Ddjsx2 no signal to audacity

 hello, i currently us my djm900 mixer to record my sets on audacity and choose my djm900 as the recording device and everything works fine.. i connect my usb (serato dj) and all works fine, but when i use my ddjsx2 to record and do the sames steps it doesnt show any signal on audacity. I follow the same steps as i do with my djm 900 mixer. Any help on this would be greatly appreciated. Thanks