Hi Jeff,
I don't know much about the PixLite, but generally, in the controller, you will have your universes set for 510 channels. This make divisibility by 3 to be 170 pixels exactly. (512 can be used, but keeping it simple for now).
Looking at the website for the PixLite MkII board, it appears that you can have 6 universes per output for a total of 1020 pixels. Your 30X16 matrix would be 480, so you can do all the matrix on one output (Starting at the Universe or Channel you have configured for that output)
In xLights, you would setup as one string with 480 nodes and 30 or 16 Strands/Strings (depending on how you have them wired up. Based on your post, it sounds like each run is 30, thus having 16 Strands/Strings.
The reason xLights only turns on some, is likely due to configuring the correct pixel count on the controller and in the setup for xLights. Only the lights that are known to exist within both will operate. Testing on the controller itself just tests all lights possible, so this is likely more of a config in your xLights, likely where the 150 counts are showing, as I am guessing since there isn't all the info avail to see.
I would also recommend setting to Unicast and setting up a static IP. At least for myself, I like keeping track of exactly what is where and the IP Address keeps things a little tidy, in my opinion.
It's late, and I thought I might be able to being some guidance. Hope this helps.
-Cybie (aka Tim)
