T02:24:27.390Z DEBUG modem << +CPINR: "SIM PIN",3
2022-10-03T02:24:27.395Z DEBUG modem << OK
2022-10-03T02:24:27.402Z DEBUG modem >> AT+CIMI
2022-10-03T02:24:27.435Z DEBUG modem << 530058721172935
2022-10-03T02:24:27.439Z DEBUG modem << OK
2022-10-03T02:24:27.443Z INFO IMSIdentity: 530058721172935
// Second attempt, also NB-IOT mode
2022-10-03T02:24:50.999Z DEBUG modem >> at+cfun=4
2022-10-03T02:24:51.023Z DEBUG modem << %CESQ: 255,0,255,0
2022-10-03T02:24:51.031Z DEBUG modem << +CEREG: 0
2022-10-03T02:24:51.040Z DEBUG modem << %XSIM: 0
2022-10-03T02:24:51.045Z DEBUG modem << OK
2022-10-03T02:25:01.464Z DEBUG modem >> at%xsystemmode=0,1,0,0
2022-10-03T02:25:01.487Z DEBUG modem << OK
2022-10-03T02:25:06.135Z DEBUG modem >> AT+CFUN=1
2022-10-03T02:25:06.172Z DEBUG modem << OK
2022-10-03T02:25:07.041Z DEBUG modem << %XSIM: 1
2022-10-03T02:25:07.077Z DEBUG modem >> AT+CPIN?
2022-10-03T02:25:07.116Z DEBUG modem << +CPIN: READY
2022-10-03T02:25:07.124Z DEBUG modem << OK
2022-10-03T02:25:07.159Z DEBUG modem >> AT+CPINR="SIM PIN"
2022-10-03T02:25:07.193Z DEBUG modem << +CPINR: "SIM PIN",3
2022-10-03T02:25:07.197Z DEBUG modem << OK
2022-10-03T02:25:07.233Z DEBUG modem >> AT+CIMI
2022-10-03T02:25:07.268Z DEBUG modem << 530058721172935
2022-10-03T02:25:07.273Z DEBUG modem << OK
2022-10-03T02:25:07.276Z INFO IMSIdentity: 530058721172935
2022-10-03T02:26:30.369Z DEBUG modem << %CESQ: 65,3,23,3
2022-10-03T02:26:30.410Z DEBUG modem << +CEREG: 2
2022-10-03T02:26:43.686Z DEBUG modem << %CESQ: 69,3,18,2
2022-10-03T02:27:40.312Z DEBUG modem >> AT+CFUN?
2022-10-03T02:27:40.380Z DEBUG modem << +CFUN: 1
2022-10-03T02:27:40.389Z DEBUG modem << OK
2022-10-03T02:27:40.454Z DEBUG modem >> AT+CGSN=1
2022-10-03T02:27:40.521Z DEBUG modem << +CGSN: "351358811472304"
2022-10-03T02:27:40.525Z DEBUG modem << OK
2022-10-03T02:27:40.531Z DEBUG modem >> AT+CGMI
2022-10-03T02:27:40.595Z DEBUG modem << Nordic Semiconductor ASA
2022-10-03T02:27:40.599Z DEBUG modem << OK
2022-10-03T02:27:40.647Z DEBUG modem >> AT+CGMM
2022-10-03T02:27:40.692Z DEBUG modem << nRF9160-SICA
2022-10-03T02:27:40.696Z DEBUG modem << OK
2022-10-03T02:27:40.702Z DEBUG modem >> AT+CGMR
2022-10-03T02:27:40.744Z DEBUG modem << mfw_nrf9160_1.3.1
2022-10-03T02:27:40.748Z DEBUG modem << OK
2022-10-03T02:27:40.752Z INFO Nordic Semiconductor ASA nRF9160-SICA [mfw_nrf9160_1.3.1] SerNr: 351358811472304
2022-10-03T02:27:40.789Z DEBUG modem >> AT+CEMODE?
2022-10-03T02:27:40.869Z DEBUG modem << +CEMODE: 0
2022-10-03T02:27:40.873Z DEBUG modem << OK
2022-10-03T02:27:40.909Z DEBUG modem >> AT%XCBAND=?
2022-10-03T02:27:40.951Z DEBUG modem << %XCBAND: (1,2,3,4,5,8,12,13,17,19,20,25,26,28,66)
2022-10-03T02:27:40.955Z DEBUG modem << OK
2022-10-03T02:27:40.999Z DEBUG modem >> AT+CMEE?
2022-10-03T02:27:41.040Z DEBUG modem << +CMEE: 1
2022-10-03T02:27:41.044Z DEBUG modem << OK
2022-10-03T02:27:41.051Z DEBUG modem >> AT+CNEC?
2022-10-03T02:27:41.091Z DEBUG modem << +CNEC: 24
2022-10-03T02:27:41.096Z DEBUG modem << OK
2022-10-03T02:27:41.101Z DEBUG modem >> AT+CGEREP?
2022-10-03T02:27:41.143Z DEBUG modem << +CGEREP: 1,0
2022-10-03T02:27:41.149Z DEBUG modem << OK
2022-10-03T02:27:41.188Z DEBUG modem >> AT+CIND=1,1,1
2022-10-03T02:27:41.230Z DEBUG modem << OK
2022-10-03T02:27:41.236Z DEBUG modem >> AT+CEREG=5
2022-10-03T02:27:41.277Z DEBUG modem << OK
2022-10-03T02:27:41.285Z DEBUG modem >> AT+CEREG?
2022-10-03T02:27:41.326Z DEBUG modem << +CEREG: 5,2
2022-10-03T02:27:41.329Z DEBUG modem << OK
2022-10-03T02:27:41.375Z DEBUG modem >> AT%CESQ=1
2022-10-03T02:27:41.416Z DEBUG modem << OK
2022-10-03T02:27:41.421Z DEBUG modem >> AT+CESQ
2022-10-03T02:27:41.430Z DEBUG modem << +CESQ: 99,99,255,255,17,68
2022-10-03T02:27:41.433Z DEBUG modem << OK
2022-10-03T02:27:41.473Z DEBUG modem >> AT%XSIM=1
2022-10-03T02:27:41.514Z DEBUG modem << OK
2022-10-03T02:27:41.554Z DEBUG modem >> AT%XSIM?
2022-10-03T02:27:41.595Z DEBUG modem << %XSIM: 1
2022-10-03T02:27:41.599Z DEBUG modem << OK
2022-10-03T02:27:41.643Z DEBUG modem >> AT+CPIN?
2022-10-03T02:27:41.685Z DEBUG modem << +CPIN: READY
2022-10-03T02:27:41.690Z DEBUG modem << OK
2022-10-03T02:27:41.731Z DEBUG modem >> AT+CPINR="SIM PIN"
2022-10-03T02:27:41.772Z DEBUG modem << +CPINR: "SIM PIN",3
2022-10-03T02:27:41.775Z DEBUG modem << OK
2022-10-03T02:27:41.784Z DEBUG modem >> AT+CIMI
2022-10-03T02:27:41.824Z DEBUG modem << 530058721172935
2022-10-03T02:27:41.828Z DEBUG modem << OK
2022-10-03T02:27:41.831Z INFO IMSIdentity: 530058721172935
// third attempt, using M1 or NB-IOT
2022-10-03T02:27:59.673Z DEBUG modem >> at+cfun=4
2022-10-03T02:27:59.709Z DEBUG modem << %CESQ: 255,0,255,0
2022-10-03T02:27:59.719Z DEBUG modem << +CEREG: 0
2022-10-03T02:27:59.730Z DEBUG modem << %XSIM: 0
2022-10-03T02:27:59.736Z DEBUG modem << OK
2022-10-03T02:28:08.520Z DEBUG modem >> at%xsystemmode=1,1,0,0
2022-10-03T02:28:08.545Z DEBUG modem << OK
2022-10-03T02:28:11.528Z DEBUG modem >> AT+CFUN=1
2022-10-03T02:28:11.571Z DEBUG modem << OK
2022-10-03T02:28:12.438Z DEBUG modem << %XSIM: 1
2022-10-03T02:28:12.472Z DEBUG modem >> AT+CPIN?
2022-10-03T02:28:12.507Z DEBUG modem << +CPIN: READY
2022-10-03T02:28:12.512Z DEBUG modem << OK
2022-10-03T02:28:12.516Z DEBUG modem << %CESQ: 51,2,3,0
2022-10-03T02:28:12.521Z DEBUG modem << +CEREG: 2,"6DD9","04955F6F",7
2022-10-03T02:28:12.560Z DEBUG modem >> AT+CPINR="SIM PIN"
2022-10-03T02:28:12.596Z DEBUG modem << +CPINR: "SIM PIN",3
2022-10-03T02:28:12.604Z DEBUG modem << OK
2022-10-03T02:28:12.608Z DEBUG modem << %CESQ: 57,2,20,2
2022-10-03T02:28:12.652Z DEBUG modem >> AT+CIMI
2022-10-03T02:28:12.686Z DEBUG modem << 530058721172935
2022-10-03T02:28:12.692Z DEBUG modem << OK
2022-10-03T02:28:12.695Z INFO IMSIdentity: 530058721172935
2022-10-03T02:28:13.443Z DEBUG modem << +CGEV: ME PDN ACT 0,0
2022-10-03T02:28:13.449Z DEBUG modem << +CNEC_ESM: 50,0
2022-10-03T02:28:13.474Z DEBUG modem >> AT+CGDCONT?
2022-10-03T02:28:13.506Z DEBUG modem << +CEREG: 1,"6DD9","04955F6F",7,,,"11100000","00011000"
2022-10-03T02:28:13.510Z DEBUG modem << +CIND: "service",1
2022-10-03T02:28:13.543Z DEBUG modem << +CGDCONT: 0,"IP","m2m","100.65.108.152",0,0
2022-10-03T02:28:13.547Z DEBUG modem << OK
2022-10-03T02:28:13.590Z DEBUG modem >> AT+CGACT?
2022-10-03T02:28:13.624Z DEBUG modem << +CGACT: 0,1
2022-10-03T02:28:13.628Z DEBUG modem << OK
2022-10-03T02:28:49.755Z DEBUG modem << %CESQ: 62,3,24,3
2022-10-03T02:29:14.787Z DEBUG modem >> AT+CFUN?
2022-10-03T02:29:14.894Z DEBUG modem << +CFUN: 1
2022-10-03T02:29:14.911Z DEBUG modem << OK
2022-10-03T02:29:14.997Z DEBUG modem >> AT+CGSN=1
2022-10-03T02:29:15.106Z DEBUG modem << +CGSN: "351358811472304"
2022-10-03T02:29:15.115Z DEBUG modem << OK
2022-10-03T02:29:15.201Z DEBUG modem >> AT+CGMI
2022-10-03T02:29:15.273Z DEBUG modem << Nordic Semiconductor ASA
2022-10-03T02:29:15.277Z DEBUG modem << OK
2022-10-03T02:29:15.282Z DEBUG modem >> AT+CGMM
2022-10-03T02:29:15.390Z DEBUG modem << nRF9160-SICA
2022-10-03T02:29:15.397Z DEBUG modem << OK
2022-10-03T02:29:15.474Z DEBUG modem >> AT+CGMR
2022-10-03T02:29:15.536Z DEBUG modem << mfw_nrf9160_1.3.1
2022-10-03T02:29:15.541Z DEBUG modem << OK
2022-10-03T02:29:15.545Z INFO Nordic Semiconductor ASA nRF9160-SICA [mfw_nrf9160_1.3.1] SerNr: 351358811472304
2022-10-03T02:29:15.597Z DEBUG modem >> AT+CEMODE?
2022-10-03T02:29:15.669Z DEBUG modem << +CEMODE: 2
2022-10-03T02:29:15.674Z DEBUG modem << OK
2022-10-03T02:29:15.741Z DEBUG modem >> AT%XCBAND=?
2022-10-03T02:29:15.804Z DEBUG modem << %XCBAND: (1,2,3,4,5,8,12,13,18,19,20,25,26,28,66)
2022-10-03T02:29:15.811Z DEBUG modem << OK
2022-10-03T02:29:15.875Z DEBUG modem >> AT+CMEE?
2022-10-03T02:29:15.934Z DEBUG modem << +CMEE: 1
2022-10-03T02:29:15.939Z DEBUG modem << OK
2022-10-03T02:29:15.992Z DEBUG modem >> AT+CNEC?
2022-10-03T02:29:16.048Z DEBUG modem << +CNEC: 24
2022-10-03T02:29:16.053Z DEBUG modem << OK
2022-10-03T02:29:16.120Z DEBUG modem >> AT+CGEREP?
2022-10-03T02:29:16.179Z DEBUG modem << +CGEREP: 1,0
2022-10-03T02:29:16.185Z DEBUG modem << OK
2022-10-03T02:29:16.257Z DEBUG modem >> AT+CIND=1,1,1
2022-10-03T02:29:16.317Z DEBUG modem << OK
2022-10-03T02:29:16.401Z DEBUG modem >> AT+CEREG=5
2022-10-03T02:29:16.462Z DEBUG modem << OK
2022-10-03T02:29:16.467Z DEBUG modem >> AT+CEREG?
2022-10-03T02:29:16.527Z DEBUG modem << +CEREG: 5,1,"6DD9","04955F6F",7,,,"11100000","00011000"
2022-10-03T02:29:16.531Z DEBUG modem << OK
2022-10-03T02:29:16.600Z DEBUG modem >> AT+COPS=3,2
2022-10-03T02:29:16.665Z DEBUG modem << OK
2022-10-03T02:29:16.740Z DEBUG modem >> AT+COPS?
2022-10-03T02:29:16.792Z DEBUG modem << +COPS: 0,2,"53005",7
2022-10-03T02:29:16.797Z DEBUG modem << OK
2022-10-03T02:29:16.853Z DEBUG modem >> AT%XCBAND
2022-10-03T02:29:16.903Z DEBUG modem << %XCBAND: 28
2022-10-03T02:29:16.907Z DEBUG modem << OK
2022-10-03T02:29:16.959Z DEBUG modem >> AT+CGDCONT?
2022-10-03T02:29:17.007Z DEBUG modem << +CGDCONT: 0,"IP","m2m","100.65.108.152",0,0
2022-10-03T02:29:17.011Z DEBUG modem << OK
2022-10-03T02:29:17.018Z DEBUG modem >> AT+CGACT?
2022-10-03T02:29:17.065Z DEBUG modem << +CGACT: 0,1
2022-10-03T02:29:17.070Z DEBUG modem << OK
2022-10-03T02:29:17.118Z DEBUG modem >> AT%CESQ=1
2022-10-03T02:29:17.167Z DEBUG modem << OK
2022-10-03T02:29:17.218Z DEBUG modem >> AT+CESQ
2022-10-03T02:29:17.278Z DEBUG modem << +CESQ: 99,99,255,255,22,60
2022-10-03T02:29:17.285Z DEBUG modem << OK
2022-10-03T02:29:17.343Z DEBUG modem >> AT%XSIM=1
2022-10-03T02:29:17.391Z DEBUG modem << OK
2022-10-03T02:29:17.398Z DEBUG modem >> AT%XSIM?
2022-10-03T02:29:17.445Z DEBUG modem << %XSIM: 1
2022-10-03T02:29:17.449Z DEBUG modem << OK
2022-10-03T02:29:17.496Z DEBUG modem >> AT+CPIN?
2022-10-03T02:29:17.541Z DEBUG modem << +CPIN: READY
2022-10-03T02:29:17.545Z DEBUG modem << OK
2022-10-03T02:29:17.553Z DEBUG modem >> AT+CPINR="SIM PIN"
2022-10-03T02:29:17.602Z DEBUG modem << +CPINR: "SIM PIN",3
2022-10-03T02:29:17.607Z DEBUG modem << OK
2022-10-03T02:29:17.662Z DEBUG modem >> AT+CIMI
2022-10-03T02:29:17.711Z DEBUG modem << 530058721172935
2022-10-03T02:29:17.716Z DEBUG modem << OK
2022-10-03T02:29:17.719Z INFO IMSIdentity: 530058721172935
2022-10-03T02:31:15.676Z DEBUG modem << %CESQ: 59,2,19,2
2022-10-03T02:31:25.915Z DEBUG modem << %CESQ: 61,3,24,3
2022-10-03T02:31:54.074Z DEBUG modem << %CESQ: 60,3,19,2
2022-10-03T02:32:01.754Z DEBUG modem << %CESQ: 61,3,24,3

Fullscreen modem log for NB-IOT connection attempts2.txt Download

// Eventually I got this as the 9160 attempted to connect
// to two different cells
2022-10-03T02:38:58.555Z DEBUG modem << %CESQ: 66,3,28,4
2022-10-03T02:38:58.587Z DEBUG modem << +CEREG: 2,"71C1","04955FD3",9
2022-10-03T02:38:59.394Z DEBUG modem << +CNEC_ESM: 111,0
2022-10-03T02:38:59.402Z DEBUG modem << +CNEC_EMM: 15
2022-10-03T02:38:59.411Z DEBUG modem << +CEREG: 2,"71C1","04955FD3",9,0,15
2022-10-03T02:39:00.127Z DEBUG modem << %CESQ: 255,0,255,0
2022-10-03T02:39:00.136Z DEBUG modem << +CEREG: 2
2022-10-03T02:39:11.194Z DEBUG modem << %CESQ: 34,1,19,2
2022-10-03T02:39:11.202Z DEBUG modem << +CEREG: 2,"D040","00096165",9
2022-10-03T02:39:12.293Z DEBUG modem << +CNEC_ESM: 111,0
2022-10-03T02:39:12.303Z DEBUG modem << +CNEC_EMM: 15
2022-10-03T02:39:12.313Z DEBUG modem << +CEREG: 2,"D040","00096165",9,0,15
2022-10-03T02:39:12.767Z DEBUG modem << %CESQ: 255,0,255,0
2022-10-03T02:39:12.811Z DEBUG modem << +CEREG: 2
2022-10-03T02:39:13.089Z DEBUG modem << %CESQ: 35,1,16,2

Regards,

  Frog

[helsing]

Hi Frog, just letting you know we have started working on this.

Regards,

Håkon

[Frog]

Update: despite earlier indications, the SIM I am using was not provisioned for NB-IOT.  This is resolved now and sometimes I am able to establish a connection, but usually I get a timeout after 2 minutes.  In my application code I am calling lte_lc_connect() and get an error code -116.  I have been told that locking to the correct frequency band reduces the time-to-connect.  I know about the AT%XBANDLOCK command but I can't see a way to request this in the nRF Connect API.  What's the best way to tackle this?

[helsing]

Hi Frog, sorry for the delay.

The error codes in the second log pointed to subscription issues and it looked like it had already tried to connect to NB-IOT.

Frog said:

I am able to establish a connection, but usually I get a timeout after 2 minutes.

Do you have any logs or modem trace from the new situation?

Frog said:

I know about the AT%XBANDLOCK command but I can't see a way to request this in the nRF Connect API.  What's the best way to tackle this?

Have you had a look at the Band lock section in Features of nRF91 Series?

Frog said:

What's the best way to tackle this?

Is the AT Interface what you are looking for?

"The Modem library supports sending AT commands to the modem, reading responses, and receiving AT notifications using the AT API found in nrfxlib/nrf_modem/include/nrf_modem_at.h."

 You might also be interested in the AT monitor.

[helsing]

Hi Frog, sorry for the delay.

The error codes in the second log pointed to subscription issues and it looked like it had already tried to connect to NB-IOT.

Frog said:

I am able to establish a connection, but usually I get a timeout after 2 minutes.

Do you have any logs or modem trace from the new situation?

Frog said:

I know about the AT%XBANDLOCK command but I can't see a way to request this in the nRF Connect API.  What's the best way to tackle this?

Have you had a look at the Band lock section in Features of nRF91 Series?

Frog said:

What's the best way to tackle this?

Is the AT Interface what you are looking for?

"The Modem library supports sending AT commands to the modem, reading responses, and receiving AT notifications using the AT API found in nrfxlib/nrf_modem/include/nrf_modem_at.h."

 You might also be interested in the AT monitor.