The citizen identifies its vehicle by entering its license plate number at the paystation. The central system is then asked to verify whether some specific rights have to be taken into account (specific tariff for resident or specific citizens, free time for short stays, fleet management …).
When the citizen validates the transaction, an order to register the virtual ticket is transmitted to the server, the money is then cashed after confirmation of the registration by the server. The paystation registers also the information of the transaction in order to allow a financial and claim follow-up. Because the ticket is registered centrally, there is no need to print a ticket, except if there is a connection problem or if a receipt has been asked.
A citizen can add more time to his stay simply walking to the nearest paystation, even miles away from where he parks or through the mobile app.