I still don't understand why you need multiple arduinos for that. Or multiple card readers. Just seems wasteful.
+1@prash_21Why not one arduino plus one reader. Tap first card, send data to PC. Tap second card, send data to PC.
A hotel has a card reader on each door, perhaps also each machine or station in the fabric has its own card reader?
I am trying to follow this, but it is rather elusive.say, a building has an entry door and a security guard.the person comes up to the building, swipes their card.the security guard leaves their desk goes outside an then authorizes entry by swiping their authorization card on the same reader.Is there some way that the security guard could authorize this without exiting the building ?
Wherever this is, this is how they want it to work. If it doesn't fit your ideas then maybe it's outside of your experience which does not make it wrong just different to what you know.
Possibly the OP can better explain in the OP's native language. That wasn't American Millennial in the first post, too many words were not 1337-spelled.
say, a building has an entry door and a security guard. .....