Code 39


Code 39
A Code 39 Barcode Label
"WIKIPEDIA" encoded in Code 39

Code 39 (also known as Alpha39, Code 3 of 9, Code 3/9, Type 39, USS Code 39, or USD-3) is a variable length, discrete barcode symbology.

The Code 39 specification defines 43 characters, consisting of uppercase letters (A through Z), numeric digits (0 through 9) and a number of special characters (-, ., $, /, +, %, and space). An additional character (denoted '*') is used for both start and stop delimiters. Each character is composed of nine elements: five bars and four spaces. Three of the nine elements in each character are wide (binary value 1), and six elements are narrow (binary value 0). The width ratio between narrow and wide can be chosen between 1:2 and 1:3.

The barcode itself does not contain a check digit (in contrast to—for instance—Code 128), but it can be considered self-checking on the grounds that a single erroneously interpreted bar cannot generate another valid character. Possibly the most serious drawback of Code 39 is its low data density: It requires more space to encode data in Code 39 than, for example, in Code 128. This means that very small goods cannot be labeled with a Code 39 based barcode. However, Code 39 is still widely used and can be decoded with virtually any barcode reader. One advantage of Code 39 is that since there is no need to generate a check digit, it can easily be integrated into existing printing system by adding a barcode font to the system or printer and then printing the raw data in that font.

Code 39 was developed by Dr. David Allais and Ray Stevens of Intermec in 1974. Their original design included two wide bars and one wide space in each character, resulting in 40 possible characters. Setting aside one of these characters as a start and stop pattern left 39 characters, which was the origin of the name Code 39.[1] Punctuation characters were later added that deviated from this pattern, expanding the character set to 43 characters. Code 39 was later standardised as ANSI MH 10.8 M-1983 and MIL-STD-1189.[2] MIL-STD-1189 has been cancelled and replaced by ANSI/AIM BC1/1995, Uniform Symbology Specification - Code 39.[3]

Contents

Encoding

The * character presented below is not a true encodable character, but is the start and stop symbol for Code 39. The asymmetry of the symbol allows the reader to determine the direction of the barcode being scanned. This code is traditionally mapped to the * character in barcode fonts and will often appear with the human-readable representation alongside the barcode.

These tables outline the Code 39 specification:

Code 39 Characters
Legend
Format1 Format2 Desc
W B Wide - Black
N b Narrow - Black
w W Wide - White
n w Narrow - White


(Note, Format1 and Format2 are just two different ways of describing the same underlying encoding, not two variants of Code 39.)

><

Code Details
Char nr for checksum Char Format1 Format2
0 0 NnNwWnWnN bwbWBwBwb
1 1 WnNwNnNnW BwbWbwbwB
2 2 NnWwNnNnW bwBWbwbwB
3 3 WnWwNnNnN BwBWbwbwb
4 4 NnNwWnNnW bwbWBwbwB
5 5 WnNwWnNnN BwbWBwbwb
6 6 NnWwWnNnN bwBWBwbwb
7 7 NnNwNnWnW bwbWbwBwB
8 8 WnNwNnWnN BwbWbwBwb
9 9 NnWwNnWnN bwBWbwBwb
10 A WnNnNwNnW BwbwbWbwB
11 B NnWnNwNnW bwBwbWbwB
12 C WnWnNwNnN BwBwbWbwb
13 D NnNnWwNnW bwbwBWbwB
14 E WnNnWwNnN BwbwBWbwb
15 F NnWnWwNnN bwBwBWbwb
16 G NnNnNwWnW bwbwbWBwB
17 H WnNnNwWnN BwbwbWBwb
18 I NnWnNwWnN bwBwbWBwb
19 J NnNnWwWnN bwbwBWBwb
20 K WnNnNnNwW BwbwbwbWB
21 L NnWnNnNwW bwBwbwbWB
22 M WnWnNnNwN BwBwbwbWb
23 N NnNnWnNwW bwbwBwbWB
24 O WnNnWnNwN BwbwBwbWb
25 P NnWnWnNwN bwBwBwbWb
26 Q NnNnNnWwW bwbwbwBWB
27 R WnNnNnWwN BwbwbwBWb
28 S NnWnNnWwN bwBwbwBWb
29 T NnNnWnWwN bwbwBwBWb
30 U WwNnNnNnW BWbwbwbwB
31 V NwWnNnNnW bWBwbwbwB
32 W WwWnNnNnN BWBwbwbwb
33 X NwNnWnNnW bWbwBwbwB
34 Y WwNnWnNnN BWbwBwbwb
35 Z NwWnWnNnN bWBwBwbwb
36 - NwNnNnWnW bWbwbwBwB
37 . WwNnNnWnN BWbwbwBwb
38 (space) NwWnNnWnN bWBwbwBwb
39 $ NwNwNwNnN bWbWbWbwb
40 / NwNwNnNwN bWbWbwbWb
41 + NwNnNwNwN bWbwbWbWb
42 % NnNwNwNwN bwbWbWbWb
* NwNnWnWnN bWbwBwBwb


Please Note: In between each character (the start and stop characters included) there is a thin space (shown as w below). For example, if you wanted a Code 39 barcode composed of the letter "A", you would need the following to be encoded (using Format 2 as described above): "*A*". [bWbwBwBwb]w[BwbwbWbwB]w[bWbwBwBwb]
The code will not be read without these spaces. Barcode fonts invariably include this space within the glyph for the character.

Code 39 mod 43

Code 39 is sometimes used with an optional modulo 43 check digit. Using it requires this feature to be enabled in the barcode reader. The code with check digit is referred to as Code 39 mod 43.

Here is how to do the checksum calculation:

  • Take the value (0 through 42) of each character in the barcode excluding start and stop codes.
  • Sum the values.
  • Divide the result by 43.
  • The remainder is the value of the checksum character to be appended.

Full ASCII Code 39

Code 39 is restricted to 43 characters. In Full ASCII Code 39 Symbols 0-9, A-Z, "." ,and "-" are the same as their representations in Code 39. Lower case letters, additional punctuation characters and control characters are represented by sequences of two characters of Code 39.

Code Details
Nr Character Encoding     Nr Character Encoding     Nr Character Encoding     Nr Character Encoding
0 NUL %U 32 [space] [space] 64 @ %V 96 ` %W
1 SOH $A 33 ! /A 65 A A 97 a +A
2 STX $B 34 " /B 66 B B 98 b +B
3 ETX $C 35 # /C 67 C C 99 c +C
4 EOT $D 36 $ /D 68 D D 100 d +D
5 ENQ $E 37 % /E 69 E E 101 e +E
6 ACK $F 38 & /F 70 F F 102 f +F
7 BEL $G 39 ' /G 71 G G 103 g +G
8 BS $H 40 ( /H 72 H H 104 h +H
9 HT $I 41 ) /I 73 I I 105 i +I
10 LF $J 42 * /J 74 J J 106 j +J
11 VT $K 43 + /K 75 K K 107 k +K
12 FF $L 44 , /L 76 L L 108 l +L
13 CR $M 45 - - 77 M M 109 m +M
14 SO $N 46 . . 78 N N 110 n +N
15 SI $O 47 / /O 79 O O 111 o +O
16 DLE $P 48 0 0 80 P P 112 p +P
17 DC1 $Q 49 1 1 81 Q Q 113 q +Q
18 DC2 $R 50 2 2 82 R R 114 r +R
19 DC3 $S 51 3 3 83 S S 115 s +S
20 DC4 $T 52 4 4 84 T T 116 t +T
21 NAK $U 53 5 5 85 U U 117 u +U
22 SYN $V 54 6 6 86 V V 118 v +V
23 ETB $W 55 7 7 87 W W 119 w +W
24 CAN $X 56 8 8 88 X X 120 x +X
25 EM $Y 57 9 9 89 Y Y 121 y +Y
26 SUB $Z 58 : /Z 90 Z Z 122 z +Z
27 ESC %A 59 ; %F 91 [ %K 123 { %P
28 FS %B 60 < %G 92 \ %L 124 | %Q
29 GS %C 61 = %H 93 ] %M 125 } %R
30 RS %D 62 > %I 94 ^ %N 126 ~ %S
31 US %E 63 ? %J 95 _ %O 127 DEL %T, %X, %Y, %Z

References


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • code — code …   Dictionnaire des rimes

  • codé — codé …   Dictionnaire des rimes

  • code — [ kɔd ] n. m. • 1220; lat. jurid. codex « planchette, recueil » 1 ♦ Recueil de lois. Le code de Justinien, et absolt le Code. Ensemble des lois et dispositions légales relatives à une matière spéciale. Livre, article d un code. Le C ODE CIVIL ou… …   Encyclopédie Universelle

  • code — [kəʊd ǁ koʊd] noun 1. [countable] LAW a complete set of written rules or laws: • Each state in the US has a different criminal and civil code. ˈbuilding code [countable] LAW a set of rules that states what features a new building, bridge etc… …   Financial and business terms

  • Code — redirects here. CODE may also refer to Cultural Olympiad Digital Edition. Decoded redirects here. For the television show, see Brad Meltzer s Decoded. For code (computer programming), see source code. For other uses, see Code (disambiguation).… …   Wikipedia

  • code — n [Old French, from Medieval Latin codex, from Latin caudex codex tree trunk, set of wood writing tablets, book] 1: a systematic compilation or revision of law or legal principles that is arranged esp. by subject: as a: one that contains the law… …   Law dictionary

  • Codé — Code Cette page d’homonymie répertorie les différents sujets et articles partageant un même nom …   Wikipédia en Français

  • Code-2 — (Computador Didáctico Elemental, versión 2), y su predecesor ODE son dos procesadores ideados por los profesores Alberto Prieto y Antonio Lloris, de la Universidad de Granada, para facilitar la compresión del funcionamiento y el diseño hardware… …   Wikipedia Español

  • Code QR — Pour les articles homonymes, voir QR. Un exemple de code QR Le code QR ou QR Code (en anglais) est un code barres en 2 dimensions (code matrice) pouvant stocker jusqu à 7089 c …   Wikipédia en Français

  • Code 46 — film poster Directed by Michael Winterbottom Produced by …   Wikipedia

  • code — code; code·less; en·code·ment; iden·ta·code; man·u·code; re·code; sar·code; mi·cro·code; post·code; zip·code; de·code; en·code; os·tra·code; …   English syllables