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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
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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
Bar Code Terminology • 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