A customer inserts their wireless card (Ezlink or NETS FlashPay card) to the water dispenser kiosk. The system holds the card.
The system checks the remaining balance on the card, and estimate the max amount of water it can release base on the card balance.
The user dispenses out the amount of water he needs. There is a real-time display to present to the user the amount dispensed and the cost incurred so far. The user cannot dispense more than the estimated maximum amount water (determined by the remaining balance amount on the card).
Once the user finishes dispensing, the user will hook back the dispenser or eject the card. It is also an acknowledge from the user to proceed with the payment.
The water dispenser kiosk will deduct from the card base on the amount of water dispensed.