Agilent Technologies Agilent 33500 Series Operating And Service Manual page 197

FM Subsystem
FM Subsystem
This summarizes the steps required to generate a frequency modulation (FM) waveform.
1. Configure carrier waveform: Use FUNCtion, FREQuency, VOLTage, and
waveform's function, frequency, amplitude, and offset.
2. Select modulation source (internal, external, CH1, or CH2):FM:SOURce. For an external modulation
source, skip steps 3 and 4.
3. Select modulating waveform:
4. Set modulating frequency:
5. Set peak frequency deviation:
6. Enable FM Modulation:FM:STATe:ON
[SOURce[1|2]:]FM[:DEViation] {< peak_deviation_in_Hz >|MINimum|MAXimum}
[SOURce[1|2]:]FM[:DEViation]? [{MINimum|MAXimum}]
Sets the peak frequency deviation in Hz. This value represents the peak variation in frequency of the modulated wave-
form from the carrier frequency.
1 μHz to 15.05 (limited to 150 kHz for RAMP); default 100 Hz
Set peak frequency deviation to 1 kHz:
FM:DEV 1000
Set peak frequency deviation to 1 μHz:
FM:DEV MIN
The deviation cannot exceed the carrier frequency. If you attempt to set a deviation that exceeds the carrier
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frequency (with FM enabled), the instrument will adjust the deviation to the maximum value allowed for that car-
rier frequency. From the remote interface, a "Settings conflict" error will also be generated.
The carrier frequency plus the deviation cannot exceed the selected function's maximum frequency plus 100 kHz.
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If you attempt to set the deviation to an invalid value, the instrument adjusts it to the maximum value allowed
with the present carrier frequency. The remote interface also generates a "Data out of range" error.
If the deviation causes the carrier waveform to exceed a frequency boundary for the current duty cycle (square
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waveform only), the instrument will adjust the duty cycle to the maximum value allowed with the present carrier
frequency. From the remote interface, a "Settings conflict" error will also be generated.
If you select the External modulating source, the deviation is controlled by the ±5 V signal level on the rear-panel
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Modulation In connector.For example, if the frequency deviation is 100 kHz, then a +5 V signal level cor-
responds to a 100 kHz increase in frequency.Lower external signal levels produce less deviation and negative sig-
nal levels reduce the frequency below the carrier frequency.
[SOURce[1|2]:]FM:INTernal:FREQuency {< frequency >|MINimum|MAXimum}
[SOURce[1|2]:]FM:INTernal:FREQuency? [{MINimum|MAXimum}]
Sets the frequency of the modulating waveform. The modulating source waveform operates at that frequency, within
the frequency limits of that waveform.
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FM:INTernal:FUNCtion
FM:INTernal:FREQuency
FM:DEViation
Parameter
VOLTage:OFFSet
Typical Return
+1.000000000000000E+03
Agilent 33500 Series Operating and Service Guide
to specify the carrier