In every alarm panel I have installed, the contact being
closed is "secure" and open is "alarm". That way, if/when
someone/something cuts the wire, it's an alarm.

Further, there is a series resistor of say 4.7K ohm. So of
someone shorts the loop say while in the store during the day;
you will get an fault at close up.


--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433