Patent ID: 7003319

Claim:
A data carrier system comprising a first data carrier selectively couplable to a communications device and a second data carrier selectively couplable to the communications device in preference to the first data carrier, the first data carrier being arranged to be decoupled from the communications device when the second data carrier is coupled to the communications device; and during a predetermined period of time the communications device is arranged to be ensured of a supply of power by maintaining the supply of power to the communications device in response to a command to extinguish the supply of power to the communications device, wherein upon receiving a command to extinguish the supply of power to the communications device; the second data carrier is arranged to be decoupled from the communications device, the first data carrier is coupled to the communications device, a communication task involving information is performed the information is used to update information in the first data carrier, the first data carrier is decoupled from the communication device, and the second data carrier is recoupled to the communication device, whereinafter the supply of power to the communication device is extinguished.