Rfid In Access Control System: (A Microcontroller Based System)

PREFACE : Radio Frequency Identification (RFID) provides contactless or distant identification. There are basically two main components of any RFID system. One is Tag or Transponder and other is Reader or Interrogator. Each tag contains the information that uniquely points to a person, an object or anything to be uniquely identified. The conversation of a reader with a tag takes place through an RF signal of fixed frequency, to which all system components are tuned. All RF data exchange between the tag and reader is encrypted using a secure algorithm. So the data can't be either read or altered. RFID technology has been used in the access control arena maintain the security in the organisation and monitor by providing identity of employee, his incoming and outgoing time, absentee, location etc. The RFID tag transmits a unique ID to sensors, which identify the person's location in real time.