Barcode readers, both wired and wireless have several different interfaces. They can be used for many different devices that way.

The basic and most common interface is USB type A. Reader connected via USB cable to the device is installed as a HID device. It works the same way as a keyboard connected with e.g. the computer.

Another interface that can be encountered in the reader is RS232 type DB9. It is most often used when connecting the reader to the cash register. However, the cash register is often equipped with RJ12 or RJ45 interface. To connect the reader with DB9 end to such a cash register a suitable adapter is needed, usually available from the cash register seller.

The last interface available is PS2 (or KBW in other words) - the so-called keyboard interface. It is an older interface type, used less and less frequently, however, it is encountered quite often still in computers or cash registers. The principle of operation of the reader with such an interface is identical to that of the USB interface.

Besides the interfaces enumerated above, some readers have also a virtual interface available, the so called Virtual COM. It is an interface allowing for setting the reader with the USB in such way, so it installs in the system as a virtual COM port.