COM.LTE (SIM7600G) HTTPINIT error



  • 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
    


  • 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



  • Hi Felix,

    AT+CGPADDR
    +CGPADDR: 1,0.0.0.0
    
    OK
    AT+HTTPTERM
    ERROR
    

    Thanks,
    Roger



  • 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



  • 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
    


  • 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
    


  • 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