R&S FSH
Spectrum Analyzer Mode
Configuring Spectrum Measurements
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► Select the "Show Compatible" menu item.
The R&S FSH shows all limit lines that are compatible to the current settings.
► Select one of the available limit lines.
► Press the "Select" softkey.
The R&S FSH activates the limit line. In the diagram, the limit line is displayed as a
red line.
If you have already selected a limit line, you can turn the limit line on and off with
the "Limits On/Off" softkey.
Alternatively, you can define a threshold that works like a limit line. A threshold is a
simple horizontal limit line.
► Press the "Upper Limit" or "Lower Limit" softkey.
► Select the "Threshold" menu item.
The R&S FSH opens a input field to define the threshold.
► Enter the threshold you need.
The R&S FSH 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 FSH 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.
► Press the "Upper Limit" or "Lower Limit" softkey
► Select the "Unselect Limit" menu item.
The R&S FSH deactivates the limit line.
3.2.8.2 Performing Limit Checks
If limit lines are active, the R&S FSH 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 FSH shows a "Pass" message in the measurement diagram. As soon as one
single value (i.e. one pixel) is outside of the limits, the R&S FSH displays a "Fail"
message in the diagram area and, in addition, sounds a beep.
A limit checks relates only to the frequency range defined by the limit line, not the
span.
