USB Serial Number Test RRS feed

  • Question

  • How do I pass a serial number test for a USB CDC Device, if I do not have a serial number? I do not want to use a serial number as I want that physical USB port "N" => comm. port "X", and physical USB port "M" => COMM Y, regardless of device.
    Friday, June 7, 2013 2:43 PM

All replies

  • First you want a USB serial number on a device, if not it is going to ask you about the device every time it installs it.  Second what makes you think using a USB port number is of any value to a user?  These port numbers have no standard and many manufacturers have differing number schemes even in the in the production of the same model system.

    Don Burn Windows Filesystem and Driver Consulting Website: Blog:

    Friday, June 7, 2013 2:46 PM
  • Having a serial number either requires a new comm. port for every new device connected to a port, or restricts a system to allowing only one device connected at a time.I want that USB physical ports are associated with an instance of the driver.
    • Edited by Kumar87 Friday, June 7, 2013 2:53 PM
    Friday, June 7, 2013 2:49 PM
  • Then there are other problems with your design.  I've sucessfully have had N USB serial devices on a system.

    Don Burn Windows Filesystem and Driver Consulting Website: Blog:

    Friday, June 7, 2013 2:55 PM
  • Windows by default creates a new COM port for every device that uses the driver and has a serial number. If you're testing a batch of devices, you can quickly reach the maximum of 256 COM ports. We don't want that. Also, we don't care if we are asked about the device every time it is installed. We have used this for many years now and don't want to change this. Is there any way to still pass the test?
    Friday, June 7, 2013 7:30 PM
  • Go to your Device Manager, click on your device, go to the "Details" tab and get the Harware_Ids" value. This is the value you have to enter in the Windows Shell during the test. 

    Moreover, make sure you have connected two devices to your Test Computer before running the test.

    Monday, June 10, 2013 9:34 AM
  • I thought the test says that if there is a device without a serial number, only one device must be connected. I am running the test using the Windows HCK GUI which takes the ID correctly (confirmed in log files). 
    Monday, June 10, 2013 1:48 PM
  • Then try the method with only one device.
    Monday, June 10, 2013 2:41 PM
  • What do you mean by "Enter this value in the Windows Shell". This is an Automated test and needs no input from me. Please explain. Thanks!
    Monday, June 10, 2013 6:20 PM
  • Eeeerrrrh sorry, I mistook with USB-IF test. Nevermind that.

    Tuesday, June 11, 2013 8:53 AM
  • @Don Burn,

    If I do use a serial number, will I face this issue: I am in the field programming say 300 devices using the usb driver. Will I be short of comm-ports after 256? If yes, what happens for the next 44 devices that I program, do they over-write the first 44 of 255? Or do they over-write the least used?


    • Edited by Kumar87 Tuesday, June 11, 2013 2:13 PM
    Tuesday, June 11, 2013 2:13 PM
  • I honestly can't say what will happen in this case, since I have never contemplated a system that would see 300 different USB serial ports.  Of course there is system restore, which could be used to rollback after something like the first 100.

    Don Burn Windows Filesystem and Driver Consulting Website: Blog:

    Tuesday, June 11, 2013 2:18 PM
  • Can you post the failure you are seeing in the test log?  Also we are talking the serial number for the USB device itself rather than the serial port number, correct?

    This posting is provided "AS IS" with no warranties, and confers no rights

    Wednesday, June 12, 2013 2:24 AM
  • Yes, we are talking about the Serial number of the USB device itself. I understand that Microsoft has made it mandatory for a device of class 02 to have a serial number to pass the test. But it does not make much sense in our case to have the serial number. Here is the error:

    Message: --Parse: Class = 02/ SubClass =02 / Protocol =01

    Message: Serial number * IS * required for above class

    Error : Serial Number * IS * required for this device class

    File: testsrc\driverstest\usb\usbnum\exe.usbnum.cpp

    Error type: BOOL

    Error code: 0x0

    Error text: Error 0x00000000

    • Edited by Kumar87 Wednesday, June 12, 2013 2:54 PM
    Wednesday, June 12, 2013 2:53 PM
  • @gerogek

    Any ideas?

    Thursday, June 13, 2013 3:49 PM
  • For requirement/policy related questions send mail I'd have to point you to Sysdev *at*

    This posting is provided "AS IS" with no warranties, and confers no rights

    Friday, June 14, 2013 8:03 PM