• Advanced
  • RFMXINSTR_ATTR_PREAMP_ENABLED
  • RFMXINSTR_ATTR_CHANNEL_COUPLING
  • RFMXINSTR_ATTR_DOWNCONVERTER_PRESELECTOR_ENABLED
  • RFMXINSTR_ATTR_MIXER_LEVEL
  • RFMXINSTR_ATTR_MIXER_LEVEL_OFFSET
  • RFMXINSTR_ATTR_RF_ATTENUATION_STEP_SIZE
  • RFMXINSTR_ATTR_OSP_DELAY_ENABLED
  • RFMXINSTR_ATTR_PHASE_OFFSET
  • RFMXINSTR_ATTR_FFT_WIDTH
  • RFMXINSTR_ATTR_CLEANER_SPECTRUM
  • RFMXINSTR_ATTR_IF_OUTPUT_POWER_LEVEL_OFFSET
  • RFMXINSTR_ATTR_DIGITIZER_DITHER_ENABLED
  • RFMXINSTR_ATTR_IF_FILTER_BANDWIDTH
  • RFMXINSTR_ATTR_FREQUENCY_SETTLING_UNITS
  • RFMXINSTR_ATTR_FREQUENCY_SETTLING
  • RFMXINSTR_ATTR_RF_HIGHPASS_FILTER_FREQUENCY
  • RFMXINSTR_ATTR_SUBSPAN_OVERLAP
  • RFMXINSTR_ATTR_DOWNCONVERTER_GAIN
  • RFMXINSTR_ATTR_AMPLITUDE_SETTLING
  • RFMXINSTR_ATTR_OVERFLOW_ERROR_REPORTING
  • RFMXINSTR_ATTR_COMMON_MODE_LEVEL
  • RFMXINSTR_ATTR_SMU_RESOURCE_NAME
  • RFMXINSTR_ATTR_SMU_CHANNEL
  • RFMXINSTR_ATTR_OPTIMIZE_PATH_FOR_SIGNAL_BANDWIDTH
  • RFMXINSTR_ATTR_INPUT_ISOLATION_ENABLED
  • RFMXINSTR_ATTR_THERMAL_CORRECTION_HEADROOM_RANGE
  • RFMXINSTR_ATTR_TEMPERATURE_READ_INTERVAL
  • RFMXINSTR_ATTR_THERMAL_CORRECTION_TEMPERATURE_RESOLUTION
  • Self Calibration
    • RFMXINSTR_ATTR_SELF_CALIBRATION_VALIDITY_CHECK
    • RFMXINSTR_ATTR_SELF_CALIBRATION_VALIDITY_CHECK_TIME_INTERVAL

Data Type:	int32
Access:	read/write
Functions:	RFmxInstr_SetAttributeI32 RFmxInstr_GetAttributeI32
Description:	Specifies whether the RF preamplifier is enabled in the system. PXIe-5644/5645/5646, PXIe-5830/5831/5832/5840/5841: If you set this attribute to Automatic, RFmx selects the preamplifier state based on the value of the Reference Level attribute and the center frequency. For PXIe-5830/5831/5832, the value is not coerced. You do not need to use a selector string if you want to configure this attribute for all signal instances. Specify the signal name in the selector string if you want to configure or read that signal instance. Refer to the Selector Strings topic for information about the string syntax. The default value for PXIe-5644/5645/5646 and PXIe-5830/5831/5832/5840/5841 is Automatic, else the default value is Disabled. Get Function: RFmxInstr_GetPreampEnabled Set Function: RFmxInstr_SetPreampEnabled
Values:

RFMXINSTR_VAL_PREAMP_DISABLED (0)	Disables the RF preamplifier. Supported Devices: PXIe-5663/5663E/5665/5668
RFMXINSTR_VAL_PREAMP_ENABLED (1)	Enables the RF preamplifier when it is in the signal path and disables it when it is not in the signal path. Only devices with an RF preamplifier on the downconverter and an RF preselector support this option. Use the RFMXINSTR_ATTR_RF_PREAMP_PRESENT attribute to determine whether the downconverter has a preamplifier. Supported Devices: PXIe-5663/5663E/5665/5668
RFMXINSTR_VAL_PREAMP_AUTOMATIC (3)	Automatically enables the RF preamplifier based on the value of the reference level. Supported Devices: PXIe-5644/5645/5646, PXIe-5830/5831/5832/5840/5841

Data Type:	int32
Access:	read/write
Functions:	RFmxInstr_SetAttributeI32 RFmxInstr_GetAttributeI32
Description:	Specifies whether the RF IN connector is AC- or DC-coupled on the downconverter. You do not need to use a selector string if you want to configure this attribute for all signal instances. Specify the signal name in the selector string if you want to configure or read that signal instance. Refer to the Selector Strings topic for information about the string syntax. Note: For the PXIe-5665/5668, this attribute must be set to AC Coupled when the DC block is present, and set to DC Coupled when the DC block is not present to ensure device specifications are met and proper calibration data is used. For more information about removing or attaching the DC block, refer to the PXIe-5665 Theory of Operation or the PXIe-5668 Theory of Operation topics in the NI RF Vector Signal Analyzers Help. The default value is RFMXINSTR_VAL_CHANNEL_COUPLING_AC_COUPLED. Valid valuesPXIe-5665 (3.6 GHz): AC Coupled DC CoupledPXIe-5665 (14 GHz): AC Coupled, DC CoupledPXIe-5668: AC Coupled Supported devices: PXIe-5665/5668 Get Function: RFmxInstr_GetChannelCoupling Set Function: RFmxInstr_SetChannelCoupling
Values:

RFMXINSTR_VAL_CHANNEL_COUPLING_AC_COUPLED (0)	Specifies that the RF input channel is AC-coupled. For low frequencies ((10 MHz), accuracy decreases because RFmxInstr does not calibrate the configuration.
RFMXINSTR_VAL_CHANNEL_COUPLING_DC_COUPLED (1)	Specifies that the RF input channel is DC-coupled. RFmx enforces a minimum RF attenuation for device protection.

Data Type:	int32
Access:	read/write
Functions:	RFmxInstr_SetAttributeI32 RFmxInstr_GetAttributeI32
Description:	Specifies whether the tunable preselector is enabled on the downconverter. You do not need to use a selector string if you want to configure this attribute for all signal instances. Specify the signal name in the selector string if you want to configure or read that signal instance. Refer to the Selector Strings topic for information about the string syntax. The default value is RFMXINSTR_VAL_DOWNCONVERTER_PRESELECTOR_DISABLED. Supported devices: PXIe-5663/5663E/5665/5668, PXIe-5644/5645/5646, PXIe-5830/5831/5832/5840/5841 Get Function: RFmxInstr_GetDownconverterPreselectorEnabled Set Function: RFmxInstr_SetDownconverterPreselectorEnabled
Values:

RFMXINSTR_VAL_DOWNCONVERTER_PRESELECTOR_DISABLED (0)	Disables the preselector.
RFMXINSTR_VAL_DOWNCONVERTER_PRESELECTOR_ENABLED (1)	The preselector is automatically enabled when it is in the signal path and is automatically disabled when it is not in the signal path. Use the RFMXINSTR_ATTR_PRESELECTOR_PRESENT attribute to determine if the downconverter has a preselector.

Data Type:	float64
Access:	read/write
Functions:	RFmxInstr_SetAttributeF64 RFmxInstr_GetAttributeF64
Description:	Specifies the mixer level. This value is expressed in dBm. The mixer level represents the attenuation value to apply to the input RF signal as it reaches the first mixer in the signal chain. If you do not set this attribute, RFmx automatically selects an optimal mixer level value based on the reference level. If you set the RFMXINSTR_ATTR_MIXER_LEVEL and RFMXINSTR_ATTR_MIXER_LEVEL_OFFSET attributes at the same time, RFmx returns an error. This attribute is read-only for PXIe-5663/5663E devices. You do not need to use a selector string if you want to configure this attribute for all signal instances. Specify the signal name in the selector string if you want to configure or read that signal instance. Refer to the Selector Strings topic for information about the string syntax. Default valuesPXIe-5665/5668-10All other devices N/A The valid values for this attribute depend on your device configuration. Supported devices: PXIe-5663/5663E/5665/5668 Get Function: RFmxInstr_GetMixerLevel Set Function: RFmxInstr_SetMixerLevel

Data Type:	float64
Access:	read/write
Functions:	RFmxInstr_SetAttributeF64 RFmxInstr_GetAttributeF64
Description:	Specifies the number of dB by which to adjust the device mixer level. Specifying a positive value for this attribute configures the device for moderate distortion and low noise, and specifying a negative value results in low distortion and higher noise. You cannot set the RFMXINSTR_ATTR_MIXER_LEVEL_OFFSET and RFMXINSTR_ATTR_MIXER_LEVEL attributes at the same time. You do not need to use a selector string if you want to configure this attribute for all signal instances. Specify the signal name in the selector string if you want to configure or read that signal instance. Refer to the Selector Strings topic for information about the string syntax. The default value is 0. The default value specifies device settings that are the best compromise between distortion and noise. Supported devices: PXIe-5663/5663E/5665/5668 Get Function: RFmxInstr_GetMixerLevelOffset Set Function: RFmxInstr_SetMixerLevelOffset

Data Type:	float64
Access:	read/write
Functions:	RFmxInstr_SetAttributeF64 RFmxInstr_GetAttributeF64
Description:	Specifies the step size for the RF attenuation level. This value is expressed in dB. The actual RF attenuation is coerced up to the next highest multiple of the specified step size. If the mechanical attenuators are not available to implement the coerced RF attenuation, the solid state attenuators are used. You do not need to use a selector string if you want to configure this attribute for all signal instances. Specify the signal name in the selector string if you want to configure or read that signal instance. Refer to the Selector Strings topic for information about the string syntax. Default values: PXIe-5601/5663/5663E0.0PXIe-5603/5665 (3.6 GHz)1.0PXIe-5605/5665 (14 GHz), PXIe-5606/56685.0 Valid values: PXIe-5601/5663/5663E0.0 to 93.0, continuousPXIe-5603/5665 (3.6 GHz)1.0 to 74.0, in 1 dB stepsPXIe-5605/5665 (14 GHz) (low band), PXIe-5606/5668 (low band)1.0 to 106.0, in 1 dB stepsPXIe-5605/5665 (14 GHz) (high band), PXIe-5606/5668 (high band)5.0 to 75.0, in 5 dB steps Supported devices: PXIe-5663, PXIe-5665, PXIe-5668 Get Function: RFmxInstr_GetRFAttenuationStepSize Set Function: RFmxInstr_SetRFAttenuationStepSize

Data Type:	int32
Access:	read/write
Functions:	RFmxInstr_SetAttributeI32 RFmxInstr_GetAttributeI32
Description:	Specifies whether to enable the digitizer OSP block to delay Reference Triggers, along with the data samples, moving through the OSP block. If you set this attribute to Disabled, the Reference Triggers bypass the OSP block and are processed immediately. Enabling this attribute requires the following equipment configurations:All digitizers being used must be the same model and hardware revision. All digitizers must use the same firmware. All digitizers must be configured with the same I/Q rate. All devices must use the same signal path. For more information about the digitizer OSP block and Reference Triggers, refer to the following topics in the NI High-Speed Digitizers Help: PXIe-5622 Onboard Signal Processing (OSP)PXIe-5142 Onboard Signal Processing (OSP)PXIe-5622 Trigger SourcesPXI-5142 Trigger SourcesPXIe-5622 Block DiagramPXI-5142 Trigger Sources You do not need to use a selector string if you want to configure this attribute for all signal instances. Specify the signal name in the selector string if you want to configure or read that signal instance. Refer to the Selector Strings topic for information about the string syntax. The default value is RFMXINSTR_VAL_OSP_DELAY_ENABLED. Supported devices: PXIe-5663/5663E/5665/5668, PXIe-5820/5830/5831/5832/5840/5841 Get Function: RFmxInstr_GetOSPDelayEnabled Set Function: RFmxInstr_SetOSPDelayEnabled
Values:

RFMXINSTR_VAL_OSP_DELAY_DISABLED (0)	Disables the attribute.
RFMXINSTR_VAL_OSP_DELAY_ENABLED (1)	Enables the attribute.

Data Type:	float64
Access:	read/write
Functions:	RFmxInstr_SetAttributeF64 RFmxInstr_GetAttributeF64
Description:	Specifies the offset to apply to the initial I and Q phases. You do not need to use a selector string if you want to configure this attribute for all signal instances. Specify the signal name in the selector string if you want to configure or read that signal instance. Refer to the Selector Strings topic for information about the string syntax. The default value is 0. Valid values are -180 degrees to 180 degrees, inclusive. Supported devices: PXIe-5644/5645/5646, PXIe-5663/5663E/5665/5668, PXIe-5820/5830/5831/5832/5840/5841 Get Function: RFmxInstr_GetPhaseOffset Set Function: RFmxInstr_SetPhaseOffset

Data Type:	float64
Access:	read/write
Functions:	RFmxInstr_SetAttributeF64 RFmxInstr_GetAttributeF64
Description:	Specifies the FFT width of the device. The FFT width is the effective bandwidth of the signal path during each signal acquisition. The lower limit for all devices that support setting the RFMXINSTR_ATTR_FFT_WIDTH attribute is 7.325 kHz. PXIe-5663/5663E: The FFT width upper limit for the PXIe-5663/5663E depends on the RF frequency and on the module revision of the PXIe-5601. For more information about determining which revision of the PXIe-5601 RF downconverter you have installed, refer to the Identifying Module Revision topic in the NI RF Vector Signal Analyzers Help. The maximum FFT width for your device is constrained to 50 MHz or 25 MHz, depending on the digitizer option you purchased. You can use the RFMXINSTR_ATTR_FFT_WIDTH attribute with in-band retuning. For more information about in-band retuning, refer to the Downconverter Center Frequency attribute. RFmx treats the device instantaneous bandwidth as the effective real-time bandwidth of the signal path. The span specifies the frequency range of the computed spectrum. A signal analyzer can acquire a bandwidth only within the device instantaneous bandwidth. If the span you choose is greater than the device instantaneous bandwidth, RFmx obtains multiple acquisitions and combines them into a single spectrum. By specifying the FFT width, you can control the specific bandwidth obtained in each signal acquisition. You do not need to use a selector string if you want to configure this attribute for all signal instances. Specify the signal name in the selector string if you want to configure or read that signal instance. Refer to the Selector Strings topic for information about the string syntax. Supported devices: PXIe-5663/5663E/5665, PXIe-5668 Get Function: RFmxInstr_GetFFTWidth Set Function: RFmxInstr_SetFFTWidth

Data Type:	int32
Access:	read/write
Functions:	RFmxInstr_SetAttributeI32 RFmxInstr_GetAttributeI32
Description:	Specifies how to obtain the lowest noise floor or faster measurement speed. Some measurements, such as Spurious Emissions enable the RFMXINSTR_ATTR_CLEANER_SPECTRUM attribute by default. You can speed up those measurements by disabling the RFMXINSTR_ATTR_CLEANER_SPECTRUM attribute. You do not need to use a selector string if you want to configure this attribute for all signal instances. Specify the signal name in the selector string if you want to configure or read that signal instance. Refer to the Selector Strings topic for information about the string syntax. PXIe-5665 Sets the FFT Width attribute to take narrower bandwidth acquisitions and avoid digitizer spurs. Uses IF filters to reduce the noise floor for frequencies below 80 MHz. PXIe-5644/5645/5646, PXIe-5840/5841 Returns the best possible spectrum. PXIe-5668 Returns the best possible spectrum. To provide the best spectrum measurement, the acquisition is reduced to 100 MHz segments for any center frequency. Other devices This attribute is ignored. The default value is RFMXINSTR_VAL_CLEANER_SPECTRUM_DISABLED. Supported devices: PXIe-5665, PXIe-5668, PXIe-5644/5645/5646, PXIe-5840/5841 Get Function: RFmxInstr_GetCleanerSpectrum Set Function: RFmxInstr_SetCleanerSpectrum
Values:

RFMXINSTR_VAL_CLEANER_SPECTRUM_DISABLED (0)	Disable this attribute to get faster measurement speed.
RFMXINSTR_VAL_CLEANER_SPECTRUM_ENABLED (1)	Enable this attribute to get the lowest noise floor and avoid digitizer spurs.

Data Type:	float64
Access:	read/write
Functions:	RFmxInstr_SetAttributeF64 RFmxInstr_GetAttributeF64
Description:	Specifies the power offset by which to adjust the default IF output power level. This value is expressed in dB. This attribute does not depend on absolute IF output power levels; therefore, you can use this attribute to adjust the IF output power level on all RFmx-supported devices without knowing the exact default value. Use this attribute to increase or decrease the nominal output level to achieve better measurement results. You do not need to use a selector string if you want to configure this attribute for all signal instances. Specify the signal name in the selector string if you want to configure or read that signal instance. Refer to the Selector Strings topic for information about the string syntax. The default value is 0. Supported devices: PXIe-5663/5663E/5665, PXIe-5668 Get Function: RFmxInstr_GetIFOutputPowerLevelOffset Set Function: RFmxInstr_SetIFOutputPowerLevelOffset

Data Type:	int32
Access:	read/write
Functions:	RFmxInstr_SetAttributeI32 RFmxInstr_GetAttributeI32
Description:	Specifies whether dithering is enabled on the digitizer. Dithering adds band-limited noise in the analog signal path to help reduce the quantization effects of the ADC and improve spectral performance. On the PXIe-5622, this out-of-band noise is added at low frequencies of up to approximately 12 MHz. PXIe-5663/5663E/5665: When you enable dithering, the maximum signal level is reduced by up to 3 dB. This signal level reduction is accounted for in the nominal input ranges of the PXIe-5622. Therefore, you can overrange the input by up to 3 dB with dither disabled. For example, the +4 dBm input range can handle signal levels up to +7 dBm with dither disabled. For wider bandwidth acquisitions, such as 40 MHz, disable dithering to eliminate residual leakage of the dither signal into the lower frequencies of the IF passband, which starts at 12.5 MHz and ends at 62.5 MHz. This leakage can slightly raise the noise floor in the lower frequencies, thus degrading the performance in high-sensitivity applications. When performing spectral measurements, this leakage can also appear as a wide, low-amplitude signal near the 12.5 MHz and 62.5 MHz frequencies. The width and amplitude of the signal depends on your resolution bandwidth and the type of time-domain window you apply to your FFT. PXIe-5668: When you enable dithering, the maximum signal level is reduced by up to 2 dB. For the PXIe-5624, the maximum input power with dither off is 8 dBm and the maximum input power level with dither on is 6 dBm. When acquiring an 800 MHz bandwidth signal, the I/Q data contains the dither even if the dither signal is not in the displayed spectrum. The dither can affect actions like power level triggering. You do not need to use a selector string if you want to configure this attribute for all signal instances. Specify the signal name in the selector string if you want to configure or read that signal instance. Refer to the Selector Strings topic for information about the string syntax.For PXIe-5820/5830/5831/5832/5840/5841, only Enabled is supported. Note For the PXIe-5668, disabling dithering can negatively affect absolute amplitude accuracy. The default value is RFMXINSTR_VAL_DIGITIZER_DITHER_ENABLED. Supported devices: PXIe-5663/5663E/5665/5668, PXIe-5820/5830/5831/5832/5840/5841 Get Function: RFmxInstr_GetDigitizerDitherEnabled Set Function: RFmxInstr_SetDigitizerDitherEnabled
Values:

RFMXINSTR_VAL_DIGITIZER_DITHER_DISABLED (0)	Disables the attribute.
RFMXINSTR_VAL_DIGITIZER_DITHER_ENABLED (1)	Enables the attribute.

Data Type:	float64
Access:	read/write
Functions:	RFmxInstr_SetAttributeF64 RFmxInstr_GetAttributeF64
Description:	Specifies the IF filter path bandwidth for your device configuration. RFmx chooses an appropriate IF filter as default IF Filter based on measurement configuration, center frequency, cleaner spectrum and downconverter preselector. You do not need to use a selector string if you want to configure this attribute for all signal instances. Specify the signal name in the selector string if you want to configure or read that signal instance. Refer to the Selector Strings topic for information about the string syntax. Note For composite devices, such as the PXIe-5665/5668, the IF filter path bandwidth includes all IF filters across the component modules of a composite device. Supported devices: PXIe-5665/5668 Get Function: RFmxInstr_GetIFFilterBandwidth Set Function: RFmxInstr_SetIFFilterBandwidth

Data Type:	int32
Access:	read/write
Functions:	RFmxInstr_SetAttributeI32 RFmxInstr_GetAttributeI32
Description:	Specifies the delay duration units and interpretation for LO settling. Specify the actual settling value using the Frequency Settling attribute. You do not need to use a selector string if you want to configure this attribute for all signal instances. Specify the signal name in the selector string if you want to configure or read that signal instance. Refer to the Selector Strings topic for information about the string syntax. Note The Frequency Settling Units attribute is not supported if you are using an external LO. The default value is RFMXINSTR_VAL_FREQUENCY_SETTLING_UNITS_PPM. Supported devices: PXIe-5644/5645/5646, PXIe-5663/5663E/5665/5668, PXIe-5830/5831/5832/5840/5841 Get Function: RFmxInstr_GetFrequencySettlingUnits Set Function: RFmxInstr_SetFrequencySettlingUnits
Values:

RFMXINSTR_VAL_FREQUENCY_SETTLING_UNITS_PPM (0)	Specifies the frequency settling in parts per million (ppm).
RFMXINSTR_VAL_FREQUENCY_SETTLING_UNITS_SECONDS_AFTER_LOCK (1)	Specifies the frequency settling in time after lock (seconds).
RFMXINSTR_VAL_FREQUENCY_SETTLING_UNITS_SECONDS_AFTER_IO (2)	Specifies the frequency settling in time after I/O (seconds).

Data Type:	float64
Access:	read/write
Functions:	RFmxInstr_SetAttributeF64 RFmxInstr_GetAttributeF64
Description:	Specifies the value used for LO frequency settling. Specify the units and interpretation for this scalar value using the Frequency Settling Units attribute. Valid values You do not need to use a selector string if you want to configure this attribute for all signal instances. Specify the signal name in the selector string if you want to configure or read that signal instance. Refer to the Selector Strings topic for information about the string syntax. Frequency Settling Units Attribute Value PXIe-5663/5663E PXIe-5665/5668 PXIe-5644/5645/5646 PXIe-5830/5831/5832/5840/5841, PXIe-5831 with PXIe-5653 (using PXIe-3622 LO), PXIe-5832 with PXIe-5653 (using PXIe-3623 LO) PXIe-5831 with PXIe-5653 (using PXIe-5653 LO) and PXIe-5832 with PXIe-5653 (using PXIe-5653 LO) PXIe-5840 with PXIe-5653 (using internal LO) PXIe-5840 with PXIe-5653 (using PXIe-5653 LO) Seconds After Lock 2 µs to 80 ms, resolution of approximately 2 µs 4 µs to 80 ms, resolution of approximately 4 µs 1 µs to 65 ms, resolution of 1 µs 1 µs to 10s, resolution of 1 µs 4 µs to 80 ms, resolution of approximately 4 µs 1 µs to 10s, resolution of 1 µs 4 µs to 80 ms, resolution of approximately 4 µs Seconds After I/O 0 µs to 80 ms, resolution of 1 µs 0 µs to 80 ms, resolution of 1 µs 1 µs to 65 ms, resolution of 1 µs 0 µs to 10s, resolution of 1 µs 0 µs to 80 ms, resolution of 1 µs 0 µs to 10s, resolution of 1 µs 0 µs to 80 ms, resolution of 1 µs PPM 1.0, 0.1, 0.01 1.0, 0.1, 0.01, 0.001 1.0, 0.1, 0.01 1.0 to 0.01 1.0 to 0.01 1.0 to 0.01 1.0 to 0.001 Note This attribute is not supported if you are using an external LO. The default value is 0.1. Supported devices: PXIe-5644/5645/5646, PXIe-5663/5663E/5665/5668, PXIe-5830/5831/5832/5840/5841 Get Function: RFmxInstr_GetFrequencySettling Set Function: RFmxInstr_SetFrequencySettling

Data Type:	float64
Access:	read/write
Functions:	RFmxInstr_SetAttributeF64 RFmxInstr_GetAttributeF64
Description:	Specifies the maximum corner frequency of the high pass filter in the RF signal path. The device uses the highest frequency high-pass filter option below or equal to the value you specify and returns a coerced value. Specifying a value of 0 disables high pass filtering silly. For multispan acquisitions, the device uses the appropriate filter for each subspan during acquisition, depending on the details of your application and the value you specify. In multispan acquisition spectrum applications, this attribute returns the value you specified rather than a coerced value if multiple high-pass filters are used during the acquisition. You do not need to use a selector string if you want to configure this attribute for all signal instances. Specify the signal name in the selector string if you want to configure or read that signal instance. Refer to the Selector Strings topic for information about the string syntax. The default value is 0. The valid values range from 0 to 26.5. Supported devices: PXIe-5668 Get Function: RFmxInstr_GetRFHighpassFilterFrequency Set Function: RFmxInstr_SetRFHighpassFilterFrequency

Data Type:	float64
Access:	read/write
Functions:	RFmxInstr_SetAttributeF64 RFmxInstr_GetAttributeF64
Description:	Specifies the amount of overlap between consecutive subspans in a multispan spectrum acquisition. Overlapping subspans can reduce the power level of spurs in the acquired data. The value you specify determines the amount of shift as a percentage of subspan width. Specifying a value of 0 disables subspan overlap. In this case, RFmx uses either a single-span acquisition or a multispan acquisition without overlap, depending on the frequency range requested and the current device settings. Specifying a value greater than 0 causes RFmx to use a multispan acquisition with the specified overlap even in situations in which it would normally use a single-span acquisition. RFmx acquires data within the overlapped percentage and uses the minimum of the acquired values. RFmx may apply further shifts to the specified value to accommodate fixed-frequency edges of components such as preselectors. You do not need to use a selector string if you want to configure this attribute for all signal instances. Specify the signal name in the selector string if you want to configure or read that signal instance. Refer to the Selector Strings topic for information about the string syntax. The default value is 0. Valid values PXIe-5820/5830/5831/5832/5840/5841: 0 PXIe-5665/5668: 0 to 100 Supported devices: PXIe-5665/5668, PXIe-5820/5830/5831/5832/5840/5841 Get Function: RFmxInstr_GetSubSpanOverlap Set Function: RFmxInstr_SetSubSpanOverlap

Data Type:	float64
Access:	read only
Functions:	RFmxInstr_GetAttributeF64
Description:	Returns the net signal gain for the device at the current RFmx settings and temperature. RFmx scales the acquired I/Q and spectrum data from the digitizer using the value of this attribute. For a vector signal analyzer (VSA), the system is defined as the RF downconverter for all interfaces between the RF IN connector on the RF downconverter front panel and the IF IN connector on the digitizer front panel. For a spectrum monitoring receiver, the system is defined as the RF preselector, RF downconverter, and IF conditioning modules including all interfaces between the RF IN connector on the RF preselector module front panel and the IF IN connector on the digitizer front panel. This attribute is not supported on a MIMO session. You do not need to use a selector string if you want to configure this attribute for all signal instances. Specify the signal name in the selector string if you want to configure or read that signal instance. Refer to the Selector Strings topic for information about the string syntax. The default value is N/A. Supported devices: PXIe-5644/5645/5646, PXIe-5663/5663E/5665/5668, PXIe-5830/5831/5832/5840/5841 Get Function: RFmxInstr_GetDownconverterGain

Data Type:	float64
Access:	read/write
Functions:	RFmxInstr_SetAttributeF64 RFmxInstr_GetAttributeF64
Description:	Specifies the amplitude settling accuracy value. This value is expressed in decibels. RFmx waits until the RF power attains the specified accuracy level after calling the RFmx Initiate function. Any specified amplitude settling value that is above the acceptable minimum value is coerced down to the closest valid value. You do not need to use a selector string if you want to configure this attribute for all signal instances. Specify the signal name in the selector string if you want to configure or read that signal instance. Refer to the Selector Strings topic for information about the string syntax. Supported Devices: PXIe-5644/5645/5646, PXIe-5820/5830/5831/5832/5840/5841 Get Function: RFmxInstr_GetAmplitudeSettling Set Function: RFmxInstr_SetAmplitudeSettling

Data Type:	int32
Access:	read/write
Functions:	RFmxInstr_SetAttributeI32 RFmxInstr_GetAttributeI32
Description:	Configures error reporting for ADC and overflows occurred during onboard signal processing. Overflows lead to clipping of the waveform. You do not need to use a selector string if you want to configure this attribute for all signal instances. Specify the signal name in the selector string if you want to configure or read that signal instance. Refer to the Selector Strings topic for information about the string syntax. The default value is RFMXINSTR_VAL_OVERFLOW_ERROR_REPORTING_WARNING. Supported devices: PXIe-5644/5645/5646, PXIe-5820/5830/5831/5832/5840/5841 Get Function: RFmxInstr_GetOverflowErrorReporting Set Function: RFmxInstr_SetOverflowErrorReporting
Values:

RFMXINSTR_VAL_OVERFLOW_ERROR_REPORTING_WARNING (0)	RFmx returns a warning when an ADC or an onboard signal processing (OSP) overflow occurs.
RFMXINSTR_VAL_OVERFLOW_ERROR_REPORTING_DISABLED (1)	RFmx does not return an error or a warning when an ADC or OSP overflow occurs.

Data Type:	float64
Access:	read/write
Functions:	RFmxInstr_SetAttributeF64 RFmxInstr_GetAttributeF64
Description:	Specifies the common-mode level presented at each differential input terminal. The common-mode level shifts both positive and negative terminals in the same direction. This must match the common-mode level of the device under test (DUT). This value is expressed in Volts. You do not need to use a selector string if you want to configure this attribute for all signal instances. Specify the signal name in the selector string if you want to configure or read that signal instance. Refer to the Selector Strings topic for information about the string syntax. The default value is 0. Supported devices: PXIe-5820 Get Function: RFmxInstr_GetCommonModeLevel Set Function: RFmxInstr_SetCommonModeLevel

Data Type:	char []
Access:	read/write
Functions:	RFmxInstr_SetAttributeString RFmxInstr_GetAttributeString
Description:	Specifies the resource name assigned by Measurement and Automation Explorer (MAX) for NI Source Measure Units (SMU) which is used as the noise source power supply for Noise Figure (NF) measurement, for example, PXI1Slot3, where PXI1Slot3 is an instrument resource name. RFMXINSTR_ATTR_SMU_RESOURCE_NAME can also be a logical IVI name. Supported devices: PXIe-4138, PXIe-4139, PXIe-4139 (40 W), and PXIe-4143 SMUs. Get Function: RFmxInstr_GetSMUResourceName Set Function: RFmxInstr_SetSMUResourceName

Data Type:	char []
Access:	read/write
Functions:	RFmxInstr_SetAttributeString RFmxInstr_GetAttributeString
Description:	Specifies the output channel to be used for noise figure (NF) measurement in RFmx. The default value is 0. Get Function: RFmxInstr_GetSMUChannel Set Function: RFmxInstr_SetSMUChannel

Data Type:	int32
Access:	read/write
Functions:	RFmxInstr_SetAttributeI32 RFmxInstr_GetAttributeI32
Description:	Optimizes RF path for the signal bandwidth that is centered on the IQ carrier frequency. You can disable this attribute to avoid changes to the RF path when changing the signal bandwidth. You do not need to use a selector string if you want to configure this attribute for all signal instances. Specify the signal name in the selector string if you want to configure or read that signal instance. Refer to the Selector Strings topic for information about the string syntax. The default value is RFMXINSTR_VAL_OPTIMIZE_PATH_FOR_SIGNAL_BANDWIDTH_AUTOMATIC. Supported devices: PXIe-5830/5831/5832/5841 Get Function: RFmxInstr_GetOptimizePathForSignalBandwidth Set Function: RFmxInstr_SetOptimizePathForSignalBandwidth
Values:

RFMXINSTR_VAL_OPTIMIZE_PATH_FOR_SIGNAL_BANDWIDTH_DISABLED (0)	Disables the optimized path for signal bandwidth.
RFMXINSTR_VAL_OPTIMIZE_PATH_FOR_SIGNAL_BANDWIDTH_ENABLED (1)	Enables the optimized path for signal bandwidth.
RFMXINSTR_VAL_OPTIMIZE_PATH_FOR_SIGNAL_BANDWIDTH_AUTOMATIC (2)	Automatically enables the optimized path based on other configurations.

Data Type:	int32
Access:	read/write
Functions:	RFmxInstr_SetAttributeI32 RFmxInstr_GetAttributeI32
Description:	Specifies whether input isolation is enabled. Enabling this attribute isolates the input signal at the RF IN connector on the RF downconverter from the rest of the RF downconverter signal path. Disabling this attribute reintegrates the input signal into the RF downconverter signal path. If you enable input isolation for your device, the device impedance is changed from the characteristic 50-ohm impedance. A change in the device impedance may increase the VSWR value higher than the device specifications. For PXIe-5830/5831/5832, input isolation is supported for all available ports for your hardware configuration. You do not need to use a selector string if you want to configure this attribute for all signal instances. Specify the signal name in the selector string if you want to configure or read that signal instance. Refer to the Selector Strings topic for information about the string syntax. The default value is RFMXINSTR_VAL_INPUT_ISOLATION_DISABLED. Supported devices: PXIe-5644/5645/5646, PXIe-5663/5663E/5665/5668, PXIe-5820/5830/5831/5832/5840/5841 Get Function: RFmxInstr_GetInputIsolationEnabled Set Function: RFmxInstr_SetInputIsolationEnabled
Values:

RFMXINSTR_VAL_INPUT_ISOLATION_DISABLED (0)	Indicates that the attribute is disabled.
RFMXINSTR_VAL_INPUT_ISOLATION_ENABLED (1)	Indicates that the attribute is enabled.

Data Type:	float64
Access:	read/write
Functions:	RFmxInstr_SetAttributeF64 RFmxInstr_GetAttributeF64
Description:	Specifies the expected thermal operating range of the instrument from the self-calibration temperature returned from the RFMXINSTR_ATTR_DEVICE_TEMPERATURE attribute. This value is expressed in degree Celsius. For example, if this attribute is set to 5.0, and the device is self-calibrated at 35 degrees Celsius, then you can expect to run the device from 30 degrees Celsius to 40 degrees Celsius with corrected accuracy and no overflows. Setting this attribute with a smaller value can result in improved dynamic range, but you must ensure thermal stability while the instrument is running. Operating the instrument outside of the specified range may cause degraded performance and ADC or DSP overflows. You do not need to use a selector string if you want to configure this attribute for all signal instances. Specify the signal name in the selector string if you want to configure or read that signal instance. Refer to the Selector Strings topic for information about the string syntax. Default valuePXIe-5830/5831/58325PXIe-5840/584110 Supported devices: PXIe-5830/5831/5832/5840/5841 Get Function: RFmxInstr_GetThermalCorrectionHeadroomRange Set Function: RFmxInstr_SetThermalCorrectionHeadroomRange

Data Type:	float64
Access:	read/write
Functions:	RFmxInstr_SetAttributeF64 RFmxInstr_GetAttributeF64
Description:	Specifies the minimum time difference between temperature sensor readings. This value is expressed in seconds. When you call the RFmx Initiate function, RFmx checks if the amount of time specified by this attribute has elapsed before reading the hardware temperature. RFmx ignores Temperature Read Interval attribute if you read the Downconverter Gain attribute. You do not need to use a selector string if you want to configure this attribute for all signal instances. Specify the signal name in the selector string if you want to configure or read that signal instance. Refer to the Selector Strings topic for information about the string syntax. The default value is 30 seconds. Supported devices: PXIe-5663/5663E/5665/5668, PXIe-5820/5830/5831/5832/5840/5841 Get Function: RFmxInstr_GetTemperatureReadInterval Set Function: RFmxInstr_SetTemperatureReadInterval

Data Type:	float64
Access:	read/write
Functions:	RFmxInstr_SetAttributeF64 RFmxInstr_GetAttributeF64
Description:	Specifies the temperature change required before RFmx recalculates the thermal correction settings when entering the running state. This value is expressed in degree Celsius. You do not need to use a selector string if you want to configure this attribute for all signal instances. Specify the signal name in the selector string if you want to configure or read that signal instance. Refer to the Selector Strings topic for information about the string syntax. Default valuePXIe-5830/5831/58320.2PXIe-5840/58411.0 Supported devices: PXIe-5830/5831/5832/5840/5841 Get Function: RFmxInstr_GetThermalCorrectionTemperatureResolution Set Function: RFmxInstr_SetThermalCorrectionTemperatureResolution

Data Type:	int32
Access:	read/write
Functions:	RFmxInstr_SetAttributeI32 RFmxInstr_GetAttributeI32
Description:	Specifies whether RFmx validates the self-calibration data. You can specify the time interval required to perform the check using the RFMXINSTR_ATTR_SELF_CALIBRATION_VALIDITY_CHECK_TIME_INTERVAL attribute. NI recommends to perform self-calibration using the RFmxInstr_SelfCalibrate function when RFmx reports an invalid self-calibration data warning. RFmx does not consider self-calibration range data during self calibration validity check. The default value is RFMXINSTR_VAL_SELF_CALIBRATION_VALIDITY_CHECK_OFF. Supported devices: PXIe-5663/5663E/5665/5668, PXIe-5644/5645/5646, PXIe-5820/5830/5840/5841 Get Function: RFmxInstr_GetSelfCalibrationValidityCheck Set Function: RFmxInstr_SetSelfCalibrationValidityCheck
Values:

RFMXINSTR_VAL_SELF_CALIBRATION_VALIDITY_CHECK_OFF (0)	Indicates that RFmx does not check whether device self-calibration data is valid.
RFMXINSTR_VAL_SELF_CALIBRATION_VALIDITY_CHECK_ENABLED (1)	Indicates that RFmx checks whether device self-calibration data is valid and reports a warning from the RFmx Commit and RFmx Initiate functions when the data is invalid.

Data Type:	float64
Access:	read/write
Functions:	RFmxInstr_SetAttributeF64 RFmxInstr_GetAttributeF64
Description:	Specifies the minimum time between two self calibration validity checks. This value is expressed in seconds. When you call RFmx Commit or Initiate functions by enabling the RFMXINSTR_ATTR_SELF_CALIBRATION_VALIDITY_CHECK attribute, RFmx checks if the amount of time specified by the Self Calibration Validity Check Time Interval attribute has elapsed before validating the calibration data. The default value is 30 seconds. Supported devices: PXIe-5663/5663E/5665/5668, PXIe-5644/5645/5646, PXIe-5820/5830/5840/5841 Get Function: RFmxInstr_GetSelfCalibrationValidityCheckTimeInterval Set Function: RFmxInstr_SetSelfCalibrationValidityCheckTimeInterval