32
Appendix C
Specifications for Code 39Code 39 (or Code 3 of 9) is the de facto standard of non-retail American
industry. It is widely used in the automotive industry (AIAG specifications) as
well as in government and military applications (LOGMARS specifications).
Code 39 is flexible, features a large character set, variable data length and
density, and bi-directional readability. Code 39 is extremely accurate;
substitution errors are almost nonexistent. Its character set consists of
numbers 0 through 9, upper case A-Z, and characters Space, $, %. / + and -.
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 9.4 cpi.
There should be a ΒΌ" "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 RF Laser Reader 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., 13th Floor
New York, NY 10036
212-642-4900
http://www.ansi.org
document ANSI/AIM BC1-1995
Code 39 has several advanced features and functions that are discussed further
in this appendix.