How to read a NFC card with USB reader

I need to read some NFC cards by a USB reader on a Linaro/Debian OS. The USB reader has a HID profile. Presenting a 13,56 MHz card the keyboard returns a code. I read about a command to send to the device but, since it is a (virtual) keyboard, I cannot send commands, and toward which device? How to dump the memory of the card? Thanks