Code 49 was developed by David Allais in 1987 at the Intermec Corporation to fill a need to pack a lot of information into a very small symbol. Code 49 accomplishes this by using a series of bar code symbols stacked one on top of another. Each symbol can have between two and eight rows. Each row consists of a leading quiet zone; a starting pattern; four data words encoding eight characters, with the last character a row check character; a stop pattern; and a trailing quiet zone. Every row encodes the data in exactly 18 bars and 17 spaces, and each row is separated by a one-module high separator bar.

The code is a continuous, variable-length symbology that can encode the complete ASCII 128-character set. Its structure is actually a cross between UPC and Code 39. Intermec has put the code in the public domain.

The minimum value of the x-dimension is 7.5 mils for a symbol to be read by an unknown reader. Assuming an x-dimension of 7.5 mils, and a minimum 8 row symbol height of .5475 inches, the maximum theoretical density is 170 alphanumeric characters per square inch. For a health industry symbol with a flag character, a 10-digit NDC number, a 5-digit expiration date, and a 10-character alphanumeric lot code, the symbol would be .3 inches by .53 inches. A 15-digit printed circuit board serial number Code 49 symbol would be only .1 inches by .3 inches.

Scanning Code 49 can be done with modified moving beam laser scanners or CCD scanner. Intermec makes a CCD scanner which will decode Code 49 symbols along with standard bar code symbologies. Labels can be printed by standard printing technologies.

For more information visit www.intermec.com.