Chapter 1 — About Simplex
5
Encoder Output
The Simplex video encoder produces a single video signal con-
taining field by field samples from all camera inputs. The sig-
nal is provided in composite format for connection to a video
recorder. All inputs are sampled in camera number order un-
til motion is detected; then sampling is weighted in favor of
the cameras where activity is detected.
The encoder uses Vertical Interval Signaling (VIS) technology
to encode system information onto video output to the VCR.
Time, date, camera title, camera number and alarm status in-
formation are placed on the 16 horizontal lines preceding the
first active video line. This technique improves vertical sync
recovery and eliminates the degraded graphics associated with
poor VCR performance.
Decoder Output
The Simplex decoder processes the video output by the VCR
during playback, recovering the video from each camera origi-
nally recorded. The decoder digitizes the playback video and
recovers the VIS information encoded onto each field. If the
recovered field is displayed, it is written to the video display
memory.
Motion Detection
The Simplex provides motion (activity) detection during record
mode. The Simplex system continuously monitors all camera
inputs for activity. When activity is detected, the Simplex
records images from that camera more often. You can set mo-
tion sensitivity for each camera input using a 192-target (16
wide by 12 high) graphic overlay. Targets can be turned on or
off as required. Target sensitivity is fixed.
Using proprietary DTD technology, the Simplex system con-
tinuously analyzes the motion content (activity) of each
camera picture. Cameras where activity is detected will be
recorded more often. Every picture sent to the VCR is encoded
with the camera number, alarm status, time and date.
