DS2: Multi-Mounts/Single Targets

I was writing up stats for a tank miniature that I have. And it brought 
up a question. This tank had 3 identical guns in its turret. It looked 
about size 4. So I placed 3 class 2 DFFC's in the turret. My question
is:
Do multi-mounts attack as 1 weapon?
  Would I roll 1 attack or 3?
    If I roll 1 attack, would I draw 6 chits for the attack or 3 sets of

2?
      6 chits makes it a very dangerous tank up close.
      3 sets of 2 makes it a weak tank for its size.

Also, I thought that I read in the rules that you can only attack with 1

type of system against 1 target. But when I went to find this again, I 
couldn't find it. Is it there or did I misread it the first time?

*** Sorry for the multiple post. My mail system is doing strange things 
***

Brian Bell
pdga6560@compuserve.com
http://ourworld.compuserve.com/homepages/pdga6560/scifi_game.html