C2R Colibri 5 Series, User Manual

Page: 114 / 168

Colibri serie 5 : User’s guide
© 2000-2008 C2R Technologie, Sarl. All rights reserved.
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Rev. C
01234565
The reader performs the check character computation below:
(0 x 3 + 1 x 1 + 2 x 3 + 3 x 1 + 4 x 3 + 5 x 1 + 6 x 3 + 5 x 1) modulo 10 = 0
Since the result is zero, the message is considered to be valid, so the reader outputs the
message: 0123456
2-1-2-1 Weighted Modulo 10 Check Character
Starting with the check character and working backward through the message, the imager applies
a multiplier of 1, then 2, then 1, then 2, and so on. When the result of the multiplication is greater
than 9, add both digits to the running sum. This is often referred to as the LUHN formula. One
common application of the LUHN formula is validate credit card numbers. This is the modulo 10
checking scheme used in MSI Code and in Code 32 Pharmaceutical (PARAF). To apply this
weighting scheme, set the OCR check character to
"0123456789x2x1" or scan the following
symbol:
2-1-2-1 Weighted Modulo 10 Check Character
Example: Scan the 2-1-2-1 Weighted Modulo 10 Check Character symbol. Also enter the OCR
template: ddddddc Then scan the string below:
0128454
The reader performs the check character computation below:
(0 x 1 + 1 x 2 + 2 x 1 + 8 x 2 + 4 x 1 + 5 x 2 + 4 x 1) modulo 10
= (0 + 2 + 2 + (1 + 6) + 4 + (1 + 0) + 4) modulo 10
= 0
Since the result is zero, the message is considered to be valid, so the reader outputs the
message: 012845
OCR ISBN Application Example
One application of OCR is to read the ISBN characters typically encoded using the OCR-A or
OCR-B font. This is especially useful when the ISBN number is not encoded in an EAN-13
barcode. The following example shows how to configure the imager to read the ISBN strings on
books in Japan. After you have followed the steps below, you will be able to scan the following
ISBN number or the additional data below it, depending on the line of text at which the imager is
aimed.