Viper 540ESP Owner Manual - Page 20

Nuisance Prevention Circuitry Your system has DEI's Nuisance Prevention Circuitry™ (NPC™). It prevents annoying repetitive trigger sequences due to faulty door pin switches or environmental conditions such as thunder, jackhammers, airport noise, etc. Example: The alarm triggers three times. Each time, the same sensor or switch is triggering the alarm. The three triggers are within 60 minutes of each other. NPC™ will interpret this pattern of triggers 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 security 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 minutes, 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 ignition on. © 1999 Directed Electronics, Inc. 19