Using DJM-450 with Traktor Scratch 2 & 2no PLX1000 (DVS System)

Hello, 

I am trying to connect my DJM 450 with 2x Pioneer PLX-1000s but when I connect my mixer to Traktor in Traktor preferences it says "DJM 450 (not connected)"

Can anyone help with getting this set up, I am really confused and can only find tutorials for the 900, which I assumed would be the same but the mixer just isn't connecting.

Any help would be much appreciated, thank you.

Harry