I'm not sure but I've seen Visa terminals that behave as if they enter some kind of offline mode when their ancient GPRS connection in the middle of the woods t

I'm not sure but I've seen Visa terminals that behave as if they enter some kind of offline mode when their ancient GPRS connection in the middle of the woods time out. In this mode you can only do smaller purchases and they are then later sent to the bank once the store gets a connection. This is for Visa debit btw, not credit.