I corrected all the channel configuration on the E682 that was not responding properly. Jim St Johns had me uncheck "chase" on the channel configuration page to get the controller to do the universe/channel math correctly. No impact on universes received, to the best of my knowledge, though... Now I am fairly sure I have all my E682s and my F16 responding correctly, but still not able to send any unicast data from xlights. I am successful on all controllers with da_e1.31--I am watching lights flash to test signals and I am seeing the info sent via wireshark, as Gil recommended last night. So, I will go to my backup plan now--I will go to multicast because that is working... Sure wanted to get unicast doing what it's supposed to do! I'm sure I'm missing some really minor detail somewhere....