When setting a barcode scanner to any of the available keyboard modes (KB-wedge / USB-keyboard), it mimics a regular keyboard and sends keystrokes, instead of characters, to the host computer. 

In order to send the proper keystrokes, the scanner must be configured to the same keyboard layout as the one being used by the host computer. This is usually done by scanning several barcodes in your scanner manual. 

If you're using an OPTICON scanner, please follow the steps describes in this manual to configure the keyboard language for your scanner.