I am about to buy a wireless security system (e.g. the GE Simon), to be monitored by NextAlarm or alarm.com.

I wonder if any of the wireless sensors I already have (left by the prev. owner) can be reused in a new system I buy, like 5 wireless 58xx Ademco components (4 doors and 1 PIR). There is also a Homesight wireless door/window senso, HMSM4140. Can anyone tell me how I figure out what might be compatible with what.

Isn't there one or a few standard protocols that is being used? I have tried to look up transmission protocols but basically been unsuccessful - perhaps I look in the wrong places? There must be a simple way of checking the specs to determine if the sensor signal can be picked up by the control panel - without having to first buy the panel and do trial and error ;-)

[I apologize if this message is posted twice; when I first submitted it "didn't stick"