Cable and Antenna Test Mode
R&S
®
Cable Rider ZPH
164
User Manual 1321.0950.02 ─ 07
tion. With the R&S Cable Rider ZPH, you can build limit lines that consist of up to 1000
points.
Values that define the horizontal characteristics of the limit line can be either absolute
values (e.g. frequency in MHz) or relative values whose reference is the center of the
measurement trace (e.g. the center frequency). Relative values are of advantage if
you, for example, measure modulated output signals and you change the center fre-
quency but need the limit line to remain the same. Absolute limit lines have the file
extension ".abslim" while relative limit lines have the file extension ".rellim"
Values that define the vertical characteristics are always level values in dB. If the scal-
ing of the vertical axis is currently a linear one (units V or W), the R&S Cable Rider
ZPH automatically switches to a logarithmic scaling after you turn on the limit line.
After turning on a limit line, the R&S Cable Rider ZPH checks if the signal violates the
shape of the limit line. If one or more signal levels exceed the limit value, the R&S
Cable Rider ZPH features several indicators that the limit check has failed.
●
A general message in the diagram header that indicates if the signal violates the
limit line, including the trace that violates the limit:
●
An audio signal that sounds every time a limit is violated
Figure 7-11: Upper and lower Limit Lines
You can create and edit limit lines with the R&S InstrumentView software and then
transfer them into the internal memory of the R&S Cable Rider ZPH. The number of
limit lines you can store in the memory depends on other datasets available on the
R&S Cable Rider ZPH or if you are using an external storage device (e.g. memory
stick).
For more information on limit lines, see
Chapter 5.9, "Managing Datasets"
,
on page 107.
Analyzing Measurement Results
