Motorola DS3508 Product Reference Manual page 229

Digit Add Right to Left
Each character in the scanned data is assigned a numeric value (see
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 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 3
Multiplier 6 5
Product 6 15
Digit add 6+ 1+5+ 8+
The Check Digit Modulus is 10. It passes because 30 is divisible by 10 (the remainder is 0).
Digit Add Right to Left
(02h)
2 4 5 6
4 3 2 1
8 12 10 6
1+2+ 1+0+ 6= 30
OCR Programming 10 - 29
OCR Check Digit Multiplier on page 10-26).