Specifications
Chapter 6 Alarms 41
RECORDED ALARMS
The multiplexer detects recorded alarm events by monitoring the
VIS information returned from tape. Each field of recorded video
is encoded with alarm status information, camera number, camera
title, time and date. The multiplexer uses this information to
identify camera related alarm events.
The multiplexer must be in tape mode to display and process re-
corded alarms. The processing of recorded alarms is completely
independent from live alarm processing. The multiplexer can per-
form both tasks at the same time. In tape mode, live alarm events
process in the background and display on the call monitor.
The multiplexer does the following when it detects a recorded
alarm while in tape mode:
Flashes the associated Camera (116) light.
Overlays the alarm camera with the ALARM message on the
main monitor.
The multiplexer remains in the alarm state until both of the
following occur:
The recorded alarm event ends.
The ALARM DURATION time elapses (the default is 4 seconds).
Multiple alarms are processed in the order in which they occur.
The multiplexer detects recorded alarm events at any playback
speed (including forward and reverse search on many VCRs).
When a tape plays at the speed it was recorded, the duration of
each alarm is the same as the original event. Other tape speeds
slow down or speed up alarm playback; however the default alarm
time remains 4 seconds.