ABSTRACT
This chapter covers the devices, starting with the simplest digital combination lock and progressing to the highly complex thumbprint and retinal scanners. The Prox card can also be installed outside with fewer problems than magnetic card readers. The wiring of the device to read Prox cards is similar to the wiring of the magnetic card reader. The credential of the Prox card can be tied to a combination lock or other second verification that only the candidate knows, otherwise, whoever has the Prox card can obtain access through doors locked and controlled by small Proximity Card readers. With the exception of the intercom system which is relatively simple there exist a number of biometric analyzers for facilities seeking higher security than can be provided by keypad or card readers. While a mechanical or electromagnetic lock protects the facility from intruders, it is important to release the lock at the appropriate time.
