EM12-G not reacting on AT commands

IoT Modules LTE-A Module
1

Hey Quectel team and friends,

I have a EM12-G, to be precise a EM12GPA-512-MSFT.

This modul was supposed to run on a FreeBSD-based firewall.

  • When I first connected on FreeBSD the connection was stuck after initial connect. I was not able to send an AT command
  • Then I got an USB to M.2 adapter and was connecting to my Windows computer. I was able to query the module and could send AT commands as expected. However, I was not able to update to a later MSFT-Firmware via DM port
  • Then I connected the USB adapter to the FreeBSD machine and I was also able to query the modem and send AT commands
  • Then I inserted a SIM card and was back to start. Connection to modem hang immediately.
  • I removed the SIM Card, but no change
  • I connected the modem back to the Windows machine, but all of a sudden also this connection was not working anymore. However, surprisingly I was able to update the firmware (although I could not check back with QNavigator or QCom due to the other issue)
  • I also tried another windows and linux machine but no success
  • The modem itself is recognized and also all com ports are available but it is just not connecting.

I am a bit puzzled what can cause this connection issue. Is this a hardware thing?

Thanks!
Chris

2

Maybe you can show some logs or screenshot.
It seems like the USB connection is not stable.

3

Please see some screenshots attached. As I can only add one file per message, I put them into a pdf document.

I am using QNavigator and QCom for connection test. And as said: This worked once.

On other systems I can observe the exact same: Connection hangs once opening the port.

screenshots.pdf (423.6 KB)

4

From this picture, it seems that the AT is not working. I suggest you check the hardware connection first. You used an M.2 to USB interface, can you show it to me? Have you tried to test it on another PC?

5

Plese see attached the adapter being used (antennas have been temporarily disconnected):

2025-01-03_11-03-19_IMG_8681
2025-01-03_11-03-19_IMG_86811920×2560 336 KB

Same behaviour on different PCs.

And same behaviour in a “native” M.2 slot on a Mainboard directly.

What I noticed though: Device Manager is continuously refreshing when the module is attached. This indicates indeed a low level connection issue.

Thanks for taking care!

6

I am not sure which usbnet mode it is. Maybe you have tried the wrong windows driver.

7

Normally with only the USB connection I think the power supply is not enough.

8

immagine
immagine238×108 32.8 KB

There are two variant: MSFT2 & MSFT3 with different pid & vid
delete all quectel drivers and let windows install…
read similar topics (vid & pid issue).

9

When AT commands were still working, I set

AT+QCFG=“usbnet”,2

I was also using the additional usb-c power, but does not change anything.

Mine is neither MSFT2 nor MSFT3 it is just MSFT.

When I remove all drivers, the refreshing in device manager is gone, which clearly links it to the driver.

But, Windows 10 does not have any driver for the device. So, I would need to install some kind of quectel drivers. Any suggestion? ;)<

Thanks for your help!