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Acquire Spectral Data from Vector Signal Transceiver Using NI-RFSA Instrument Driver

This example shows how to connect to a simulated NI PXIe-5841 Vector Signal Transceiver (VST) and acquire a finite amount of spectral data from it.

Connect to Instrument

Connect to a simulated VST instrument using the ividev function. For this example, specify the driver name as niRFSA, the resource name as PXI1Slot2, and the IVI driver setup name-value argument as Model:5841. Alternatively, you can leave the resource name unspecified ("") for simulated hardware. The driver setup is also optional. If you do not specify a name-value argument for the driver setup, ividev uses default setup values. For more information about default argument values, see ividev.

isSimulated = true;
if isSimulated
    dev = ividev("niRFSA", "PXI1Slot2", Simulate=true, DriverSetup="Model:5841")
    dev = ividev("niRFSA", "PXI1Slot2")
dev = 
  niRFSA with properties:

                    Model: "NI PXIe-5841" 
             Manufacturer: "National Instruments" 
             SerialNumber: "" 
             ResourceName: "PXI1Slot2" 
             VendorDriver: "niRFSA" 
                 Simulate: 1 

               ChannelIDs: "0" 
          FIFOEndpointIDs: "FIFOEndpoint0" 
            UserSourceIDs: "usersource0" 

                 Vertical: [1x1 Vertical] 
               SignalPath: [1x1 SignalPath] 
              Acquisition: [1x1 Acquisition] 
                 Clocking: [1x1 Clocking] 
                 Triggers: [1x1 Triggers] 
                   Events: [1x1 Events] 
    DeviceCharacteristics: [1x1 DeviceCharacteristics] 
               PeerToPeer: [1x1 PeerToPeer] 
        ConfigurationList: [1x1 ConfigurationList] 
    InherentIVIAttributes: [1x1 InherentIVIAttributes] 
              Deembedding: [1x1 Deembedding] 
          SelfCalibration: [1x1 SelfCalibration] 
       FactoryCalibration: [1x1 FactoryCalibration] 
        ExternalAlignment: [1x1 ExternalAlignment] 
           DeviceSpecific: [1x1 DeviceSpecific] 
          AcquisitionType: IQ 

Show all functions

Configure Acquisition Properties

Configure the VST to acquire spectral data, centered around a frequency of 1 GHz, on channel "0". For single channel devices, you do not need to specify the channel (use ""). Set the following parameters to the specified value:

  • Reference clock — onboard clock

  • Acquisition type — spectrum

  • Reference level — 0 dB

  • Start frequency — 990 MHz

  • Stop frequency — 1010 MHz

  • Resolution bandwidth — 10 KHz

Explore different options by using tab completion in the Live Editor.

ch = "0";
configureRefClock(dev, "OnboardClock", 1e7);
configureAcquisitionType(dev, "SPECTRUM");
configureReferenceLevel(dev, ch, 0);
configureSpectrumFrequencyStartStop(dev, ch, 990e6, 1010e6);
configureResolutionBandwidth(dev, ch, 10e3);

Acquire Spectrum

Acquire spectral data at the spectral lines determined by the acquisition configuration.

numSpectralLines = dev.Acquisition.Spectrum.NumberOfSpectralLines;
timeout = 10; % sec
[powerSpectrumData, spectrumInfo] = readPowerSpectrumF64(dev, ch, timeout, numSpectralLines);

Plot Spectrum

Construct the frequency values vector using information from the spectrumInfo structure.

f0 = spectrumInfo.initialFrequency;
fincr = spectrumInfo.frequencyIncrement;
n = double(spectrumInfo.numberOfSpectralLines);
f = f0 + fincr.*(0:n-1);

Display spectral data.

plot(f, powerSpectrumData)
axis tight
grid minor
title("Power Spectrum")

Clean Up

Disconnect and clear the ividev object from the workspace.

clear dev

See Also

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