Question for you Forge masters

Here’s what I want…

A map which can be played as either Slayer, or Flood.

Now here is the tricky part…

If I place the Dominion Turrets, I can activate them all MANUALLY, 1 by 1 and have them work.

What I want is to be able to put the Dominion command terminal (Whatever it is called), and have that activate all turrets at the same time INITIALLY.

So far I haven’t been able to get that part down. Any of you guys know how I would pull that off?