| 摘要 |
A security card which incorporates an electronic key communicates with a control device on a vehicle, civil engineering plant or machinery such that the machinery is operable when the key is within a first predetermined distance, and partially or totally inoperable when the key is further than a second predetermined distance from the control device. The key may communicate an ID code using radio frequency signals. The key may be programmed to operate several different machines and a machine may be operable by several different keys. The key may be incorporated in a security badge to be worn by authorised operators and the key may act as an access key to particular buildings or site areas. The key may co-operate with recording machinery to record the movements of the key carrier and the time when a piece of machinery is used. |
