| 摘要 |
A system for controlling access in multiple regions is provided in which each region comprises one or more sites having building areas to which access is controlled. The system includes multiple regional databases, where each regional database is associated with one of the regions, and a master database storing system information, cardholder information and access control information. A master computer system is coupled to the master database, and a regional computer system, capable of data communication to the master computer system, is coupled to each of the regional databases. Initially, the master computer system downloads the system information and cardholder information from the master database to each of the regional databases, and each regional computer system uploads the access control information from its regional database to the master database to provide the stored access control information for the region at the master database. Each region operates independently of the master database, and can change (add, modify, or delete) access control information and cardholder information stored in its regional database. The regional computer system of each region periodically uploads to the master database any changes in the access control information of the regional database, and any changes in the cardholder information of the regional database. The master computer system periodically downloads from the master database to each regional database any changes in cardholder information made by other regions. Thus, the system, cardholder, and access control information stored in the master database is maintained identical to the corresponding information at each of the regional databases, and cardholder information changes made at each region are distributed to other regions through the master database.
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