Thanks guys. Here's slightly modified versions of the 2 scripts, that I use in my game;
:state=0:lightoff,etimerstart,state=1
:state=1,etimergreater=500:lighton,etimerstart,state=2
:state=2,etimergreater=250:lightoff,etimerstart,state=3
:state=3,etimergreater=250:lighton,etimerstart,state=4
:state=4,etimergreater=250:lightoff,etimerstart,state=5
:state=5,etimergreater=750:lighton,state=2
:state=0:lightoff,etimerstart,state=1
:state=1,etimergreater=1000:lighton,etimerstart,state=2
:state=2,etimergreater=250:lightoff,etimerstart,state=3
:state=3,etimergreater=250:lighton,etimerstart,state=4
:state=4,etimergreater=250:lightoff,etimerstart,state=5
:state=5,etimergreater=750:lighton,state=2
They give 2 very quick flashes between pauses, and look more like modern Police Lights IMO.
I've attached a sample .fpm file to show you the modified scripts in action.