JASI Barcodes

JASI uses 14-digit Codabar barcodes for items stickers and patrons cards.
  • Digit 1 indicates the type of barcode:  2 = patron, 3 = item (book)
  • Digits 2-5 identify the institution
  • The next 8 digits (00010 586) identify the individual patron or item
  • Digit 14 is the checksum

Check Digit (Checksum character)

The purpose of a check digit is to verify that the information on the barcode has been entered correctly. Your barcode scanner autmatically calculates the checksum by performing a series of mathematical operations on the digits that precede the check digit, and comparing the result of the calculation to the value of the check digit. If this comparison macthes, the barcode is valid. If it doesn't match, it could mean the barcode is worn out and the scanner is not able to read it properly or the barcode itself is defective.

How the Checksum is Calculated

To calculate the checksum, start with the total set to zero and scan the 13 digits from left to right:

  1. If the digit is in an even-numbered position (2, 4, 6...) add it to the total.
  2. If the digit is in an odd-numbered position (1, 3, 5...) multiply the digit by 2.  If the product is equal to or greater than 10, subtract 9 from the product.  Then add the product to the total.
  3. After all digits have been processed, divide the total by 10 and take the remainder.
  4. If the remainder = 0, that is the check digit.  If the remainder is not zero, the check digit is 10 minus the remainder.