Bar Codes / Bar Code type details |
Details on the codabar-18 bar code type.
Codabar 18 can be used to encode text of variable length by using characters from this character set:
Reference Number | Character |
---|---|
0 | 0 |
1 | 1 |
2 | 2 |
3 | 3 |
4 | 4 |
5 | 5 |
6 | 6 |
7 | 7 |
8 | 8 |
9 | 9 |
10 | - |
11 | $ |
12 | : |
13 | / |
14 | . |
15 | + |
16 | a |
17 | b |
18 | c |
19 | d |
16 | t |
17 | n |
18 | * |
19 | e |
The first character of any code must be either 'a', 'b', 'c' or 'd'. The last character of any code must be either 't', 'n', '*' or 'e'. All other characters must have an ordinal value less than 16.
The last but one character is the checksum character that is calculated as follows:CS=16-(Sum(i=1 to n of Ref(i))) mod 16) Where Ref(i) is the reference number of the character i, and n is the total number of characters. Example: codeValue="a37859n"CS=16-((16+3+7+8+5+9+17) mod 16),CS=16-(65 mod 16),CS=15 Looking up reference number 15 yields the character '+'. The full code value including checksum is therefore: codeValue="a37859+n"
When the system is supplied with a value that is one digit shorter than specified by noDigits then the check digit is automatically calculated.
The nominal height is 20mm. The nominal width of a thin bar is THINBARWIDTH=0.165mm. The width of a character is 2.095mm. Between digits a gap with the width GAPWIDTH=THINBARWIDTH/ thinToGapRelation is drawn. The padding on both sides measures 10*THINBARWIDTH.