Msi/Plessey Specifications - Worth Data 7100 RF Terminal Series Owner's Manual

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:

Form a number from the odd positions, starting in the units position

Multiply the new number by 2

Add the digits of product

Add the even digits of the original number to the result in 3

Subtract the result from the next highest multiple of 10

New Check Digit:

Data with check digit is:
The MSI Mod 11 check digit is calculated as follows:
The example bar code data is:

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:

Multiply the checking factor with its assigned number and add the products:

Divide the sum by 11

Subtract remainder from 11

New Check Digit

Data with check digit is:
82345
(835) x 2 = 1670
1 + 6 + 7 + 0 = 14
2 + 4 + 14 = 20
20 - 20 = 0
0
823450
943457842
2,3,4,5,6,7,2,3,4,5,6,7...
4 + 12 + 32 + 35 + 30 + 28 + 6 + 12 + 36 = 195
195/11 = 17 remainder 8
11 - 8 = 3
(If the remainder is 10, no check digit is added.)
943457823
835
3
88