A
Open on pair 1,2 near the smart remote. A positive
reflection indicates an increase in impedance. Opens are
large increases in impedance and create large positive
reflections.
B
Short on pair 1,2 near the smart remote. A negative
reflection indicates a decrease in impedance. Shorts are
large decreases in impedance and create large negative
reflections.
C
Bad patch cord at about 33 m.
Diagnosing Copper Cabling Faults
D
A link with a section of cable that has higher impedance
(120 Ω) than the rest of the cable. The bad section starts
at about 54 m. Note the positive pulse where the
impedance increases at the beginning of the bad
section, and the negative pulse where impedance
decreases at the end of the section.
E
A link with a section of cable that has poor return loss.
The section produces reflections along its entire length.
6
The HDTDR Analyzer
6-13