One or more lock or key units of a secure entry system is equipped with a radio receiver. The receiver permits a memory in the lock or key unit to be updated with new data that is modulated onto a radio frequency signal. By this technique, system-wide changes of programming data, such as changes of lockout...http://www.google.fr/patents/US5602536?utm_source=gb-gplus-shareBrevet US5602536 - Data synchronization method for use with portable, microprocessor-based device
Data synchronization method for use with portable, microprocessor-based device
