Desktop Station supports marklin and trix cranes. You can easily contorol your crane cars. You don't need external controller, e.g. trix crane controller. Because of Desktop Station can control Marklin Motorola 2 and DCC protocol same time.
Locomotive address may be 77 or 78. See your crane's instruction.
See the following video.
Trix and Marklin crane car use Marklin Motorola 2 (MM2) protocol. The decoder of crane car work with a combination of function and locomotive speed, direction. The function number means the parts of crane's moving elements. The direction means the rotation direction of the moving element. The speed means rolling up.