The Lionel Command base Cable (6-14191) is hooked to the Command base right bottom of picture. That cable connects to the Right TPC along with daisy chained (Blue-Blue/White) Cat5 twisted pair telephone wire, that connects to the Left TPC. There is a loop of Cat5 twisted pair telephone wire to each device, (2) BPC's Block Power Controllers (Left in picture near the PH 135's), and (6) ASC's Accessory Switch Controllers (Above the silver TPC's . (10) devices hardwired to the older Command Base. 
Note the green, green white twisted pair wire and the blue, blue/white twisted pair wires that loop (daisy chain) to all the Dat and Comm terminals.
The last device on the Dat/Comm daisy chain loop is the lower right ASC. There is only one wire.
