| 摘要 |
A door operator provides enhanced security for controlled vehicle access by employing transmitters having unique identity codes that are fixed in manufacture. A receiver includes a nonvolatile read/write identity code memory for storing the authorized identity codes. If a received identity code is found within this memory, then the user is authorized and the door is opened. Otherwise, the user is not authorized and entry is refused. A remotely disposed memory controller controls the authorized identity codes stored in the identity code memory, which is preferably electrically erasable programmable read only memory (EEPROM). The memory controller is preferably a desk top computer including a data base program with the identity of authorized users. The identity code of transmitter held by a formerly authorized used can be determined via the data base program and deleted from the identity code memory without requiring return of the transmitter. Pass back is restricted by preventing from additional door accesses for a predetermined time following each access. In an alternative embodiment a two button transmitter includes both a fixed identity code and a user selectable identity code. One button transmits the selectable identity code to individualized receiver/operators also having a user settable identity code.
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