Write a Cue that has all your LEDs at full. Then either FAN the delay time, or highlight the Intensity column with your cursor and type the start and end range of the delay time you are looking for (ie 0 thru 4).
write a cue with all the leds at 50% intensity. add a sine effect on the dimmer an put effect lenght to 100%. adjust the speed. play around with fan and offset till you get the pulse you want....