How to disable MC7430 auto data connection?

Embedded wireless modules MC/EM Series
#1

Hello all,

We have a few MC7430 modules that we recently purchased to migrate from older 3G modules. These modules come from our supplier configured in a way that, when given power, they automatically start a data session without any PPP interface or QMI activity. This causes problems for us when it comes time for the embedded linux OS to make a QMI or AT connection. Sometimes this connection succeeds, and sometimes it results in repeated authentication attempts to the carrier without a data session starting.
I am trying to fault-find why this is, but for the time being I’d like to be able to disable this automatic connection behavior if possible. I’ve looked through the AT command reference, but I can’t find/don’t know what to look for regarding this function.

Is there any way to stop the MC7430 from establishing it’s own data connection before the machine behind it attempts the same?

Thanks for any assistance.

#2

Hi,

By default the unit only starts the default bearer, however, there is a setting within our SDK which might enable an automatic connection of a user bearer within the slqs3GPPConfigItem API, note this explicitly has to be set by the application and the unit will not activate it. If you are setting this then I think it will connect.

If you are using the open source QMI library I do not know what might set this parameter.

pDefaultPDNEnabled

Always Connect Default PDN
    A single BYTE value indicating the status of Always connect default PDN
        0 - disabled
        1 - enabled
    Optional parameter
    function SLQSGet3GPPConfigItem() returns a default value 255 if no 3gpp configuration is present

Regards

Matt

#3

Could it be these ones?

$ qmicli -d /dev-cdc-wdm0 --wds-get-autoconnect-settings
$ qmicli -d /dev-cdc-wdm0 --wds-set-autoconnect-settings=enabled,roaming-allowed
$ qmicli -d /dev-cdc-wdm0 --wds-set-autoconnect-settings=enabled,home-only
$ qmicli -d /dev-cdc-wdm0 --wds-set-autoconnect-settings=disabled
$ qmicli -d /dev-cdc-wdm0 --wds-set-autoconnect-settings=paused
#4

Hi mlw, thank you and aleksander0m for your responses. Could you possibly elaborate on the unit starting the default bearer?

I have tested our MC7430 units and determined the pDefaultPDNEnabled setting is not enabled on them, and is not enabled by them during the boot process. I assume this also lines up with the !SCACT AT command referenced in the documentation, but I’m not certain about this.

The MC7430 unit still attaches and starts an LTE data session on our private APN even when it is not plugged into any host (simply powered up via USB). When plugged into a host, we see two authentication requests come in before the host has a proper data session with IP; one from the radio itself, then one from the host dialing through the radio.
We do not want the radio to attempt an IP connection before the host machine dials through the modem, but cannot find any way to stop this.

EDIT: This behavior occurs whenever AT+CGDCONT=1 is configured with a valid APN for the SIM (when using the modem interface). We need to do this to dial, but we don’t want the radio to start the session on it’s own…

How to properly disconnect from carrier network?
#5

Hi,

If it is connecting to your private APN then it will be getting its IP address from there, this is standard LTE operation, it uses this for it signalling (unlike in 2G/3G), without it LTE will not work so it has to come up. The APN is going to be hosted by the service provider and it might be starting a session with your server as part of it config, I don’t know about that.

Either way the default bearer has to come up ad it will use the APN in CID 1, this is standard operation for any LTE device.

Regards

Matt

#6

Thanks mlw. Does this mean that an LTE network attachment requires an IP address?

#7

Hi,

Yes it does require an IP address to be assigned to the unit, as I say this is called the default bearer.

Regards

Matt

#8

How to change the sku with command AT!PRIID?
Thank you for your kind reply!
Hope to be able to communicate with friends who have solved this problem :smiley:

#9

You cannot change the SKU with the PRIID command, this is used to change the carrier PRI file that the unit is using so what exactly do toy want to do?

Regards

Matt