Ok - the following is how I think things should be done. Please correct where you see necessary? I've attached a hand drawn picture on how I think things should be hooked up.
All 8 DZ-1000s are connected to the 2 ASCs I have for my layout.
The DZ-1000s yellow and green wires are attached to the appropriate terminals on the ASCs. The red wires from the DZ-1000s are spliced together and then that single wire goes to the A (hot) terminal on my transformer.
The COMM terminals from the ASCs are spliced together and then that single wire goes to the U (ground) terminal on my transformer.
Now for the non-derail feature.
Each of my 8 switches are spliced into the yellow and green leads going into the ASC - as shown in the hand drawn picture. The rails from where the wires that are spliced into the yellow and green wires are cut - to create the insulated track. Separate leads from the common rail going into each switch are then spliced together and that wire can be spliced into the wire that is going to the U (ground) terminal on my transformer.
