RIGOL
2-46
DS4000E Programming Guide
:CALCulate:FFT
Command List:
:CALCulate:FFT:HCENter
Syntax
:CALCulate:FFT:HCENter <center>
:CALCulate:FFT:HCENter?
Description
Sets or queries the center frequency of FFT operation. The default unit is Hz.
Parameter
Name
Type
Range
Default
<center>
Real
FFT horizontal po 7 x FFT horizontal scale
8.750 MHz
Return Format
The query returns the center frequency in scientific notation.
:CALCulate:FFT:HOFFset
Syntax
:CALCulate:FFT:HOFFset <offs>
:CALCulate:FFT:HOFFset?
Description
Sets or queries the horizontal position of the FFT operation waveform. The default unit is Hz.
Parameter
Name
Type
Range
Default
<offs>
Real
Refer to Remarks
0
Remarks
The range of <offs> is related to the on/off status of the anti-aliasing function, FFT sample rate (Sa),
and FFT horizontal scale (Hspan). The relationship is shown as below:
When the anti-aliasing function is disabled, the range of <offs> is from (max{-0.5 x Sa, -14 x Hspan})
to (0.5 x Sa).
When the anti-aliasing function is enabled, the range of <offs> is from (max{-0.4 x Sa, -14 x Hspan})
to (0.4 x Sa).
Note: max{A, B} indicates selecting a greater value from A and B.
FFT Sample Rate = Number of Pixels Per Grid Horizontally/Horizontal Time Base
Wherein, Number of Pixels Per Grid Horizontally is related to the on/off status of FFT anti-aliasing
function. When the function is disabled, Number of Pixels Per Grid Horizontally is 50; when enabled, it
