To enable RFID you will first need to Enable RFID in the emulation parameters and then set the RFID Enable Key, also in the emulation parameters.. Once you have an active connection into your server, you can click on the enable RFID key you set and the RFID should start working for you..
On keyboards that have both Numeric and Alpha input for one button there is usually a a toggle type button to select either ALPHA or Numeric..