Re: USB Device with 2 virtual com-ports

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From: Mathias Ellinger (me_at_nospam.de)
Date: 01/04/05 

Date: Tue, 04 Jan 2005 04:29:06 -0800

Rahul wrote:

> Hello,
> I am trying to emulate virtual Com Port using my USB Device on Windows
> 2000 with SP 4 using usbser.sys.
> I was able to get one Virtual COM Port working properly with windows.
>
> Now, when i try to add functionality of one more COM Port , windows
> machine crashes.
> I want to use the two com ports to provide two different
> functionalities at the same time and i don't want to write any vendor
> specific driver for windows.
>
> Can't i use this usbser.sys for both the com-ports.
> On my device, i receive Set Configuration 1 from the Host.
> And on the Host side it asks for the inf file, while copying the
> driver the windows crashes(restarts).
>
> I don't know whether usbser.sys supports composite device.
> But windows supports composite devices i think :)
>
> Regards,
> Rahu Kaul.

write a new PnP serial driver with special interface to your own USB driver.
This architectur is much better. One driver for USB interface and serial devices emulation
is a bad design. Here is some trouble when a application has open the serial device
and the USB device is plugged out. My architecture use always 2 device driver and
I have never had a problem.

elli

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