Motorola PTP 500 用户手册
Before plugging the RJ45 connector fitted to the lower LPU (or if not fitted the ODU)
into the PIDU check the following resistances at the RJ45;
a.
Check the cable resistance between pins 1&2, 3&6, 4&5 and 7&8 at the RJ45.
Check against column 2 in Table 1.
Check against column 2 in Table 1.
b.
Resistances for each pair should be within 1ohm of each other.
c.
Check the resistance between pins 1&3 and 4&7 at the RJ45. Check against
column 3 and 4 in Table 1.
column 3 and 4 in Table 1.
d.
Ensure that there is greater than 100K ohms between pins 1 & 8 for all cable
lengths.
lengths.
e.
Ensure that there is greater than 100K ohms between pin 1 and ODU ground for
all cable lengths.
all cable lengths.
f.
Ensure that there is greater than 100K ohms between pin 8 and ODU ground for
all cable lengths.
all cable lengths.
Table 1 - Resistance Table Referenced to the RJ45 at the PIDU Plus
Cat5E
Length
(meters)
Resistance
between pins
1&2, 3&6, 4&5
and 7&8
(ohms)
Resistance
between pins
1&3
(ohms)
Resistance
between pins
4&7
(ohms)
0
0.8
1.0
1.6
10
2.5
2.7
3.3
20
4.2
4.4
5.0
30
5.9
6.1
6.7
40
7.6
7.8
8.4
50
9.3
9.5
10.1
60
11.0
11.2
11.8
70
12.7
12.9
13.5
80
14.4
14.6
15.2
90
16.1
16.3
16.9
100
17.8
18
18.6
13
Pre-Power Testing
Identification of pin 1
1
8