Change network between NB-IOT/LTEm1/EGPRS

End-of-Life Product Cellular IoT Application Shield
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1

Hi, im using of librarty celluariot.py. If i changed serial port to “/dev/ttyUSB3”

And if i want to set network to NB-IOT/LTEm1/eGPRS i have error that no such file or directory /dev/ttyUSB3. Its the same error when i want getQueryNetworkInfo(). If i use this port to for example readTemp() is correct.
How to change network ?
Im using ttyS0 to establish internet by PPP protocol.

2

Hi @byczek2102,

You can change the network by sending the following AT command via the ttyS0 port.

AUTO MODE(LTE Cat M1-> LTE Cat NB1 -> GSM):

AT+QCFG="nwscanseq",00,1
AT+QCFG="nwscanmode",0,1
AT+QCFG="iotopmode",2,1

GSM MODE:

AT+QCFG="nwscanseq",01,1
AT+QCFG="nwscanmode",1,1
AT+QCFG="iotopmode",2,1

Cat M1 MODE:

AT+QCFG="nwscanseq",02,1
AT+QCFG="nwscanmode",3,1
AT+QCFG="iotopmode",0,1

Cat NB1 MODE:

AT+QCFG="nwscanseq",03,1
AT+QCFG="nwscanmode",3,1
AT+QCFG="iotopmode",1,1

Check BG96 AT Commands Manual for more details.

Then check the connection status with the AT+QNWINFO command.

3

Thanks its working :slight_smile:

4

Please use ttyUSB3 or ttyUSB2 to send AT commands.
Since ttyS0 is busy, sending AT commands over ttyS0 will result in errors.

6

Hi ensar, I have problem with connect to LTE NB-IoT.

I send : AT+QNWINFO:
response:
+QNWINFO: “CAT-NB1” ,“26002”, “LTE BAND 20”, 6397

but not always, sometimes i have: No service… WHY ?

But AT+CSQ is
CSQ: 99,99

Can you help me ?
My sim card supports LTE NB-IoT

Best regards

7

Hi,

Make sure your network provider supports NB-IoT in your location. Also, your carrier may have different APN for nb1, please ask your mobile carriers for those info if you have any questions.

Useful commands to check the configuration of your module:

ATI
AT+QGMR
AT+CPAS
AT+COPS?
AT+QIACT?
AT+CGDCONT?
AT+QCFG="nwscanseq"
AT+QCFG="nwscanmode"
AT+QCFG="iotopmode"
AT+QCSQ
AT+CFUN?

More: Quectel BG96 AT Commands Manual

9

Can I change network mode by via ttyUSB3 port?

10

Yes, you can change it.