Fluke 990DSL, Руководство пользователя, Страница: 191 / 242

TDR Testing and Fault Location
TDR Auto-Test
6
6-9
Table 6-3. TDR Auto-Test Softkeys
Press this key first Then press
V
OP
Pulse
The
F
or
H
key to respectively increase or
decrease the current VOP value from 0.300 to
0.999.
The
I
or
G
key to respectively decrease or
increase the pulse width from 20 ns to 5000 ns.
Gain
Zoom
The
F
or
H
key to respectively increase or
decrease the waveform vertical gain (size).
The
I
or
G
key to respectively compress or
expand the waveform horizontal scale about the
reflection cursor.
V.Pos’n.
H.Pos’n.
The
F
or
H
key to respectively move the entire
waveform up or down in the display window.
The
I
or
G
key to respectively move the entire
waveform left or right in the display window.
Fltr Avg
Scan
The
F
key to apply the Power Filter (Fltr). Press
F
again to remove the filter.
The
H
key to apply the Averaging Filter (Avg).
Press
H
again to remove the filter.
The
I
or
G
key to respectively move Cursor 2 (C2)
left or right (Scan) to the next detected reflection on
the displayed waveform. If the next reflection is
outside of the current view, the waveform
automatically shifts position to bring it into view.
Note
The tester is designed to automatically find and classify reflections
based on a complex set of testing algorithms. However, due to the
variety of cable types and faults that may be encountered, a visual
waveform interpretation may be required to resolve the actual
problem. For example, the tester may not mark a reflection exactly at
its start point. In this case, manually move the reflection cursor to the
exact start of the reflection to get the proper distance.