Keysight E6640A, Measurement Applications User & Programmer Reference

Page: 673 / 2870

9 ACP Measurement
FREQ Channel
FREQ Channel
Accesses a menu of keys that allow you to control the Frequency and Channel parameters of the
instrument.
Some features in the Frequency menu are the same for all measurements – they do not change as you
change measurements. Settings like these are called “Meas Global” and are unaffected by Meas Preset.
For example, the Center Freq setting is the same for all measurements - it does not change as you change
measurements.
Key Path
Front-panel key
Initial S/W Revision Prior to A.02.00
Center Freq
Sets the frequency that corresponds to the horizontal center of the graticule (when frequency Scale Type
is set to linear). While adjusting the Center Frequency the Span is held constant, which means that both
Start Frequency and Stop Frequency will change.
Pressing Center Freq also sets the frequency entry mode to Center/Span. In Center/Span mode, the
center frequency and span values are displayed below the graticule, and the default active function in the
Frequency menu is Center Freq.
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 Settings key in its Mode Setup menu.
The Center Freq function sets (and queries) the Center Frequency for the currently selected input. If your
analyzer has multiple inputs, and you select another input, the Center Freq changes to the value for that
input. SCPI commands are available to directly set the Center Freq for a specific input.
Center Freq is remembered as you go from input to input. Thus you can set a Center Freq of 10 GHz with
the RF Input selected, change to BBIQ and set a Center Freq of 20 MHz, then switch to External Mixing and
set a Center Freq of 60 GHz, and when you go back to the RF Input the Center Freq 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 676
See Ext Mix Center Freq
See "I/Q Center Freq" on page 678
See "Center Frequency Presets" on page 674
Key Path
FREQ Channel
Scope Meas Global
Remote Command
[:SENSe]:FREQuency:CENTer <freq>
[:SENSe]:FREQuency:CENTer?
W-CDMA & HSPA Measurement Applications Reference 673