User's Guide

Table Of Contents
9 Troubleshooting (Fault Finding)
169
9.1.6 Connection is not 100BaseT
If the Ethernet connection to the network is only 10BaseT, when 100BaseT is expected,
perform the following test on the RJ45 cable that connects the PIDU Plus to the LPU or ODU:
1. Check that the wiring to pins 4&5 and 7&8 is correct. For example, the wiring to pins
4 and 7 may be crossed.
2. If this test fails, replace or repair the RJ45 cable.
9.1.7 Test RJ45 Resistance
If the above procedures fail to diagnose the issue, there may be a fault in the wiring of the
RJ45 cable that connects the ODU (or LPU) to the PIDU Plus. Unplug this cable from the
PIDU Plus, then perform the following test procedure:
1. Check the cable resistance between pins 1&2, 3&6, 4&5 and 7&8 at the RJ45. Check
against column 2 in Table 17. Resistances for each pair should be within 1 ohm of
each othe
r.
2. Check the cable resistance between pins 1&3 and 4&7 at the RJ45. Check against
columns 3 and 4 respectively in Table 17.
3.
Ensure that there is greater than 100K ohms between pin 1 and ODU ground for all
cable lengths.
4. Ensure that there is greater than 100K ohms between pin 8 and ODU ground for all
cable lengths.
5. Ensure that there is greater than 100K ohms between pin 1 and pin 8 for all cable
lengths.