(also known as Modified Plessey
) is a barcode symbology
developed by the MSI Data Corporation, based on the original Plessey Code
symbology. It is a continuous symbology that is not self-checking. MSI is used primarily for inventory control, marking storage containers and shelves in warehouse environments.
Character set and binary lookup
The MSI character set consist of the numbers 0..9 as well as two "guard" characters (representing the beginning and end of the barcode). The symbology does not support alphabetic characters.
Each digit and guard character is represented by a binary number, as shown in the table below.
To produce a barcode image from this map, one simply must consider the digit 1 to be a black bar and the digit 0 to be a white bar and produce an image accordingly.
Check digit calculation
The MSI barcode uses one of five possible schemes for calculating a check digit
- No check digit (least common)
- Mod 10 (most common)
- Mod 11
- Mod 1010
- Mod 1110
Mod 10 Check Digit
When using the Mod 10 check digit algorithm, a string to be encoded 1234567 will be printed with a check digit of 4:
The Mod 10 check digit algorithm, IBM
.uses the Luhn algorithm
Mod 11 Check Digit
1. Reverse the string to be encoded (in this case 1234567).
Let S be the reverse of the string to be encoded
S = 7654321
2. The string is then "weighted" using a repeating weighting factor... Read More