BC92: Signal strength = 99

Technical Subjects
1

Hello all!
I´m using a BC92 module with a ThingsMobile DataSIM-Card (O2 network) to send some sensor data via NB-IoT network.
But unfortunately, there doesn´t seem any connection or signal. The board containing the BC92 module uses a Quectel YE0008AA antenna with the PCB design according to Quectel´s design recommendations.
I am sending the following AT-commands via UART (simple RX/TX connection, without RTS/CTS). The answers from BC92 are in italic.

AT+QRST=1\r
OK
RDY
+CFUN=1

[WAIT 5000ms]

AT+CIMI
234500008xxxxx4

[WAIT 5000ms]

AT+CPIN
+CPIN: READY

[WAIT 5000ms]

AT+CESQ
+CESQ: 99,99,255,255,255,255

So the SIM-Card is OK and detected normally, but there isn´t any signal. Current consumption of the whole board does not exceed 30mA. Also AT+COPS=?\r returns ERROR.

Do I have to set other settings before? What am I doing wrong?

Thanks and kind regards

2

please run

AT+CPIN?
AT+CFUN=0
AT+QCSEARFCN=0
AT+CSCON=1
AT+CGDCONT= //config APN
AT+CFUN=1
AT+CEREG?
AT+QENG=0
AT+CESQ

3

Hello,
thanks for the answer. I tried it, but there is still no connection. I don´t know if the PDP context could be wrong? I guess it should detect the APN from the SIM.
See communication below.

AT+CPIN?
+CPIN: READY

OK
AT+CFUN=0
OK
AT+QCSEARFCN=0
OK
AT+CSCON=1
OK
AT+CGDCONT=2,"IP"
OK
AT+CFUN=1
OK
AT+CEREG?
+CEREG: 0,2

OK
AT+QENG=0
OK
AT+CESQ
+CESQ: 99,99,255,255,255,255
4

Quectel_Coolwatcher操作指导与参考(CN&EN)_BC25&BC32&BC65&BC92&BC95B5R&BC35GR.pdf (1.4 MB)
By analyzing the result of your command execution, the module may not find the appropriate base station cell, or you may not wait enough time after executing the command, or you may grab the debug port log for analysis