Chapter 10: Bar Code Commands for 9-Pin Printers112where parameter m designates the number of characters which will follow in the data. If youwish to include a check digit, enter the ASCII character @ (64 Dec, 40 Hex) at the end of thedata.Postnet Bar Code CommandPostnet bar coding is used by the United States Post Office for sorting mail by automatedequipment. It incorporates a coding system using five bars and four spaces for each digit.Select/Print Postnet Bar Code Data CommandThe commandESC DLE C P 1 [data]selects Postnet bar codes and initiates the printing of the zip code + 4 data which you enter aspart of the command. Each digit of data can be any ASCII character from 0 to 9 (48 to 57 Dec,30 to 39 Hex). The data must be the full ZIP + 4 code.Postnet Parameter P1Parameter P 1 tells the printer how many bytes of bar code data to expect. Its value can be anyASCII character from NUL to DC4 (1 to 20 Dec, 01 to 14 Hex): any values for P 1 outside thisrange will cause the data to be ignored.The print density for Postnet bar codes will be 240 dpi. Printing is accomplished in two printpasses with a 1/144" line feed. The bar height will be as follows:High Bar: 16/144" (eight dots in two passes)Low Bar: 6/144" (three dots in two passes)To include the check digit, enter the ASCII character @ (64 Dec, 40 Hex) at the end of the data.
