Wiring piezo siren/strobe with tamper to HAI?

I'm wiring in some ATW Doberman Plus siren/strobe units (with tamper switches) to my HAI OP2, and want to confirm the wiring.
 
My understanding is that i should wire as follows (OP2 ---> ATW):

• Horn GND -> Common (BLACK)
• Horn EXT -> Positive (strobe & siren) (RED)
• Zone +/- -> (non-polarized) Tamper (BLUE, YELLOW)

There is also a Positive (strobe only) that, I presume, is an optional connection that I could make to an output to turn the strobe on and off independently of the siren? (and in that case I would not make any connection to the output GND, i.e. I can just rely on the Horn GND which goes to Common, right?)
 
Also: I want to confirm that 22 AWG (I ran a 22/4) will be sufficiently large wire.
 
thanks!
--js

Probably should've used 18 AWG. 22 will work, but it's not ideal for driving a siren.

Thanks DEL for the response, good advice as always.  sorry it has taken me so long to post again.  
 
I finally got around to running an 18/2 for the siren, and used the 22/4 for the tamper zone and strobe output.  While the siren works, the tamper switch and strobe-only output don't work.  I've checked and rechecked the wiring, and I believe I have made proper connections to the siren and to the Omnipro.  
 
Here's how I've wired it:
 

• Horn GND -> Common (BLACK)
• Horn EXT -> Positive (strobe & siren) (RED)
• Zone 9 + -> Tamper (BLUE)
• Zone 9 - -> Tamper (YELLOW)
• Output 1 -> Strobe Only (BROWN)

When I depress the Tamper switch, I don't see any change in the loop value shown on the console (253).  Do I need to add a 1k resistor across the zone?  If so, what's the best way to wire it: at the siren end, wired in series?
 
As for the strobe, it works when I trigger the siren but, when I turn the output on, I don't see any change.  Do I also need to wire the siren to the Output GND somehow?  Or is there something else I'm doing wrong?

You need to determine if the tamper is NO or NC. Most tampers are NC. The resistor wiring method depends on what style of circuit it is. NO would be parallel, NC would be series.
 
I would need to grab a meter to be sure, but some panels lift the ground on the bell output instead of the positive leg. The HAI panel may be the same way, which is why you might not be getting the strobe only. I'd need to either physically duplicate it or grab some manuals out to look for other examples to see which way the HAI works.