a collective payment and control system has a variety of self - service devices that dispense different types of goods . the system has a primary dispenser such as a self - service fuel pump and a secondary dispenser such as a self - service vending machine . a customer enters a charge card into one of the dispensers , usually the primary dispenser . once the card is validated , the primary dispenser together with secondary dispenser associated with the primary dispenser , are activated . products that are available to purchase from either the primary dispenser or the associated secondary dispensers are displayed to the customer at the primary and / or secondary dispenser . the customer then selects any of the displayed products either directly from the primary dispenser or from each of the primary and / or secondary dispensers . the cost for the selected products are then totaled by the primary dispenser and a single payment transaction is made , such as by a credit / debit charge . alternatively , the cost can be totaled by a separate controller interface . a timeout feature is provided , and the system also allows for remote inventory assessment and pricing . the inventory assessment or stocking request can be transmitted to a remotely - located central facility .