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Acquire Signal Spectrum on a Rohde & Schwarz® Spectrum Analyzer using the IVI-C Driver

This example shows how to initialize the driver, read a few properties of the driver and acquire signal spectrum using Rohde & Schwarz spectrum analyzer and visualize the spectrum in MATLAB®.

Requirements

This example requires the following to be installed on the computer:

  • Rohde & Schwarz Spectrum Analyzer IVI-C x64 driver version 1.0 or newer

Enumerate Available IVI-C Drivers On The Computer

This enumerates the IVI drivers that have been installed on the computer.

IviInfo = instrhwinfo('ivi');
IviInfo.Modules
ans = 

  Columns 1 through 6

    'Ag33220'    'Ag3352x'    'Ag34410'    'Ag34970'    'Ag532xx'    'AgAC6800'

  Columns 7 through 11

    'AgE36xx'    'AgInfiniiVision'    'AgMD1'    'AgRfSigGen'    'AgXSAn'

  Columns 12 through 13

    'KtRFPowerMeter'    'rsspecan'

Create MATLAB Instrument Driver And Connect To The Instrument

% Create the MATLAB instrument driver
makemid('rsspecan','rsspecan.mdd')

% Use icdevice with the MATLAB instrument driver name and instrument's
% resource name to create a device object. In this example the instrument
% is connected by GPIB at board index 0 and primary address 1.
myInstrument = icdevice('rsspecan.mdd', 'GPIB0::01::INSTR','optionstring','simulate=true');

% Connect driver instance
connect(myInstrument);

Get General Device Properties

Query information about the driver and instrument

Utility = get(myInstrument,'Utility');
InherentIviAttributesInstrumentIdentification = get(myInstrument, 'Inherentiviattributesinstrumentidentification');
InherentIviAttributesDriverIdentification = get(myInstrument,'Inherentiviattributesdriveridentification');
Revision = get(InherentIviAttributesDriverIdentification, 'Revision');
Vendor = get(InherentIviAttributesDriverIdentification, 'Driver_Vendor');
Description = get(InherentIviAttributesDriverIdentification, 'Description');
InstrumentModel = get(InherentIviAttributesInstrumentIdentification, 'Model');
FirmwareRev = get(InherentIviAttributesInstrumentIdentification, 'Firmware_Revision');
% Print the queried driver properties
fprintf('Revision:        %s\n', Revision);
fprintf('Vendor:          %s\n', Vendor);
fprintf('Description:     %s\n', Description);
fprintf('InstrumentModel: %s\n', InstrumentModel);
fprintf('FirmwareRev:     %s\n', FirmwareRev);
fprintf(' \n');
Revision:        Driver: rsspecan 1.0 (1.0.0.14), Compiler: CVI 13.00, Components: IVIEngine 14.00, VISA-Spec 5.40
Vendor:          Rohde&Schwarz
Description:     Rohde & Schwarz Signal and Spectrum Analyzer IVI-C Driver
InstrumentModel: FSW-26
FirmwareRev:     1.30
 

Attributes and Variables Definition

% These constants are defined in the IVI header file 'IviSpecAn.h'
IVISPECAN_VAL_DETECTOR_TYPE_AUTO_PEAK = 1;
IVISPECAN_VAL_VERTICAL_SCALE_LINEAR = 1;
IVISPECAN_VAL_AMPLITUDE_UNITS_DBM = 1;

Setting Center frequency and Span

Configure the frequency range of the spectrum analyzer using the center frequency and the frequency span.

FrequencyCenter = 2E+9;
FrequencySpan = 500E+6;
Configuration = get(myInstrument, 'Configuration');
invoke(Configuration, 'configurefrequencycenterspan', FrequencyCenter,FrequencySpan);

Setting Single Sweep

Configure the acquisition attributes of the spectrum analyzer.

SweepModeContinuous = false;
NumberOfSweeps = 1;
DetectorTypeAuto = true;
DetectorType = IVISPECAN_VAL_DETECTOR_TYPE_AUTO_PEAK;
VerticalScale = IVISPECAN_VAL_VERTICAL_SCALE_LINEAR;
Configuration = get(myInstrument, 'Configuration');
invoke(Configuration, 'configureacquisition', SweepModeContinuous,NumberOfSweeps,DetectorTypeAuto,DetectorType,VerticalScale);

Configure Reference Level and Range

Configure the vertical attributes of the spectrum analyzer. This corresponds to attributes like amplitude units, input attenuation, input impedance, reference level, and reference level offset

AmplitudeUnits = IVISPECAN_VAL_AMPLITUDE_UNITS_DBM;
InputImpedance = 50.0;
ReferenceLevel = -10.0;
ReferenceLevelOffset = 0;
AttenuationAuto = false;
Attenuation = 10.0;
invoke(Configuration, 'configurelevel', AmplitudeUnits, InputImpedance, ReferenceLevel, ReferenceLevelOffset, AttenuationAuto, Attenuation);

Configure Resolution Bandwidth (RBW), Video Bandwidth (VBW) and Sweep Time

Configure the coupling and sweeping attributes of the spectrum analyzer

ResolutionBandwidthAuto = false;
ResolutionBandwidth = 1.0E+6;
VideoBandwidthAuto = false;
VideoBandwidth = 1.0E+6;
SweepTimeAuto = false;
SweepTime = 5.0E-3;
invoke(Configuration, 'configuresweepcoupling', ResolutionBandwidthAuto,ResolutionBandwidth,VideoBandwidthAuto,VideoBandwidth,SweepTimeAuto,SweepTime);

Perform the sweep

Initiate a signal acquisition based on the present instrument configuration. It then waits for the acquisition to complete, and returns the trace as an array of amplitude values. The amplitude array returns data that represent the amplitude of the signals of the sweep from the start frequency to the stop frequency. The Amplitude Units attribute determines the units of the points in the amplitude array.

Tracename = 0;
MaximumTimeMs = 5000;
ArrayLength = 501;
AmplitudeX = 1.75e+09:0.1e+07:2.25e+09;
AmplitudeY = zeros(ArrayLength,1);
Measurement = get(myInstrument, 'Measurement');
[ActualPointsY,AmplitudeY] = invoke(Measurement, 'readytrace', Tracename,MaximumTimeMs,ArrayLength,AmplitudeY);

Visualize Data And Display Any Errors

% Display the acquired spectrum
plot(AmplitudeX,AmplitudeY);
title('Spectrum Analyzer Trace Plot');
xlabel('Frequency (Hz)');
ylabel('Amplitude (dBm)');

% If there are any errors, query the driver to retrieve and display them.
ErrorNum = 1;
while (ErrorNum ~= 0)
    [ErrorNum, ErrorMsg] = invoke(Utility, 'errorquery');
    fprintf('ErrorQuery: %d, %s\n', ErrorNum, ErrorMsg);
end
ErrorQuery: 0, No error. 

Disconnect Device Object And Clean Up

disconnect(myInstrument);
% Remove instrument objects from memory.
delete(myInstrument);

Additional Information:

This example shows the setup and acquisition of data from an spectrum analyzer using the IVI driver. Once the measured spectrum is retrieved from the instrument, MATLAB can be used to visualize and perform analyses on the data using the rich library of functions in the Signal Processing Toolbox™ and Communications Systems Toolbox™. Using Instrument Control Toolbox™, it is possible to automate control of instruments, and, build test systems that use MATLAB to perform analyses that may not be possible using the built-in capability of the hardware.

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