The instructions for my new CADDX wireless motion detector say to mount on an outside wall looking it. That is interesting. My old system (professional installation) had the detector on an inside wall looking out towards the door and windows. I guess if I mount it on the outside wall at a height of 7.5 feet (as specified) tilted down, it will cover the door and windows. It would be mounted between the door and windows. Is this the usual way to mount a motion detector? Would aiming it at the door/windows be a problem?