BBC Moneybox - contactless hiccups

[Roland Perry]

In article <20130520144013.GB48009 at davros.org>, Clive D.W. Feather 
<clive at davros.org> writes
>> There are several collision avoidance mechanisms for RFID cards.
>
>Cambridgeshire Libraries has an automated checkout system that uses some
>kind of RFID tags in the book. I've tried putting a stack of 6 books on the
>reader and it found all of them.

I'd expect collision detection to work well for RFID chips of the kind 
used in products, but the ones in transaction cards do seem to interfere 
with each other. They also have a very short time to complete the 
transaction.
-- 
Roland Perry