Multiple sync charge hubs can be plugged into USB ports on a single host computer. Using a Mac, the USB device limit is 127 per host controller. The board used in the DS-SC-U16 consumes 21 of the 127 devices and each has a hub depth of two. The USB maximum hub depth is five. A USB hub device consumes one of the allowed 127 devices regardless of whether there are any downstream devices connected.
So, if you have one ‘master’ U16 (sync charge board) you can connect an additional five to it. This would give you 11 ports spare from the master, plus 80 ports from the other five U16s — or 91 ports total. These 91 ports consume 126 of the 127 allowed to one host controller. This would be the way to make best use of a single USB host controller.
Most computers have more than one host controller so you can do the same again (on the same host at the same time). In “system profiler,” you should be able to see the number of high-speed USB host controllers on your host computer.
Datamation Systems universal sync charge hubs have expansion ports that permit the hubs to be daisy-chained, adding to the capacity of such configurations.