Supra Products, Inc.

Slc Technologies

John M Kniffin

John W Sherman

Wayne F Larson

Ron McCauley

Ralph H Wells, Iii

Kenneth L Reviea

Lynn L Schreiner

David Babler

Richard W Danler

Ron M Chapin

A secure entry system makes use of radio transmissions to communicate with locks, keys, and related components throughout the system. The radio transmissions can be made using a paging system, a cellular telephone system, or any other RF carrier. Some embodiments employ a cellular telephone in lieu of an electronic key. Others integrate a paging receiver within an electronic key to provide a unit with dual functionality. The system is illustrated with reference to exemplary applications in the industrial site security, real estate lockbox, and transportation fields.

Secure entry system with radio communications

Access control device featuring key ordering or key simultaneity

An electronic real estate lockbox system includes a number of operational features, including facsimile reporting capability, bilateral locking solenoids, improved shackle latching capabilities, improved key-compartment release operation, two-wire bilateral lock-key communications, improved case design, viral lockout list propagation, an update code grace period, packet formatted data transmission with error recovery, FSK audio data downloading, and high security challenge-response authorization procedures. A variety of other operational features are also disclosed.

Electronic security system

Growing community of inventors

Portland, OR, United States of America

John M Kniffin