Punto HGT Alarm Help

[hgtdan]

HI,

I am trying to work out if the standard alarm on my Punto HGT has a negative trigger input?

Or if anybody can tell me what each of the wires connect to the siren do?

I am looking into installing a Dual Zone Microwave sensor but it requires a negative trigger input apparently.

This is what i would liketo install?...

http://cgi.ebay.co.uk/DUAL-ZONE-MIC...ryZ75329QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Is it possible?