I got a hardware setup to power 40 servos and only use one USB2Dynamixel adapter. So i can address all 40 servos directly with one control software, only need to handle one usb-port.
Here is a picture, where you can see that every 6-port-hub is connected with its own power supply and every 6-port-hub is then inter-connected with each other only with the data-line of the 3-pin connector.
On every 6-port-hub then are 4-hubs available for servo-use.
