Printronix L7032 Programmer's Reference Manual page 258

Chapter 3
Bar Codes
Quiet Zone
The bar code structure requires a completely blank quiet zone which extends
4.75 inches from the right edge of the mail piece. In addition, a minimum quiet
zone of 0.040-inch above and below the bar code data must also be provided.
You must provide sufficient space for this zone.
Start/Stop Code
The start and stop codes are referred to as "framing bars" in POSTNET. The
start and stop codes are each one tall bar, one identifying the leading and
trailing end of the bar code. The start/stop code is automatically produced
with each bar code. The start/stop code structure permits bar code scanning
in a left-to right direction only.
Data Field
The bar code data produces a single field of 30 bars for a 5-digit field, 50 bars
for a 9-digit data field, or 60 bars for an 11-digit data field. The bars are
grouped in sets of five. Each set of five bars (comprised of two tall bars and
three short bars) represents one of the five digits of the zip code, plus the
four-digit zip code extension. If the Delivery Point Bar Code is used, an
additional two-digit code is also added to make an 11-digit data field.
Exact bar code dimensions depend on the type of printer used, but fall within
the following specifications:
Each bar width is equal and is .020-inch ± .005-inch. Each bar height is either
a tall (full) or short (half) bar, representing a 1 or 0, respectively. Each tall bar
is .125-inch ± .010-inch; each short bar is .050-inch ± .010-inch. Horizontal
spacing between bars (pitch) is 22 bars ± 2 bars per inch over any 0.50-inch
portion of the bar code. Horizontal spacing at 24 and 20 bars per inch is
0.0416-inch and .050-inch, respectively, with a clear vertical space ranging
from 0.012-inch to 0.040-inch between bars.
Check Digit
The sixth, tenth, or twelfth digit represents the automatic check digit character
for the 5, 9, or 11-digit data field, respectively. The Mod 10 check digit is
added automatically to verify accurate scanning.
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