by trialnerror » Sun Mar 04, 2018 1:32 pm
I've just installed on my ADT system and it works as described. You do need to know how to program the ADT panel, at least well enough to get in and ensure there is a keypad address enabled AD can use that won't conflict with your existing keypads. Also note that the field for enabling the LRR cited in the Vista20p programming panel doesn't seem to exist on the ADT system, at least it doesn't answer a '#' trying to examine its current settings in programming mode.
I just picked up a cheap (<$50) Vista20p on amazon. May just switch to it if I dump ADT so the programming manual matches the panel.