| 摘要 |
An access control system for a public transport system comprises, at each entrance/exit location (1) of the transport system, at least one entrance gate (12) provided with a ticket reader (8), at least one exit gate (20) provided with a ticket reader (16), a ticket issuing machine (22) and a local data processor (10) with which the other items communicate. The local processors (10) communicate via a central processor (14). The tickets bear unique identification codes which are stored, upon issue, in the local processors (10) at the location (1) at which they are valid for entry. Upon entry using a ticket the relevant code is cancelled at all locations and then it is stored again in the local processors (10) at those locations (1) at which it is valid for exit. Upon exit using a ticket the relevant code is cancelled at all locations. If entry or exit is attempted at a location (1) at which the relevant code is not stored, the relevant gate (12 or 20) is barred. |
