What is the Sensor?
A, Door Contact, PiR, DT, IR Beam, Pressure mat, Inertia, Safe Limpet, Foil, USD, Break Glass Detector, T/W Frame, Roller Shutter Contact, MWD, PAB, get the idea?
We can't help when no information is offered.
As above plus location, circumstances etc.
acorn, December 2011