Radio frequency and identification technology has been in use since the 1970s. There are 3 types of RFID tags: active, semi-passive, and passive. The devices that use this technology can store a vast amount of information.
- Active tags contain batteries that power their internal circuits, and transmit signals to a RFID reader, within a range of 100 feet. With additional batteries, this range can be increased to 300 feet.
- Semi-passive tags have internal batteries that are used only to power their internal circuits.
- Passive tags don't have internal batteries.
- Semi-passive and passive tags draw their power to broadcast a signal from a RFID reader, which is a device that can transmit and receive radio signals. It is built to store encoded data in the tag's microprocessor.
- Because of their high cost, active and semi-passive RFID tags are used for valuable asset tracking.
An RFID tag consists of an integrated circuit and an antenna, which enables it to function as a transponder. It can be attached to any item, and the information about this item stored in the tag. Details such as name, origin, price, ownership of an item, etc., can be a part of the information that is stored in the tag's microchip.
When a RFID reader tries to read data from a tag, its antenna emits electromagnetic energy that is received by the tag's antenna. The tag's microchip uses this energy to emit a radio signal using the antenna.
The reader receives this signal, and passes the information to a computer network, which can provide information about these tagged items and their present status to a computer user.
The system consists of books attached with an RFID tag, an RFID reader, a computer network, and related software to handle the information. The staff conducts lending, returning, sorting, and book tagging operations.
A person can locate books that are tagged by using the RFID reader, which identifies and locates the book based on the emitted signals. When it is carried to the counter, the staff can either activate or deactivate the electronic article surveillance bit in the book's tag.
If a book is borrowed, then the surveillance bit is deactivated, and the opposite happens when it is returned by the reader.
The main entrance of the library is equipped with a RFID antenna, which receives radio signals from the RFID tags that are attached to each of the books, which are being carried out of the library. It signals a warning, in case the book's tag has its surveillance bit active.
In this way, the system controls the inflow or outflow of tagged books, and prevents the theft of books. When a book is returned, the surveillance bit in its tag is activated, and the book cannot be taken past the entrance of the library, without an alarm being sounded.
Borrowing and returning of books can be fully automatized with the help of self check-in/check-out systems. This system involves installation of a special software. A person using this system to borrow books, is presented with options on a computer screen.
The person has to identify himself with a code, or any form of unique identity code assigned to him by the management. Books selected by the person are identified by the system's RFID reader, and the surveillance bit in the book's tag is deactivated by the system. When a book is returned, the check-in/check-out system activates the tag's surveillance bit.
Most of the library staff's time is spent in recording information of incoming and outgoing books. Using this technology in libraries saves time by automatizing their tasks. It also saves a user's precious time, which would have been spent in waiting for his turn in a line.