As stated above, the yellow wire from the HDS power cable should be connected to the yellow wire from the box power cable. That will turn the box on when the HDS is on and turn it off when the HDS is turned off.
Connect yellow wire or put on switch.
One HDS unit will control StructureScan3D power if their yellow wires are used.
Multiple HDS units & StructureScan3D on a switch puts the switch in control.
I also Ethernet all my HDS units directly to the StructureScan3D box.