Wouter van Ooijen wrote :

> > AFAIK the PID must be programmed as a hex number,
> > selling a multiply of 10,
> > doesn't it give  a huge administration,
> > both for you and the customer,
> > and also a low level source of errors ??
> 
> You use a PID to identify a product, not an individual item. In most
> cases the PID of the USB device will be fixed in the 
> firmware, and also
> in the corresponding PC drivers. So not much administration there.
> 
> IIRC each USB item can also have a serial number, which is used to
> identify the individual item. If it has a serial number it will remain
> the same 'thing' (from instance COM17:) to the PC independent 
> of the USB
> port it is plugged into. If it has none its identity is the port. But
> maybe an USB-expert can correct (or confirm) this. 
> Unfortunately buying
> a VID does not make me an instant USB-expert :(
> 
> As for the administrative effort on my side: I do like Python, even
> though it is just an interpreter!
> 
> Wouter van Ooijen

I read Stef's post as saying "10 is not a power of 2".
And that  that might make a "series" of 10 numbers easier to
get wrong when programming them in hex.
But maybe I misunderstod Stef's remark...

Jan-Erik.



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