
Common Measurement Settings
R&S
®
FSMR3000
126
User Manual 1179.0116.02 ─ 02
Offset
Analyzer
Generator
F
ator
Deno
Numerator
F
F
min
Equation 7-1: Output frequency of the generator
Where:
F
Generator
= output frequency of the generator
F
Analyzer
= current frequency at the RF input of the R&S
FSMR3
Numerator = multiplication factor for F
Analyzer
Denominator = division factor for F
Analyzer
F
Offset
= frequency offset for F
Analyzer
, for example for frequency-converting measure-
ments or harmonics measurements
The value range for the offset depends on the selected generator. The default setting is
0
Hz. Offsets other than 0
Hz are indicated by the "FRQ" label in the channel bar (see
also
"Displayed Information and Errors"
Swept frequency range
If the resulting frequency range exceeds the allowed ranges of the signal generator, an
error message is displayed (see
"Displayed Information and Errors"
values are corrected to comply
with the range limits.
TTL synchronization
Some Rohde
&
Schwarz signal generators support TTL synchronization when connec-
ted via GPIB. The TTL interface is included in the AUX control connector of the Exter-
nal Generator Control option.
When pure GPIB connections are used between the R&S
FSMR3 and the signal gen-
erator, the R&S
FSMR3 sets the generator frequency for each frequency point individu-
ally via GPIB, and only when the setting procedure is finished, the R&S
FSMR3 can
measure the next sweep point.
For generators with a TTL interface, the R&S
FSMR3 sends a list of the frequencies to
be set to the generator before the beginning of the first sweep. Then the R&S
FSMR3
starts the sweep and the next frequency point is selected by both the R&S
FSMR3 and
the generator using the TTL handshake line "TRIGGER". The R&S
FSMR3 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
FSMR3 is directly coupled with the frequency step-
ping 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-
Input and Frontend