D-1
Appendix D
Interleaved 2 of 5 Code
Interleaved 2 of 5 Code is a numeric-only, even-number-of-digits bar code. It is widely used in warehouse
and industrial applications. A combination of five elements, two wide and three narrow represent each
character. Odd-number position digits are encoded in the bars,
even-number positions in the spaces.
Interleaved 2 of 5 Code is so susceptible to partial scans being interpreted as valid reads that we
recommend at least one of the following safeguards:
Use one length of I 2 of 5 code. Using one length of data allows you to tell the USB Laser Scanner to look for one length of
I 2 of 5 code only. By default, the USB Laser Scanner is set to look for a
6 digit
I 2 of 5 code but you can set the length to
something different using the
USB Laser Setup Menu
. Setting the length to 00 digits allows variable length bar codes
scanning. Using the 00 setting is not recommended as you will easily get misreads with different length I 2 of 5 codes.
Use a check digit. Worth Data' LabelRIGHT printing program automatically calculates and prints a check digit upon request
using the method below:
Interleaved 2 of 5 Mod 10 check digit calculation
1. Assume that the bar code data is 1987.
2. Starting with the least significant digit (in this case, a 7), label the digits alternatively even and odd.
7 - even
8 - odd
9 - even
1 - odd
3.
Take the sum of the odd digits:
8 + 1 = 9
4.
Multiply the sum of the even digits by 3:
(7 + 9) x 3 = 48
5. Add the results of steps 3 and 4:
9 + 48 = 57
6. Subtract the result of step 5 from the next highest multiple of 10:
60 - 57 = 3
7. The checksum becomes the low-order digit:
19873
8. Because the data now has an odd length, a leading zero is added, for the final result of:
019873
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123456