Product Add Right To Left; Digit Add Left To Right - Motorola DS6878 Product Reference Manual

14 - 28 DS6878 Product Reference Guide

Product Add Right to Left

Each character in the scanned data is assigned a numeric value (see OCR Check Digit Multiplier on page 14-26).
The check digit multiplier is reversed in order. Each value representing a character in the scanned data is multiplied
by its corresponding digit in the reversed multiplier, resulting in a product for each character in the scanned data.
The sum of these products is computed. The check digit passes if this sum modulo Check Digit Modulus is zero.
Example:
Scanned data numeric value is 132459 (check digit is 9)
Check digit multiplier string is 123456
Digit 1 3
Multiplier 6 5
Product 6 15
Product add 6+ 15+
The Check Digit Modulus is 10. It passes because 60 is divisible by 10 (the remainder is 0).
Product Add Right to Left

Digit Add Left to Right

Each character in the scanned data is assigned a numeric value (see OCR Check Digit Multiplier on page 14-26).
Each value representing a character in the scanned data is multiplied by its corresponding digit in the multiplier,
resulting in a product for each character in the scanned data. The sum of each individual digit in all of the products
is then calculated. The check digit passes if this sum modulo Check Digit Modulus is zero.
Example:
Scanned data numeric value is 132456 (check digit is 6)
Check digit multiplier string is 123456
Digit 1
Multiplier 1
Product 1
Digit add 1+
The Check Digit Modulus is 12. It passes because 36 is divisible by 12 (the remainder is 0).
2 4 5 9
4 3 2 1
8 12 10 9
8+ 12+ 10+ 9= 60
(01h)
3 2 4 5
2 3 4 5
6 6 16 25
6+ 6+ 1 +6+ 2+5+ 3+6= 36
6
6
36
Digit Add Left to Right
(04h)