| 摘要 |
<p>A credit transfer system is provided for transferring credit, representing credited consumption of a metered service G issued to a consumer, to a consumer metering apparatus (1, 2) which is selectively operable to cut-off the supply of the service to the consumer. The system comprises payment means (2) for controlling supply of the metered service G by the consumer metering apparatus in dependence on received credit. The payment means (2) has a memory for storing received credit data indicative of the total of all credit ever received by the payment means. The system includes a portable data storage device (3), associated with the payment means (2), for storing issued credit data indicative of the total of all credit ever issued for the payment means (2). The system also includes means for verifying the association of the data storage device (3) and payment means (2). The payment means (2) is operative to read the issued credit data from the associated data storage device (3) and, if the association is verified, to determine from the issued credit data and said received credit data the amount of any newly issued credit, and to update said received credit data in accordance with the newly issued credit so determined.</p> |
