Configuring a Mini PCI-E Modem for USB2.0 Mode

[JimHelms]

There are occasions (and applications) where a Mini PCI-E modem (i.e., Sierra Wireless MC7455, Telit LM940/LM960, Quectel EP06) must be configured in USB2.0 mode to function on a certain device.

Taping (isolating) various pins on a modem (PINS 23 thru 33 on a MC7455) is sometimes used to accomplish this task. However, AT-Commands may also be used to obtain the same results.

We will first demonstrate the commands necessary for the Sierra Wireless MC7455, and the Telit LM940/LM960 thereafter.

SIERRA WIRELESS MC7455

To use this function and AT-Command on the MC7455, the modem must be first be updated to the latest Generic firmware.

To update the firmware will require a USB to Mini PCI-E adapter to connect the modem to a PC.

In order for a Windows machine to detect and communicate with the MC7455, the Sierra Wireless Generic Driver Software for Windows will need to installed on the PC.

Warning: Never allow a Windows machine to "Manage" an internet connection with the MC7455 as it can change the composition of the modem to an undesired mode. In other words, if you are using an USB to Mini PCI-E adapter enclosure, remove the SIM Card where Windows will not try to manage the modem. Windows is used strictly to update the Sierra modem's firmware using the Generic Driver Software.

Plug the USB adapter (with the MC7455) into the Windows machine and run the GN_9999999_9904609_SWI9X30C_02.30.03.00_00_GENERIC_002.046_001 executable file.

When the update is completed, you should see this window with these results:

Updating the MC7455 Firmware.png

If your window reflects these "exact" results, press the Enter key and the window will disappear.

If your results look any different, press Enter key, and update the firmware a second time.

Note: As a general practice, I personally prefer to always flash a firmware on a modem a second time. It is also often required on the EM7565.

After the firmware has been updated, we will use the Huawei Terminal to issue the necessary AT Commands.

Open the Huawei Terminal and select the WWAN Modem COM Port, and Connect:

Selecting the WWAN Modem COM Port.png

Once connected, run the following AT Commands:

Code: Select all

AT!ENTERCND="A710"
AT!USBSPEED=0
AT!RESET

Once the last AT Command responds with OK, Close ( X ) out the Terminal.

AT Commands for USB Mode.png

You may now remove the MC7455 and install it in the device which should not function properly with the MC7455.


In the event you need to restore the MC7455 to it previous USB OEM setting:

Code: Select all

AT!ENTERCND="A710"
AT!USBSPEED=1
AT!RESET

TELIT LM940/LM960

The AT Commands for the Telit for USB2.0 are:

Code: Select all

AT#USBSWITCH=1
AT#REBOOT

Quectel

The AT Commands for Quectel EP06 (requires latest firmware);

Code: Select all

AT+QUSBCFG="SS",0
+QUSBCFG: "SS",0