EM20-G won't connect. Please help

[LTEFix0404]

I just installed my EM20-G modem, downgraded the firmware, and connected it to my WG3526 router with the latest version of WiFiX. It does not appear to connect. Can someone help me troubleshoot? I'm sure it's just a matter of the right AT commands, but I have no knowledge or resource for those. Here is the debug info:

Code: Select all

OK
ATI
Quectel
EM20
Revision: EM20GRAR01A06M4G
OK
AT+CNUM
ERROR
AT+CPBR=?
TIMEOUT ERROR
  
Wed Jun 17 14:30:37 2020 : /dev/ttyUSB2 AT+CGMI
Quectel
OK
  
Wed Jun 17 14:30:38 2020 : /dev/ttyUSB2 AT+CGMM
EM20
OK
  
Wed Jun 17 14:30:39 2020 : /dev/ttyUSB2 AT+CGSN
864505040019005
OK
  
Wed Jun 17 14:30:41 2020 : /dev/ttyUSB2 AT+QCFG="nwscanmode"
+QCFG: "nwscanmode",0
OK
  
Wed Jun 17 14:30:42 2020 : /dev/ttyUSB2 AT+CIMI
ERROR
  
Wed Jun 17 14:30:44 2020 : /dev/ttyUSB2 AT+CRSM=176,12258,0,0,10
+CME ERROR: unknown
  
Wed Jun 17 14:30:59 2020 : /dev/ttyUSB2 AT+CMGS=?;+CMGL=?;+CMGR=?
+CME ERROR: SIM busy
  
Wed Jun 17 14:31:00 2020 : /dev/ttyUSB2 AT+COPS=0
ERROR
  
Wed Jun 17 14:31:01 2020 : /dev/ttyUSB2 AT+CGDCONT=?
+CGDCONT: (1-42),"IP",,,(0-3),(0-4),(0-1),(0-1)
+CGDCONT: (1-42),"PPP",,,(0-3),(0-4),(0-1),(0-1)
+CGDCONT: (1-42),"IPV6",,,(0-3),(0-4),(0-1),(0-1)
+CGDCONT: (1-42),"IPV4V6",,,(0-3),(0-4),(0-1),(0-1)
OK
  
Wed Jun 17 14:31:03 2020 : /dev/ttyUSB2 AT+CGDCONT?;+CFUN?
ERROR
  
Wed Jun 17 14:31:06 2020 : /dev/ttyUSB2 AT+CGDCONT=1,"IPV4V6","r.ispsn";+CFUN=0;+CFUN=1
ERROR

[bjames]

It appears to be SIM Card related as it is not reading the numbers on the SIM Card:

Code: Select all

AT+CNUM
ERROR

Run the AT Command and post the results:

Code: Select all

AT+CPIN?

Are you using a SIM Card adapter?

[LTEFix0404]

Yes I am using a SIM card adapter. I ran that command and it said SIM not detected, so I checked the SIM and it was upside down... I guess I lost orientation of up from down after removing the M.2 PCB from the USB enclosure. I seem to have inserted it correctly now.

However it still won't connect. The debug info just keeps repeating this line:

Code: Select all

Wed Jun 17 16:10:06 2020 : /dev/ttyUSB2 AT+CPMS="SM"
+CPMS: 0,0,0,0,0,0
OK

Any ideas?

[bjames]

I notice the router is passing the APN "r.ispsn" to the modem so I assume you are using Sprint.

I seem to remember the Quectel modems need to be placed in LTE only to use with Sprint.

Code: Select all

AT+QCFG="nwscanmode",3,1

[LTEFix0404]

Yes I'm using a Sprint hotspot SIM. That command seems to have done the trick. Thanks for your help.

I notice I get a couple errors such as:

Code: Select all

Wed Jun 17 20:16:57 2020 : /dev/ttyUSB2 AT+CFUN=1
OK
ATI
Quectel
EM20
Revision: EM20GRAR01A06M4G
OK
AT+CNUM
OK
AT+CPBR=?
+CME ERROR: unknown

and:

Code: Select all

Wed Jun 17 17:44:50 2020 : /dev/ttyUSB2 AT+CREG=2;+CREG?;+CREG=0
+CREG: 2,0
OK
AT+CEREG=2;+CEREG?;+CEREG=0
+CEREG: 2,1,"7DE5","4960A31",7
OK
AT+C5GREG=2;+C5GREG?;+C5GREG=0
ERROR

but the modem is otherwise working as expected. Do you know what those errors mean and think they need to be addressed?

[Viper67857]

CPBR reads phone book entries... Not sure why it's even attempting that, but it's probably erroring due to an empty phone book..?

C5GREG might be a typo for CGREG, which just checks GPRS registration, or it might be for 5G, which the EM-20 doesn't support. Either way, it can be ignored since no one cares about GPRS (2g-3g) anymore...