MC7304 on windows 8.1 Embedded


We are using a standard windows operating system (Windows embedded 8.1) and the MC7304 module to create a permanent connection to the internet on a remote managed computer. It is critical that this remains connected at all times.

We are running into an issue where the computer gets into a state where the modem will not connect to the network. It’s like the MC7304 card has crashed or stopped responding for unknown reason. When it gets into this state we found that a re-boot of the system will fix the problem. We have also found that disabling the associated network interfaces and re-enabling them would also work correct the issue.

The network interfaces are set to auto connect, but when it is in this state it will attempt to connect and fail. There is good signal strength during the tests.

We have confirmed and witnessed this issue on more then one system, so it’s definitely a serious issue for us.

We have not been able to reliably re-produce the issue, and it appears to happen randomly for no discernable reason. It can take potentially weeks for the issue to occur, but at times only a few days.

Below is our setup:

These systems operate in a headless mode unattended, so this is a very serious issue for us as when we loose connection to the computer the only way to fix it is to send someone out to site to reset the computer.

Hi matvdl,

Issue is so random, are you using Windows MBB to setup the data connection? Can you try the Sierra connection manager?

Also, can you capture log or send AT commands on the headless system to understand why connection failed?

But for info, FW is the latest approved FW for Telstra, may worth to try too.


I am not familiar with Windows MBB, after installation of the drive package qmi build 4208 that I have listed in my original post, windows manages the connection automatically for us. We select Auto Connect on the selected network interfaces and the system manages and maintains the connections.

We are running some tests currently and have been able to re-produce the issue. Currently we are running 12 systems and if we remove the antenna from these systems for 1-2 days when we re-attach the antenna we had 8 systems did not recover or re-connect.

This is using the 16.02 firmware.

We will upgrade the firmware to the 26.02 tomorrow and repeat the test. Hopefully they will all connect with the more recent firmware.

I will report back once the test is completed.


We have completed extensive testing - we now have 15 systems all configured the same to test this issue. This is what we have found:

All systems are upgraded to the latest firmware 26.02 for Telstra
We start-up all 15 computers, they all connect to internet
We then remove the antenna for all systems - they all loose connection
We leave them in this state for at least 2 days
After this time we then re-attach all antenna’s and up to 8 do not reconnect.

The computers that don’t reconnect show that the network card has no signal
We have confirmed that if we disable the nic’s (there are three mobile nic’s) and re-enable them the system will immediately reconnect.

We are looking into writing some software that is able to disable and re-enable the nic’s when connection is lost - but this is a very bad solution, ideally we would like windows and the sierra drivers/setup to just work.

Does anyone else have any further suggestions for how to fix this?

Below it was suggested we capture the AT commands - How do we capture the AT commands that windows is sending to the modems?

I drove myself nuts trying to get a similar, EM7355, card working on both Windows 8.1 and Windows 10 (tech preview). I’ve worked with and troubleshooted a lot of hardware issues before but the problems I saw with this device and windows 8+ are beyond me. I eventually deemed the issues as witchcraft, reverted to Windows 7, and haven’t had any problems since.

A few things that allowed me to successfully get it to work in windows 8 were:

  • Disable automatic installation of drivers
  • Remove every driver related to the card (probably the safest way would be to just start with a fresh installation of windows)
  • Follow these steps for reinstallation:
  1. Shut down the computer
  2. Remove BOTH the physical wifi card and the Sierra module
  3. Boot windows, re-confirm all drivers related to wireless and sierra are removed
  4. Shut down the computer again
  5. Install ONLY the Sierra module, boot the computer back up
  6. At this point you might actually be able to get a connection, if not then manually install the driver through Add Hardware
  7. Reboot a few times making sure the driver installation is complete and you can disconnect/reconnect the Sierra card from the internet
  8. Shut down the computer for the last time
  9. Install wireless card, boot the computer back up, and install wifi drivers if necessary

Those are the only steps that actually got the card working and connected reliably – but it was almost always temporarily fixed from what I could tell. I wasn’t able to ever pinpoint the exact thing that would cause the card to stop working again.

After spending 2 months trying to get it working, I eventually gave up and reverted to Windows 7 and everything works perfectly. Do yourself a favor, ditch Windows 8 :wink:

Let me know if any of the steps work for you, and if so please let me know if you’re able to pinpoint any of the voodoo going on