Modulation Analysis
R&S
®
Cable Rider ZPH
284
User Manual 1321.0950.02 ─ 07
The limit line file is created using the "Ama AM Limits" or "Ama FM Limits" editor in the
R&S InstrumentView software package.
For information on the analog modulation limit line editor, see R&S InstrumentView
software manual.
1. Press [LINES] key.
2. Select the "Select Limits" softkey.
The R&S Cable Rider ZPH opens the "File Manager" dialog to select the limit line
file.
3. Select the limit line file you require from the file manager.
Note: The limit line is edited using the Ama AM or FM limit line editor from R&S
InstrumentView software package.
4. Select the "Load" softkey.
The R&S Cable Rider ZPH activates and loads the limit line values in the table.
See
Figure 12-2
.
5. Select the "Audio Beep" to turn on or off the acoustic audio signal for the limit line
check status.
See index 5 of
Figure 12-2
.
See also
"Audio signal"
on page 248.
6. Select the "Clear Limits" to unload the limit line file.
12.2
Digital Demodulation
The Digital Demodulation measurement analyzes the Amplitude Shift Keying (ASK)
and Frequency Shift Keying (FSK) modulated signals and calculates the digital modu-
lation parameters. The results are displayed in four different
display mode
diagrams:
"Eye Diagram", "Symbols", "Modulation Depth" for ASK or "Modulation Deviation" for
FSK and "Modulation Error".
The firmware option R&S ZPH-K7 provides the necessary measurement functions to
analyze ASK and FSK modulated signals.
Example:
ASK signal modulated with a carrier frequency 500MHz, using root cosine filter with roll
factor of 0.5 and symbol rate of 10ksym/s is generated. External reference signal from
the generator is connector to the R&S Cable Rider ZPH.
Digital Demodulation
