Barcode Guide

Bar Codes and Variable Data  Unlimited Applications –Inventory Control –Sorting, Tracking –Verification –Quality Control –Automated Warehousing –Shop Floor Control –Product Identification –Addressing

What is a Bar Code?  A Pattern of dark and light areas –Can be bars (Linear) or cells (2D)  The pattern represents the encoded information  May contain letters, numbers, characters or a mix

Why use a Bar Code?  Accurate  Eliminate data entry errors –Errors due to bar codes: less than 0.001% –Coded information errors: 1 every 10,000,000 characters –Manual information errors: 1 every 100 characters  Fast –Read and decode infinitely faster than manually  Easy and cheap to produce

Bar Code Terminology  Bars and Spaces –The elements of the bar code. Made up of narrow and wide lines  Human Readable –The ASCII interpretation of the coded information –Can be printed near the bar code for verification  Quiet Zone –Clear area before and after the printed code –Allows scanner to “calibrate” to the image

Bar Code Terminology –Quiet zone is required to read data –Minimum quiet zone can vary with different symbology  Discrete Bar Code –Unique pattern for each character. Can be manually decoded

Bar Code Terminology  Continuous Bar Code –Bar patterns overlap. Each character’s symbol relates to the ones around it –Can not be easily manually decoded

Bar Code Terminology  Check Digit –Confirms integrity of the encoded and decoded data –A formula uses the bar code data to generate a digit which is then added to the encoded information –The reader calculates a check digit based on what is decoded and compares this number to the encoded number

Bar Code Terminology  Aspect Ratio –The ratio of Bar Height to Symbol Length  Code Density –Number of data characters which can be encoded in a linear inch (characters/inch)  Message Overhead –Space occupied by start, stop and check digit symbols. Increase the size of the barcode

Bar Code Terminology  Bar Width –Thickness of bar measured from the edge closest to the start character to the edge farthest from the start character  Bar Length (Bar Height) –Dimension perpendicular to the bar width  Bi-Directional –Symbol type has no defined read direction –Can be decoded in either direction

Bar Code Terminology  Character –A single group of bars and spaces representing a single element of data –A graphic shape representing a letter, numeral or symbol  Character Set –Group of valid symbols which can be encoded in a given bar code type

Bar Code Terminology  Data Identifier –Message prefixes, conforming to standards that are incorporated in a bar code that define the category or use of the data that follows  Decoder –A device that uses algorithms to interpret the signals set by the scanner and generate meaningful data  Scanner –A device that reads the bar code

Bar Code Terminology  Depth of field –The distance between the minimum and maximum read distance from the scanner to the bar code  EAN –European Article Numbering System –International standard for product coding  UPC –Universal Product Code –U.S. standard for retail package coding

Bar Code Terminology  First Read Rate –Percentage of correct readings obtained in one pass of the scanner  Fixed Beam Scanner –Scanner reading in a fixed plane –Requires more precise code placement  Rastering Scanner –Scan line sweeps along the bar height –Code placement does not need to be as precise

 Horizontal Bar Code (Picket Fence) –Bars are presented so the bar length is in the direction of travel  Vertical Bar Code (Ladder, Rotated) –Bars are presented so the bar width is in the direction of travel Bar Code Terminology

 Inter Character Gap –The space between two adjacent characters in a discrete bar code  Interleaved Bar Code –Characters are paired together using bars to represent the first character and spaces to represent the second –Increases bar code density  Misread –Output of reader does not match encoded data

Bar Code Terminology  No-Read –Absence of scanner output due to no code, defective code, scanner failure or operator error  OCR-A and -B –Character font set used in Optical Character Recognition and automatic identification –Both human and machine readable –Defined by ANSI standards

Bar Code Terminology  Optical Throw –Minimum distance from the scanner to the code for successful reading  Read Rate –Ratio of successful first scan reads to the total number of read attempts  Reflectance –The light reflected by the white spaces –This is what the scanner actually reads

Bar Code Terminology  Resolution –The narrowest element division which can be distinguished by a particular scanner  Self Checking –A code that uses a checking algorithm which can be independently applied to each character to guard against errors  Error Checking & Correction (ECC) –A self checking code whose algorithm can fix errors in the encoding or decoding of data

Bar Code Terminology  Space –Light element of a bar code –Usually formed by the substrate  Stacked Code –Long symbol is broken into sections and stacked on itself similar to sentences in a paragraph –Code 49 and 16K are examples of this type

Bar Code Terminology  Start-Stop Character –A special character which helps the scanner decode the symbol –Start character is normally at the left end of a horizontally oriented symbol, the stop is normally at the right  ISBN – International Standard Book Number –Unique number to identify books, audio and video products and software

Bar Code Terminology  ISSN – International Standard Serial Number –Unique number to identify serial publications such as magazines, newspapers, etc.

Selecting A Bar Code  Amount and Type of Characters encoded  Quality  Available Space  Industry Standards  How and by whom it will be decoded –Linear codes can be read by a simple scanner –2D codes may require a more expensive imager

Linear Symbologies  Pros –Well established, common codes –Numerous different formats to choose from –Fast and inexpensive reading and decoding –Can include human readable interpretation  Cons –Limited data capacity –Can be space prohibitive –Type of data encoded can be limited by symbol

UPC  Universal Product Code  First widely accepted bar code symbol  Now a subset of the EAN symbology  Fixed in length  Numbers only  Continuous symbol with four element widths  Number is unique and is registered to a particular product and packaging

UPC-A  10 digits and two overhead digits  First overhead digit is the type of product  Second overhead digit is the check digit  5 digits identify the manufacturer, 5 identify the product

UPC-E  Similar to UPC-A  Zero digits are dropped, making the code smaller

Other UPC  UPC-B –11 digits + 1 Overhead, no check digit  UPC-C –12 digits + 2 Overhead  UPC-D –Variable length –At least 10 digits + 2 Overhead

EAN  European Article Numbering Code  8 and 13 are similar to UPC codes with the addition of “Flag” digits  Flag digits identify the country where the product identification number was issued  Flag digits do not determine where the product is manufactured

EAN-8  Two Flag digits, five data digits and 1 check digit

EAN-13  Most common EAN symbol  Identical to UPC-A except for Flag Digit

Supplementals  UPC and EAN 8 and 13 can have a supplemental bar code attached to carry additional information  EAN13+5  UPC-A+5  UPC-E+5

EAN-128  Extremely versatile symbol for package ID  Application Identifiers determine the purpose of the data following (Serial Number, Weight, Box Dimensions, etc.)  Same as Code 128 except for the addition of Identifiers

Code 128  General purpose alphanumeric and extended ASCII  Reference symbology for UCC Serial Shipping Container Symbol  Same as EAN-128 without Application Identifiers

Codabar  All numeric data  Four unique stop/start characters to convey additional information  Optional check digit

Code 39  Most used symbol for inventory and shipping  Alphanumeric data set  Extended Code 39 allows upper and lower case characters and punctuation  Most popular symbol outside of retail (UPC) industry

Interleaved 2 of 5 (ITF)  Mainly used in the distribution industry for coding corrugated cartons  Numeric only  Must be an even number of digits  Continuous bar code, characters overlap

ITF-14  UPC Shipping Container Symbol  Used on cartons, cases or pallets of UPC or EAN coded products  14 digit ITF symbol  Indicates the package type, quantity in carton and UPC of packaged item

Pharmacode  Security Verification System for Pharmaceutical Industry –Insures that leaflet, label, container, carton, contents and other packing materials match and are correct

Postnet  Used by the US Postal Service to sort mail  Evenly spaced bars of two different heights  Contains a 5 (zip), 9 (zip+4), or 11 (delivery point code) digit routing code

2D Stacked Symbologies  Pros –More data in the same amount of space as linear codes  Cons –Still require larger area for the code –Require an imager or rastering scanner for reading –Human readable interpretation is not available

Code 49  High information density of full ASCII set

Code 16K  High information density of full ASCII set  Double density encoding of numeric data  Capable of handing extended ASCII

PDF417  Easily decoded by CCD or laser scanner  Selectable levels of error correction  Able to encode extended ASCII set  Thousands of characters capacity

Micro PDF417  Similar to PDF417  Smaller data capacity than PDF417  Limited set of symbol sizes and error correction levels

2D Matrix Symbologies  Pros –Extremely small area for amount of data encoded –Unobtrusive on most products adds aesthetic values for consumer products  Cons –Expensive imaging scanners required –Can be slower to decode –Error correction and detection is essential due to the complexity of the code

3-DI  Proprietary Code  Suited for shiny, curved metal surfaces

Array Tag  Proprietary Code  Can be read at distances up to 50 meters  Primary use is for logs and lumber

DataGlyphs  Proprietary Code  Tolerant to ink marks, bad copies, staples etc.  Can be used as a logo or tint behind text or graphics

Dot Code A (Philips Dot Code)  Designed for low precision marking systems  Up to 12x12 matrix allows up to 42 billion, billion, billion, billion (a big number) individual items to be uniquely coded  Used on laboratory glassware and laundry

MaxiCode  Originally called UPSCode  About 100 characters in a 1”x1” square  Can still be read with up to 25% of the code destroyed  Primarily used by United Parcel Service

MiniCode  Proprietary code  Patented method of encoding low resolution (tracking/sortation) and high resolution (manifest information) data

Data Matrix ECC 200  Up to 3116 characters in a 144x144 matrix  High density, very small code  Very easy to scan under a variety of conditions  Being adopted as standard in a variety of industry groups

Aztec Code  Public Domain  characters, 15x15 – 151x151  Easy printing and decoding

QR Code  Quick Response Code  Public Domain code  Up to 7366 characters  Capable of handling Japanese Kanji and Kana characters

Snowflake  Owned by Videojet  Proprietary, pay per use code

Composite Bar Codes  Two Symbols Printed in close proximity  Data is linked between the two  Typically one linear and one stacked or matrix symbol  Used in applications that require different parts of data to be used at different times

Bar Code Quick Reference

Bar Code Quick Reference (Cont.)