Fluke CableAnalyzer DSP-4100, Руководство пользователя

Страница: 81 / 216

Autotest
Autotest Results for Twisted Pair Cabling
3
3-15
Pressing
# View Plot
produces the NEXT plot screen. Figure 3-6
describes an example of the screen.
6
5
4
3
2
1
oy11c.eps
1
The cable pairs relevant to the plot.
2
Frequency range in MHz. Use
U D
to switch between scales. To switch to the next lowest
or highest range, use
L R
to move the cursor beyond the left or right side of the plot.
3
The NEXT level, frequency, and margin at the cursor’s position. The cursor aligns to the
frequency that produced the worst margin. Margin is the difference between the limit and
measured values plotted at the cursor’s position. If you move the cursor beyond the highest
test frequency specified by the selected test standard, the readout shows the NEXT value
at the cursor’s position.
4
The limits for NEXT, as defined by the selected test standard. A crosshair is shown if the
limit is defined for only one frequency. The limit line is dashed at frequencies where the
attenuation is less than 4 dB.
5
Decibels of crosstalk attenuation (NEXT) between the cable pairs.
6
The measured NEXT for the cable pairs.
Figure 3-6. The NEXT Plot Screen