Multimeter Tests
Copper and G.fast/VDSL2/ADSL2+ Multi-play Test Set
131
Resistive Balance
Resistive Balance
The
Resistive Balance
test measures and compares the resistance of each
leg. This test requires you to short Tip and Ring (T-R/A-B) to ground/earth at
the far end (T-R-G/A-B-E short) before proceeding with the test. EXFO's
TS-125 FED (Far End Device) can automatically set the far end condition.
Snapshot
The
Resistive Balance
test is valuable in understanding the presence of
resistive faults on one side versus the other (series resistance). A 5 %
difference in the ohms value between T/A and R/B is common (95 %
balance), but for higher speed DSL such as VDSL2, imbalance is more
critical and should be 2-3 % when possible (97-98 % balance). There will
be low-ohm values when measuring resistance with a short at the far end.
For example, on 24 AWG cable at 21 °C (70 °F), you will see 520
Ω
for a 3 m
(10 ft) cable. If both Tip and Ring have 520 ohms, the pair is balanced
perfectly, but there will normally be some small difference and a much
larger value on one side; for example, 800
Ω
indicates a significant series
fault on that side.
The resistive balance
Snapshot
shows results for
R
/
B-Leg
,
T
/
A-Leg
,
Loop
resistance, and the pass/fail
status for
Resistive Balance
in
Ω
and %. Parameters
are as follows:
Current Group
is the current test group name, for
example
Multimeter
.
Current Test
displays the test being measured.
When FED is
Enabled
, the FED icon and numeric
state are displayed beside the
Current Test
.
Here you can switch to another test from the given
list. However, this action will terminate the
ongoing measurement test.
Summary of Contents for MAX-635G
Page 1: ...User Guide Copper and G fast VDSL2 ADSL2 Multi play Test Set MAX 635G www EXFO com ...
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Page 270: ...TDR 260 MAX 635G Continuous Examples of Common Faults Short Fault ...
Page 271: ...TDR Copper and G fast VDSL2 ADSL2 Multi play Test Set 261 Continuous Open ...
Page 272: ...TDR 262 MAX 635G Continuous Bridged Tap ...
Page 273: ...TDR Copper and G fast VDSL2 ADSL2 Multi play Test Set 263 Continuous Splice Joint ...
Page 274: ...TDR 264 MAX 635G Continuous Peak Function ...
Page 275: ...TDR Copper and G fast VDSL2 ADSL2 Multi play Test Set 265 Continuous Dual Trace View ...
Page 276: ...TDR 266 MAX 635G Continuous Load Coil ...
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