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
recorded alarms. The processing of recorded alarms is com-
pletely independent from live alarm processing. The multi-
plexer can perform 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 (1–16) 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.