Barcode readers are equipped with various interfaces with which we can connect them to the target device. Among them, we distinguish the USB, RS232 and PS2 connectors. The choice of a reader with a specific type of interface determines the way of its connection and gives various possibilities.

The most popular and present in the vast majority of scanners is the USB interface. The readers use a USB type A connector. Thanks to the use of this type of interface, after connecting the scanner with a USB cable, it is installed and visible in the system as an HID device acting as a standard keyboard. Thanks to this, scanning the code causes it to be immediately sent to the computer to an open text file, for example to Notepad.

The same applies to the PS2 interface, the principle of operation does not change. The difference is the type of connector used in the cable.

When purchasing a barcode reader, we can choose one that offers an RS232 interface. The principle of operation is significantly different from readers with a USB and PS2 interface. After connecting the device via the RS232 interface, the scanner is installed in the system as a COM port. This type of connection was created for the reader to cooperate with a specific program or application. The information contained in the bar code is not transferred to the open text file after scanning because the scanner passes it to the program used by the user after it is read.

The last interface worth paying attention to is Virtual COM, i.e. the virtual interface. It is available on selected models of barcode readers. This functionality, when connected via the USB interface, allows you to set the device in such a way that it works as when connected via the RS232 connector. This solution gives you more options. Thanks to it, we gain the ability to send information contained in the bar code to a specific program or directly to the computer to an open text file.