What means RFID?

RFID stands for "Radio Frequency IDentification".

With RFID any piece, box or item can be electronically identified.

The device attached to the object which should be indentified is called TAG. The number of each TAG is world wide unique.
The TAGs are already so small, that they can be integrated into stickers, paper, boxes or buttons of clothing.

There are different versions of TAGs and therefore a selection of the right TAG is necessary for each application.

The main criterias are:

• Coverage
  The distance between the reader and the TAG which can range between some centimeters and several hundret meters.
  
  
• Limitations due to water and metal
  The TAGs use different frequencies (125 kHz -- 2,54 GHz).
  The different frequencies react differently on metal and water.
  
  
• Memory Size
  Simple RFID TAGs just have one function: they transmit their unique ID to the RFID reader. Other RFID TAGs have read/write memory which can be used by RFID reader/-writers. This way additional information about the item to which the TAG is attached can be stored on the TAG. For example a TAG may be attached to a pet. The TAG would store the address of the owner.
  
  
• Life Span
  there are active and passive TAGs.
  • Passive TAGs have a smaller range of operation but on the other side do not need a battery. The life span of these TAGs is viually unlimited. These TAGs are not produced that long, so real life experience regarding the durability is not given.
  • Active TAGs have a battery which gives them a life span of typically 5 to 10 years.
    
    
• Price
  The dream of the logistics companies is a price under 1 Euro Cent. Only then it is comercially acceptable to provide every pack of milk with a TAG. The super market would know what you have bought before you even pay!
  Reality is a bit different still:
  • Passive TAGs cost around 20 Euro Cent to 1 Euro a piece.
  • Active TAGs cost 15 - 50 Euros a piece.
    
    

  Today RFID applications are only profitable if the costs for TAGs don't carry to much weight.