Tips and Tricks for Logic Pro  
   Linking Controllers  
     
     
  Linking Controllers  Keyboard  
  1.Press Command + L. This puts Logic in "LEARN MODE".

2.Manipulate the controller (Knob, Slider,  Button etc. ) in logic you want to link.

3. Manipulate the controller on the Keyboard you want to link it to. ( a confirmation message will
    appear "Assignment Learned".

4. Close the Controller Assignments window. (DO NOT FORGET THIS!)

Your Controllers should be linked.

Repeat steps 2- 3 to link as many controllers as you want before closing the
      controller assignments window.