NI RFmx SpecAn Spectrum Attributes

Spectrum Attributes

• RFMXSPECAN_ATTR_SPECTRUM_MEASUREMENT_ENABLED
• RFMXSPECAN_ATTR_SPECTRUM_SPAN
• RFMXSPECAN_ATTR_SPECTRUM_POWER_UNITS
• RBW Filter
  • RFMXSPECAN_ATTR_SPECTRUM_RBW_FILTER_AUTO_BANDWIDTH
  • RFMXSPECAN_ATTR_SPECTRUM_RBW_FILTER_BANDWIDTH
  • RFMXSPECAN_ATTR_SPECTRUM_RBW_FILTER_TYPE
  • RFMXSPECAN_ATTR_SPECTRUM_RBW_FILTER_BANDWIDTH_DEFINITION
• VBW Filter
  • RFMXSPECAN_ATTR_SPECTRUM_VBW_FILTER_AUTO_BANDWIDTH
  • RFMXSPECAN_ATTR_SPECTRUM_VBW_FILTER_BANDWIDTH
  • RFMXSPECAN_ATTR_SPECTRUM_VBW_FILTER_VBW_TO_RBW_RATIO
• Sweep Time
  • RFMXSPECAN_ATTR_SPECTRUM_SWEEP_TIME_AUTO
  • RFMXSPECAN_ATTR_SPECTRUM_SWEEP_TIME_INTERVAL
• Detector
  • RFMXSPECAN_ATTR_SPECTRUM_DETECTOR_TYPE
  • RFMXSPECAN_ATTR_SPECTRUM_DETECTOR_POINTS
• Noise Calibration
  • RFMXSPECAN_ATTR_SPECTRUM_NOISE_CALIBRATION_MODE
  • RFMXSPECAN_ATTR_SPECTRUM_NOISE_CALIBRATION_AVERAGING_AUTO
  • RFMXSPECAN_ATTR_SPECTRUM_NOISE_CALIBRATION_AVERAGING_COUNT
• Noise Compensation
  • RFMXSPECAN_ATTR_SPECTRUM_NOISE_COMPENSATION_ENABLED
  • RFMXSPECAN_ATTR_SPECTRUM_NOISE_COMPENSATION_TYPE
• Averaging
  • RFMXSPECAN_ATTR_SPECTRUM_AVERAGING_ENABLED
  • RFMXSPECAN_ATTR_SPECTRUM_AVERAGING_COUNT
  • RFMXSPECAN_ATTR_SPECTRUM_AVERAGING_TYPE
• RFMXSPECAN_ATTR_SPECTRUM_MEASUREMENT_MODE
• FFT
  • RFMXSPECAN_ATTR_SPECTRUM_FFT_WINDOW
  • RFMXSPECAN_ATTR_SPECTRUM_FFT_PADDING
• RFMXSPECAN_ATTR_SPECTRUM_AMPLITUDE_CORRECTION_TYPE
• RFMXSPECAN_ATTR_SPECTRUM_NUMBER_OF_ANALYSIS_THREADS
• Results
  • RFMXSPECAN_ATTR_SPECTRUM_RESULTS_PEAK_AMPLITUDE
  • RFMXSPECAN_ATTR_SPECTRUM_RESULTS_PEAK_FREQUENCY
  • RFMXSPECAN_ATTR_SPECTRUM_RESULTS_FREQUENCY_RESOLUTION

RFMXSPECAN_ATTR_SPECTRUM_MEASUREMENT_ENABLED

Data Type:	int32
Access:	read/write
Functions:	RFmxSpecAn_SetAttributeI32 RFmxSpecAn_GetAttributeI32
Description:	Specifies whether to enable the spectrum measurement. You do not need to use a selector string to configure or read this attribute for the default signal instance. Refer to the Selector Strings topic for information about the string syntax for named signals. The default value is RFMXSPECAN_VAL_FALSE. Get Function: RFmxSpecAn_SpectrumGetMeasurementEnabled Set Function: RFmxSpecAn_SpectrumSetMeasurementEnabled

RFMXSPECAN_ATTR_SPECTRUM_SPAN

Data Type:	float64
Access:	read/write
Functions:	RFmxSpecAn_SetAttributeF64 RFmxSpecAn_GetAttributeF64
Description:	Specifies the frequency range around the center frequency, to acquire for the measurement. This value is expressed in Hz. You do not need to use a selector string to configure or read this attribute for the default signal instance. Refer to the Selector Strings topic for information about the string syntax for named signals. The default value is 1 MHz. Get Function: RFmxSpecAn_SpectrumGetSpan Set Function: RFmxSpecAn_SpectrumSetSpan

RFMXSPECAN_ATTR_SPECTRUM_POWER_UNITS

Data Type:	int32
Access:	read/write
Functions:	RFmxSpecAn_SetAttributeI32 RFmxSpecAn_GetAttributeI32
Description:	Specifies the units for the absolute power. You do not need to use a selector string to configure or read this attribute for the default signal instance. Refer to the Selector Strings topic for information about the string syntax for named signals. The default value is RFMXSPECAN_VAL_SPECTRUM_POWER_UNITS_DBM_PER_HZ. Get Function: RFmxSpecAn_SpectrumGetPowerUnits Set Function: RFmxSpecAn_SpectrumSetPowerUnits
Values:

RFMXSPECAN_VAL_SPECTRUM_POWER_UNITS_DBM (0)	The absolute powers are reported in dBm.
RFMXSPECAN_VAL_SPECTRUM_POWER_UNITS_DBM_PER_HZ (1)	The absolute powers are reported in dBm/Hz.
RFMXSPECAN_VAL_SPECTRUM_POWER_UNITS_DBW (2)	The absolute powers are reported in dBW.
RFMXSPECAN_VAL_SPECTRUM_POWER_UNITS_DBV (3)	The absolute powers are reported in dBV.
RFMXSPECAN_VAL_SPECTRUM_POWER_UNITS_DBMV (4)	The absolute powers are reported in dBmV.
RFMXSPECAN_VAL_SPECTRUM_POWER_UNITS_DBUV (5)	The absolute powers are reported in dBuV.
RFMXSPECAN_VAL_SPECTRUM_POWER_UNITS_WATTS (6)	The absolute powers are reported in W.
RFMXSPECAN_VAL_SPECTRUM_POWER_UNITS_VOLTS (7)	The absolute powers are reported in volts.
RFMXSPECAN_VAL_SPECTRUM_POWER_UNITS_VOLTS_SQUARED (8)	The absolute powers are reported in volts2.

Spectrum RBW Filter

RFMXSPECAN_ATTR_SPECTRUM_RBW_FILTER_AUTO_BANDWIDTH

Data Type:	int32
Access:	read/write
Functions:	RFmxSpecAn_SetAttributeI32 RFmxSpecAn_GetAttributeI32
Description:	Specifies whether the measurement computes the resolution bandwidth (RBW). You do not need to use a selector string to configure or read this attribute for the default signal instance. Refer to the Selector Strings topic for information about the string syntax for named signals. The default value is RFMXSPECAN_VAL_SPECTRUM_RBW_AUTO_TRUE. Get Function: RFmxSpecAn_SpectrumGetRBWFilterAutoBandwidth Set Function: RFmxSpecAn_SpectrumSetRBWFilterAutoBandwidth
Values:

RFMXSPECAN_VAL_SPECTRUM_RBW_AUTO_FALSE (0)	The measurement uses the RBW that you specify in the RFMXSPECAN_ATTR_SPECTRUM_RBW_FILTER_BANDWIDTH attribute.
RFMXSPECAN_VAL_SPECTRUM_RBW_AUTO_TRUE (1)	The measurement computes the RBW.

RFMXSPECAN_ATTR_SPECTRUM_RBW_FILTER_BANDWIDTH

Data Type:	float64
Access:	read/write
Functions:	RFmxSpecAn_SetAttributeF64 RFmxSpecAn_GetAttributeF64
Description:	Specifies the bandwidth of the resolution bandwidth (RBW) filter used to sweep the acquired signal, when you set the RFMXSPECAN_ATTR_SPECTRUM_RBW_FILTER_AUTO_BANDWIDTH attribute to RFMXSPECAN_VAL_SPECTRUM_RBW_AUTO_FALSE. This value is expressed in Hz. You do not need to use a selector string to configure or read this attribute for the default signal instance. Refer to the Selector Strings topic for information about the string syntax for named signals. The default value is 10 kHz. Get Function: RFmxSpecAn_SpectrumGetRBWFilterBandwidth Set Function: RFmxSpecAn_SpectrumSetRBWFilterBandwidth

RFMXSPECAN_ATTR_SPECTRUM_RBW_FILTER_TYPE

Data Type:	int32
Access:	read/write
Functions:	RFmxSpecAn_SetAttributeI32 RFmxSpecAn_GetAttributeI32
Description:	Specifies the shape of the digital resolution bandwidth (RBW) filter. You do not need to use a selector string to configure or read this attribute for the default signal instance. Refer to the Selector Strings topic for information about the string syntax for named signals. The default value is RFMXSPECAN_VAL_SPECTRUM_RBW_FILTER_TYPE_GAUSSIAN. Get Function: RFmxSpecAn_SpectrumGetRBWFilterType Set Function: RFmxSpecAn_SpectrumSetRBWFilterType
Values:

RFMXSPECAN_VAL_SPECTRUM_RBW_FILTER_TYPE_FFT_BASED (0)	No RBW filtering is performed.
RFMXSPECAN_VAL_SPECTRUM_RBW_FILTER_TYPE_GAUSSIAN (1)	The RBW filter has a Gaussian response.
RFMXSPECAN_VAL_SPECTRUM_RBW_FILTER_TYPE_FLAT (2)	The RBW filter has a flat response.

RFMXSPECAN_ATTR_SPECTRUM_RBW_FILTER_BANDWIDTH_DEFINITION

Data Type:	int32
Access:	read/write
Functions:	RFmxSpecAn_SetAttributeI32 RFmxSpecAn_GetAttributeI32
Description:	Specifies the bandwidth definition which you use to specify the value of the RFMXSPECAN_ATTR_SPECTRUM_RBW_FILTER_BANDWIDTH attribute. The default value is RFMXSPECAN_VAL_SPECTRUM_RBW_FILTER_BANDWIDTH_DEFINITION_3DB. Get Function: RFmxSpecAn_SpectrumGetRBWFilterBandwidthDefinition Set Function: RFmxSpecAn_SpectrumSetRBWFilterBandwidthDefinition
Values:

RFMXSPECAN_VAL_SPECTRUM_RBW_FILTER_BANDWIDTH_DEFINITION_3DB (0)	Defines the RBW in terms of the 3dB bandwidth of the RBW filter. When you set the RFMXSPECAN_ATTR_SPECTRUM_RBW_FILTER_TYPE attribute to RFMXSPECAN_VAL_SPECTRUM_RBW_FILTER_TYPE_FFT_BASED, RBW is the 3dB bandwidth of the window specified by the RFMXSPECAN_ATTR_SPECTRUM_FFT_WINDOW attribute.
RFMXSPECAN_VAL_SPECTRUM_RBW_FILTER_BANDWIDTH_DEFINITION_6DB (1)	Defines the RBW in terms of the 6dB bandwidth of the RBW filter. When you set the RFMXSPECAN_ATTR_SPECTRUM_RBW_FILTER_TYPE attribute to FFT Based, RBW is the 6dB bandwidth of the window specified by the RFMXSPECAN_ATTR_SPECTRUM_FFT_WINDOW attribute.
RFMXSPECAN_VAL_SPECTRUM_RBW_FILTER_BANDWIDTH_DEFINITION_BIN_WIDTH (2)	Defines the RBW in terms of the spectrum bin width computed using FFT when you set the RFMXSPECAN_ATTR_SPECTRUM_RBW_FILTER_TYPE attribute to FFT Based.
RFMXSPECAN_VAL_SPECTRUM_RBW_FILTER_BANDWIDTH_DEFINITION_ENBW (3)	Defines the RBW in terms of the ENBW bandwidth of the RBW filter. When you set the RFMXSPECAN_ATTR_SPECTRUM_RBW_FILTER_TYPE attribute to FFT Based, RBW is the ENBW bandwidth of the window specified by the RFMXSPECAN_ATTR_SPECTRUM_FFT_WINDOW attribute.

Spectrum VBW Filter

RFMXSPECAN_ATTR_SPECTRUM_VBW_FILTER_AUTO_BANDWIDTH

Data Type:	int32
Access:	read/write
Functions:	RFmxSpecAn_SetAttributeI32 RFmxSpecAn_GetAttributeI32
Description:	Specifies whether the video bandwidth (VBW) is expressed directly or computed based on the VBW to RBW ratio. You do not need to use a selector string to configure or read this attribute for the default signal instance. Refer to the Selector Strings topic for information about the string syntax for named signals. The default value is RFMXSPECAN_VAL_SPECTRUM_VBW_FILTER_AUTO_BANDWIDTH_True. Get Function: RFmxSpecAn_SpectrumGetVBWFilterAutoBandwidth Set Function: RFmxSpecAn_SpectrumSetVBWFilterAutoBandwidth
Values:

RFMXSPECAN_VAL_SPECTRUM_VBW_FILTER_AUTO_BANDWIDTH_False (0)	Specify the video bandwidth in the RFMXSPECAN_ATTR_SPECTRUM_VBW_FILTER_BANDWIDTH attribute. The RFMXSPECAN_ATTR_SPECTRUM_VBW_FILTER_VBW_TO_RBW_RATIO attribute is disregarded in this mode.
RFMXSPECAN_VAL_SPECTRUM_VBW_FILTER_AUTO_BANDWIDTH_True (1)	Specify video bandwidth in terms of the VBW to RBW ratio. The value of the video bandwidth is then computed by using the RFMXSPECAN_ATTR_SPECTRUM_VBW_FILTER_VBW_TO_RBW_RATIO attribute and the RFMXSPECAN_ATTR_SPECTRUM_RBW_FILTER_BANDWIDTH attribute. The value of the RFMXSPECAN_ATTR_SPECTRUM_VBW_FILTER_BANDWIDTH attribute is disregarded in this mode.

RFMXSPECAN_ATTR_SPECTRUM_VBW_FILTER_BANDWIDTH

Data Type:	float64
Access:	read/write
Functions:	RFmxSpecAn_SetAttributeF64 RFmxSpecAn_GetAttributeF64
Description:	Specifies the video bandwidth (VBW) in Hz when you set the RFMXSPECAN_ATTR_SPECTRUM_VBW_FILTER_AUTO_BANDWIDTH attribute to RFMXSPECAN_VAL_SPECTRUM_VBW_FILTER_AUTO_BANDWIDTH_False. You do not need to use a selector string to configure or read this attribute for the default signal instance. Refer to the Selector Strings topic for information about the string syntax for named signals. The default value is 30000. Get Function: RFmxSpecAn_SpectrumGetVBWFilterBandwidth Set Function: RFmxSpecAn_SpectrumSetVBWFilterBandwidth

RFMXSPECAN_ATTR_SPECTRUM_VBW_FILTER_VBW_TO_RBW_RATIO

Data Type:	float64
Access:	read/write
Functions:	RFmxSpecAn_SetAttributeF64 RFmxSpecAn_GetAttributeF64
Description:	Specifies the VBW to RBW Ratio when you set the RFMXSPECAN_ATTR_SPECTRUM_VBW_FILTER_AUTO_BANDWIDTH attribute to RFMXSPECAN_VAL_SPECTRUM_VBW_FILTER_AUTO_BANDWIDTH_True . You do not need to use a selector string to configure or read this attribute for the default signal instance. Refer to the Selector Strings topic for information about the string syntax for named signals. The default value is 3. Get Function: RFmxSpecAn_SpectrumGetVBWFilterVBWToRBWRatio Set Function: RFmxSpecAn_SpectrumSetVBWFilterVBWToRBWRatio

Spectrum Sweep Time

RFMXSPECAN_ATTR_SPECTRUM_SWEEP_TIME_AUTO

Data Type:	int32
Access:	read/write
Functions:	RFmxSpecAn_SetAttributeI32 RFmxSpecAn_GetAttributeI32
Description:	Specifies whether the measurement computes the sweep time. You do not need to use a selector string to configure or read this attribute for the default signal instance. Refer to the Selector Strings topic for information about the string syntax for named signals. The default value is RFMXSPECAN_VAL_SPECTRUM_SWEEP_TIME_AUTO_TRUE. Get Function: RFmxSpecAn_SpectrumGetSweepTimeAuto Set Function: RFmxSpecAn_SpectrumSetSweepTimeAuto
Values:

RFMXSPECAN_VAL_SPECTRUM_SWEEP_TIME_AUTO_FALSE (0)	The measurement uses the sweep time that you specify in the RFMXSPECAN_ATTR_SPECTRUM_SWEEP_TIME_INTERVAL attribute.
RFMXSPECAN_VAL_SPECTRUM_SWEEP_TIME_AUTO_TRUE (1)	The measurement calculates the sweep time based on the value of the RFMXSPECAN_ATTR_SPECTRUM_RBW_FILTER_BANDWIDTH attribute.

RFMXSPECAN_ATTR_SPECTRUM_SWEEP_TIME_INTERVAL

Data Type:	float64
Access:	read/write
Functions:	RFmxSpecAn_SetAttributeF64 RFmxSpecAn_GetAttributeF64
Description:	Specifies the sweep time when you set the RFMXSPECAN_ATTR_SPECTRUM_SWEEP_TIME_AUTO attribute to RFMXSPECAN_VAL_SPECTRUM_SWEEP_TIME_AUTO_FALSE. This value is expressed in seconds. You do not need to use a selector string to configure or read this attribute for the default signal instance. Refer to the Selector Strings topic for information about the string syntax for named signals. The default value is 0.001. Get Function: RFmxSpecAn_SpectrumGetSweepTimeInterval Set Function: RFmxSpecAn_SpectrumSetSweepTimeInterval

Spectrum Detector

RFMXSPECAN_ATTR_SPECTRUM_DETECTOR_TYPE

Data Type:	int32
Access:	read/write
Functions:	RFmxSpecAn_SetAttributeI32 RFmxSpecAn_GetAttributeI32
Description:	Specifies the type of detector to be used. You do not need to use a selector string to configure or read this attribute for the default signal instance. Refer to the Selector Strings topic for information about the string syntax for named signals. The default value is RFMXSPECAN_VAL_SPECTRUM_DETECTOR_TYPE_NONE. Refer to Spectral Measurements topic for more information on detector types. Get Function: RFmxSpecAn_SpectrumGetDetectorType Set Function: RFmxSpecAn_SpectrumSetDetectorType
Values:

RFMXSPECAN_VAL_SPECTRUM_DETECTOR_TYPE_NONE (0)	The detector is disabled.
RFMXSPECAN_VAL_SPECTRUM_DETECTOR_TYPE_SAMPLE (1)	The middle sample in the bucket is detected.
RFMXSPECAN_VAL_SPECTRUM_DETECTOR_TYPE_NORMAL (2)	The maximum value of the samples within the bucket is detected if the signal only rises or if the signal only falls. If the signal, within a bucket, both rises and falls, then the maximum and minimum values of the samples are detected in alternate buckets.
RFMXSPECAN_VAL_SPECTRUM_DETECTOR_TYPE_PEAK (3)	The maximum value of the samples in the bucket is detected.
RFMXSPECAN_VAL_SPECTRUM_DETECTOR_TYPE_NEGATIVE_PEAK (4)	The minimum value of the samples in the bucket is detected.
RFMXSPECAN_VAL_SPECTRUM_DETECTOR_TYPE_AVERAGE_RMS (5)	The average RMS of all the samples in the bucket is detected.
RFMXSPECAN_VAL_SPECTRUM_DETECTOR_TYPE_AVERAGE_VOLTAGE (6)	The average voltage of all the samples in the bucket is detected.
RFMXSPECAN_VAL_SPECTRUM_DETECTOR_TYPE_AVERAGE_LOG (7)	The average log of all the samples in the bucket is detected.

RFMXSPECAN_ATTR_SPECTRUM_DETECTOR_POINTS

Data Type:	int32
Access:	read/write
Functions:	RFmxSpecAn_SetAttributeI32 RFmxSpecAn_GetAttributeI32
Description:	Specifies the number of trace points after the detector is applied. You do not need to use a selector string to configure or read this attribute for the default signal instance. Refer to the Selector Strings topic for information about the string syntax for named signals. The default value is 1001. Get Function: RFmxSpecAn_SpectrumGetDetectorPoints Set Function: RFmxSpecAn_SpectrumSetDetectorPoints

Spectrum Noise Calibration

RFMXSPECAN_ATTR_SPECTRUM_NOISE_CALIBRATION_MODE

Data Type:	int32
Access:	read/write
Functions:	RFmxSpecAn_SetAttributeI32 RFmxSpecAn_GetAttributeI32
Description:	Specifies whether the noise calibration and measurement is performed manually by the user or automatically by RFmx. Refer to the measurement guidelines section in the Noise Compensation Algorithm topic for more information. You do not need to use a selector string to configure or read this attribute for the default signal instance. Refer to the Selector Strings topic for information about the string syntax for named signals. The default value is RFMXSPECAN_VAL_SPECTRUM_NOISE_CALIBRATION_MODE_AUTO. Get Function: RFmxSpecAn_SpectrumGetNoiseCalibrationMode Set Function: RFmxSpecAn_SpectrumSetNoiseCalibrationMode
Values:

RFMXSPECAN_VAL_SPECTRUM_NOISE_CALIBRATION_MODE_MANUAL (0)

When you set the RFMXSPECAN_ATTR_SPECTRUM_MEASUREMENT_MODE attribute to RFMXSPECAN_VAL_SPECTRUM_MEASUREMENT_MODE_CALIBRATE_NOISE_FLOOR, you can initiate instrument noise calibration for the spectrum measurement manually. When you set the RFMXSPECAN_ATTR_SPECTRUM_MEASUREMENT_MODE attribute to RFMXSPECAN_VAL_SPECTRUM_MEASUREMENT_MODE_MEASURE, you can initiate the spectrum measurement manually.

RFMXSPECAN_VAL_SPECTRUM_NOISE_CALIBRATION_MODE_AUTO (1)

When you set the RFMXSPECAN_ATTR_SPECTRUM_NOISE_COMPENSATION_ENABLED attribute to RFMXSPECAN_VAL_SPECTRUM_NOISE_COMPENSATION_ENABLED_TRUE, RFmx sets the Input Isolation Enabled attribute to Enabled and calibrates the intrument noise in the current state of the instrument. RFmx then resets the Input Isolation Enabled attribute and performs the spectrum measurement, including compensation for noise from the instrument. RFmx skips noise calibration in this mode if valid noise calibration data is already cached. When you set the RFMXSPECAN_ATTR_SPECTRUM_NOISE_COMPENSATION_ENABLED attribute to RFMXSPECAN_VAL_SPECTRUM_NOISE_COMPENSATION_ENABLED_FALSE, RFmx does not calibrate instrument noise and performs only the spectrum measurement without compensating for the noise from the instrument.

RFMXSPECAN_ATTR_SPECTRUM_NOISE_CALIBRATION_AVERAGING_AUTO

Data Type:	int32
Access:	read/write
Functions:	RFmxSpecAn_SetAttributeI32 RFmxSpecAn_GetAttributeI32
Description:	Specifies whether RFmx automatically computes the averaging count used for instrument noise calibration. You do not need to use a selector string to configure or read this attribute for the default signal instance. Refer to the Selector Strings topic for information about the string syntax for named signals. The default value is RFMXSPECAN_VAL_SPECTRUM_NOISE_CALIBRATION_AVERAGING_AUTO_TRUE. Get Function: RFmxSpecAn_SpectrumGetNoiseCalibrationAveragingAuto Set Function: RFmxSpecAn_SpectrumSetNoiseCalibrationAveragingAuto
Values:

RFMXSPECAN_VAL_SPECTRUM_NOISE_CALIBRATION_AVERAGING_AUTO_FALSE (0)	RFmx uses the averages that you set for the RFMXSPECAN_ATTR_SPECTRUM_NOISE_CALIBRATION_AVERAGING_COUNT attribute.
RFMXSPECAN_VAL_SPECTRUM_NOISE_CALIBRATION_AVERAGING_AUTO_TRUE (1)	RFmx uses a noise calibration averaging count of 32.

RFMXSPECAN_ATTR_SPECTRUM_NOISE_CALIBRATION_AVERAGING_COUNT

Data Type:	int32
Access:	read/write
Functions:	RFmxSpecAn_SetAttributeI32 RFmxSpecAn_GetAttributeI32
Description:	Specifies the averaging count used for noise calibration when you set the RFMXSPECAN_ATTR_SPECTRUM_NOISE_CALIBRATION_AVERAGING_AUTO attribute to RFMXSPECAN_VAL_SPECTRUM_NOISE_CALIBRATION_AVERAGING_AUTO_FALSE. You do not need to use a selector string to configure or read this attribute for the default signal instance. Refer to the Selector Strings topic for information about the string syntax for named signals. The default value is 32. Get Function: RFmxSpecAn_SpectrumGetNoiseCalibrationAveragingCount Set Function: RFmxSpecAn_SpectrumSetNoiseCalibrationAveragingCount

Spectrum Noise Compensation

RFMXSPECAN_ATTR_SPECTRUM_NOISE_COMPENSATION_ENABLED

Data Type:	int32
Access:	read/write
Functions:	RFmxSpecAn_SetAttributeI32 RFmxSpecAn_GetAttributeI32
Description:	Specifies whether RFmx compensates for the instrument noise while performing the measurement when you set the RFMXSPECAN_ATTR_SPECTRUM_NOISE_CALIBRATION_MODE attribute to RFMXSPECAN_VAL_SPECTRUM_NOISE_CALIBRATION_MODE_AUTO, or when you set the RFMXSPECAN_ATTR_SPECTRUM_NOISE_CALIBRATION_MODE attribute to RFMXSPECAN_VAL_SPECTRUM_NOISE_CALIBRATION_MODE_MANUAL and RFMXSPECAN_ATTR_SPECTRUM_MEASUREMENT_MODE to RFMXSPECAN_VAL_SPECTRUM_MEASUREMENT_MODE_MEASURE. Refer to the Noise Compensation Algorithm topic for more information. You do not need to use a selector string to configure or read this attribute for the default signal instance. Refer to the Selector Strings topic for information about the string syntax for named signals. The default value is RFMXSPECAN_VAL_SPECTRUM_NOISE_COMPENSATION_ENABLED_FALSE. Supported Devices: PXIe-5663/5665/5668, PXIe-5830/5831/5832 Get Function: RFmxSpecAn_SpectrumGetNoiseCompensationEnabled Set Function: RFmxSpecAn_SpectrumSetNoiseCompensationEnabled
Values:

RFMXSPECAN_VAL_SPECTRUM_NOISE_COMPENSATION_ENABLED_FALSE (0)	Disables compensation of the spectrum for the noise floor of the signal analyzer.
RFMXSPECAN_VAL_SPECTRUM_NOISE_COMPENSATION_ENABLED_TRUE (1)	Enables compensation of the spectrum for the noise floor of the signal analyzer. The noise floor of the signal analyzer is measured for the RF path used by the Spectrum measurement and cached for future use. If signal analyzer or measurement parameters change, noise floors are measured again.

RFMXSPECAN_ATTR_SPECTRUM_NOISE_COMPENSATION_TYPE

Data Type:	int32
Access:	read/write
Functions:	RFmxSpecAn_SetAttributeI32 RFmxSpecAn_GetAttributeI32
Description:	Specifies the noise compensation type. Refer to the Noise Compensation Algorithm topic for more information. You do not need to use a selector string to configure or read this attribute for the default signal instance. Refer to the Selector Strings topic for information about the string syntax for named signals. The default value is RFMXSPECAN_VAL_SPECTRUM_NOISE_COMPENSATION_TYPE_ANALYZER_AND_TERMINATION. Get Function: RFmxSpecAn_SpectrumGetNoiseCompensationType Set Function: RFmxSpecAn_SpectrumSetNoiseCompensationType
Values:

RFMXSPECAN_VAL_SPECTRUM_NOISE_COMPENSATION_TYPE_ANALYZER_AND_TERMINATION (0)	Compensates for noise from the analyzer and the 50 ohm termination. The measured power values are in excess of the thermal noise floor.
RFMXSPECAN_VAL_SPECTRUM_NOISE_COMPENSATION_TYPE_ANALYZER_ONLY (1)	Compensates for the analyzer noise only.

Spectrum Averaging

RFMXSPECAN_ATTR_SPECTRUM_AVERAGING_ENABLED

Data Type:	int32
Access:	read/write
Functions:	RFmxSpecAn_SetAttributeI32 RFmxSpecAn_GetAttributeI32
Description:	Specifies whether to enable averaging for the spectrum measurement. You do not need to use a selector string to configure or read this attribute for the default signal instance. Refer to the Selector Strings topic for information about the string syntax for named signals. The default value is RFMXSPECAN_VAL_SPECTRUM_AVERAGING_ENABLED_FALSE. Get Function: RFmxSpecAn_SpectrumGetAveragingEnabled Set Function: RFmxSpecAn_SpectrumSetAveragingEnabled
Values:

RFMXSPECAN_VAL_SPECTRUM_AVERAGING_ENABLED_FALSE (0)	The measurement is performed on a single acquisition.
RFMXSPECAN_VAL_SPECTRUM_AVERAGING_ENABLED_TRUE (1)	The spectrum measurement uses the RFMXSPECAN_ATTR_SPECTRUM_AVERAGING_COUNT attribute as the number of acquisitions over which the spectrum measurement is averaged.

RFMXSPECAN_ATTR_SPECTRUM_AVERAGING_COUNT

Data Type:	int32
Access:	read/write
Functions:	RFmxSpecAn_SetAttributeI32 RFmxSpecAn_GetAttributeI32
Description:	Specifies the number of acquisitions used for averaging when you set the RFMXSPECAN_ATTR_SPECTRUM_AVERAGING_ENABLED attribute to RFMXSPECAN_VAL_SPECTRUM_AVERAGING_ENABLED_TRUE. You do not need to use a selector string to configure or read this attribute for the default signal instance. Refer to the Selector Strings topic for information about the string syntax for named signals. The default value is 10. Get Function: RFmxSpecAn_SpectrumGetAveragingCount Set Function: RFmxSpecAn_SpectrumSetAveragingCount

RFMXSPECAN_ATTR_SPECTRUM_AVERAGING_TYPE

Data Type:	int32
Access:	read/write
Functions:	RFmxSpecAn_SetAttributeI32 RFmxSpecAn_GetAttributeI32
Description:	Specifies the averaging type for averaging multiple spectrum acquisitions. The averaged spectrum is used for spectrum measurement. You do not need to use a selector string to configure or read this attribute for the default signal instance. Refer to the Selector Strings topic for information about the string syntax for named signals. The default value is RFMXSPECAN_VAL_SPECTRUM_AVERAGING_TYPE_RMS. Get Function: RFmxSpecAn_SpectrumGetAveragingType Set Function: RFmxSpecAn_SpectrumSetAveragingType
Values:

RFMXSPECAN_VAL_SPECTRUM_AVERAGING_TYPE_RMS (0)	The power spectrum is linearly averaged. RMS averaging reduces signal fluctuations but not the noise floor.
RFMXSPECAN_VAL_SPECTRUM_AVERAGING_TYPE_LOG (1)	The power spectrum is averaged in a logarithmic scale.
RFMXSPECAN_VAL_SPECTRUM_AVERAGING_TYPE_SCALAR (2)	The square root of the power spectrum is averaged.
RFMXSPECAN_VAL_SPECTRUM_AVERAGING_TYPE_MAXIMUM (3)	The peak power in the spectrum at each frequency bin is retained from one acquisition to the next.
RFMXSPECAN_VAL_SPECTRUM_AVERAGING_TYPE_MINIMUM (4)	The least power in the spectrum at each frequency bin is retained from one acquisition to the next.

RFMXSPECAN_ATTR_SPECTRUM_MEASUREMENT_MODE

Data Type:	int32
Access:	read/write
Functions:	RFmxSpecAn_SetAttributeI32 RFmxSpecAn_GetAttributeI32
Description:	Specifies whether the measurement calibrates the noise floor of analyzer or performs the spectrum measurement. Refer to the measurement guidelines section in the Noise Compensation Algorithm topic for more information. You do not need to use a selector string to configure or read this attribute for the default signal instance. Refer to the Selector Strings topic for information about the string syntax for named signals. The default value is RFMXSPECAN_VAL_SPECTRUM_MEASUREMENT_MODE_MEASURE. Get Function: RFmxSpecAn_SpectrumGetMeasurementMode Set Function: RFmxSpecAn_SpectrumSetMeasurementMode
Values:

RFMXSPECAN_VAL_SPECTRUM_MEASUREMENT_MODE_MEASURE (0)	Spectrum measurement is performed on the acquired signal.
RFMXSPECAN_VAL_SPECTRUM_MEASUREMENT_MODE_CALIBRATE_NOISE_FLOOR (1)	Manual noise calibration of the signal analyzer is performed for the spectrum measurement.

Spectrum FFT

RFMXSPECAN_ATTR_SPECTRUM_FFT_WINDOW

Data Type:	int32
Access:	read/write
Functions:	RFmxSpecAn_SetAttributeI32 RFmxSpecAn_GetAttributeI32
Description:	Specifies the FFT window type to use to reduce spectral leakage. You do not need to use a selector string to configure or read this attribute for the default signal instance. Refer to the Selector Strings topic for information about the string syntax for named signals. The default value is RFMXSPECAN_VAL_SPECTRUM_FFT_WINDOW_FLAT_TOP. Get Function: RFmxSpecAn_SpectrumGetFFTWindow Set Function: RFmxSpecAn_SpectrumSetFFTWindow
Values:

RFMXSPECAN_VAL_SPECTRUM_FFT_WINDOW_NONE (0)	Analyzes transients for which duration is shorter than the window length. You can also use this window type to separate two tones with frequencies close to each other but with almost equal amplitudes.
RFMXSPECAN_VAL_SPECTRUM_FFT_WINDOW_FLAT_TOP (1)	Measures single-tone amplitudes accurately.
RFMXSPECAN_VAL_SPECTRUM_FFT_WINDOW_HANNING (2)	Analyzes transients for which duration is longer than the window length. You can also use this window type to provide better frequency resolution for noise measurements.
RFMXSPECAN_VAL_SPECTRUM_FFT_WINDOW_HAMMING (3)	Analyzes closely-spaced sine waves.
RFMXSPECAN_VAL_SPECTRUM_FFT_WINDOW_GAUSSIAN (4)	Provides a good balance of spectral leakage, frequency resolution, and amplitude attenuation. Hence, this windowing is useful for time-frequency analysis.
RFMXSPECAN_VAL_SPECTRUM_FFT_WINDOW_BLACKMAN (5)	Analyzes single tone because it has a low maximum side lobe level and a high side lobe roll-off rate.
RFMXSPECAN_VAL_SPECTRUM_FFT_WINDOW_BLACKMAN_HARRIS (6)	Useful as a good general purpose window, having side lobe rejection greater than 90 dB and having a moderately wide main lobe.
RFMXSPECAN_VAL_SPECTRUM_FFT_WINDOW_KAISER_BESSEL (7)	Separates two tones with frequencies close to each other but with widely-differing amplitudes.

RFMXSPECAN_ATTR_SPECTRUM_FFT_PADDING

Data Type:	float64
Access:	read/write
Functions:	RFmxSpecAn_SetAttributeF64 RFmxSpecAn_GetAttributeF64
Description:	Specifies the factor by which the time-domain waveform is zero-padded before FFT. The FFT size is given by the following formula: waveform size * padding This attribute is used only when the acquisition span is less than the device instantaneous bandwidth of the device. You do not need to use a selector string to configure or read this attribute for the default signal instance. Refer to the Selector Strings topic for information about the string syntax for named signals. The default value is -1. Get Function: RFmxSpecAn_SpectrumGetFFTPadding Set Function: RFmxSpecAn_SpectrumSetFFTPadding

RFMXSPECAN_ATTR_SPECTRUM_AMPLITUDE_CORRECTION_TYPE

Data Type:	int32
Access:	read/write
Functions:	RFmxSpecAn_SetAttributeI32 RFmxSpecAn_GetAttributeI32
Description:	Specifies whether the amplitude of the frequency bins, used in the measurement, is corrected for external attenuation at the RF center frequency, or at the individual frequency bins. Use the RFmxInstr_CfgExternalAttenuationTable function to configure the external attenuation table. You do not need to use a selector string to configure or read this attribute for the default signal instance. Refer to the Selector Strings topic for information about the string syntax for named signals. The default value is RFMXSPECAN_VAL_SPECTRUM_AMPLITUDE_CORRECTION_TYPE_RF_CENTER_FREQUENCY. Get Function: RFmxSpecAn_SpectrumGetAmplitudeCorrectionType Set Function: RFmxSpecAn_SpectrumSetAmplitudeCorrectionType
Values:

RFMXSPECAN_VAL_SPECTRUM_AMPLITUDE_CORRECTION_TYPE_RF_CENTER_FREQUENCY (0)	All the frequency bins in the spectrum are compensated with a single external attenuation value that corresponds to the RF center frequency.
RFMXSPECAN_VAL_SPECTRUM_AMPLITUDE_CORRECTION_TYPE_SPECTRUM_FREQUENCY_BIN (1)	An individual frequency bin in the spectrum is compensated with the external attenuation value corresponding to that frequency.

RFMXSPECAN_ATTR_SPECTRUM_NUMBER_OF_ANALYSIS_THREADS

Data Type:	int32
Access:	read/write
Functions:	RFmxSpecAn_SetAttributeI32 RFmxSpecAn_GetAttributeI32
Description:	Specifies the maximum number of threads used for parallelism for spectrum measurement. The number of threads can range from 1 to the number of physical cores. The number of threads you set may not be used in calculations. The actual number of threads used depends on the problem size, system resources, data availability, and other considerations. You do not need to use a selector string to configure or read this attribute for the default signal instance. Refer to the Selector Strings topic for information about the string syntax for named signals. The default value is 1. Get Function: RFmxSpecAn_SpectrumGetNumberOfAnalysisThreads Set Function: RFmxSpecAn_SpectrumSetNumberOfAnalysisThreads

Spectrum Results

RFMXSPECAN_ATTR_SPECTRUM_RESULTS_PEAK_AMPLITUDE

Data Type:	float64
Access:	read only
Functions:	RFmxSpecAn_GetAttributeF64
Description:	Returns the peak amplitude, of the averaged spectrum. When you set the RFMXSPECAN_ATTR_SPECTRUM_SPAN attribute to 0, the measurement returns the peak amplitude in the time domain power trace. The amplitude is reported in units specified by the value of the RFMXSPECAN_ATTR_SPECTRUM_POWER_UNITS attribute. You do not need to use a selector string to read this result for default signal and result instance. Refer to the Selector Strings topic for information about the string syntax for named signals and results. Get Function: RFmxSpecAn_SpectrumGetResultsPeakAmplitude

RFMXSPECAN_ATTR_SPECTRUM_RESULTS_PEAK_FREQUENCY

Data Type:	float64
Access:	read only
Functions:	RFmxSpecAn_GetAttributeF64
Description:	Returns the frequency at the peak amplitude of the averaged spectrum. This value is expressed in Hz. This attribute is not valid if you set the RFMXSPECAN_ATTR_SPECTRUM_SPAN attribute to 0. You do not need to use a selector string to read this result for default signal and result instance. Refer to the Selector Strings topic for information about the string syntax for named signals and results. Get Function: RFmxSpecAn_SpectrumGetResultsPeakFrequency

RFMXSPECAN_ATTR_SPECTRUM_RESULTS_FREQUENCY_RESOLUTION

Data Type:	float64
Access:	read only
Functions:	RFmxSpecAn_GetAttributeF64
Description:	Returns the frequency bin spacing of the spectrum acquired by the measurement. This value is expressed in Hz. This attribute is not valid if you set the RFMXSPECAN_ATTR_SPECTRUM_SPAN attribute to 0. You do not need to use a selector string to read this result for default signal and result instance. Refer to the Selector Strings topic for information about the string syntax for named signals and results. Get Function: RFmxSpecAn_SpectrumGetResultsFrequencyResolution