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Spectrum Analyzer Mode
R&S
®
Cable Rider ZPH
247
User Manual 1321.0950.02 ─ 07
5. Select the "Load" softkey.
The R&S Cable Rider ZPH activates the limit line. In the diagram, the limit line is
displayed as a red line. See
Figure 8-13
.
If you have already selected a limit line, you can turn the limit line on and off with
the "Show Limit Lines" softkey.
Alternatively, you can define a threshold that works like a limit line. A threshold is a
simple horizontal limit line.
1. Select the "Upper Limit" or "Lower Limit" softkey.
2. Select the "Set Threshold" menu item.
The R&S Cable Rider ZPH opens an input field to define the threshold.
3. Enter the threshold you need.
The R&S Cable Rider ZPH displays the line and performs a limit check for that
threshold.
Threshold line and display line
Like the display line, a threshold line is a straight horizontal line. The difference is that
the R&S Cable Rider ZPH performs a limit check for threshold lines, but not for display
lines.
A failed limit check may be an issue if you want to create a measurement report,
because measurements with failed limits are not included in this report.
Using a display line, you can use a line and are able to create a measurement report at
the same time, regardless if any limits have been violated or not.
The process of turning off a limit line completely is similar to that of selecting a line.
1. Press the "Show Limit Lines" softkey.
The R&S Cable Rider ZPH hides the limit line.
2. To remove the limit lines, select the "Upper Limit" or "Lower Limit" softkey.
3. Select the "Remove" softkey.
The R&S Cable Rider ZPH removes the limit line.
8.2.10.2
Performing Limit Checks
If limit lines are active, the R&S Cable Rider ZPH automatically checks the trace for
limit violations after each frequency sweep. As long as the signal does not violate the
limit line, the R&S Cable Rider ZPH shows a "Pass" message in the measurement dia-
gram. As soon as one single value (i.e. one pixel) is outside of the limits, the R&S
Cable Rider ZPH displays a "Fail" message in the diagram area and, in addition,
sounds a beep.
A limit check relates only to the frequency range defined by the limit line, not the span.
Configuring Spectrum Measurements