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.

The attendance machine is equipped with a built-in printing device, which can directly print out the original attendance records. Clocking in can be divided into electronic and mechanical types. The main advantages of electronic clock in machines are that they are noiseless when not clocking in, have a small size, and can automatically swipe and retract cards, use a perpetual calendar, power outage clock in, automatically swipe and retract cards, recognize the front and back sides, automatically shift, and have external standard output bell functions. The appearance varies in size, including LCD, pointer, panel, or a combination of both. Low one-time investment cost, low after-sales maintenance cost, easy to use, and easy to operate. The disadvantage is that it is suitable for a small number of people, usually used by less than 200 people. The main advantages of mechanical check-in machines are their durability and durability. The disadvantage is that the accuracy is not high, there is noise when not clocking in, and manual card entry is necessary. It is suitable for large factories or units with a large number of people to use. At present, mechanical punch cards are very rare on the market.