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Re: Regarding multiple devices installed
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Re: Regarding multiple devices installed



Hi Samuel,

I'm not sure I understand your question.

On Oct 21, 2003, at 10:26 PM, samuel wrote:

Hi,
	I want to install two usb devices with the same vendor ID and
product ID and the same class (say printer class). How do I do this?

What do you mean by "install" in this case? You apparently mean something other than just plugging in both devices.


When I tried to install two printers of the same make & model, the later
installation overwrites the previous installation. Is this the standard
behaviour?

The standard USB approach is for vendors to add a serial number to each device so you can tell them apart. This is an optional field, and serializing each device can add incremental cost so many devices don't have this field.


Apple has implemented what we call the "location ID", which is guaranteed to be the same for a given device, even across reboots, so long as the bus topology is unchanged. You can use the location ID to distinguish between two otherwise identical devices in your code.

Does this help?

Thanks,
--gc
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 >Regarding multiple devices installed (From: samuel <email@hidden>)



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