35
CHAPTER 4: Operation
By contrast, coaxial cables (standard for Apple and Sun applications, required
for XGA applications) do much better at maintaining video quality, as shown
in Table 4-3 below. (For the meaning of quality numbers
3
,
2
, and
1
, see the
bottom of page 34.) As before, the distances in the table are total cable
lengths measured from the CPU to the monitor. Also as before, the table
assumes a single ServManager is between the CPU and monitor; if there is a
submaster as well, video quality will always be lower.
Table 4-3. Video Quality vs. Distance for Coaxial Cables
Resolution
Distance
10 ft.
20 ft.
30 ft.
50 ft.
75 ft.
100 ft.
150 ft.
200 ft.
(3 m) (6.1 m) (9.1 m) (15.2 m) (22.9 m) (30.5 m) (45.7 m) (61 m)
640 x 480
3
3
3
3
3
3
2
2
800 x 600 noninterl.
3
3
3
3
3
3
2
2
1024 x 768 interlaced
3
3
3
3
3
3
2
2
1024 x 768 noninterl.
3
3
3
3
2
2
2
1
1280 x 1024 interlaced
3
2
2
2
2
1
1
1
1280 x 1024 noninterl.
3
2
2
1
1
1
1
1
CAUTION!
Some CPUs can’t drive or receive keyboard and mouse signals across
longer runs of coaxial cable. Consult with the manufacturers of your
CPUs before installing this cable in lengths greater than 20 ft. (6.1 m).
For CPU-to-monitor distances over 200 feet (61 m), Station Extenders might
be required. Call Black Box for technical support.
One last note of caution about video: The IBM 9515, 9517, and 9518
monitors that come with some PS/2 systems are not normal VGA monitors
and require special cabling in order for video to be correctly sized and
synchronized. Call Black Box for technical support if you want to use one of
these monitors.
Содержание ServManager SW995A-R2
Страница 84: ...NOTES...
Страница 85: ...NOTES...
