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USB

OSR_Community_UserOSR_Community_User Member Posts: 110,217
Hello friends,
I am facing a strange problem. I have written a Application(Using
SDK calls). What this applicatin does is that it uses CREATEFILE to get a
handle to given Device Name(eg COM1). And then writes ono that device using
WRITEFILE.

My problem is When i run this Application with device name as COM1
then it runs fine. But when i run it for USB port The CREATE FILE returns an
error value of 2(means Unable to find device).

OBJDIR utility of DDK displays name of USB device as
USB#ROOT_HUB#4&2c3f8097&0#{f18a099-c30c-11d0-8815-00a00c906bed8}
And Symbolik link as USBPDO-0

What does this type of Device name mean??
I have tried all the Possible combinations of this device name in my
application.

Thanks in Advance
Navin Saini

Comments

  • OSR_Community_UserOSR_Community_User Member Posts: 110,217
    > My problem is When i run this Application with device name as COM1
    >then it runs fine. But when i run it for USB port The CREATE FILE returns an
    >error value of 2(means Unable to find device).
    >
    > OBJDIR utility of DDK displays name of USB device as
    >USB#ROOT_HUB#4&2c3f8097&0#{f18a099-c30c-11d0-8815-00a00c906bed8}
    >And Symbolik link as USBPDO-0

    Offhand, your device can't talk to a PDO (physical device object), it needs
    to talk to a LDO (logical device object). Some driver will need to create
    an LDO when notified of the device arrival. The PnP string identifying the
    device will determine which driver gets to create a LDO layered above the PDO.

    - Jan
  • OSR_Community_UserOSR_Community_User Member Posts: 110,217
    Hello Jan,
    Can you please elaborate!!!!!!!

    Who creates LDO & when. Where can i see the LDO listing

    Navin Saini

    > ----------
    > From: Jan Bottorff[SMTP:[email protected]]
    > Reply To: NT Developers Interest List
    > Sent: Saturday, July 29, 2000 3:07 PM
    > To: NT Developers Interest List
    > Subject: [ntdev] Re: USB
    >
    > > My problem is When i run this Application with device name as COM1
    > >then it runs fine. But when i run it for USB port The CREATE FILE returns
    > an
    > >error value of 2(means Unable to find device).
    > >
    > > OBJDIR utility of DDK displays name of USB device as
    > >USB#ROOT_HUB#4&2c3f8097&0#{f18a099-c30c-11d0-8815-00a00c906bed8}
    > >And Symbolik link as USBPDO-0
    >
    > Offhand, your device can't talk to a PDO (physical device object), it
    > needs
    > to talk to a LDO (logical device object). Some driver will need to create
    > an LDO when notified of the device arrival. The PnP string identifying the
    > device will determine which driver gets to create a LDO layered above the
    > PDO.
    >
    > - Jan
    >
    > ---
    > You are currently subscribed to ntdev as: [email protected]
    > To unsubscribe send a blank email to $subst('Email.Unsub')
    >
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