[MC7700] Stuck in MBIM only mode - No available Serial Ports

IoT Modules MC/EM Series
1

Hi there,

I have a MC7700 unlocked Module that presents a Mobile Broadband interface only with no available Modem or serial ports whatsoever,
The available MBIM network adapter works perfectly fine and i am able to connect to my provider’s network with no issues. However with no Modem or DM ports available and my MC7354 being out for warranty repair, my development work has screeched to an unpleasant standstill as i have very little knowledge of working with MBIM at the moment.

I noticed that Sierra’s Skylight application can find the module with no issue and gives me all the usual information such as signal strength, SMS capabilities etc. But aside from providing the modules basic information, it doesn’t really help me all that much.

So, my question is this:

Is there any known method to force the module to expose the standard Serial ports (DM, AT, NMEA) while its in MBIM only mode?

I have the QMI version of the module with VID:1199 and PID:68A2
In Windows Device Manager i have USB/VID_1199&PID_68A2_MI:c0
and in linux, the only device that shows is /dev/cdc-wdm0

the /dev/cdc-wdm0 works somewhat when used with mbimcli from the libmbim-utils but not with the qmicli from libqmi-utils. And i can’t see a listed method for enabling serial ports.

Can anyone help me out with this?

Im running the module in my laptop at the moment through its mini-pcie port.

2

So after a little more searching i found this thread [url]https://forum.sierrawireless.com/t/my-mc7710-cant-work-on-linux-after-plug-in-it-to-windows8/7986/9] but im stuck on the step where im requesting the profile switch to the equivalent USBCOMP=8 via QMI command embedded in MBIM, but its not returning the expected string of Bytes that indicate it was successful. Does anyone have any ideas what i would be doing wrong by any chance?

I know that through the normal method with AT Commands, we need to issue the AT!ENTERCND=“A710” before it will accept AT!UDUSBCOMP change command. Could i be facing a similar issue here through the QMI method?

3

Issue Resolved

https://forum.sierrawireless.com/t/my-mc7710-cant-work-on-linux-after-plug-in-it-to-windows8/7986/1