Hello Quectel Community,
I am currently encountering an issue while attempting to activate NB-IoT on a Quectel BC92 modem using a Vodafone ioteasyconnect SIM card. The modem successfully connects to the 2G network, but I’m encountering an error (CME ERROR: 53) during the activation of the PDP context for NB-IoT.
Here is the sequence of AT commands leading to the error:
AT+CFUN?
Response: +CFUN: 1
AT+QBAND?
Response: +QBAND: 3,5,8,20,28
AT+CSQ
Response: +CSQ: 13,99
AT+CGACT?
Response: OK
AT+QCGDEFCONT="IP","lpwa.vodafone.com"
Response: OK
AT+CGATT=1
Response: OK
AT+CGACT=1,1
Response: +CME ERROR: 53
I have double-checked the APN configuration, and the SIM card is recognized successfully (AT+CPIN? returns +CPIN: READY). The modem reports a good signal strength (CSQ: 13,99). Vodafone Czech Republic should have a full NB-IoT coverage in their network.
What else can I check? Is there any configuration I’m missing? Your guidance would be highly appreciated. Thank you in advance for your time and support.
coolwatcher I have sent to your email
Thank you @herbert.pan-Q for your quick response.
I have generated debug logs (826.5 KB) for the BC92 with the Vodafone SIM card. The AT commands sequence is:
AT+CFUN?
AT^TRACECTRL=1
AT+CMEE=1
AT+QBAND?
AT+CSQ
AT+CGACT?
AT+QCGDEFCONT="IP","lpwa.vodafone.com"
AT+QRST=1
AT+CGATT=1
AT+CGACT=1,1
AT+COPS?
Thank you in advance for your time and support.
Is your device only connected to the GSM network? Not NB Network?
Change to
AT+CGDCONT=“IP”,“lpwa.vodafone.com”
BC92 with Vodafone SIM card connects only to 2G and never NB-IoT. The SIM card itself is NB-IoT ioteasyconnect and I’m in an area with NB-IoT coverage. I was working with the 1nce SIM card before and I was able to connect to NB-IoT without any problem. But not with Vodafone SIM.
The AT+COPS? output is the following: +COPS: 0,2,"23003",0, indicating a connection to GSM rather than NB-IoT.
I have tried various troubleshooting steps, including setting bands to 3, 5, 8, 20, 28, deleting stored EARFCNs using AT+QCSEARFCN=1 and AT+QCSEARFCN=0 , and disabling eDRX with AT+CEDRXS=0,5. Unfortunately, none of these had any results.
Is there a way to reset or delete all configurations stored in NVM, essentially returning the BC92 to its factory settings?
An additional question to my previous message: what are the other, undocumented parameters of the command QCGDEFCONT? The PDF describing BC92 AT commands mentions this:
But when I query the AT+QCGDEFCONT? I get +QCGDEFCONT: "IP","lpwa.vodafone.com","","",0. What is the meaning of the third, fourth and fifth parameters? I expect it is username and password. What is the last 0?
yes,username,password
you add the at command
AT+CFGRATPRIO=4
then try again
Thank you. I tried the AT command and the result is:
AT+CFUN=0
AT+CMEE=2
AT+CFGRATPRIO=4
+CME ERROR: The excute command not support
This is the same error I get when trying to set networking mode:
AT+QNWCFG=0,0
+CME ERROR: The excute command not support
Sorry, please run AT+CFGDUALMODE=1,0 as a prerequisite
Command AT+CFGDUALMODE, but AT+CFGRATPRIO is still giving me errors. This is my attempt with Vodafone SIM card:
AT+CFUN=0
OK
AT+CFGDUALMODE=?
+CFGDUALMODE: support=[0-2](0-NotSupport; 1-SingleStand; 2-Dualstand), fastswitch=[0,1]
OK
AT+CFGRATPRIO=?
+CFGRATPRIO: DualModeRatPriority=[2,4](2-2G; 4-NB)
OK
AT+CFGDUALMODE=1,0
OK
AT+CFGRATPRIO?
+CFGRATPRIO: 2
OK
AT+CFGRATPRIO=4
+CME ERROR: The excute command not support
AT+CFGRATPRIO=4
+CME ERROR: The excute command not support
I tried the same with 1nce SIM card (which I know works with the BC92 and connects to the NB-IoT) and this is the result:
AT+CFGDUALMODE=1,0
OK
AT+CFGRATPRIO=4
OK
Note: I have an old development board with Quectel BC95-G modem, so I tried this modem with Vodafone SIM card. The modem is able to connect to the NB-IoT Vodafone network without any issue and it took just few seconds. So the problem seems to be combination of BC92 and Vodafone SIM.
Is there any other command I can try? Any more logs I can print?
Thank you for your help, @herbert.pan-Q I appreciate your time and support.
The result of this output is very strange, is the 1nce SIM card normal on the BC92?
As I wrote in my last post, the 1nce SIM card (which is T-Mobile in my country) is behaving as expected and the AT+CFGRATPRIO or AT+QNWCFG commands work.
To summarize:
- 1nce SIM works without problem with BC92 and connects to the NB-IoT.
- Vodafone SIM works without problem with BC95-G and connects to the NB-IoT.
- Vodafone SIM does NOT work with BC92. It doesn’t connect to the NB-IoT, only to the 2G.
Here is the output of the ATI command showing the FW revision of our modems:
Quectel_Ltd
Quectel_BC92
Revision: BC92RBR01A04
This information may help.
I have sent you the latest firmware version to your email, please check
