Digital BUS-WATCH
®
47
Radio Engineering Industries, Inc.
640333
Rev 0 -- 1/1/2006
RECORD MODE:
Can be set to either FRAME or FIELD. This sets whether the
unit is recording video fields, or full frames. Frames require more disk-space per
image, so they reduce recording time but provide a better quality image. Fields
reduce video quality but increase recording time.
RECORD QUALITY:
This setting corresponds to the compression ratio of the
video data. There are four options: SUPER, HIGH, NORMAL, and BASIC.
SUPER gives the best quality image but reduces the length of recording time.
BASIC gives the longest recording time, but the recorded image quality is
reduced.
FRAME RATE:
Has many different options, ranging from 0.5P to 60P. The
number equates to fields or frames per second. The four cameras share the
frame rate, so at 60P, each camera saves 15 fields per second.
These three settings all have a significant effect on recording capacity of a given
hard drive. Below is a chart giving the approximate recording capacity of a
120GB drive at each of the above settings. Drives of larger sizes have
proportionally larger recording capacities.
Note:
These numbers can vary significantly with a color vs. black-and-white
camera, frame composition, and light level. This table is representative of 4 color
cameras. A system using a black and white cameras generally has a slightly
higher recording capacity.
Hours of Recording Time with a 120 GB Hard Drive
Field Frame Field Frame
Field Frame Field Frame
FPS
Quality
0.5P
0.5P
1P
1P
2P
2P
4P
4P
Basic
10368
5760
5184
2880
2592
1440
1296
720
Normal
7776
4320
3888
2160
1944
1080
972
540
High
5184
2880
2592
1440
1296
720
648
360
Super
2592
1440
1296
720
648
360
324
180
Field Frame Field Frame
Field Frame Field Frame
FPS
Quality
8P
8P
15P
15P
30P
30P
60P
60P
Basic
648
360
346
192
173
96
86
48
Normal
486
270
259
144
130
72
65
36
High
324
180
173
96
86
48
43
24
Super
162
90
86
48
43
24
22
12
Figure 46
