False Alarm Reduction Features; Exit Error Logic; Exit Delay Reset; • Cross-Zoning - ADEMCO VISTA-120 Installation And Setup Manual

False Alarm Reduction Features

This section provides the following information:
General Information
This control supports features which help minimize false alarms from occurring. Most false
alarms occur either upon exiting the premises, or because of a zone which tends to go into
alarm either due to environmental factors, or because the zone's resistance to the control
may be on the edge of acceptability. We call this condition an "intermittent sensor."
Features which prevent false alarms due to these circumstances are:
• Autobypass Logic and related reports

• Exit Delay Reset

• Cross-Zoning
Autobypass Logic
This feature is intended to reduce the incidence of false alarms due to exit doors that are left
open after the exit delay has expired. If this feature is enabled in programme field 1*20, the
following will occur:
At the end of the exit delay, if a door is left open or an interior zone is faulted, the system
will start the entry delay period, and will sound the bell(s),siren(s) and keypad sounders for
the duration of entry delay. This gives the user time to re-enter the premises and disarm the
system before autobypass occurs. If field *07 is enabled, the faulted zone(s) are autobypassed
at the end of exit delay (no entry delay is activated).
If the user does not re-enter the premises and disarm the system, the system will bypass the
faulted entry/exit and/or interior zone(s). The rest of the system will be armed. In addition,
the following dialler reports will be sent to the central station if programmed:
• Autobypass by User (not sent if using ADEMCO High Speed format
• Autobypass by Zone (Sent as regular alarm if using ADEMCO High Speed format)
• Bypass reports
NOTE: If field *07 is enabled and field 1*20 is not enabled, then faults remaining in the
Another report, designed to notify the central station that an alarm has occurred within five
minutes of arming, is called the Recent Close report.
autobypass reports, are programmed in data fields 1*40 and 1*41.
Exit Delay Reset
This feature is designed to allow an operator to re-enter the premises to retrieve a forgotten
item without triggering an alarm. This feature is enabled in programme field 1*21, and
works in the following way:
When the panel is armed, the normal exit delay begins. After the user exits, and the door
closes, the exit delay time is reset to 60 seconds. If, within this 60 second period, the entry
door is re-opened, the panel will restart the exit delay sequence again using the programmed
exit delay time. This feature will only be activated once after arming.
SECTION 3
• General information about false alarms
• Exit Error Logic and related reports
• Exit Delay Reset
• Cross-Zoning

• Call Waiting Defeat

exit route at the end of the exit delay will cause an immediate alarm.
This report, as well as the
– 11 –