On Sep 22, 10:53 am, Owain wrote:

Some IP CCTV cameras have alarm inputs which can trigger recording
events.

Yes those are installed already.

A thermal CCTV camera can be very effective at detecting human sized
intruders in complete darkness

Lots of sensor lights do the job very cheaply, and scare off the
intruders.

what is the point of alerting the guard if he is lying unconscious
somewhere?

The buildings have monitored alarms. But the intruders can be in and
out very quickly even though they set off the alarms. I'm trying to
alert the guard as soon as the intuders climb over or cut the fence.