Tailgate Detection Systems shall be provided to monitor and detect tailgating of pedestrians at certain card reader controlled doors as indicated on the plans. The tailgate detection system shall provide monitoring and control of pedestrian for "Card-in/Free-exit", or "Card-in/Card out" conditions as detailed. The tailgate detection system shall have the ability to detect that only one pedestrian enters a card reader controlled door for each valid card read. The "One Read/One Entry" rule shall be monitored by IR sensors located behind the IR acrylic window that establishes two (2) narrow walls of detection to determine the direction of travel. The microprocessor shall evaluate and combine the signals to detect and report violations. The system shall sense and process the direction. Entry access initiated when a valid card is used. During entry access the ES5200 senses and reports violations according to its configuration, "Card-in/Free-exit", or "Card- in/Card-out"