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USS-TSS Unattended Scanning Systems Technical Support & Services Barcodes and 2D codes Place - DD/MM/YYYY - Session XX Bar Codes Fundamentals. Agenda. When: Day DD/MM/YYYY Where: Place Who: Speaker / Professional qualification What: Bar Codes Fundamental Duration: HH:MM hours
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USS-TSSUnattended Scanning SystemsTechnical Support & ServicesBarcodes and 2D codesPlace - DD/MM/YYYY - Session XXBar Codes Fundamentals
Agenda • When: Day DD/MM/YYYY • Where: Place • Who: Speaker / Professional qualification • What: Bar Codes Fundamental • Duration: HH:MM hours • Level: Basic
Module’s Contents • Main Bar Code Characteristics • Code 2 of 5 Interleaved • Code 39 • Code 128 • Code EAN128 and Application Identifiers (AI) • A Comparison Between Codes 2/5, 39, 128 • EAN/UPC/JAN Family • Other codes • Summary
Bar Code Principles (1/2) • Element or Module Bar or Space • Bar Count number of Bars and Spaces • Start/Stop fixed patterns used to detect bar code • Resolution X module size width of the narrowest element in mm (mils in USA) • Aspect Ratio Bar’s height to symbol’s length • Quiet Zone White margins • Overflow Quiet Zone time duration) Usually the Quiet Zone width must be 10 times X
Bar Code Principles (2/2) Start pattern Stop pattern Quiet Zone Quiet Zone 123456 Scan Line
Bar Code Types: Levels • 2 Levels Bar Codes (Interleaved 2 of 5, Code 39, Codabar …): • Elements can assume only two different widths: 1X (Narrow), 2X (Wide) • N = Printing Ratio = ratio between the wide and the narrow element • The range of N is from 2 : 1 to 3 : 1 • 4 Levels Bar Codes (Code 128, EAN 128, EAN-8, EAN-13, UPC-A, UPC-E, JAN …): • Elements can assume only four different widths:1X, 2X, 3X, 4X • Printing Ratio N does not apply
Bar Code Types: Continuous/Discrete Edge of next character • Continuous: all spaces within the symbol are parts of characters. Examples: IL2/5, 128, EAN128, EAN-8, EAN-13, UPC-A, UPC-E … • Discrete: the spaces between the characters (Inter Characters Gap) are not part of the characters. Examples: code 39, Codabar … Character 3 Character 1 Character 2 Inter Character gaps Character 1 Character 2 Character 3
Bar Code Types: Self-check • Self-Checking: a single printing defect will not cause a character to be transposed into another valid character in the same symbology • Non Self-Checking: without self checking feature
Bar Code Families • Most used in Transportation & Logistics • Code Interleaved 2 of 5 • Code 39 • Code 128 and EAN-128 • Codabar (NW-7 in Japan) • Other common Bar Code families (Retail) • EAN/UPC family (EAN-8, EAN-13, UPC-A, UPC-E with or without ADD-ON 2 and ADD-ON 5) • Other older or uncommon Bar Code families: • Code 93 • 2 of 5 Compressed, Industrial, 5 Bars, 3 Bars Matrix, BCD Matrix, 11 Matrix, 3 bars Datalogic • Plessey • MSI
Code 2 of 5 Interleaved (1/5) • 2 levels bar code • Numeric only • Continuous • Self-checking • Optional check digit (modulo 10) • Variable length, but always with an even number of digits • Use of the check digit with an even number of digits is possible by adding a leading “0” • Each digit is represented by 5 elements (all bars OR all spaces), 2 of which are wide (2 of 5) • Odd digits are coded by bars while even digits are coded by spaces • Bars of the odd digits are interlaced (Interleaved) with the spaces of the even digits
Code 2 of 5 Interleaved (2/5) 9 8 7 6 1 9 0 2
Code 2 of 5 Interleaved (3/5) • START pattern is made up of 2 narrow bars and 2 narrow spaces • STOP pattern is made up of one wide bar, one narrow space and one narrow bar • Left and Right Quiet Zones width must be at least 10 times the module size X • The wide elements are N times the narrow ones • N is the Printing Ratio and can range: • from 2 : 1 to 3 : 1 for X >= 0.508 mm (20 mils) • from 2.2 : 1 to 3 : 1 for X < 0.508 mm (20 mils)
Code 2 of 5 Interleaved (4/5) • quite compact, but … • ... not extremely safe • Start and Stop pattern caneasily be found inside a code • Variable length should be avoided (possible truncations using code reconstruction) • Use of check digit only reduces but does not eliminate the risk of misreading • AIM IL 2/5 Uniform Symbology Specification says:“… There is no guarantee that a partial scan of the symbol will not produce a valid read for an embedded symbol having fewer characters. It is strongly recommended that USS I 2/5 should not be used in an application where the number of characters can vary …”
Code 2 of 5 Interleaved (5/5) • Length of the Start: 4X • Length of a Character: 3X + 2NX • Length of the Stop: 2X + NX • Total Code Length : 4X + D(3 X+2NX) + 2X + NX = X (6 + N) + DX(3 + 2N) = X [6 + N + D(3 + 2N)] • The number of Digits can be easily calculated as follows: D = (Bar Count - 7) / 5orD = (Number of Wide Bars – 1)(where 7 are the elements of the Start and the Stop patternsand 5 are the elements which represent each single digit)
Code 2 of 5 IL: ITF Codes (1/3) • A particular code Interleaved 2 of 5 is referred to as ITF-14 (EAN specifications) • It is very common on carton boxes for large distribution • The same code can assume other names: • DUN-14 (Delivered Unit Number) • TUN-14 (Traded Unit Number) • ITF-6 is similar but with 6 digits instead of 14
Code 2 of 5 IL: ITF Codes (2/3) • As per EAN specifications, the dimensions in the picture are related to Magnification Factor 1, where X = 1.016 mm (40 mils) and H = 31.8 mm
Code 2 of 5 IL: ITF Codes (3/3) ITF Magnification Factors and dimensions table (EAN specifications)
Code 2 of 5 IL: IATA Codes (1/3) • A particular code Interleaved 2 of 5 is referred to as IATA Code and it is used in airport applications (IATA Resolution 740) • It is a 10 digits 2 of 5 IL code with the following characteristics • X = 0.5 mm • N = 2 : 1 • H min = 48 mm • 2 possible layouts: • “T” type label • “Linear” or “Single” type label
Code 2 of 5 IL: IATA Codes (2/3) • Code 2 of 5 IL IATA “T” Type: the same code is repeated in orthogonal positions
Code 2 of 5 IL: IATA Codes (3/3) • Code 2 of 5 IL IATA “Linear” Type: the code is printed only in one direction
Code 39 (1/4) • 2 levels bar code • Self-checking • Full Alphanumeric(numbers and upper case letters)and 7 special characters (- . Space $ / + %) • Discrete (Intercharacter Gap) • Optional Check Digit (Modulo 43) • Variable length • Each digit is represented by 9 elements (5 bars and 4 intervening spaces), 3 of which are wide (3 of 9) • Each digit is separated from the following by a space called Intercharacter Gap (ICG)
Code 39 (2/4) * B A R *
Code 39 (3/4) • START and STOP patterns are both made up of 9 elements and represent the asterisk character (often included in the human readable part) • Left and Right Quiet Zones width must be at least 10 times the module size X • The wide elements are N times the narrow ones • N is the Printing Ratio and can range: • from 2:1 to 3:1 for X >= 0.508 mm (20 mils) • from 2.2:1 to 3:1 for X < 0.508 mm (20 mils) • The nominal width of the Intercharacter Gap should be: • minimum: X • maximum: 5.3X for X < 0.25 mm or 3X or 1.35mm whichever is greater for X >= 0.25mm
Code 39 (4/4) • Length of the Start: 6 X + 3 N X + ICG • Length of a Character: 6 X + 3 N X + ICG • Length of the stop: 6 X + 3 N X • Total Code Length: 6X+3NX + D(6X+3NX) + 6X + 3NX + (D+1) ICG = X[12+6N+D(6+3N)] + (D+1) ICG if ICG = X X[13+6N+7D+3DN] • the number of characters can be easily calculated as follows: D = (Bar Count - 19) / 10 (where 19 are the elements of the Start and the Stop patterns plus one Intercharacter Gap and 10 are the elements which represent each single digit plus the Intercharacter Gap)
Code 39: Full ASCII • Code 39 “FULL ASCII” feature:it is possible to encode theentire ASCII 128 characterset by using two-characterssequences made up of oneof the standard code 39symbols ($ + % /) followedby one of the 26 letters
Code 128 (1/6) • 4 levels bar code • Self-checking • Continuous • Variable length • Alphanumeric (128 ASCII characters) • Check Digit is always included (Modulo 103) • 3 alternate character sets A, B and C are available • Each characters set has its own start pattern • It is possible to switch from one set to another inside a code by the use of the shift character • The stop pattern is always the same
Code 128 (2/6) START Set A STOP STOP START Set B START Set C STOP
Code 128 (3/6) • The Start pattern, each Character and the Check Digit are represented by 6 elements with a width of 11 modules • The Stop pattern is represented by 7 elements with a width of 13 modules • A very important parameter is the Bar Count (BC).From the value of the Bar Count it is possible to calculate the real number of characters inside the code as follows: D = (BC - 19) / 6
Code 128 (4/6) 1 2 3 4 5 6 7 8 9 10 11 12 13 START CHAR CHECK STOP
Code 128 (6/6) • Length of the Start (A,B,C): 11 X • Length of a Character: 11 X • Length of the Check Digit: 11 X • Length of the Stop: 13 X • Total Code Length: L = X (35 + 11 D) • From the total bar code length L (quite zones not included) the Module Size (X) can be easily calculated as follows: X = L / (35 + 11 D)
EAN 128 • Same as Code 128, but with FNC1 as first character • Can use AI (Application Identifiers)
EAN 128: Application Identifiers (1/5) • Application Identifier (AI) specifies particular meanings tobe assigned to the code content • AI are coded as the 2-4 first digits into the code and there is no separators between the AI andthe field content Legenda N Numeric only AN Alphanumeric F Fixed Length V Variable Length
EAN 128: Application Identifiers (2/5) • Some of the most used Application Identifiers (AI) are: SSCC-18 SSCC-14 • Codes EAN128 with Application Identifier 00 (SSCC) are also known as 128 Case Codes
EAN 128: Application Identifiers (3/5) • It is possible to concatenate two or more AI fields in the same bar code: • Some rules for concatenation: • Each field must be separated from the previous by a FNC1 character • In the output message the FNC1 character will be converted to a GS (Group Separator) ASCII character (29 decimal) • It is possible to avoid the FNC1 character separator if the previous field is a fixed length one or, if variable, the maximum number of characters were used
EAN 128: Application Identifiers (5/5) EAN 128 Application Identifiers warnings: • Please remember that the scanners make no check about the correct use of Application Identifiers or their concatenation • An evaluation of the quality of the code made only by naked eyes can reserve a lot of (bad) surprises! • A parcel sent to the “No Read” exit not necessarily means that the code was not read by the scanners
IL 2 of 5/Code 39/Code 128 (2/2) Some considerations: • With the same number of digits and the same module size, Code 128 Set C is more compact than Interleaved 2 of 5 • Code 39 is the widest • Code 128 already includes a check digit • Code 128 is a 4 level bar code, thus requires more printing accuracy with respect to I 2/5 and 39 • With variable length, Code 128 is more error proof than Interleaved 2 of 5 (truncations)
EAN/UPC Family • UPC (Universal Product Code): • UPC is a fixed length numeric symbology normally used in retail applications to identify type of product, manufacturers code and the and specific product • UPC numbers are assigned to specific products and manufacturers by the Uniform Code Council (UCC) • EAN (European Article Number) • EAN is a European version of UPC family. It uses the same size requirements and a similar encoding scheme as for UPC codes • EAN bar code numbers are assigned to specific products and manufacturers by an organization called ICOF in Belgium • JAN (Japanese Article Number) • JAN is a Japanese version of EAN family
EAN-13 (1/8) • 4 levels bar code • Numeric only • Continuous • Self-checking • Check Digit is always included • Fixed length : 13 (12+1) digits • Each of the 12 digits is represented by 4 elements for a total length of 7 modules • An EAN-13 code can be printed with different Magnification Factors (MF) • JAN (Japan Article Number) codes are similar to the EAN-13 codes, but starting with 45 or 49
EAN-13 (3/8) • There are 2 Guard patterns on the left and on the right of 3 elements (3 modules Bar-Space-Bar) • There is a Center pattern of 5 elements (5 modules Space-Bar-Space-Bar-Space) • Left Quiet Zone is 11 modules wide • Right Quiet Zone is 7 modules wide • Bar Count is fixed to 59 (BC = 3+5+3+4*12=59) • The length of the code is: L = X*95 (without Quiet Zones)
EAN-13 (4/8) • An EAN-13 code can be printed with different Magnification Factor (MF) • All Dimensions are defined by EAN for the MF = 1 • Module size for MF = 1 is X = 0.33 mm • When printing the code with MF different from 1, ALL the dimensions must be proportional to the MF used. • Examples: • if MF = 1 module size X = 0.33 mm, bars height = 22.85 mm • if MF = 0.8module size X = 0.26 mm, bars height = 18.28 mm • if MF = 1.5module size X = 0.50 mm, bars height = 34.28 mm
EAN-13 (5/8) Dimensions (mm) are referred to Magnification Factor 1 (X = 0.33 mm)
EAN-13 (6/8) • MF can only range between 0.8 and 2 • An alternative way to define the code dimensions is by the SC factor, as per the following cross reference tableSC Factor Magnification Factor 0 0.8 1 0.9 2 1.0 3 1.1 4 1.2 5 1.4 6 1.5 7 1.7 8 1.85 9 2.0
EAN-13 (7/8) • EAN-13 code structure: • The first 6 digits on the left are coded with a variable sequence of Set A (Odd parity) or Set B (Even parity) depending on the 13th digit of data • The second 6 digits on the right are all coded with Set C (even parity). Odd or Even parity of a set is given by the number of 1s in each digit • The 13th digit defines the sequence of set A or set B used to code the 6 digits on the left • The first 2 or 3 digits represent the code country in which the EAN13 code was requested or other particular use of the code (like ISSN or ISBN)
EAN-13 Supplemental • EAN-13 has been adopted as the standard in the publishing industry for encoding ISBN numbers on books and ISSN numbers on periodicals • ISSN (International Standard Serial Number) • Serial Publication and Periodicals • Starts with 977 • ISBN (International Standard Book Number) • Books (Bookland) • Starts with 978 or 979
EAN-8 (1/4) • 4 levels bar code • Numeric only • Continuous • Self-checking • Fixed length : 8 digits • Check Digit is always included • Each of the 8 digits is represented by 4 elements for a total length of 7 modules • The left hand 4 digits are coded in set A (odd parity), while the right hand 4 digits are coded in set C (even parity) • Dimensioning considerations are the same of EAN-13 code