Worth Data RF Terminal 7000 - Manual (Page 98)

MSI/Plessey Specifications
Plessey is a variable length numeric only bar code. MSI Bar Code is a variable length, numeric-only code
with an automatically appended Modulus 10 check digit. MSI is sometimes called Modified Plessey Code.
If the user specifies an additional check digit, the MSI code can be 14 digits long, otherwise it has a
maximum length of 13 characters. This is how the MSI check digit(s) are calculated:
The MSI Mod 10 check digit is calculated as follows:
The example bar code data is:
82345
• Form a number from the odd positions, starting in the units position.
835
• Multiply the new number by 2
(835) x 2 = 1670
• Add the digits of product
1 + 6 + 7 + 0 = 14
• Add the even digits of the original number to the result in 3
2 + 4 + 14 = 20
• Subtract the result from the next highest multiple of 10
20 - 20 = 0
• New Check Digit
0
• Data with check digit is:
823450
The MSI Mod 11 check digit is calculated as follows:
The example bar code data is:
943457842
• Assign a checking factor to each number, starting with the units position of the number (in this example, the
2) up to the highest order position (the 9). Use checking factors of:
2,3,4,5,6,7,2,3,4,5,6,7...
• Multiply the checking factor with its assigned number and add the products:
4 + 12 + 32 + 35 + 30 + 28 + 6 + 12 + 36 = 195
• Divide the sum by 11
195/11 = 17 remainder 8
• Subtract remainder from 11
11 - 8 = 3
• New Check Digit
3
(If the remainder is 10, no check digit is added.)