The barcode attendance machine uses photoelectric reading of barcode card numbers, resulting in a low failure rate. Disadvantages: Cards are prone to forgery (except for specialized stock masking barcodes), and the sensitivity decreases and there are errors when the barcodes become dirty.

Simple and intuitive, without the need for computer knowledge, the price is relatively low. Disadvantages: cumbersome statistics, monthly replacement of cards, high mechanical failure rate (card sockets are easily damaged). Applicable scope: Units with less than 100 people and good environment. Magnetic card attendance machines can use computers to collect attendance data. Disadvantage: Magnetic cards and heads are vulnerable (perhaps there are more reliable magnetic card devices). Scope of application: Places with good hygiene environment and high personnel quality (mostly used for access control, banks, etc.).