@johnk, main question is of the door/windows magnetic sensors has a build in resitor?
If YES you need to measure how many Ohms there is when door/window is closed and open.
Contact a satel dealer and ask him the question if your windows/door sensors going to work on a satel system with the meassured value’s!
I know from the past that a satel system can work with different values of resistors and the inputs can be configured for different configurations , see screenshot in dutch 
if you dutch take a look at topic Magneet contact met 1k weerstand opnemen in homey
