Common Measurement Settings
R&S
®
ESW
157
User Manual 1177.6298.02 ─ 08
When pure GPIB connections are used between the R&S
ESW and the signal genera-
tor, the R&S
ESW sets the generator frequency for each frequency point individually
via GPIB, and only when the setting procedure is finished, the R&S
ESW can measure
the next sweep point.
For generators with a TTL interface, the R&S
ESW sends a list of the frequencies to be
set to the generator before the beginning of the first sweep. Then the R&S
ESW starts
the sweep and the next frequency point is selected by both the R&S
ESW and the gen-
erator using the TTL handshake line "TRIGGER". The R&S
ESW 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, because
the frequency stepping of the R&S
ESW 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
Data Input and Output
