摘要:
An electronic payment system for conducting transactions by presenting a contactless payment card to a card reader. The card reader is configured to process transactions when only one card is present in its operating field. The card reader uses collision detection and avoidance algorithms to detect and report instances where multiple cards are present in the operating field. In response to a reported collision, the collision may be cleared by manual intervention, i.e., by physically removing excess cards from the reader's operating field.