The "LF Frequency Sweep" dialog is used to configure and activate an LF frequency sweep signal.
To open the "LF Frequency Sweep" dialog, select "Mod Gen > Configure > LF Frequency Sweep" or use the MENU key under "Mod Gen".
The LF sweep mode is activated and the sweep mode is selected. The buttons are used to reset the LF sweep (all sweep modes) or to execute the LF sweep ("Single" mode).
The sweep range, sweep spacing and dwell time are set in the bottom of the section.
Activates the LF frequency sweep signal generation.
Activating a sweep mode automatically deactivates other sweeps and the list mode.
Selects the LF frequency sweep mode.
If you change the sweep mode during the execution, the signal generator stops the sweep and starts with the next trigger event at the initial value.
The "Reset Sweep" button sets the sweep to the start value.
"Auto" | Generates a continuously repeating sweep signal immediately after activating the sweep mode. The sweep steps are performed atomatically, controlled by the dwell time, see "Dwell Time - LF Sweep". |
"Single" | Generates a single sweep cycle after a trigger event. The sweep steps within the cycle are performed automatically, controlled by the dwell time. If one cycle is completed, the instrument waits for the next trigger event. To trigger the sweep, use "Execute Single Sweep" button, or the corresponding remote control commands, for example *TRG. |
"Step" | Generates the sweep signal step-by-step, manually triggered. To perform the sweep steps, enter the frequency value under "Current Freq".
Example: SOUR:LFO:SWE:FREQ:MODE MAN SOUR:LFO:FREQ:MODE SWE SOUR:LFO:SWE:FREQ:SPAC LIN SOUR:LFO:SWE:FREQ:STEP:LIN 1E34 SOUR:LFO:FREQ:MAN 12 kHz The value entered with command SOUR:LFO:SWE:FREQ:STEP:LIN|LOG sets the step width. The value entered with command SOUR:LFO:FREQ:MAN has no effect, the command only sets the next sweep step. In remote control only a step-by-step sweep from start to stop frequency is possible. |
"Extern Single" | Generates a single sweep cycle when an a external trigger event occurs. The sweep steps within the cycle are performed automatically, controlled by the dwell time. If one cycle is completed, the instrument waits for the next trigger event. To trigger the sweep, apply an external trigger signal. Refer to the description of the rear panel for information on the connectors for external trigger signal input (see "Rear Panel Tour"). |
"Extern Step" | Generates the sweep signal step-by-step, manually triggered. To trigger a sweep step, apply an external trigger signal. The step width corresponds to the step width set for the rotary knob. |
"Extern Start/Stop" | Generates a continuously repeating sweep signal that is started, stopped and restarted by subseqeunt external trigger events. The sweep steps are performed automatically, controlled by the dwell time. Refer to the description of the rear panel for information on the connectors for the external trigger signal input (see "Rear Panel Tour"). |
Starts a sweep manually. This trigger button is displayed in "Single" mode.
Remote command:Resets a sweep.
With the next trigger event, the sweep starts with at the initial value.
Remote command:Selects the sweep source.
Remote command:Sets the start frequency.
Remote command:Sets the stop frequency.
Remote command:Displays the current frequency.
In sweep "Step" mode, the parameter is editable and you can enter frequency for the next step.
Remote command:Selects the mode for the calculation of the frequency sweep intervals.
"Linear" | Takes the frequency value entered as an absolute value in Hz |
"Logarithmic" | Takes the value entered as a lograithmic value, that means as a constant fraction of teh current frequency in %. |
Selects the waveform shape of the sweep signal.

"Sawtooth" | The sweep runs from the start to the stop frequency. Each subsequent sweep starts at the start frequency, that means the shape of the sweep sequence resembles a sawtooth. |
"Triangle" | The sweep runs from start to stop frequency and back, that means the shape of the sweep resembles a triangle. A subsequent sweep starts at the start frequency. |
Activates that the signal changes to the start frequency value while it is waiting for the next trigger event.
You can enable this feature, when you are working with sawtooth shapes in sweep mode "Single" or "External Single", see "Mode".

Sets the step width for the individual frequency sweep steps.
At each step this value is added to the current frequency.
Depending on the "Spacing" mode you have set, the corresponding parameter is displayed.
"Step Lin" | The step width is a constant value in Hz. Remote command: |
"Step Log" | The step width is determined logarithmically in %, that means as a constant fraction of the current frequency. Remote command: |
Defines the duration of the individual sweep steps.

The "Dwell Time" set by the user is used as the step time of the sweep. The effective net dwell time is shorter, reduced by the setting time. This setting time may be greater than the time specified in the data sheet.
It is recommended to switch off the display update for optimum sweep performance especially with short dwell times (see "Display Update").
Sets the polarity of the active slope of an externally applied instrument trigger.
This setting affects the INST TRIG input (BNC connector at the rear of the instrument).
"Positive" | activates the rising edge of the trigger signal. |
"Negative" | activates the falling edge of the trigger signal. |
Imprint | Statement of Privacy | Terms & Conditions | © 2016 ROHDE & SCHWARZ |