RF-Attendance Attendance Automation System Introduction To RFID

What Is RFID - Radio Frequency Identification?

RFID is an acronym for Radio Frequency Identification - The use of wireless communications to establish the identity of a physical object. RFID term is used to describe a system that transmits the identity (in the form of a unique serial number – EPC – Electronic Product Code) of an object wirelessly, using radio waves. RFID technology provides wireless identification of people, books or assets. A RFID tag is attached to an object and contains information about that object.

RFID Components:

A typical RFID system is made up of three components: Tags (RFID ID Cards), Readers and the host computer system.

Tag(RFID ID Cards): Tag is made up of an integrated antenna and memory. The information can be written and rewritten on Tag memory. The unique ID written on Tag while manufacturing is known as the EPC (Electronic Product Code). This Tag is enclosed in a Rectangular Plastic Card of the size of Bank Debit / credit card.

Reader: An RFID reader is a device that is used to read RFID tag data. The reader has an antenna that emits radio waves; the tag responds by sending back data stored in it to Reader.

Host Computer: It reads/writes data from / to the tags through the reader. It stores and evaluates obtained data and links the transceiver to applications..

Features and benefits of RFID over barcodes

• No line of slight is required to read a RFID card / tag. So no need of Oriented reading like bar code
• Multiple RFID Cards can be read.
• No human error like bar code reading while reading a card. Can be read in any orientation.
• Very Limited data can be stored in bar code.
• Re-usable for other purpose.

Different Types of RFID

There are several versions of RFID that operate at different radio frequencies. The choice of frequency is dependent on the business requirements and read environment. Three primary frequency bands are being used for RFID:

• Low Frequency (125/134KHz) – Most commonly used for Attendance & access control.
• High- Frequency(13.56 MHz) – Used where medium data rate and read ranges up to about 1.5 meters are acceptable. This frequency also has the advantage of not being susceptible to interference from the presence of water or metals.
• Ultra-High-Frequency(850 MHz to 950 MHz) – offer the longest read ranges of up to approximately 3 meters and high reading speeds.
• Active RFID Tags are battery powered. They broadcast a signal to the reader and can transmit over the greatest distances (100+ meters). Typically they can cost Rs. 500 or more and are used to track high value goods like vehicles and large containers of goods. Shipboard containers are a good example of an active RFID tag application.
• Passive RFIDTags do not contain a battery. Instead, they draw their power from the radio wave transmitted by the reader. The reader transmits a low power radio signal through its antenna to the tag, which in turn receives it through its own antenna to power the integrated circuit (chip).

Network LF Readers With Biometric (Thumb) for Attendance

Features & Technical Sects. of Network Biometric RFID Readers