BNC 645 - Manual (Page 141)

141
and the maximum frequency of the function used.
Maximum center frequency = Maximum frequency – span/2
FREQuency:CENTer? [MINimum|MAXimum]
The center frequency in sweeps will be returned in hertz.
FREQuency:SPAN{<frequency>|MINimum|MAXimum }
Specify the frequency span in sweeps. The range is from 0 Hz to 200 kHz for
ramps, from 0 Hz to 10 MHz for arbitrary waveforms, from 1µHz to 25 MHz for
square, and from 1µHz to 50 MHz for sine. The default is 900 Hz. The minimum
value is 0 Hz and the maximum value is calculated based on the center
frequency and the maximum frequency of the function used.
Maximum frequency span = 2 X (Maximum frequency – center frequency)
--To sweep up in frequency, specify a positive frequency span.
--To sweep down in frequency, specify a negative frequency span.
The following equation shows the relationship between frequency span and
start/stop frequency.
Frequency span = Stop frequency – Start frequency
FREQuency:SPAN? [MINimum|MAXimum]
The frequency span in hertz will be returned.
FSKey: FREQuency {<frequency>|MINimum|MAXimum}
Specify the FSK alternate (or ”hop”) frequency. The range is from 1 μHz to 200
kHz for ramps, 1 μHz to 10 MHz for arbitrary waveforms, from 1µHz to 25 MHz
for square, and from 1µHz to 50 MHz for sine, and the default is 100Hz.
FSKey: FREQuency? [MINimum|MAXimum]
Query the “hop” frequency in FSK. The “hop” frequency in hertz will be returned.
FSKey: INTernal:RATE {<rate in Hz>|MINimum|MAXimum }
Specify the rate at which the output frequency “shifts” between the carrier and
the hop frequency. The range is from 2 mHz to 100 kHz and the default is 10 Hz.
This FSK rate is used only when the FSK source is internal (FSK:SOUR INT).