3 VMA Mode
3.5 Channel Power Measurement
For example, Center Frequency is the same for all measurements — it does not
change as you change measurements.
3.5.6.1 Settings
Contains controls that pertain to the X axis parameters of the measurement. These
parameters control how data on the vertical (X) axis is displayed and control
instrument settings that affect the horizontal axis.
Center Frequency
Sets the frequency that corresponds to the horizontal center of the graticule. While
adjusting Center Frequency, "Span" on page 865 is held constant.
The Center Frequency setting is the same for all measurements within a mode, that
is, it is Meas Global. Some Modes are also able to share a Mode Global Center
Frequency value. If this is the case, the Mode will have a Global tab in its Meas
Setup menu.
The Center Frequency function sets (and queries) the center frequency for the
currently selected input. If your instrument has multiple inputs, and you select
another input, Center Frequency changes to the value for that input. SCPI
commands are available to directly set Center Frequency for a specific input.
Center Frequency is remembered as you go from input to input. Thus, you can set a
Center Frequency of 10 GHz with the RF Input selected, change to BBIQ and set a
Center Frequency of 20 MHz, then switch to External Mixing and set a Center
Frequency of 60 GHz, and when you go back to the RF Input, Center Frequency will
go back to 10 GHz; back to BBIQ and it is 20 MHz; back to External Mixing and it is
60 GHz.
See:
–
"RF Center Freq" on page 863
–
"Ext Mix Center Freq" on page 864
–
"I/Q Center Freq" on page 865
–
"Center Frequency Presets" on page 861
–
"VXT Models with Radio Heads/CIU Frequency Range" on page 863
Remote Command
[:SENSe]:FREQuency:CENTer <freq>
[:SENSe]:FREQuency:CENTer?
Example Set Center Frequency to 50 MHz:
:FREQ:CENT 50 MHz
Vector Modulation Analyzer Mode User's &Programmer's Reference 860