PORTS Forum

Ports and Interfaces => USB => Topic started by: paulr on May 24, 2010, 11:29:18 am

Title: USB HUB - Identical Device Identification
Post by: paulr on May 24, 2010, 11:29:18 am

Dear USB Group:

What is the conventional way for a host to distinguish between multiple identical devices
attached to a HUB ?  I think using the interface number may be sufficient, but both
the interface number and serial number are needed.  Of course,  the convention
could be something completely different. Note this question is general and does
not apply to a particular operating system.

Best Regards,

Paul R.
 

Title: Re: USB HUB - Identical Device Identification
Post by: Jan Axelson on May 24, 2010, 12:37:21 pm

How host applications access a device depends on the driver the host assigns. For example, most OSes assign a drive letter to each mass-storage device. Windows treats all HID keyboards as a single device, though applications can use Raw Input to access a specific keyboard. For generic HIDs (not keyboards or mice), applications can open a handle to each HID interface.

If you need to keep track of which device is which even after rebooting or detach and reattach, you'll need to use serial numbers or other vendor-defined, device-specific data.

Thanks for posting your question!

Jan

Title: reply this topic
Post by: HelenJames on July 30, 2010, 08:02:55 pm

The similar subject was already observed somewhere at this thread