Configuring a 4 channel DMX lamp to one slider.


I have several lamps like the one above, and a Behringer EuroLight LC 2412.
I am trying to configure it, so all channels for each lamp go on one slider, but I don’t seem able to do it. I have configured the first lamp on channel 1, the next on channel 5 and so on, At the moment, I need to use 4 sliders, for the first lamp, and the next 4 sliders, for the second lamp. But when I use the first 8 sliders, the first lamp starts blinking. I have tried following the instructions and video clips, but not quite there yet.
Does this make sense?
Can anybody please help?