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
installation overwrites the previous installation. Is this the standard
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.