Appendix D
Specifications for Code 39
Code 39 (or Code 3 of 9) is the de facto standard of
123ABC government and military applications (LOGMARS specifications). Code 39 is flexible, features a large character set, variable data length and density, and
39 is extremely accurate; substitution errors are almost nonexistent. Its character set consists of numbers 0 through 9, upper case
The name "Code 39" comes from both the fact that its character set originally contained 39 characters (it now has 43) and from its structure. Each character is formed of three wide and six narrow elements, made up of five bars and four spaces. Code 39's density can vary from a low of .75 characters per inch (cpi) to a high of
9.4cpi. There should be a ¼" "quiet zone" (white space) to the left and right of the bar code. Code 39 uses an asterisk (*) as a start and stop character. This character must precede and follow the data in the bar code. The WDP gives you the option of transmitting or not transmitting these characters when the bar code is read.
Exact specifications for Code 39 and other bar code symbologies can be obtained from ANSI at the address below:
American National Standards Institute
Customer Service
11 West 42nd St.
New York, NY 10036
http://web.ansi.org
document ANSI/AIM
The cost is $36.