FREQuency Subsystem

The FREQuency subsystem sets the instrument's output frequency. In two-channel instruments, the channels' frequencies may be coupled in various ways.

FREQuency:COUPle[:STATe] {ON|OFF|ONCE} enables or disables coupling, or using the ONCE, one channel's is copied to the other, but not coupled to it.

FREQuency:COUPle:MODE {OFFSet|RATio} specifies the frequency coupling mode.

FREQuency:MODE allows you to specify a frequency mode to use, including a sweep, frequency list, or fixed frequency.

Example

The remaining FREQuency commands are used to generate a sweep, as summarized below:

  1. Select the waveform shape, amplitude and offset: Use APPLy or the equivalent FUNCtion, FREQuency, VOLTage, and VOLTage:OFFSet commands to select the function, frequency, amplitude, and offset. You can select any non-arbitrary waveform.
  2. Set frequency boundaries of the sweep: FREQuency:STARt and FREQuency:STOP, or FREQuency:CENTer and FREQuency:SPAN.
  3. Select sweep mode (linear or logarithmic): SWEep:SPACing
  4. Set sweep time in seconds: SWEep:TIME
  5. Select sweep trigger source: TRIGger[1|2]:SOURce
  6. Set frequency at which signal on front panel Sync connector goes low during sweep (optional): MARKer:FREQuency

[SOURce[1|2]:]FREQuency {<frequency>|MINimum|MAXimum|DEFault}
[SOURce[1|2]:]FREQuency? [{MINimum|MAXimum}]

Sets the output frequency. This command is paired with FUNCtion:PULSe:PERiod; whichever one is executed last overrides the other.

Parameter Typical Return
1 μHz to maximum instrument frequency. Default 1 kHz. +1.000000000000000E+03
Set output frequency to 60 Hz:
FREQ 60

[SOURce[1|2]:]FREQuency:CENTer {<frequency>|MINimum|MAXimum|DEFault}
[SOURce[1|2]:]FREQuency:CENTer? [{MINimum|MAXimum}]

Sets the center frequency. Used with frequency span for a frequency sweep.

Parameter Typical Return
1 μHz to maximum instrument frequency, Default 550 Hz +1.000000000000000E+03
Set sweep center frequency to 1 kHz:
FREQ:CENT 1000

[SOURce[1|2]:]FREQuency:COUPle[:STATe] {ON|1|OFF|0}
[SOURce[1|2]:]FREQuency:COUPle[:STATe]?

Enables/disables frequency coupling between channels in a two-channel instrument.

Parameter Typical Return
{ON|1|OFF|0}, default OFF 0 (OFF) or 1 (ON)
Turn on the frequency couple state:
FREQ:COUP ON

[SOURce[1|2]:]FREQuency:COUPle:MODE {OFFSet|RATio}
[SOURce[1|2]:]FREQuency:COUPle:MODE?

Sets the type of frequency coupling between frequency coupled channels; OFFSet specifies a constant frequency offset between channels; RATio specifies a constant ratio between the channels' frequencies.

Parameter Typical Return
{OFFSet|RATio}, default RATio with ratio 1.0 OFFS or RAT
Set  frequency coupling mode to OFFSet:
FREQ:COUP:MODE OFFS

[SOURce[1|2]:]FREQuency:COUPle:OFFSet {<frequency>|MINimum|MAXimum|DEFault}
[SOURce[1|2]:]FREQuency:COUPle:OFFSet?

Sets the offset frequency when an instrument is in frequency coupled mode OFFSet.

Parameter Typical Return
A number between plus and minus the instrument's maximum frequency for the waveform; default 0. +7.650000000000000E+05

Set frequency of channel 2 to 10.245 MHz above frequency of channel 1:
FREQ:COUP:OFFS 10.245 MHZ

Set frequency of channel 1 to 350 kHz above frequency of channel 2:
SOUR2:FREQ:COUP:OFFS 350 KHZ

Set frequency of channel 1 to 455 kHz below frequency of channel 2:
SOUR2:FREQ:COUP:OFFS -455 KHZ

[SOURce[1|2]:]FREQuency:COUPle:RATio <ratio>
[SOURce[1|2]:]FREQuency:COUPle:RATio?

Sets offset ratio between channel frequencies in frequency coupled mode RATio.

Parameter Typical Return
0.001 to 1000, default 1 +7.500000000000000E-01

Set frequency of channel 2 to twice the frequency of channel 1:
FREQ:COUP:RAT 2.0

Set frequency of channel 1 to 3.14 times the frequency of channel 2:
SOUR2:FREQ:COUP:RAT 3.14

[SOURce[1|2]:]FREQuency:MODE {CW|LIST|SWEep|FIXed}
[SOURce[1|2]:]FREQuency:MODE?

Sets the type of frequency mode as a continuous wave at a fixed frequency (CW or FIXed), a frequency sweep (SWEep), or a frequency list (LIST).

Parameter Typical Return
{CW|LIST|SWEep|FIXed}, default CW CW, LIST, SWE, or FIX
Set frequency mode to LIST:
FREQ:MODE LIST

[SOURce[1|2]:]FREQuency:SPAN {<frequency>|MINimum|MAXimum|DEFault}
[SOURce[1|2]:]FREQuency:SPAN? [{MINimum|MAXimum}]

Sets frequency span (used in conjunction with the center frequency) for a frequency sweep.

Parameter Typical Return
± instrument's maximum frequency for the waveform, default 900 Hz +1.000000000000000E+02
Set sweep frequency span to 100 kHz:
FREQ:SPAN 100 KHZ

[SOURce[1|2]:]FREQuency:STARt {<frequency>|MINimum|MAXimum|DEFault}
[SOURce[1|2]:]FREQuency:STARt? [{MINimum|MAXimum}]

[SOURce[1|2]:]FREQuency:STOP {<frequency>|MINimum|MAXimum|DEFault}
[SOURce[1|2]:]FREQuency:STOP? [{MINimum|MAXimum}]

Sets the start and stop frequencies for a frequency sweep.

Parameter Typical Return
± instrument's maximum frequency for the waveform, default 100 Hz +1.000000000000000E+02
Set sweep start and stop frequency to 100 Hz and 1 kHz, respectively:
FREQ:STAR 100
FREQ:STOP 1000