If you prefer to keep the panel in place and your existing keypads working there are other options discussed in this forum like alarm server and this one that I implemented:
#AD2SmartThings#
##Integrate Your Honeywell or Ademco Alarm Panel Into Your SmartThings Physical Graph##
ADT / Honeywell / Ademco / Vista / Alarm / SmartThings / Alarm Panel / Home Alarm
###A project by Stan Dotson and Michael Ritchie###
Wish you could use your existing home alarm sensors with SmartThings? Do you hate the hassle arming your panel and having to rush to disarm? Wish you could control your alarm panel on our smartphone but dont want to pay the higher monthly service bill? Do you want to install another keypad and don’t want to deal with your alarm company? Do you have an alarm panel and never use it?
This is a relatively simple project that effectively integrates your Honeywell or Ademco alarm panel with SmartThings. These panels are typically installed by ADT or other a…
The device you hook up to ur panel acts as another keypad.