you can use these together without daisy chaining them together over MIDI, having each one directly connected via a USB port.
you may want to modify the name that shows up however. my driver installed them giving eaach one the same name (e.g. the common "behringer fader/rotary 2000").
you can change the "friendly name" in the registry for each instance however, and set them how you see fit. i do this, so i can properly disconnect one or the other, and just see what's actually attached by name. behringer should the fix the driver/installer to assign the proper name, but it's not a big deal once you know what to tweak here.
it also appears i get x2 the number of MIDI ports channels being able to address either unit, from the suggested daisy chain setup described in the manual (as you might expect?).
p.s. you may need to change the write permission on the registry hive containing the value you want to change (seem windows has a default of read only on those values -- see my other post on that).
update: looks like the devices aren't named --it's the ports. so plug in a fader into the usb port previously renamed to rotary and you get the rotary name. behringer did not stamp a device id here, and that's why you get the naming convension issue in the first place (and why they use the common name for both). unless you always hook them in the same physical port.
you could name each instance device 1, device 2 --or port 1, port 2 to distinguish them apart. likely this is also why their modus operanti is to daisy chain them togather over midi, not use individual usb connections.
eh, and midi is probably fine since i haven't run out of midi ports really.