Videolarm qsdpc2-70na5 用户指南
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250 ft
3
4
5
8
13
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300 ft
4
5
6
10
16
�
400 ft
5
6
8
13
21
�
500 ft
6
8
10
16
26
�
600 ft
8
10
12
19
31
�
800 ft
10
13
16
25
42
�
1000 ft
13
16
20
32
52
�
1250 ft
16
20
25
40
65
�
1500 ft
19
24
30
48
78
�
1750 ft
23
28
35
55
91
�
2000 ft
26
32
40
63
104
�
2500 ft
32
40
49
79
131
�
3000 ft
39
48
59
95
157
�
3500 ft
45
56
69
111
183
�
4000 ft
52
64
79
127
209
�
5000 ft
65
80
99
158
261
�
6000 ft
78
95
119
190
313
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8000 ft
104
127
158
253
418
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Unshielded Twisted-Pair Wire Gauge (AWG)
Cable
Distance
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24
22
20
19
18
Unshielded Twisted-Pair Wire Gauge (AWG)
Distance
24
22
20
19
18
Unshielded Twisted-Pair Wire Gauge (mm)
Distance
0.5
0.6
0.7
0.8
1.0
3
4
5
8
13
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4
5
6
10
17
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5
7
8
13
21
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6
8
10
16
26
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9
10
13
21
34
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13
16
19
31
51
�
17
21
26
42
69
�
21
26
32
52
86
�
26
31
39
62
103
�
32
39
49
78
129
�
38
47
58
94
154
�
43
52
65
104
171
�
51
63
78
125
206
�
64
78
97
156
257
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77
94
117
187
309
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102
125
156
249
411
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Cable
Cable
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75 m
100 m
125 m
150 m
200 m
300 m
400 m
500 m
600 m
750 m
900 m
125 m
150 m
200 m
300 m
400 m
500 m
600 m
750 m
900 m
1000 m
1200 m
1200 m
1500 m
1800 m
2400 m
1800 m
2400 m
75 m
100 m
125 m
150 m
200 m
300 m
400 m
500 m
600 m
750 m
900 m
125 m
150 m
200 m
300 m
400 m
500 m
600 m
750 m
900 m
1000 m
1200 m
1200 m
1500 m
1800 m
2400 m
1800 m
2400 m
3
5
6
9
13
�
4
7
9
12
18
�
6
8
11
15
22
�
7
10
13
18
27
�
9
13
17
24
36
�
13
20
26
36
54
�
18
27
35
48
72
�
22
33
43
60
90
�
26
40
52
72
108
�
33
50
65
89
135
�
40
60
78
107
162
�
44
66
86
119
179
�
53
80
104
143
215
�
66
100
130
179
269
�
79
120
155
215
323
�
106
159
207
286
431
�
Wiring Notes
Wire — What to DO
1. DO use point-to-point Unshielded Twisted Pair wire, gauge 24 or
thicker, stranded or solid, Category 2, 3, 4, or 5.
2. The video signal may co-exist in the same wire bundle as other
video, telephone, data, control signals, or low-voltage power. It
is also OK to run NVT video signals in or near electromagnetic
fields (in accordance with National Electrical Code, local, or other
local safety requirements).
is also OK to run NVT video signals in or near electromagnetic
fields (in accordance with National Electrical Code, local, or other
local safety requirements).
3. DO measure the wire distance. Use only transceivers that are
designed for that distance.
4. DO make sure the pair of wires carrying the video signal is sent
as a twisted pair
(e.g. the blue-white/white-blue wires twisted
together as a pair), not a “split-pair” (e.g. blue-white conductor,
part of one pair/orange-white conductor, part of another pair).
part of one pair/orange-white conductor, part of another pair).
Wire — What NOT to DO
1. DO NOT USE SHIELDED TWISTED PAIR WIRE. It will
severely degrade the distance performance. Short runs may be
used with some signal degradation (for example elevator traveler
cables). Multi-pair wire with an overall shield is OK.
used with some signal degradation (for example elevator traveler
cables). Multi-pair wire with an overall shield is OK.
2. DO NOT USE UN-TWISTED WIRE. It will reduce the NVT
product’s inherent interference immunity.
3. DO NOT allow your installation to have “bridge-taps”, loading
coils, talk-battery, or MOV type protectors. Bridge-taps are where
a twisted pair is connected to two twisted pairs (such as an
extension phone at home). Bridge-taps cause reflections as the
signal propagates, resulting in “ghosts” in the video image, and
are to be avoided.
a twisted pair is connected to two twisted pairs (such as an
extension phone at home). Bridge-taps cause reflections as the
signal propagates, resulting in “ghosts” in the video image, and
are to be avoided.
4. If the phone company is providing the cable runs between
buildings, make sure it’s “dry copper” i.e. it should have none
of the following: dial-tone, 48 volts, loading coils, bridge-taps,
switching, or long paths to the phone company’s central office
and back.
of the following: dial-tone, 48 volts, loading coils, bridge-taps,
switching, or long paths to the phone company’s central office
and back.
5. Due to near-end crosstalk, DO NOT send a transmit and a
receive signal in the same wire bundle. Exceptions: Less than
1,000 ft (300m), or Category 5 cable, up to 2,000 ft (600m) are
OK.
1,000 ft (300m), or Category 5 cable, up to 2,000 ft (600m) are
OK.
6. DO NOT send “Up-the-Coax” Pan/Tilt/Zoom signals through
active (amplified) NVT transceivers.
Measure your wire distance
Note: All NVT quoted distance specifications include any coax in the
run. It is recommended that the wire distance be measured to ensure
that the capability of the NVT product is correct.
run. It is recommended that the wire distance be measured to ensure
that the capability of the NVT product is correct.
Wire resistance may be measured with an ohm-meter by shorting
the two conductors together at the far end, and measuring the loop-
resistance out and back. Compare your readings with the charts in
the next column.
the two conductors together at the far end, and measuring the loop-
resistance out and back. Compare your readings with the charts in
the next column.
7. For safety, never put NVT signals in the same conduit as
high-voltage wiring.
8. WARNING — to reduce a risk of fire or electrical shock, do
not expose this product to rain or moisture.