NIRFSG_ATTR_IQ_RATE

NIRFSG_ATTR_IQ_RATE

Description

This attribute specifies the I/Q rate of the arbitrary waveform. The I/Q rate is coerced to a value the hardware can achieve. Read this value back after setting it to see the actual I/Q rate. NI-RFSG internally uses an FIR filter with flat response up to (0.4 × IQ rate). Given a desired signal with the maximum frequency content f, sample the signal at an I/Q rate greater than or equal to (f/0.4).

This attribute applies only when the NIRFSG_ATTR_GENERATION_MODE attribute is set to NIRFSG_VAL_ARB_WAVEFORM or NIRFSG_VAL_SCRIPT.

Note  Use this attribute to associate an I/Q rate with a waveform.

To set this attribute, the NI-RFSG device must be in the Configuration state.

Valid Values:

Device	I/Q Rates
PXIe-5644/5645	Up to 120 MS/s.
PXIe-5646	Up to 250 MS/s.
PXI-5670	50 MS/s*
	100 MS/s
PXI-5671	50 MS/s*
	100 MS/s
	*(100 MS/s)/n, where n is divisible by 2 between 12 to 512, and divisible by 4 between 512 to 1,024 (n = 12, 14, 16, ..., 512, 516, 520, ..., 1,024). Setting the I/Q rate to one of these value enables the DUC.
PXIe-5672	Up to 100 MS/s.
PXIe-5673/5673E	Up to 200 MS/s. Note  If an PXIe-5450 with module revisions A or B is used as part of your PXIe-5673/5673E, the NI-FGEN NIFGEN_ATTR_COMPENSATE_FOR_FILTER_GROUP_DELAY attribute is disabled if the requested I/Q rate is less than 1.5 MS/s.
PXIe-5820/5830/5831/5832/5840/5841	Up to 1.25 GS/s.
Setting this attribute to 50 MS/s on the PXI-5670/5671 and PXIe-5672 has the following implications: NI-RFSG is forced to place the carrier frequency at 18 MHz ± 1 MHz to avoid aliasing. Forcing the IF carrier frequency to that point implies that NI-RFSG cannot select a carrier frequency that could optimize the waveform size if phase continuity is enabled. Output signal bandwidth must be <5 MHz to avoid aliasing. Close-in phase noise is higher.

Supported Devices: PXIe-5644/5645/5646, PXI-5670/5671, PXIe-5672/5673/5673E, PXIe-5820/5830/5831/5832/5840/5841

Related Topics

Streaming

Assigning Properties or Attributes to a Waveform—Refer to this topic for more information about using this attribute to associate an I/Q rate with a waveform.

Digital Upconverter