Strobe hotkey on SC6000?

Yesterday I discovered by accident that there is a combination of buttons (incl. Loop) on my SC6000 that makes my strobe go off. I was able to do this twice, but after that I couldn’t do it anymore. Does anyone know the hotkey combinations in Engine Lighting?

Could be using the Roll-function👌

…or a fast loop: 1/4, 1/2