Input Routing Djm 2000 with Traktor

Hi guys, 

I connected my djm 2000 nexus and both my cdj 2000 to my Mac. The CDJs correspond perfectly with tractor and all functions work as expected. The DJM is also connected to Traktor. In the Traktor settings the output routing immediately changed for the DJM 2000. However the input routing says " not connected". 

What am I doing wrong? 

Can anybody give me a clear instruction how to set up the dim 2000 perfectly with Traktor, would be a great help!!.

Regards & Thanks!

Max