cascading i-controls pro ???

I bought 2 pieces of ICON i-controls pro (midi-controller with motorized faders), a few days ago.

I stayed up all night trying to daisy-chain them together with cubase (7.5 and 8), but I haven’t succeded so far. I have tried everything I possibly can think of, tried with connecting the usb-chords in different ways, tried with both as masters, both as slaves, and one as master, one as slave.

I´ve also tried to configure cubase in different ways, one instance of mackie control, two instances, upgraded firmware (though I think the new was the same as the old, v 1.2), but never got both to work at the same time, only one of them.

Does anyone know something about this?