But I'm taking 2 mag swipes followed by a bar code on a production line.
Each field has a specific length that I stop at and validate the data (format, dupes, etc). I then jump to the next field.
After all three, I store into a database, log everything, clear out the fields, and prep for the next group.

The issue is when a person scans or swipes the wrong thing. Wrong length, bad validation, etc.

The goal is zero keyboard usage, but I can live with making them clear it out on error.