In PixelMad f24 the first fixture does not have DMX output enabled (or at least it it does not respond to the colours placed over it and the DMX output at the corresponding addresses stay at zero).

Also when you select it in the DMX preview window it does not flash orange in the same way as the other fixtures.

Workaround:

Start all your patching at the second fixture.

Ie. If you had 5 54 channel pixel-lines with DMX 1, 55, 109, 163, 217 then

fixture 2 will have address 1,
fixture 3 will have address 55

and so on.

This was observed in PixelMad8 V2.0 f24.

Rob Fowler