USB connection problem


Hi All,

I have a problem connecting module Q2686 via usb. I am trying to make to work “Q2686H-431 6.63F I311” module. I am not using a development kit. Circuitry USB connection is made from the manual “Sierra Wireless AirPrime Q2686 Customer Design Guidelines Rev003” p.55.
Starting the device is as follows:

  1. plug the external power supply 3.6V
  2. switch Power ON
  3. wait 5 sec and connect usb cable…
    and nothing happened :frowning: …device is not detected OS (Windows XP). also detection usb devices were performed using ‘USB Device Viewer’ program.
    VPAD-USB signal (3.3) exist at 52 pin (Q2686 module), but at 54 (USB-DP) and 56(USB-DM) pins always in logical zero. after switching (power on) the current consumption is changing, it is evident that the device works.
    I do not know which way to dig :frowning:

Thanks in advance for your help :slight_smile:



awneil, thanks for your answer!

I tried “AT+WMFM=0,1,3” and “AT+WMFM=0,1,3,1” but Windows cannot find the USB driver for ‘WAVECOM wireless cpu’ with result - USB detected by PC as unknown device.

USB Viewer program -
Device Descriptor:
bcdUSB: 0x0000
bDeviceClass: 0x00
bDeviceSubClass: 0x00
bDeviceProtocol: 0x00
bMaxPacketSize0: 0x00 (0)
idVendor: 0x0000
idProduct: 0x0000
bcdDevice: 0x0000
iManufacturer: 0x00
iProduct: 0x00
iSerialNumber: 0x00
bNumConfigurations: 0x00

ConnectionStatus: DeviceFailedEnumeration
Current Config Value: 0x00
Device Bus Speed: Low
Device Address: 0x00
Open Pipes: 0

Thanks in advance.


The driver should be available on the SiWi website - but it might be easier to ask your distributor to give it to you…


Of course, drivers were installed. Driver was downloaded and installed from here.
tested on three PC and the result is the same. the question is, why the VendorID and ProductID equal to zero? how can I check these IDs using AT-commands?

Thanks in advance.