The Spectrum Application
R&S
®
FPC
132
User Manual 1178.4130.02 ─ 07
5. Enter the required threshold.
The R&S
FPC displays the threshold line. The threshold line is represented by a
straight red line.
Hiding a limit line
Hiding a limit line allows you to switch quickly between showing and hiding a limit line
and evaluate a limit check, without
When you hide a limit line, a limit check is no longer performed, but the limit line
remains in the memory.
1. Press the "Lines" key top open the lines menu.
2. Select the "Show Limit Line" menu item.
● "Show Limit Line" is highlighted: displays the limit line and evaluates the limit
check.
● "Show Limit Line" is not highlighted: hides the limit line and does not evaluate
the limit check.
Removing limit lines
When you remove a limit line, it is no longer considered in the signal evaluation. You
have to deliberately
it again if you want to use the limit line again.
1. Press the "Lines" key top open the lines menu.
2. Select the "Upper Limit" or the "Lower Limit" menu item.
3. Select the "Remove" menu item.
Performing limit checks
If limit lines are active, the R&S
FPC 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
FPC shows a "Pass" message in the measurement diagram. As soon as one sin-
gle value (= one pixel) is outside of the limits, the R&S
FPC displays a "Fail" message
in the diagram area.
A limit check relates only to the frequency range defined by the limit line, not the span.
Limit violation
Note that a limit check fails only if the signal exceeds the limit line.
If the signal level is the same as the limit value, the limit check passes.
You can also turn on an audio signal that sounds an alarm if a limit check fails.
1. Press the "Lines" key top open the lines menu.
2. Select the "Audio Beep" menu item.
The "Audio Beep" menu item.
If the audio beep is active, the R&S
FPC beeps each time a limit is violated.
Limit Lines
