Introduction:

Radio frequency identification (RFID) is a generic term that is used to describe a system that transmits the identity (in the form of a unique serial number) of an object or person wirelessly, using radio waves. It's grouped under the broad category of automatic identification technologies.

RFID is in use all around us. If you have ever chipped your pet with an ID tag, used EZPass through a toll booth, or paid for gas using SpeedPass, you've used RFID. In addition, RFID is increasingly used with biometric technologies for security.

Unlike ubiquitous Bar Code technology, RFID technology does not require contact or line of sight for communication, so RFID data can be read through the human body, clothing and non-metallic materials.

Working of RFID Systems:

A basic RFID system consists of three components:

  • A Tag or a Transponder
  • An Interrogator or Reader
  • A Host Computer which contains a Software Infrastructure specially developed for RFID Applications

Tags:

An RFID tag is a tiny radio device that is also referred to as a transponder, smart tag, smart label or radio barcode. The tag comprises of a simple silicon microchip (typically less than half a millimeter in size) attached to a small flat aerial and mounted on a substrate. The whole device can then be encapsulated in different materials (such as plastic) dependent upon its intended usage. The finished tag can be attached to an object, typically an item, box or pallet and read remotely to ascertain its identity, position or state.

Readers:

The reader, sometimes called an interrogator or scanner, sends and receives RF data to and from the tag via antennas. A reader may have multiple antennas that are responsible for sending and receiving radio waves.

Host Computer:

The data acquired by the readers is then passed to a host computer, which may run specialist RFID software or middleware to filter the data and route it to the correct application, to be processed into useful information.

 

Purpose of RFID:

The purpose of an RFID system is to enable data to be transmitted by a portable device, called a tag, which is read by an RFID reader and processed according to the needs of a particular application. The data transmitted by the tag may provide identification or location information, or specifics about the product tagged, such as price, color, date of purchase, etc. RFID technology has been used by thousands of companies for a decade or more. RFID quickly gained attention because of its ability to track moving objects. As the technology is refined, more pervasive - and invasive - uses for RFID tags are in the works.

 

Benefits of RFID:

How can we maximize our profit by adopting RFID technology?

This is the basic question which is asked by the business community whenever RFID is discussed. So, following are some benefits of RFID;

Improved visibility (tracking & monitoring) allows companies to save by reducing:

  • Safety stocks and general inventory
  • Out of stock situations
  • Supply chain theft
  • Vendor fraud
  • Labor associated with bar code scanning

Hands-free scanning reduces human error that helps companies by

  • Improving supply & order accuracy
  • Reducing administrative errors
  • Reducing charge backs
  • Increasing overall data accuracy for better planning

Savings for logistics providers include:

  • Better asset utilization resulting from the ability to identify inefficiencies in delivery operations
  • Fewer lost assets due to better tracking of everything from cardboard trays to aircraft
  • Labor savings resulting from automating processes, such as the tracking and monitoring of trailers and containers
  • Increased efficiency due to fewer errors in routing shipments
  • Increased safety and security through identification of package contents without visual inspection

Do you need any or all of the above benefits through RFID solutions………?

 

Categories of RFID:

RFID can be categorized with respect to;

  • Range
  • Read/Write Property

Range:

RFID tags are further broken down into two categories;

  1. Active RFID Tags
  2. Passive RFID Tags

Active RFID Tags:

They are battery powered. They broadcast a signal to the reader and can transmit over the greatest distances (100+ meters). Typically they can cost £5 - £20 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 RFID Tags:

They 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). The tag will briefly converse with the reader for verification and the exchange of data. As a result, passive tags can transmit information over shorter distances (typically 3 meters or less) than active tags. They have a smaller memory capacity and are considerably lower in cost (less than £1) making them ideal for tracking lower cost items.

Read/Write Property:

There are two basic types of chips available on RFID tags;

  • Read Only
  • Read / Write

Read only:

These chips are programmed with unique information stored on them during the manufacturing process – often referred to as a ‘number plate’ application. The information on read only chips can not be changed.

Read-Write:

With these chips, the user can add information to the tag or write over existing information when the tag is within range of the reader. Read / Write chips are more expensive that Read Only chips. Applications for these may include field service maintenance or ‘item attendant data’ – where a maintenance record associated with a mechanical component is stored and updated on a tag attached to the component.

Another method used is something called a "WORM" chip (Write Once Read Many). It can be written once and then becomes "Read Only" afterwards.

RFID Vs Bar Code:

It is important to understand the significant differences between RFID and bar code to appreciate the benefits RFID can provide. Bar code and RFID are both identification technologies that hold data that is accessed by some type of reader. In actuality, they complement each other very well and can be used effectively side by side in many applications. Bar code is an optical technology, and RFID is a radio technology. The ways these technologies exchange data account for most of the differences between RFID and bar code and help determine where each identification technology is best put to use.

As a radio technology, RFID requires no line of sight between the reader and the tag to exchange data. RFID tags therefore can be read through packaging, including cardboard containers and plastic wrap used to seal pallets. RFID is subject to interference, however, particularly from metal, so potential sources of interference must be recognized and accounted for during system planning.

Because no line of sight is required, tagged objects can be read regardless of their orientation through the use of optimized RFID systems. Items don’t have to be placed label side up onto conveyers to be read, paving the way for unattended handling. If workers are required to place items on conveyers to be read, they will be more productive if they don’t have to locate and align labels when handling objects.

RFID readers can automatically recognize and differentiate all the RF tags/inlays in their reading field. This simultaneous processing capability provides additional flexibility for material handling, packaging, and sorting operations because there is no need to maintain spacing between objects to ensure they will be read. The ability to read dozens or even hundreds of tags per second makes RFID ideal for high speed sorting, receiving, cross docking, and other applications. The data capacity of RFID tags/inlays enables them to carry all the same information as bar codes and more. Just as bar codes differ in data capacity, RFID tags/inlays are available with various memory size and encoding options.

 

 

RFID
Bar Code
Read Rate High throughput. Multiple (>100) tags can be read simultaneously. Very low throughput. Tags can only be read manually, one at a time.
Line of Sight Not required. Items can be oriented in any direction, as long as it is in the read range, and direct line of sight is never required. Definitely required. Scanner must physically see each item directly to scan, and items must be oriented in a very specific manner.
Human Capital Virtually none. Once up and running, the system is completely automated. Large requirements. Laborers must scan each tag.
Read/Write Capability More than just reading. Ability to read, write, modify, and update. Read only. Ability to read items and nothing else.
Durability High. Much better protected, and can even be internally attached, so it can be read through very harsh environments. Low. Easily damaged or removed; cannot be read if dirty or greasy.
Security High. Difficult to replicate. Data can be encrypted, password protected, or include a "kill" feature to remove data permanently, so information stored is much more secure. Low. Much easier to reproduce or counterfeit.
Event Triggering Capable. Can be used to trigger certain events (like door openings, alarms, etc.). Not capable. Cannot be used to trigger events.
 
 
 
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