First, update the TRAKTOR series to the latest version (TRAKTOR 1.2.3 or later).
Also, in addition to the TRAKTOR series and the CDJ, one USB cable is required per CDJ player.
Connect the CDJ and your computer by USB cable.
Press the LINK button on the CDJ-2000, then select "USB MIDI" from the display to connect to the TRAKTOR series. "Turn Encoder" is displayed on the CDJ's display section. Turn the rotary encoder to select the deck to be controlled, then press the encoder. Control using the CDJ is now possible.
Also, the user can assign the various functions of the TRAKTOR series to the desired buttons on the CDJ by changing the mapping.
For details on how to update the TRAKTOR series, the operating environment, etc., see the Native Instruments website.