Reproducing SFP Configurations Using the NI-RFSA Driver

The NI-RFSA Soft Front Panel (SFP) automatically performs the configurations necessary for certain measurement settings. If you perform the same measurements using SFP session access, you may need to manually make certain configuration changes to achieve the same results when you resume your application without the SFP.

The following example illustrates a situation in which you use NI-RFSA in your application to duplicate behavior that is automatically performed by the SFP:

  1. You use the SFP to connect to a device session.
  2. Using the SFP, you configure your measurement to display the sum of two traces. The SFP automatically performs the math operations and displays the result. You want to log the data to a file.
  3. You exit SFP control (local) to return to your application. The math operations are no longer performed for you, and you no longer receive trace sum data.
  4. You manually update your application to return the sum of the two traces using math functions and log the data to a file.

The following table displays the special configurations performed by the SFP. Refer to the National Instruments website at ni.com/info and enter the Info Code exmdfm for examples of how to duplicate SFP configuration using NI-RFSA.

SFP Control Button Label Configuration Performed by SFP Result of Exiting SFP Local Mode or SFP Application
Trigger»IQ Power Edge The SFP sets the Acquisition Type to I/Q, acquires I/Q samples, and uses the I/Q samples to calculate the power spectrum. NI-RFSA Acquisition Type remains IQ.
Trigger»External Digital
Trigger»Software
Trigger»External Digital»Delay When the trigger delay is positive, the SFP configures pre trigger samples as 0 and reference trigger delay as the delay value. When the trigger delay is negative, the SFP configures pre trigger samples using delay and IQ rate, and configures reference trigger delay to 0. The calculated values do not change from the last configured settings.
Trigger»IQ Power Edge»Delay
BW»RBW»Automatic The SFP automatically calculates and configures the RBW value using dependent controls. RBW calculation mode reverts to Manual using the last automatically calculated value.
BW»VBW For explanations of how the SFP performs video bandwidth (VBW) filtering, refer to the National Instruments website at ni.com/info and enter one of the following Info Codes:
  • Enter code exsqb5 for a conceptual overview of video bandwidth and detector emulation.
  • Enter code exmdfm for an example of how the SFP performs VBW filtering.
 No VBW filter is applied to the acquired spectrum. The VBW value reverts to bypass.
BW»Coupling Ratios The SFP provides an option to define how span, RBW, and VBW values are coupled with each other in RBW automatic mode and VBW automatic mode. Parameters are decoupled.
Amptd»PSD The SFP analyzes the acquired spectrum and displays the power level per unit bandwidth and displays the data in unit/Hz. The acquired power spectrum is returned in the configured unit, not as PSD.
Trace/Detector»Average The SFP retains the average of the point-by-point values of the previous trace data and the newly acquired data. If Average Control is configured to SFP, NI-RFSA configures Averaging mode to no averaging.
Trace/Detector»Max Hold The SFP retains the maximum point-by-point values of the previous trace data and the newly acquired data.
Trace/Detector»Min Hold The SFP retains the minimum point-by-point values of the previous trace data and the newly acquired data.
Trace/Detector»Detector»Average The SFP displays the average of signals within a bin. For explanations of how the SFP applies detectors, refer to the National Instruments website at ni.com/info and enter one of the following Info Codes:
  • Enter code exsqb5 for a conceptual overview of video bandwidth and detector emulation.
  • Enter code exmdfm for an example of how the SFP performs VBW filtering and detector emulation.
 The trace detector mode reverts to sample.
Trace/Detector»Detector»Positive Peak The SFP displays the highest amplitude within a bin. For explanations of how the SFP applies detectors, refer to the National Instruments website at ni.com/info and enter one of the following Info Codes:
  • Enter code exsqb5 for a conceptual overview of video bandwidth and detector emulation.
  • Enter code exmdfm for an example of how the SFP performs VBW filtering and detector emulation.
Trace/Detector»Detector»Negative Peak The SFP displays the lowest amplitude within a bin. For explanations of how the SFP applies detectors, refer to the National Instruments website at ni.com/info and enter one of the following Info Codes:
  • Enter code exsqb5 for a conceptual overview of video bandwidth and detector emulation.
  • Enter code exmdfm for an example of how the SFP performs VBW filtering and detector emulation.
Trace/Detector»Math The SFP supports displaying the acquired spectrum in four different traces. You can apply predefined mathematical operations to display the sum of traces, the difference between traces, or trace offsets. No math operations are applied to the acquired spectrum.
Trace/Detector»Trace Math
Trace/Detector»AverageControl When Averaging Control is configured to Driver, the driver averaging mode is set to the value configured in the SFP. When Averaging Control is configured to SFP, the driver averaging mode is set to None and averaging is performed by the SFP. If Average Control is configured to SFP, Averaging mode is configured to no averaging.