| Barcode
Basics
Carefully determining
the size and position of barcodes before printing can save a
great deal of effort and prevent unforeseen costs.
Be sure to count the stop and start characters as well as check
digits when totaling the number of digits in a given barcode.
It is not necessary, and sometimes problematic, to increase
the barcode size beyond 4 characters per inch at 200 dpi or
6 characters per inch at 300 dpi. While BSCAN will read down
to ½ the specified size, possibly reading 100% during preliminary
testing, Image Access does not recommend relying on the smaller
barcodes for accuracy unless it is absolutely necessary.
In situations where the barcodes have already been printed
or are coming from the field rather than being generated specifically
for the scanning process, we recommend that you send several
original samples for testing. Image Access will perform testing
and report results for the samples provided. To speed the testing
process, you may choose to upload digitized (tiff G4) files
to Image Access for testing.
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Why
a Check Digit
If your barcodes are
very small or damaged it's a good idea to include a check digit.
After scanning, a wide bar looks narrow or a narrow bar looks
wide, the interpreted data could change. Check digit provides
an additional degree of security that when a barcode is read
it is right.
Enabling
BSCAN's CRC
While
most barcode printing software packages are capable of including
a check digit automatically, some are not. Check digits can
be calculated and implemented by other means, but most software
packages include the ability to add check digits. Enable either
from the menu or in the configuration script. For example:
BarTypes=CODE39,CRC
Be sure
that check digits are present before using the CRC parameter
above. BSCAN will not read any barcode if the CRC parameter
is set and the barcode being read has no check digit.
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