Hi Muddy,

Being an alarm installer by trade I tried doing this to a Napco MA3000 panel several years ago. After a couple of hours of trying different things including the 4066's on the keypad lines, I asked the guy I was doing this for for the version of software the panel was operating on. The latest version had a feature that allowed a zone input to be programmed to act as a keyswitch to arm and disarm the panel. It worked out great for the project. A wine cellar in a church basement where sometimes the people would forget to re-arm the system. My add-on watched for the door to close. If the system wasn't armed and the door was open, the add-on would sit and wait for the door to close. If the door was closed and they didn't turn the system on within 1 minute my add-on would re-arm the system.

I always look for ways to connect to a system that won't violate the U.L. Listing on the panel. Making something that would enter a code where you have modified the device could end up costing you should anything ever happen that could prevent the system from detecting whatever it is suppose to detect. Most systems today have wireless keyfobs. Perhaps you to tie into the contacts on the wireless key and use that to trigger the system. There are only a couple of systems that have a U.L. Listing on their wireless devices.

BobK