Directed Electronics MERLIN 2000 - Manual (Page 20)

20 © 2001 Directed Electronics, Inc. Vista, CA
nuisance prevention circuitry
Nuisance Prevention ® Circuitry (NPC ® ) is designed to prevent repeating triggers, such as those from an
out-of-adjustment sensor or temporary environmental conditions. If NPC detects the same zone triggering three
times, and these three triggers are within an hour of each other, that zone will be bypassed for sixty minutes.
Remember this when testing: NPC's memory is reset with ignition, not by arming and disarming!
diagnostics
The system constantly monitors all of its inputs, or zones. When you arm the system, the siren will inform you
by chirping the siren and flashing the status LED in patterns, if any there are any status irregularities. When you
disarm the system, the siren will also indicate with extra chirps if the vehicle has been tampered with while you
were away.
If the siren chirps once when the system is initially armed and then chirps again a few seconds later, this indi-
cates that the system sensed an input that normally would have triggered it. This is called Bypass Notification.
The system will also ignore, or bypass, that zone until the trigger stops.
If four chirps are heard when disarming (Tamper Alert), the system was triggered in your absence. If five chirps
are heard, a zone was triggered so many times that Nuisance Prevention Circuitry has bypassed that zone. In
either case, the status LED will indicate which zone was triggered (see the Table of Zones section of this guide).
The system retains this information in its memory, and chirps four times each time the system is disarmed, until
the next time the ignition is turned on.
disarming diagnostics
arming diagnostics