Resetting EM7355

IoT Modules MC/EM Series
1

Dear all,

what are the ways to reset EM7355-based modem (under Linux), without powering-off the whole machine? I’m using AT-interface and sometimes it becomes unresponsive (for example after passing modem interface as serial port into virtual machine, estabilishing connection and transmitting larger amount of data). Reloading module doesn’t seem to fix it.
So my questions are:

  1. How to track what exactly caused modem to hang? Or i
  2. How to reset it using MBIM or QMI ? AT!GRESET usually don’t work in that case…
  3. Is it possible to reset the modem using USB functions (like using usbreset program or removing usb authorizations or other usb-related activities?
  4. is it possible to reset the modem using any other ways ?

Regards,
Krzysztof

2

Hi,
Did you try with AT!RESET command? or your AT port got hang?
Can you share your syslog…
what exactly are you doing? what is the use case?
Thanks,
Alex

3

Hi,

AT!RESET doesn’t work, AT port isn’t responding.
However, swtiching to MBIM mode, turning radio off and on makes it responding again.
The use case is that the serial AT port needs to be passed remotely over network and it may stuck in uknown state - especially when the network connection is lost without clean serial disconnect.

Regards,
Krzysztof