Application Note
Using the Fluke Networks 990DSLWT
CopperPro for qualifying a POTS telephone
pair for ADSL service includes three basic
components:
1. Verify passive metallic properties of
the pair to carry service.
• AC and DC voltage on pair within
acceptable limits
• No open shorted or grounded
conductors
• Longitudinal, capacitive and resistive
balance within acceptable limits
• Verify pair length within acceptable
limits (<15000 ft.)
• Verify no load coils or bridge taps are
present
2. Verify noise and other interference are
within limits required to carry service.
This includes:
• Immunity to power influence
• Metallic noise
• Wideband spectral noise
3. Verify ADSL transmission
characteristics.
• Insertion loss for each DMT bin
frequency
• Signal to noise ratio for each of DMT
frequency
• Bits encoded per tone for each bin
frequency
• Estimated upstream and downstream
data rate
The procedure outlined in this paper is
based on testing an out-of-service pair and
can be performed segment-by-segment or
end-to-end. If the pair is in service, the heat
coil must be removed at the main distribu-
tion frame in the central office. This test
does not verify performance of ADSL trans-
mission equipment (DSLAM or subscriber
modem), subscriber wiring, ATM or IP
configuration.
ADSL Qualification Procedure
Equipment required:
• Two 990DSLWT CopperPro Loop Testers
• Two sets of test leads for tip, ring and
ground of each 990DSLWT
• One strapping cord (included with each
990DSLWT)
• 990DSL User Guide (for reference)
Instrument Set-up
This procedure is based on the U.S. English
set-ups (found in user options). For linear
and gauge settings in metrics, use the UK
English set-ups. For more information, con-
sult the Users Guide, Section 3.
Before testing, zero test leads on both
test sets (found in user options). For more
information, see Section 3 of the Users
Guide.
POTS Auto-Test
Tests completed:
• Opens, capacitive balance and length
• Shorts and grounds
• Load coils
• Longitudinal balance
• Voice frequency noise (power influence
and metallic noise)
Set-Ups
• Power up the test set, the POTS Auto-Test
should be highlighted
• Press the blue soft key #4 to enter the
set-up menu
• Configure the test as shown below - press
the BACK key to return to the main menu
If required, set the cable type and gauge. These
settings are found in the individual set-ups for the
Shorts and Grounds and Opens tests located in the
POTS Tool box.
• Connect the test leads to tip and ring
conductors and ground sheath. Assure that
POTS Auto-Test is highlighted and press
the TEST key
ADSL Qualification Procedure Using
CopperPro
™
990DSLWT
