Directed Electronics ESP 540 User Manual
Page 20
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©
1999 Directed Electronics, Inc.
Your system has DEI's Nuisance Prevention Circuitry
™
(NPC
™
). It pre-
vents annoying repetitive trigger sequences due to faulty door pin
switches or environmental conditions such as thunder, jackham-
mers, airport noise, etc.
Example: The alarm triggers three times. Each time, the same sen-
sor or switch is triggering the alarm. The three triggers are within
60 minutes of each other. NPC
™
will interpret this pattern of trig-
gers as false alarms. After the third trigger, NPC
™
ignores, or
bypasses, that sensor or switch (along with any other sensors or
switches sharing the same zone).
If the bypassed sensor tries to trigger the security system while it
is being bypassed, the 60-minute bypass period will start over. This
ensures that a sensor that is continually being triggered will
remain bypassed.
The vehicle doors are protected by NPC
™
differently. If your securi-
ty system is triggered by an open door for three full cycles, the
security system will bypass the vehicle doors until the trigger
ceases.
NOTE: Arming and disarming the system does not reset this function! The
only ways to reset a bypassed zone are for it to not trigger for 60 min-
utes, or to turn on the ignition. If testing your system, it is important to
remember that the NPC
™
programming can cause zones to be bypassed
and appear to stop working. If five chirps are heard when disarming, NPC
™
has been engaged. If you wish to clear the NPC
™
memory, turn the igni-
tion on.
Nuisance Prevention Circuitry