The following process shows one method for generating library numbers from the student ID encoded on the mag stripe. In this case the institutions existing system utilizes a 14-digit barcode and the unique ID number encoded on the magnetic stripe of the card is a 16-digit ISO number. Other scenarios exist, but function in much the same way.
- The card is swiped through the magnetic stripe reader, and the 16-digit number is captured. Example – “1234 5678 9012 3456”
- In an ISO numbering scheme the first 6 digits identify the card issuer (e.g. the bank, the school) and are the same for all cardholders. The reader strips away these first six leaving 10 remaining digits that form a unique number that identifies only one cardholder. Example – “78 9012 3456”
- The reader adds a single digit that is the identifier used in the existing library system to denote a patron (rather than a book or resource) and places it in the first position. – Example “2”
- Next, the reader adds a 2 digit code that is the identifier used in the existing system to denote the specific library location. Example – “09”
- Now we have created a 13-digit number. The final step is for the reader to perform a mathematical calculation using the previous 13 digits. This calculation, called a mod ten check digit calculation, creates a final digit to append to the end of the number. Example – “0”
- The pieces are put together to form a 14 digit ID number that provides the same meaningful data to the system as was previously supplied by the barcode. Example – “2 09 78 9012 3456 0”
The system had been geared to accept a 14 digit number read from the barcode. In this new model, the mag stripe and reader provide a unique 14 digit number. The actual library numbers have changed (and will require that the new numbers replace the old numbers in the library database), but the form is the same so the existing system requires no software alteration. Voila!
For more details on this process, see Using your card for patron ID.