Data is often placed on cards such as credit cards by printing on the cards, embossing the cards, depositing data on a magnetic strip on the card, or depositing data in an integrated circuit on the card. The placement of data on the cards by any of the methods listed above is generally done by a card processing machine. Cards to be processed by the machine are often placed stacked in a hopper adjacent the card processing machine. The cards normally are fed one by one from the hopper into the card processing machine and automatically restacked in another hopper after process of the cards is completed. Processing of the cards may proceed continuously or cards may be fed into the machine periodically in response to the demand for a card.
After the cards have been placed in the hopper, the hopper is covered and locked to prevent manipulation or theft of the cards prior to processing. If an exception card must be processed in addition to the cards in the hopper (non-exception cards), the hopper must be unlocked and the cover removed exposing the non-exception cards to manipulation or theft. This might occur, for example, when a hopper is filled with a stack of standard credit cards and there is a need to process a premium credit card.