Paxar 9402 Reference Manual page 112

2. Each digit in the field is multiplied by the weight assigned to it:
field:
weight string:
products:
3. Next, the digits of the products are added together. Two-digit
products are treated as two separate digits.
This is the sum of the digits.
2 + 0 + 2 + 6 + 6 + 1 + 6 + 5 + 4 + 3 + 3 + 6 = 44
4. Divide the sum of the digits by the modulus (10 in this case),
only to the whole number. The balance is called the
remainder.
5. Subtract the remainder from the modulus.
The result becomes the check digit. In this case, the check
digit is 6.
10 - 4 = 6
4-20 Defining Field Options
4
10 44
40
4
5 2 3 2 4 5 2 1 9
4 1 2 3 4 1 2 3 4
20 2 6 6 16 5 4 3 36