I got four led bars to practice MadLight and get into DMX world:
Stairville LED Bar 252 DMX RGB
Manual with DMX CHART:
http://images.thomann.de/pics/prod/255346_manual_en.pdf
Without any knowledge of DMX I had some problems getting my fixtures to work, but eventually I found out that I have to create 3 fixtures to fully operate the unit.
according to the CHART:

fixture 1: CH 1: main control 1x1 L (with LRGB sliders in MadMapper set manually 100% L 60% R that gives an amount which turns the 3 segment mode of pixel bar)
fixture 2: CH 2: shutter control 1x1 L (with LRGB sliders in MadMapper set manually 100% L that gives an amount which switches off the strobe and the light is on)
these two have to be placed on a white colour in order to stay at the desired value (otherwise anything darker switches them off)
fixture 3: CH 3-11: 3x1 fixture controlling the RGB values for 3 segments of pixel bar
fixture 3 becomes fully operational and responsive only whit other 2 fixtures.
Or I'm doing something wrong here ????

MY SUGGESTION:
It would be nice if you could make some "fake" fixtures for that purpose which could have more precise control of the values and ability to transfer them no matter what.
or have a switch in a fixture settings that makes it live on a surface or a standalone dmx transmitter with precise numerical values of the signal.[/b]