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Chapter 3 Bar Codes
Quiet Zone
Both ends of the bar code structure require blank quiet zones. The quiet
zones must be at least 0.25 inches wide and completely blank to ensure
accurate reading of the start/stop codes and to prevent adjacent bar codes
from overlapping. Be sure to provide sufficient space on the form for the quiet
zones.
Start/Stop Codes
The start/stop code is a unique character 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 bidirectional bar code
scanning.
Data Field
The bar code symbol uses a series of wide and narrow bars and spaces to
represent standard alphanumeric characters. Each wide or narrow bar or
space is one element; each character in the data field has nine elements. The
structure is three wide elements (bars or spaces) out of the nine total
elements which compose one character.
Readable Data
The optional readable data field provides a readable interpretation of the bar
code data. It can be printed above or below the bar code symbol.
Check Digit
The optional modulo-43 check digit can be inserted into the bar code to verify
accurate scanning.
Codabar Command Format
BARCODE
CODABAR [CD];[
DIR
;] [
MAG
;] [H
n
[.
m
];] [BF
n;L;
] [DARK;]
SR; SC
[
(D)data field(D)
]
[PDF
[;
LOC
] [;
FONT
]]
STOP
BARCODE The Bar Code command; enter BARCODE.
CODABAR CD
Designates bar code type Codabar; enter
CODABAR. To calculate and plot the optional
modulo-43 check digit with the bar code symbol
automatically, enter CD.
DIR
Optional parameter that allows for rotating a
barcode. Enter CW for clockwise rotation. Enter
CCW or VSCAN for counter-clockwise rotation.
Enter INV for inverted rotation. If
DIR
is not
entered, the barcode is horizontally oriented.