Code 39 Advanced Features and Functions
Mod 43 Check Character
Standard Code 39 can be printed with a "Mod 43 Check Character". This Mod 43 check character cannot be used with Full ASCII Code 39. The check character is derived by assigning a value to each character in the data to be bar coded from the table as follows:
Char | value | Char | value | Char | value | Char | value |
0 | 0 | B | 11 | M | 22 | X | 33 |
1 | 1 | C | 12 | N | 23 | Y | 34 |
2 | 2 | D | 13 | O | 24 | Z | 35 |
3 | 3 | E | 14 | P | 25 | - | 36 |
4 | 4 | F | 15 | Q | 26 | . | 37 |
5 | 5 | G | 16 | R | 27 | space | 38 |
6 | 6 | H | 17 | S | 28 | $ | 39 |
7 | 7 | I | 18 | T | 29 | / | 40 |
8 | 8 | J | 19 | U | 30 | + | 41 |
9 | 9 | K | 20 | V | 31 | % | 42 |
A | 10 | L | 21 | W | 32 |
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Table C-1. Mod 43 Check character calculation for Code 39
Here is an example to illustrate how the check character is calculated for bar code data of 123XYZ:
1.Take the sum of the values assigned to each character:
1 + 2 + 3 + 33 + 34 + 35 = 108
1 2 3 X Y Z
2.Divide the sum by 43: (thus the name modulus 43)
108/43 = 2 with a Remainder of 22
3.Find the character corresponding with the remainder.
M (value 22) is the CHECK CHARACTER
The data becomes 123XYZM, with M added as the
33
