Chapter 4 Automatic Identification System EC5103PA_Apr2008
15 July 2008 (Tuesday) • CPA Class Test 1 • Chapter 1 to 3 • During project lesson
Automatic Identification System • Basic structure and operating principles of various identification system • Bar codes • Magnetic stripe • Radio frequency identification • Smart card
What is Automatic Identification System? • Auto ID, also refer as AIDC (Automatic Identification and Data Capture) • Auto ID refers to the method of capturing or collecting data via automatic means (i.e. without the use of a keyboard), and storing data in a microprocessor-controlled devices (computer). • All AIDC technologies support two common goals: • Accuracy To eliminate errors associated with identification and/or data collection • ProductivityTo accelerate the through-put process
Types of Auto ID Technologies • AutoID technologies can be roughly divided into six categories: • Optical • Magnetic • Electromagnetic • Biometrics • Touch • Smart card
Automatic Identification System – Bar Codes • A symbol that represents a series of numbers and/or letters • Symbol is designed such that it can be read by scanners which communicate with the computers • Scanning a bar code initiates same action as entering data into a computer
Bar codes Applications Some specific applications are: • Retail point of sale • Baggage tracking • Package tracking • Book tracking • Statistical process control • Time and attendance • Patient tracking • Inventory and access control • Retrieval of client files.
Bar code System • Bar code generator software - to design and print original bar code labels. - to add graphics and text to bar codes. • CCD Scanner and wedge – A CCD scanner scans the bar codes and collect data. - A wedge is the interface that interprets the scanned data and enters it into the open application of the computer. • Data collection software – All bar codes must be scanned into an open application on your computer through which you can compile the information replayed by the scans.
Bar code Symbology • Bar code language, also known as symbology, is a graphic representation for numbers or alphabetic characters. • Types of symbology available: • Linear (1D) Symbologies • 2D Symbologies • Composite Symbologies
Linear (1D) Bar Code Symbologies • Well-established, read-only, optical-read technology • Low cost label-based symbol • Low capacity, typically 15~50 characters, depending upon symbology and form used • Accurate and fast though requires line-of-sight machine readability • Wide range of symbol formation software
UPC Codabar Linear (1D) Bar Code Symbologies • Wide range of encodation symbologies such as: • Interleaved 2-of-5 , ITF • Code 39 (Pioneered by defense and automotive) • Code 128 • Universal Product Code, UPC (Used in supermarket) • Codabar (Used in blood banks)
Linear (1D) Bar Code Symbologies Universal Product Code (UPC) • Consists of : • Machine-readable bar code • 12-digit readable UPC number • Format of UPC: • UPC number – 6 39382 • specific products and manufacturers by the Uniform Code Council (UCC). • Item number – 00039 (product code) • Check digit – Last digit of UPC
2-Dimenstional Bar Code Symbologies • A need to encode more information in a smaller space result the use of 2D bar code • Two types of 2D bar codes in use are: • Stacked Symbologies • Matrix Symbologies
PDF417 2-Dimenstional Bar Code Symbologies • Stacked Codes • Matrix Symbologies AZTEC CODE DATA MATRIX MAXICODE
Composite Bar Code Symbologies • Newly-emerging class of symbology in which two symbols are printed in close proximity to each other and contain linked data • Typically one component is a linear symbol and the other either a stacked or a matrix symbol • Example of composite symbol : UCC.EAN
Disadvantages of Bar Codes • In order to keep up with inventories, companies must scan each bar code on every box of a particular product. • Going through the checkout line involves the same process of scanning each bar code on each item. • Bar code is a read-only technology, meaning that it cannot send out any information.
Auto-ID System – Bar codes – Scanning & Verification • Bar code scanners are electro-optical systems that include a means of illuminating symbol and measuring reflected light. • Light waveform data is converted from analog to digital in order to be processed by a decoder and further transmitted to software application. • Type of bar code scanners: • Contact wands scanner • CCD scanner • Laser scanner
Auto-ID System – Bar codes – Scanning & Verification • Contact Wands bar code scanner • Least expensive way to read bar code • Handheld bar code scanner • Must be placed in contact with bar code symbol and moved across entire symbol to correctly read the symbol • Low cost, light weight and suitable for rugged used
Auto-ID System – Bar codes – Scanning & Verification • CCD Scanner • Mid-range price handheld bar code reader • Use a stationary flood of light to reflect symbol image back to an array of photo sensors. • Depth of field (DOF), optimal distance for scanner to read the bar code ranges from contact to six inches. • More rugged than laser scanner as there are no moving parts • Capable of reading 2D matrix
Auto-ID System – Bar codes – Scanning & Verification • Laser Scanner • Expensive handheld bar code reader • Laser diode created a beam which is spread into horizontal arc by means of rapidly moving mirror • Light sweeps @ 40 scans per second • Revolving polygons or oscillating mirrors may be used to produce a more reliable reading • Larger area of scanning view and can achieve a distance of 6 to 12 inches • Laser Scanner can tolerate symbol skew
Auto-ID System – Magnetic Strip – Introduction • Magnetic stripes technology uses the same technology as audio or videotape – digital magnetic recording. Rather than sounds or images being encoded, digital data is encoded on a magnetic stripe.
Auto-ID System – Magnetic Strip – Introduction • Magnetic stripe is adhered to the back of cards or tickets. • Information is encoded on the stripe using low and high-energy electromagnetic charges – alternating the polarity of small sections of the magnetic material. • When the card is swiped through the reader, electromagnetic charged particles are read as binary data that is then translated and converted into letters and numbers for computer processing.
Auto-ID System – Magnetic Strip – Tracks Layout • Magnetic strip may contain up to three tracks (according to ISO7811) • Track 1 (Read-Only) – Capacity of 79 alphanumeric characters can hold user’s account number, name, expiration date • Track 2 (Read-Only)– Contains 40 numeric characters • Track 3 (Read and Write) – Contains cardholder’s accounts and may be encoded each time it is used. This track is used for security purposes.
Auto-ID System – Magnetic Strip – Advantages & Disadvantages • Advantage of magnetic strip • Flexibility, can be re-encoded at any time as compared to bar codes. • Durability, enable up to 100,000 swipes on a single card and over 2 million swipes on a reader. • Reliability, ten years of performance for both cards and readers. • Disadvantage of magnetic strip • Ability of a magnetic field to erase the card ‘s encryption. • Data on the stripe can easily be read, written, deleted or changed with off-the-shelf equipment. • not the best place to store sensitive information.
Magnetic Strip Applications • Magnetic stripes is used everywhere such as: • Bank Card • Airline Ticket and Boarding pass • Phone card • Transit ticket • Parking lot ticket
Review Questions • What are the two main objectives of AIDC technologies? • Name four common types of Auto-ID technologies. • State three types of bar code symbology.
What is Radio Frequency Identification? • RFID is a technology used for automatic data capture which allows contact-less identification of objects via Radio Frequency(RF). • RFID relies on storing and remotely retrieving data using devices called RFID tags or transponders. • An RFID tag is an object that can be applied to or incorporated into a product, animal, or person for the purpose of identification using radio waves. • Some tags can be read from several meters away and beyond the line of sight of the reader.
Components of a RFID System A basic RFID system consists of three components: • A transponder (RFID tag) • Reader or Interrogator • Host computer
Components of a RFID System A transponder (Also called a tag) • a tiny radio device that is also referred to as a transponder, smart tag, smart label, or radio barcode. • contain at least two parts. • integrated circuit for storing and processing information, modulating and demodulating a (RF) signal, and other specialized functions. • an antenna for receiving and transmitting the signal. • Fig 12 An EPC RFID tag used by Wal-Mart
Components of a RFID System Reader or Interrogator • RFID readers or receivers are composed of a radio frequency module, a control unit and an antenna to interrogate electronic tags via radio frequency (RF) communication. • The main objective of an RFID reader is to control the reading and writing of data to an RFID tag. • A radio frequency field is generated around the RFID reader's antenna to generate power for the passive tags as well as provide means for data transfer from the tag to the reader.
Components of a RFID System • 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.
RFID tags • RFID tags are categorized as either passive, active and semi-passive.
Passive RFID tags • Have no internal power supply. • draw 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. • The tag chip can contain non-volatile, writable EEPROM for storing data. • Simple, low cost & small • Shorter read range (typically 3m of less)
Active RFID tags • have internal power source, which is used to power the integrated circuits and to broadcast the response signal to the reader. • larger and more expensive than passive tags. • transmit at higher power levels than passive tags, allowing them to be more robust in "RF challenged" environment. • with humidity and spray or with dampening targets (including humans/cattle, which contain mostly water), reflective targets from metal (shipping containers, vehicles), or at longer distances. • used to track high value goods like vehicles and large containers of goods. • Provide longer range (typically tens of metres) • Larger memories than passive tags • Tags could last up to 10 years due to battery life time 2.45GHz RFID Temperature Sensor Active Tag
Semi-Passive RFID tags • have own power source, but the battery only powers the on-board microchip and does not power the broadcasting of a signal to the reader. • battery can be used to power data storage. • Some semi-passive tags sleep until they are woken up by a signal from the reader, which conserves battery life. These tags are sometimes called battery-assisted tags. • Main advantages:- 1) Greater sensitivity than passive tags. 2) Longer battery powered life cycle than active tags. 3) Can perform active functions (such as temperature logging) under its own power, even when no reader is present for powering the circuitry.
RFID Frequencies • Type of tags are also categorized by radio frequency: • Low frequency tags (125 or 134.2 khz) • High frequency tags(13.56MHz) • UHF tags (850 to 960 MHz) • Microwave tags (2.45GHz)
Automatic Identification System – Advantages • Real-time updates • Contactless technology • Line-of-sight not required • High Security • Fast reading speed • Simultaneous reading
Automatic Identification System – Application • RFID in Metro Group
Components of a RFID System A basic RFID system consists of three components: • A transponder (RFID tag) • Reader or Interrogator • Host computer
Auto-ID System – Smart Card– Introduction • Provide greater memory capacity for storing of information • Allows reprogramming of adding, deleting of data • Provide greater security features than magnetic stripe
Integrated Circuit What is a Smart Card ? • A credit card size plastic card containing an integrated circuit (IC) that carried relatively large amounts of information. • The microchip can contain just a memory module, or a microprocessor with a memory module.
What is a Smart Card ? • Information contained in the microchip can include monetary data, personal identification, security credentials or medical history. • Allows reprogramming of adding, deleting of data
A Smart Card System • A smart card is a part of a larger system which includes: • Smart Card reader/writerAllow transfer of information between smart card and machine interfacing with card (i.e. ATM) • Client ApplicationSoftware which performs on-line transactions between card and system providers (i.e. banks) • Card Management System (or Card Operating System)Software and protocol that control the card operation
Types of smart card Memory card (Also known as “dumb’ card) • has an embedded memory chip with predefined operations, such as acting as a cash card. • It does not contain logic or perform calculations; they simply store data. • use ROM and EEPROM to store from 1KB to 15KB of information. • Without a processor, a memory card relies on a CAD (card acceptance device) to process the card information upon each card use. • Memory card are used in NETS CashCard, pay phone, retail or vending machines, game-station.
Types of smart card Microprocessor card (Smart card) • Microprocessor with memory is embedded in the card • can process and manipulate its own data • Not dependent on reader to make application work • Microprocessor cards are used in ATM, credit & debit cards.
Types of Smart Card Interface • Types of smart card interface: • Contact • Contactless • Dual interface - Hybrid card- Dual interface chip card (Combi Card)
Types of Smart Card Interface • Contact smart card • Require physical contact with device known as reader • Has 6 contacts point (usually gold plated) for power and data communication
Types of Smart Card Interface • Contact smart card • Prone to electric shock through the contacts which may result a destruction of IC • Contact point prone to corrosion • Lower cost of smart card series
Types of Smart Card Interface • Contactless smart card • Communicates with reader without physical contact • Contains an antenna which embedded inside the card for wireless communication • No contact to wear out • Used in applications such as :- • transit fare payment cards • government and corporate identification cards • electronic passports and visas, and • financial payment cards.