A vending machine door monitoring system for an audit system is provided. This door monitoring system may utilize the same door switch utilized by the vending machine controller (VMC) in order to detect the state of an access door for the vending machine. This door monitoring system may have a separate...http://www.google.com.au/patents/US7385504?utm_source=gb-gplus-sharePatent US7385504 - Vending machine door monitoring system
