I am using Madrix to talk to an E681. Below is my E681 set up and my Madrix set up. Basically I am looking to control 4 differnt pixel set ups on the 4 Universes. The reason is to show a pixel controller driving different pixels in a practical implementation at our CLAP meeting. The other reason is to show our attendees what the ramps look like in a side by side comparizon of the different 5-12bit pixels. U1 = 2801 pixel Strip - U2= 6803 square pixel - U3= 2801 square Pixel - U4 = 3001 square pixel. I am only trying to drive 2 strings each of 50ct pixels, and the Strip is 160 pixels. In testing the E681, all universes/pixels test fine. When I drive the E681 via Madrix, U4 with the 3001's do not light at all. I think I read a post a while back about this but can't remember which forum and a search here turned up nothing. I am not sure what could be causing this. Any ideas? Thanks.