11 Tdr - EXFO MaxTester 635G User Manual

11 TDR

The TDR (time domain reflectometry) test is a useful tool to locate cable
faults. The test is used after a fault has been identified by running other
tests, since TDR reacts to all faults and conditions on a typical cable pair,
revealing multiple events, some of which may be acceptable conditions.
TDR can see events as close as the ends of the test leads. The graph
controls allow you to see the reflections and their distances so that you can
find and resolve faults; you can view the graph in either Portrait or
Landscape Mode.
There are 3 modes of operation to choose from:
1. Auto TDR automatically searches and
determines the length of the cable, finds the
nearest significant event, and optimizes the
ranges, pulse width, and gain. Range and
Gain are updated to reflect the optimized TDR
settings but can be edited. Auto TDR displays
the distance for the Largest Event and
updates results in real time, until you stop the
test. The last valid results then remain
displayed.
2. Manual TDR does not automate any function
nor settings and gives you full control over
TDR parameters such as Range, Gain, VOP ,
and Pulse Width. The test displays results in
graphical format, updating them in real time, until you stop the test.
The last valid results then remain displayed.
3. xTalk (crosstalk) TDR allows you to locate split pairs between tip (A)
and ring (B) copper wires which may be causing service disruptions.
The test transmits on pair one and receives on pair two to locate the
split pairs.
To select and run a test:
1. Press the left/right navigation keys to select the desired icon.
2. Press
Copper and G.fast/VDSL2/ADSL2+ Multi-play Test Set
to run the test.
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