Fluke 990DSL, Руководство пользователя

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XDSL Testing and Loop Qualification
The XDSL Toolbox
5
5-29
•
From the setup menu for a particular XDSL test, press
K
.
To stop a running test, press
M
or
K
.
WB Noise/Level Test
The WB Noise / Level test measures metallic noise or signal level present on a
pair. The test provides a snapshot WB or BB measurement on either spare
pairs (in Terminated mode) or on active pairs (in Bridged mode).
The test employs DSP techniques to perform measurements at multiple
frequencies at the same time. Depending on the choices you make in the test
Setups, the tester takes measurements with either the higher resolution Nyquist
frequency set (
Fine
, up to 1.2 MHz) at 508 Hz spacing, or with the DMT
frequency set (Coarse, up to 18 MHz) at 4.3 kHz spacing.
Setting Up a WB Noise/Level Test
To set up a WB Noise / Level test, select the test on the XDSL Toolbox and
press
D
(
Setups
). Refer to Table 5-4 for Setup parameters for the test.
Table 5-4. WB Noise/Level Test Setup Parameters
Parameter Setting (default in bold)
Target Service Type ADSL/2 (1.1 MHz), HDSLx (1.1 MHz), ADSL2+
(2.2 MHz), VDSL (12 MHz), VDSL (18MHz)
Termination Mode Terminated or Bridged
Measurement Filter G (ADSL) , 1.3 MHz, E (ISDN BR), F (HDSL)
{20 MHz Filter used for VDSL service}
Measurement Mode Coarse (DMT) or Fine (HDSL only)
Noise Pass Threshold
≤
-50 dBm (Range = 0 to -99)
WB Weighted Noise Pass
Threshold
≤
55 dBrn (Range = 0 to 99)
{Not used on ADSL2+ & VDSL Service Types}
ADSLx Modem Filter N (Disabled) or Y (Enabled)