COM.LTE (SIM7600G) HTTPINIT error

Veto6017

Hi,

Using the AT+HTTPINIT command returns ERROR but I don't know why. The same code worked without problems when I had a 4G connection but now with 3G it doesn't work. Please see the log below:

Module Reset, please wait

RDY

+CPIN: READY

SMS DONE

PB DONE
AT+CPIN?
+CPIN: READY

OK
AT+CSQ
+CSQ: 20,99

OK
AT+CGREG?
+CGREG: 0,5

OK
AT+COPS?
+COPS: 0,0,"Swisscom Things Mobile",2

OK
AT+HTTPINIT
ERROR

felmue

Hello @Veto6017

did you check if the SIM7600G has received an IP address using AT+CGPADDR?

also did you try to issue an AT+HTTPTERM command, maybe HTTP was already initialised?

Thanks
Felix

Veto6017

Hi Felix,

AT+CGPADDR
+CGPADDR: 1,0.0.0.0

OK
AT+HTTPTERM
ERROR

Thanks,
Roger

felmue

Hello @Veto6017

ok, so for whatever reason the SIM7600G did not receive an IP address. That is probably the reason HTTP init fails.

Have you set the APN? Maybe the 3G APN is different from the 4G APN?

Thanks
Felix

Veto6017

Hi Felix,

I'm using a SIM card from thingsmobile and as far as I understand the APN should always be the same. I've just contacted the thingsmobile support and they did a SIM reset. Sadly I'm now always getting a 4G connection and everything works fine.

I've tried with AT+CNMP=48 to disable LTE connections to further debug but the setting is reset after AT+CRESET and also after a power reset. Although the manuals states: The set value will retain after module reset. I'm able to execute AT+HTTPINIT after changing preferred mode selection but I want to try it after a reset.

Do you have an idea how I can force the SIM7600 to connect using 3G?

Please also see the logs below.

Thanks, Roger

Changing APN without success
AT+CGDCONT=1,"IP","TM"
OK

AT+CGPADDR
+CGPADDR: 1,0.0.0.0

OK
AT+CGDCONT=?
+CGDCONT: (1-24),"IP",,,(0-2),(0-4),(0-1),(0-1)
+CGDCONT: (1-24),"PPP",,,(0-2),(0-4),(0-1),(0-1)
+CGDCONT: (1-24),"IPV6",,,(0-2),(0-4),(0-1),(0-1)
+CGDCONT: (1-24),"IPV4V6",,,(0-2),(0-4),(0-1),(0-1)

When I have a 4G connection it works
AT+CGPADDR
+CGPADDR: 1,10.118.92.113

OK

AT+COPS?
+COPS: 0,0,"Swisscom Things Mobile",7

OK

AT+HTTPINIT
OK

Changing Preferred mode selection

AT+CNMP?
+CNMP: 2

OK
AT+CNMP=48
OK
AT+CNMP?
+CNMP: 48

OK
AT+COPS?
+COPS: 0,0,"Swisscom Things Mobile",2

OK
AT+HTTPINIT
OK

Veto6017

When I use AT+CNMP=48 to disable LTE connections and then check the current IP address using AT+CGPADDR shows no IP (0.0.0.0) but calling AT+HTTPINIT works without an error and after this command I've got a valid IP (see the log below). I will check the device in the field again on the end of this week.

AT+COPS?
+COPS: 0,0,"Swisscom Things Mobile",7

OK
AT+CGPADDR
+CGPADDR: 1,10.118.68.169

OK
AT+CNMP=48
OK
AT+CGPADDR
+CGPADDR: 1,0.0.0.0

OK
AT+CGPADDR
+CGPADDR: 1,0.0.0.0

OK
AT+COPS?
+COPS: 0,0,"Swisscom Things Mobile",2

OK
AT+CGPADDR
+CGPADDR: 1,0.0.0.0

OK
AT+HTTPINIT
OK
AT+CGPADDR
+CGPADDR: 1,10.109.3.47

OK

felmue

Hello @Veto6017

thank you for reporting back - this is quite interesting.

I used AT+COPS=1,2,"22802",2 to manually select UTRAN (2) instead of EUTRAN (7).
Note: "22802" is provider Sunrise in Switzerland.
BTW: AT+COPS=0 gets you back to automatic selection.

Thanks
Felix