Chapter 6 — Alarms
33
Tape Playback Mode
Alarm Response
When the Simplex system is in tape playback mode, only the
call monitor responds to live alarm events by displaying the
associated camera. The Simplex sends nothing to the VCR,
does not display graphic messages, and does not flash the LEDs.
RECORDED ALARMS
The Simplex must be in tape playback mode to display and
process recorded alarms. The Simplex detects recorded alarm
events by monitoring the VIS information returned from tape.
Each field of recorded video is encoded with alarm status in-
formation, camera number, camera title, time and date. The
Simplex uses this information to identify camera related alarm
events.
When the recorded alarm is detected in tape playback mode,
the following events occur:
1. The associated
CAMERA
LED flashes.
2. The system overlays the video image of the associated cam-
era with an
ALARM
or
VIDLOSS
graphic.
Multiple alarms are processed in the order in which they
occurred.
The Simplex can detect recorded alarm events at any playback
speed (including forward and reverse search on many VCRs).
When a tape is played at the speed it was recorded, the dura-
tion of each alarm is the same as the original event. Other tape
speeds can be used to speed up or slow down alarm playback.
VIDEO LOSS ALARMS
The Simplex system can detect loss of the video signal at any
connected camera input. It does so by detecting the loss of the
video sync signal. The
VIDEO LOSS ALARM
menu option con-
trols this feature. When this option is
ON
(the default), the
system responds to the loss of camera video with a blinking
LED above the
CAMERA
button and displays the
VIDLOSS
message on the main monitor.
