PDF-417

PDF-417 is a high-capacity stacked 2D symbology, invented in 1991, capable of storing up to about 1,800 printable ASCII characters or 1,100 binary characters per symbol.

PDF417 is a stacked symbology invented by Ynjiun Wang in 1991 at Symbol Technologies. PDF-417 can store up to about 1,800 printable ASCII characters or 1,100 binary characters per symbol. The symbol is rectangular; its shape can be adjusted to some extent by setting the width and letting the height grow with the data. It is also possible to break large amounts of data across several PDF-417 symbols that are logically linked. There is no theoretical limit on the amount of data that can be stored in a group of PDF-417 symbols.

The capacity of PDF-417 is helpful in applications where the data must travel with the labeled item and a host database is not always available for quick lookup. PDF-417 is used for hazardous materials labeling; storing technical specifications and calibration data on electronic instruments; and encoding fingerprints and photographs on the backs of drivers' licenses.

The maximum data density is determined by the smallest elements that can be reliably printed and scanned. Using the smallest recommended element size of 0.0075 inch wide by 0.010 inch high, the maximum data density in binary mode is 686 bytes per square inch (106.2 bytes per square centimeter). In printable ASCII mode the density is 1,144 characters per square inch (177.2 characters per square centimeter).

PDF-417 symbols require a 2-D scanner, or a standard CCD or laser scanner combined with special decoding software (a wand scanner will not work). A number of scanners on the market use both laser and CCD camera technologies. PDF-417 symbols can be printed using most professional-grade thermal transfer label printers on the market.

For more information visit www.symbol.com and www.pdf417.com.