User manual

The byte immediately following the Checksum control code (D) defines the type

of checksum that will be used:

Row Checksums (0) perform a checksum calculation on all characters preced-

ing them up to the first character on the same row. Block Checksums (1) per-

form a checksum calculation on all characters up to the very first character in

the template; they span multiple rows. The 5 bit Modulo Value stores the

Checksum Modulo - 5. The stored number can range from 1, which is a Check-

sum Modulo value of 6, to 31, which describes a Checksum Modulo of 36. A

Modulo value of 0 (Checksum Modulo of 5) is illegal. The characters within a

checksum field have a numerical value that is used in the checksum calculation.

Digits are converted to their numerical value (0-9), while uppercase letters

range from 10 for an “A” to 36 for a “Z.” All punctuation characters have a value

of 0 for checksum purposes. However, they do count as a spot for determining

the weight values used in calculating the checksum.

Weight Scheme

The Weight Scheme defines how the values described above can be changed

based on their character position. The default weight scheme is 1. This means

that the checksum is based only on the character value and is not dependent on

Checksum Table

Bit Position(s) Meaning

7,6: Weight Scheme 00: Weight Scheme: 1

01: Weight Scheme: 12

10: Weight Scheme: 13

11: Weight Scheme: 137

5: Checksum Type 0: Row

1: Block

4-0: Modulo Value Checksum Modulo - 5