Title: Re: Need to identify a physical USB hub
port
Hello list and Fernando:
Perhaps I should clarify my question in the context of what I now
understand about locationID. I originally framed my question as
follows:
"I have an N port hub connected to a Mac USB port.
This hub is permanently connected. Each of the N ports of my external
hub has an SD reader device permanently connected. When a removable SD
flash is inserted into one of the readers I get a volume mounted event
so that I can get the name of the mounted volume and then copy a file
from my hard drive to the SD flash ... no problem. I would like my
code to tell me which physical reader contains the mounted
volume."
Now I see that each flash reader will acquire a 32 bit locationID
when it is connected to the USB bus system and I can pick up those
numbers with a callback which responds to a deviceAdded notification.
Of course, I can't know the ordering of the USB enumeration, so I
can't know which locationID binds with which physical port.
Additionally, my code supports a mount event so that I have a callback
that responds to a flash media being put into one of the USB reader
devices. The fundamental question is how can I determine which
physical port contains the flash media that mounts? Inasmuch as I
can't know which locationID binds with which physical port, I don't
see how knowing the locationIDs for each of the readers helps
me.
At 10:25 PM -0600 5/25/05, Fernando Urbina wrote:
>I think that the best that you can do is get the locationID
of the device in question. This number is persistent across
restarts, as long as the bus topology remains the same (which sounds
like it will from your description). What you do with this
location ID is up to you ;-)
>
>HTH,
>
>--
>Fernando Urbina
>USB Technology Team
>Apple Computer, Inc.
>
>On May 25, 2005, at 10:07 PM, B. Mitchell Loebel wrote:
>
>> As an example, Windows explorer binds a drive letter to a
reader whether or not the removable flash is inserted in the reader.
And that drive letter persists for the entire session even after the
removable flash has been removed. How can I do the same under OSX ...
Carbon, please?
>>
>>
--
-----
B. Mitchell
Loebel 408 425-9920 cell
Executive
Director
The Tech Startup
Connection
(formerly The PARALLEL Processing
Connection)
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