Basics on I/Q Data Acquisition and Processing
R&S
®
FSV/A3000 I/Q
Analyzer
33
User Manual 1178.8536.02 ─ 01
When pure GPIB connections are used between the R&S
FSV/A and the signal gener-
ator, the R&S
FSV/A sets the generator frequency for each frequency point individually
via GPIB, and only when the setting procedure is finished, the R&S
FSV/A can mea-
sure the next sweep point.
For generators with a TTL interface, the R&S
FSV/A sends a list of the frequencies to
be set to the generator before the beginning of the first sweep. Then the R&S
FSV/A
starts the sweep and the next frequency point is selected by both the R&S
FSV/A and
the generator using the TTL handshake line "TRIGGER". The R&S
FSV/A can only
measure a value when the generator signals the end of the setting procedure via the
"BLANK" signal.
Using the TTL interface allows for considerably higher measurement rates than pure
GPIB control, because the frequency stepping of the R&S
FSV/A is directly coupled
with the frequency stepping of the generator.
Reverse sweep
The frequency offset for automatic coupling can be used to sweep in the reverse direc-
tion. To do so, define a negative offset in the external generator measurement configu-
ration. (Note that the frequency is defined as the unsigned value of the equation, thus a
negative frequency is not possible.)
Example: Example for reverse sweep
F
AnalyzerStart
= 100 MHz
F
AnalyzerStop
= 200 MHz
F
Offset
= -300 MHz
Numerator = Denominator = 1
→
F
GeneratorStart
= 200 MHz
→
F
GeneratorStop
= 100 MHz
If the offset is adjusted so that the sweep of the generator crosses the minimum gener-
ator frequency, a message is displayed in the status bar ("Reverse Sweep via min. Ext.
Generator Frequency!").
Example: Example for reverse sweep via minimum frequency
F
AnalyzerStart
= 100 MHz
F
AnalyzerStop
= 200 MHz
F
Offset
= -150 MHz
F
min
= 20 MHz
Numerator = Denominator = 1
→
F
GeneratorStart
= 50 MHz
→
F
GeneratorStop
= 50 MHz via F
min
Basics on External Generator Control
