niRFSA Fetch IQ VI

NI RF Vector Signal Analyzers (NI-RFSA 18.1) Help

Edition Date: June 2018

Part Number: 372058U-01

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Transfers acquired waveform data from device memory to computer memory; this process is also known as fetching. The data transferred was acquired to onboard memory previously by the hardware after the acquisition was initiated.

If the number of samples specified in samples to read is not available after the time duration specified in timeout, this VI returns no data with a timeout error.

This VI is not necessary if you use the niRFSA Read IQ VI, because the niRFSA Read IQ VI automatically performs the fetch.

Supported Devices: PXIe-5644/5645/5646, PXI-5661, PXIe-5663/5663E/5665/5667/5668, PXIe-5820/5840

Related Topics

None (Trigger Type)

Use the pull-down menu to select an instance of this VI.

niRFSA Fetch IQ (Complex WDT 1Rec 1Chan)

Fetches I/Q data from a single record in an acquisition.

Supported Devices: PXIe-5644/5645/5646, PXI-5661, PXIe-5663/5663E/5665/5667/5668, PXIe-5820/5840

niRFSA Fetch IQ (Complex WDT 1Rec 1Chan)

/images/reference/en-XX/help/372058U-01/cio.gif

instrument handle identifies your instrument session. instrument handle is obtained from the niRFSA Initialize VI or the niRFSA Initialize With Options VI.

/images/reference/en-XX/help/372058U-01/ci32.gif

samples to read specifies the number of samples to fetch. A value of -1 specifies that NI-RFSA fetches all samples. The default value is -1.

Note  Setting samples to read to –1 fetches all remaining samples currently available depending on the Fetch Relative To property and the Fetch Offset property settings.
/images/reference/en-XX/help/372058U-01/cdbl.gif

timeout specifies the time, in seconds, allotted for the VI to complete before returning a timeout error for the PXI-5661, PXIe-5663/5665/5667. Specifies the time, in seconds, allotted to receive the reference trigger for the PXIe-5644/5645/5646, PXIe-5668, and PXIe-5820/5840.

Note   A value of -1 specifies that the VI waits until all data is available. A value of 0 specifies the VI immediately returns available data. The default value is 10.
/images/reference/en-XX/help/372058U-01/cenum.gif

timestamp type specifies the time format of the data output. The default value is Relative.

Relative The timestamp corresponds to the difference, in seconds, between the first sample returned and the Reference Trigger location.
Absolute The timestamp corresponds to the date and time of the acquisition of the first sample returned.
Note  The value of the absolute timestamp returned is always 0 for the PXIe-5644/5645/5646, PXIe-5668, and PXIe-5820/5840. The value of the relative timestamp returned is always 0 for the PXIe-5644/5645/5646.
/images/reference/en-XX/help/372058U-01/ci32.gif

record to fetch specifies the record to retrieve. Record numbers are zero-based. The default value is 0.

/images/reference/en-XX/help/372058U-01/cerrcodeclst.gif

error in describes error conditions that occur before this node runs. This input provides standard error in functionality.

/images/reference/en-XX/help/372058U-01/iio.gif

instrument handle out passes a reference to your instrument session to the next VI. instrument handle is obtained from the niRFSA Initialize VI or the niRFSA Initialize With Options VI and identifies a particular instrument session.

/images/reference/en-XX/help/372058U-01/iwfm.gif

data returns the baseband (downconverted) time-domain data for demodulation.

/images/reference/en-XX/help/372058U-01/ierrcodeclst.gif

error out contains error information. This output provides standard error out functionality.

niRFSA Fetch IQ (Complex Cluster 1Rec 1Chan)

Fetches I/Q data from a single record in an acquisition.

Supported Devices: PXIe-5644/5645/5646, PXI-5661, PXIe-5663/5663E/5665/5667/5668, PXIe-5820/5840

niRFSA Fetch IQ (Complex Cluster 1Rec 1Chan)

/images/reference/en-XX/help/372058U-01/cio.gif

instrument handle identifies your instrument session. instrument handle is obtained from the niRFSA Initialize VI or the niRFSA Initialize With Options VI.

/images/reference/en-XX/help/372058U-01/ci32.gif

samples to read specifies the number of samples to fetch. A value of -1 specifies that NI-RFSA fetches all samples. The default value is -1.

Note  Setting samples to read to –1 fetches all remaining samples currently available depending on the Fetch Relative To property and the Fetch Offset property settings.
/images/reference/en-XX/help/372058U-01/cdbl.gif

timeout specifies the time, in seconds, allotted for the VI to complete before returning a timeout error for the PXI-5661, PXIe-5663/5665/5667. Specifies the time, in seconds, allotted to receive the reference trigger for the PXIe-5644/5645/5646, PXIe-5668, and PXIe-5820/5840.

Note   A value of -1 specifies that the VI waits until all data is available. A value of 0 specifies the VI immediately returns available data. The default value is 10.
/images/reference/en-XX/help/372058U-01/ci32.gif

record to fetch specifies the record to retrieve. Record numbers are zero-based. The default value is 0.

/images/reference/en-XX/help/372058U-01/cerrcodeclst.gif

error in describes error conditions that occur before this node runs. This input provides standard error in functionality.

/images/reference/en-XX/help/372058U-01/iio.gif

instrument handle out passes a reference to your instrument session to the next VI. instrument handle is obtained from the niRFSA Initialize VI or the niRFSA Initialize With Options VI and identifies a particular instrument session.

/images/reference/en-XX/help/372058U-01/icclst.gif

data returns the acquired data as a cluster.

/images/reference/en-XX/help/372058U-01/idbl.gif

t0 returns the start time of the first sample returned. The timestamp corresponds to the difference in seconds between the first sample returned and the Reference Trigger location.

Note  The value of t0 returned in data is always 0 for the PXIe-5644/5645/5646.
/images/reference/en-XX/help/372058U-01/idbl.gif

dt returns the time interval between data points in the acquired signal. The I/Q data sample rate is the reciprocal of this value.

/images/reference/en-XX/help/372058U-01/i1dcdb.gif

Y returns the complex-value time domain data array.

The real and imaginary parts of this complex data array correspond to the in-phase (I) and quadrature-phase (Q) data, respectively. To calculate the instantaneous power of a sampled I/Q point, use the equation (I2 + Q2)/2R, where R is the input impedance in ohms (Ω). For vector signal analyzers, R=50 Ω.

Note  The size of the array can vary per record if the Number of Samples property changes per step during RF list mode.
/images/reference/en-XX/help/372058U-01/ierrcodeclst.gif

error out contains error information. This output provides standard error out functionality.

niRFSA Fetch IQ (Complex Cluster CSGL 1Rec 1Chan)

Fetches I/Q data from a single record in an acquisition.

Supported Devices: PXIe-5644/5645/5646, PXI-5661, PXIe-5663/5663E/5665/5667/5668, PXIe-5820/5840

niRFSA Fetch IQ (Complex Cluster CSGL 1Rec 1Chan)

/images/reference/en-XX/help/372058U-01/cio.gif

instrument handle identifies your instrument session. instrument handle is obtained from the niRFSA Initialize VI or the niRFSA Initialize With Options VI.

/images/reference/en-XX/help/372058U-01/ci32.gif

samples to read specifies the number of samples to fetch. A value of -1 specifies that NI-RFSA fetches all samples. The default value is -1.

Note  Setting samples to read to –1 fetches all remaining samples currently available depending on the Fetch Relative To property and the Fetch Offset property settings.
/images/reference/en-XX/help/372058U-01/cdbl.gif

timeout specifies the time, in seconds, allotted for the VI to complete before returning a timeout error for the PXI-5661, PXIe-5663/5665/5667. Specifies the time, in seconds, allotted to receive the reference trigger for the PXIe-5644/5645/5646, PXIe-5668, and PXIe-5820/5840.

Note   A value of -1 specifies that the VI waits until all data is available. A value of 0 specifies the VI immediately returns available data. The default value is 10.
/images/reference/en-XX/help/372058U-01/ci32.gif

record to fetch specifies the record to retrieve. Record numbers are zero-based. The default value is 0.

/images/reference/en-XX/help/372058U-01/cerrcodeclst.gif

error in describes error conditions that occur before this node runs. This input provides standard error in functionality.

/images/reference/en-XX/help/372058U-01/iio.gif

instrument handle out passes a reference to your instrument session to the next VI. instrument handle is obtained from the niRFSA Initialize VI or the niRFSA Initialize With Options VI and identifies a particular instrument session.

/images/reference/en-XX/help/372058U-01/icclst.gif

data returns the acquired data as a cluster.

/images/reference/en-XX/help/372058U-01/idbl.gif

t0 returns the start time of the first sample returned. The timestamp corresponds to the difference in seconds between the first sample returned and the Reference Trigger location.

Note  The value of t0 returned in data is always 0 for the PXIe-5644/5645/5646.
/images/reference/en-XX/help/372058U-01/idbl.gif

dt returns the time interval between data points in the acquired signal. The I/Q data sample rate is the reciprocal of this value.

/images/reference/en-XX/help/372058U-01/i1dcsg.gif

Y returns the complex-value time domain data array.

The real and imaginary parts of this complex data array correspond to the in-phase (I) and quadrature-phase (Q) data, respectively. To calculate the instantaneous power of a sampled I/Q point, use the equation (I2 + Q2)/2R, where R is the input impedance in ohms (Ω). For vector signal analyzers, R = 50 Ω.

/images/reference/en-XX/help/372058U-01/ierrcodeclst.gif

error out contains error information. This output provides standard error out functionality.

niRFSA Fetch IQ (1D I16)

Fetches binary I/Q data from a single record in an acquisition.

Supported Devices: PXIe-5644/5645/5646, PXI-5661, PXIe-5663/5663E/5665/5667/5668, PXIe-5820/5840

niRFSA Fetch IQ (1D I16)

/images/reference/en-XX/help/372058U-01/cio.gif

instrument handle identifies your instrument session. instrument handle is obtained from the niRFSA Initialize VI or the niRFSA Initialize With Options VI.

/images/reference/en-XX/help/372058U-01/ci32.gif

samples to read specifies the number of samples to fetch. A value of -1 specifies that NI-RFSA fetches all samples. The default value is -1.

Note  Setting samples to read to –1 fetches all remaining samples currently available depending on the Fetch Relative To property and the Fetch Offset property settings.
/images/reference/en-XX/help/372058U-01/cdbl.gif

timeout specifies the time, in seconds, allotted for the VI to complete before returning a timeout error for the PXI-5661, PXIe-5663/5665/5667. Specifies the time, in seconds, allotted to receive the reference trigger for the PXIe-5644/5645/5646, PXIe-5668, and PXIe-5820/5840.

Note   A value of -1 specifies that the VI waits until all data is available. A value of 0 specifies the VI immediately returns available data. The default value is 10.
/images/reference/en-XX/help/372058U-01/ci32.gif

record to fetch specifies the record to retrieve. Record numbers are zero-based. The default value is 0.

/images/reference/en-XX/help/372058U-01/cerrcodeclst.gif

error in describes error conditions that occur before this node runs. This input provides standard error in functionality.

/images/reference/en-XX/help/372058U-01/iio.gif

instrument handle out passes a reference to your instrument session to the next VI. instrument handle is obtained from the niRFSA Initialize VI or the niRFSA Initialize With Options VI and identifies a particular instrument session.

/images/reference/en-XX/help/372058U-01/i1di16.gif

data returns the acquired unscaled, complex waveform. The array is composed of interleaved I and Q samples, where the order of the array is as follows:

Array[0] = I(0)

Array[1] = Q(0)

Array[2] = I(1)

Array[3] = Q(1)

/images/reference/en-XX/help/372058U-01/inclst.gif

wfm info contains the absolute and relative timestamps for the operation, the time interval, and the actual number of samples read.

/images/reference/en-XX/help/372058U-01/idbl.gif

absolute timestamp returns the timestamp, in seconds, of the first fetched sample that is comparable between records and acquisitions.

Note  The value of the absolute timestamp returned is always 0 for the PXIe-5644/5645/5646, PXIe-5668, and PXIe-5820/5840.
/images/reference/en-XX/help/372058U-01/idbl.gif

relative timestamp returns a timestamp that corresponds to the difference, in seconds, between the first sample returned and the Reference Trigger location.

Note  The value of the relative timestamp returned is always 0 for the PXIe-5644/5645/5646.
/images/reference/en-XX/help/372058U-01/idbl.gif

dt returns the time interval between data points in the acquired signal. The I/Q data sample rate is the reciprocal of this value.

/images/reference/en-XX/help/372058U-01/ii32.gif

actual samples read returns an integer representing the number of samples in the waveform.

/images/reference/en-XX/help/372058U-01/idbl.gif

offset returns the offset to scale data, (b), in mx + b form.

/images/reference/en-XX/help/372058U-01/idbl.gif

gain returns the gain to scale data, (m), in mx + b form.

/images/reference/en-XX/help/372058U-01/ierrcodeclst.gif

error out contains error information. This output provides standard error out functionality.

niRFSA Fetch IQ (1D Complex WDT NRec 1Chan)

Fetches I/Q data from multiple records in an acquisition.

Supported Devices: PXIe-5644/5645/5646, PXI-5661, PXIe-5663/5663E/5665/5667/5668, PXIe-5820/5840

niRFSA Fetch IQ (1D Complex WDT NRec 1Chan)

/images/reference/en-XX/help/372058U-01/cio.gif

instrument handle identifies your instrument session. instrument handle is obtained from the niRFSA Initialize VI or the niRFSA Initialize With Options VI.

/images/reference/en-XX/help/372058U-01/ci32.gif

samples to read specifies the number of samples to fetch. A value of -1 specifies that NI-RFSA fetches all samples. The default value is -1.

Note  Setting samples to read to –1 fetches all remaining samples currently available depending on the Fetch Relative To property and the Fetch Offset property settings.
/images/reference/en-XX/help/372058U-01/cdbl.gif

timeout specifies the time, in seconds, allotted for the VI to complete before returning a timeout error for the PXI-5661, PXIe-5663/5665/5667. Specifies the time, in seconds, allotted to receive the reference trigger for the PXIe-5644/5645/5646, PXIe-5668, and PXIe-5820/5840.

Note   A value of -1 specifies that the VI waits until all data is available. A value of 0 specifies the VI immediately returns available data. The default value is 10.
/images/reference/en-XX/help/372058U-01/cenum.gif

timestamp type specifies the time format of the data output. The default value is Relative.

Relative The timestamp corresponds to the difference, in seconds, between the first sample returned and the Reference Trigger location.
Absolute The timestamp corresponds to the date and time of the acquisition of the first sample returned.
Note  The value of the absolute timestamp returned is always 0 for the PXIe-5644/5645/5646, PXIe-5668, and PXIe-5820/5840. The value of the relative timestamp returned is always 0 for the PXIe-5644/5645/5646.
/images/reference/en-XX/help/372058U-01/ci32.gif

number of records specifies the number of records to fetch. A value of -1 specifies that NI-RFSA fetches all records in an acquisition. Record numbers are zero-based. The default value is -1.

If starting record is set to a value greater than 0, setting number of records to –1 returns an error. If you set starting record to a value greater than 0, set number of records to the exact number of records to fetch.

Note  If you set number of records to 0, this VI returns an error.
/images/reference/en-XX/help/372058U-01/ci32.gif

starting record specifies the first record to retrieve. Record numbers are zero-based. The default value is 0.

/images/reference/en-XX/help/372058U-01/cerrcodeclst.gif

error in describes error conditions that occur before this node runs. This input provides standard error in functionality.

/images/reference/en-XX/help/372058U-01/iio.gif

instrument handle out passes a reference to your instrument session to the next VI. instrument handle is obtained from the niRFSA Initialize VI or the niRFSA Initialize With Options VI and identifies a particular instrument session.

/images/reference/en-XX/help/372058U-01/i1dwfm.gif

data returns the acquired waveform.

/images/reference/en-XX/help/372058U-01/ierrcodeclst.gif

error out contains error information. This output provides standard error out functionality.

niRFSA Fetch IQ (1D Complex Cluster NRec 1Chan)

Fetches I/Q data from multiple records in an acquisition.

Supported Devices: PXIe-5644/5645/5646, PXI-5661, PXIe-5663/5663E/5665/5667/5668, PXIe-5820/5840

niRFSA Fetch IQ (1D Complex Cluster NRec 1Chan)

/images/reference/en-XX/help/372058U-01/cio.gif

instrument handle identifies your instrument session. instrument handle is obtained from the niRFSA Initialize VI or the niRFSA Initialize With Options VI.

/images/reference/en-XX/help/372058U-01/ci32.gif

samples to read specifies the number of samples to fetch. A value of -1 specifies that NI-RFSA fetches all samples. The default value is -1.

Note  Setting samples to read to –1 fetches all remaining samples currently available depending on the Fetch Relative To property and the Fetch Offset property settings.
/images/reference/en-XX/help/372058U-01/cdbl.gif

timeout specifies the time, in seconds, allotted for the VI to complete before returning a timeout error for the PXI-5661, PXIe-5663/5665/5667. Specifies the time, in seconds, allotted to receive the reference trigger for the PXIe-5644/5645/5646, PXIe-5668, and PXIe-5820/5840.

Note   A value of -1 specifies that the VI waits until all data is available. A value of 0 specifies the VI immediately returns available data. The default value is 10.
/images/reference/en-XX/help/372058U-01/ci32.gif

number of records specifies the number of records to fetch. A value of -1 specifies that NI-RFSA fetches all records in an acquisition. Record numbers are zero-based. The default value is -1.

If starting record is set to a value greater than 0, setting number of records to –1 returns an error. If you set starting record to a value greater than 0, set number of records to the exact number of records to fetch.

Note  If you set number of records to 0, this VI returns an error.
/images/reference/en-XX/help/372058U-01/ci32.gif

starting record specifies the first record to retrieve. Record numbers are zero-based. The default value is 0.

/images/reference/en-XX/help/372058U-01/cerrcodeclst.gif

error in describes error conditions that occur before this node runs. This input provides standard error in functionality.

/images/reference/en-XX/help/372058U-01/iio.gif

instrument handle out passes a reference to your instrument session to the next VI. instrument handle is obtained from the niRFSA Initialize VI or the niRFSA Initialize With Options VI and identifies a particular instrument session.

/images/reference/en-XX/help/372058U-01/icclst.gif

data returns the acquired data as a cluster.

/images/reference/en-XX/help/372058U-01/idbl.gif

t0 returns the start time of the first sample returned. The timestamp corresponds to the difference in seconds between the first sample returned and the Reference Trigger location.

Note  The value of t0 returned in data is always 0 for the PXIe-5644/5645/5646.
/images/reference/en-XX/help/372058U-01/idbl.gif

dt returns the time interval between data points in the acquired signal. The I/Q data sample rate is the reciprocal of this value.

/images/reference/en-XX/help/372058U-01/i1dcsg.gif

Y returns the complex-value time domain data array.

The real and imaginary parts of this complex data array correspond to the in-phase (I) and quadrature-phase (Q) data, respectively. To calculate the instantaneous power of a sampled I/Q point, use the equation (I2 + Q2)/2R, where R is the input impedance in ohms (Ω). For vector signal analyzers, R = 50 Ω.

/images/reference/en-XX/help/372058U-01/ierrcodeclst.gif

error out contains error information. This output provides standard error out functionality.

niRFSA Fetch IQ (1D Complex Cluster CSGL NRec 1Chan)

Fetches I/Q data from multiple records in an acquisition.

Supported Devices: PXIe-5644/5645/5646, PXI-5661, PXIe-5663/5663E/5665/5667/5668, PXIe-5820/5840

niRFSA Fetch IQ (1D Complex Cluster CSGL NRec 1Chan)

/images/reference/en-XX/help/372058U-01/cio.gif

instrument handle identifies your instrument session. instrument handle is obtained from the niRFSA Initialize VI or the niRFSA Initialize With Options VI.

/images/reference/en-XX/help/372058U-01/ci32.gif

samples to read specifies the number of samples to fetch. A value of -1 specifies that NI-RFSA fetches all samples. The default value is -1.

Note  Setting samples to read to –1 fetches all remaining samples currently available depending on the Fetch Relative To property and the Fetch Offset property settings.
/images/reference/en-XX/help/372058U-01/cdbl.gif

timeout specifies the time, in seconds, allotted for the VI to complete before returning a timeout error for the PXI-5661, PXIe-5663/5665/5667. Specifies the time, in seconds, allotted to receive the reference trigger for the PXIe-5644/5645/5646, PXIe-5668, and PXIe-5820/5840.

Note   A value of -1 specifies that the VI waits until all data is available. A value of 0 specifies the VI immediately returns available data. The default value is 10.
/images/reference/en-XX/help/372058U-01/ci32.gif

number of records specifies the number of records to fetch. A value of -1 specifies that NI-RFSA fetches all records in an acquisition. Record numbers are zero-based. The default value is -1.

If starting record is set to a value greater than 0, setting number of records to –1 returns an error. If you set starting record to a value greater than 0, set number of records to the exact number of records to fetch.

Note  If you set number of records to 0, this VI returns an error.
/images/reference/en-XX/help/372058U-01/ci32.gif

starting record specifies the first record to retrieve. Record numbers are zero-based. The default value is 0.

/images/reference/en-XX/help/372058U-01/cerrcodeclst.gif

error in describes error conditions that occur before this node runs. This input provides standard error in functionality.

/images/reference/en-XX/help/372058U-01/iio.gif

instrument handle out passes a reference to your instrument session to the next VI. instrument handle is obtained from the niRFSA Initialize VI or the niRFSA Initialize With Options VI and identifies a particular instrument session.

/images/reference/en-XX/help/372058U-01/i1dcclst.gif

data returns the acquired waveform.

/images/reference/en-XX/help/372058U-01/idbl.gif

t0 returns the start time of the first sample returned. The timestamp corresponds to the difference in seconds between the first sample returned and the Reference Trigger location.

Note  The value of t0 returned in data is always 0 for the PXIe-5644/5645/5646.
/images/reference/en-XX/help/372058U-01/idbl.gif

dt returns the time interval between data points in the acquired signal. The I/Q data sample rate is the reciprocal of this value.

/images/reference/en-XX/help/372058U-01/i1dcdb.gif

Y returns the complex-value time domain data array.

The real and imaginary parts of this complex data array correspond to the in-phase (I) and quadrature-phase (Q) data, respectively. To calculate the instantaneous power of a sampled I/Q point, use the equation (I2 + Q2)/2R, where R is the input impedance in ohms (Ω). For vector signal analyzers, R=50 Ω.

Note  The size of the array can vary per record if the Number of Samples property changes per step during RF list mode.
/images/reference/en-XX/help/372058U-01/ierrcodeclst.gif

error out contains error information. This output provides standard error out functionality.

niRFSA Fetch IQ (2D I16)

Fetches binary I/Q data from multiple records in an acquisition.

Supported Devices: PXIe-5644/5645/5646, PXI-5661, PXIe-5663/5663E/5665/5667/5668, PXIe-5820/5840

niRFSA Fetch IQ (2D I16)

/images/reference/en-XX/help/372058U-01/cio.gif

instrument handle identifies your instrument session. instrument handle is obtained from the niRFSA Initialize VI or the niRFSA Initialize With Options VI.

/images/reference/en-XX/help/372058U-01/ci32.gif

samples to read specifies the number of samples to fetch. A value of -1 specifies that NI-RFSA fetches all samples. The default value is -1.

Note  Setting samples to read to –1 fetches all remaining samples currently available depending on the Fetch Relative To property and the Fetch Offset property settings.
/images/reference/en-XX/help/372058U-01/cdbl.gif

timeout specifies the time, in seconds, allotted for the VI to complete before returning a timeout error for the PXI-5661, PXIe-5663/5665/5667. Specifies the time, in seconds, allotted to receive the reference trigger for the PXIe-5644/5645/5646, PXIe-5668, and PXIe-5820/5840.

Note   A value of -1 specifies that the VI waits until all data is available. A value of 0 specifies the VI immediately returns available data. The default value is 10.
/images/reference/en-XX/help/372058U-01/ci32.gif

number of records specifies the number of records to fetch. A value of -1 specifies that NI-RFSA fetches all records in an acquisition. Record numbers are zero-based. The default value is -1.

If starting record is set to a value greater than 0, setting number of records to –1 returns an error. If you set starting record to a value greater than 0, set number of records to the exact number of records to fetch.

Note  If you set number of records to 0, this VI returns an error.
/images/reference/en-XX/help/372058U-01/ci32.gif

starting record specifies the first record to retrieve. Record numbers are zero-based. The default value is 0.

/images/reference/en-XX/help/372058U-01/cerrcodeclst.gif

error in describes error conditions that occur before this node runs. This input provides standard error in functionality.

/images/reference/en-XX/help/372058U-01/iio.gif

instrument handle out passes a reference to your instrument session to the next VI. instrument handle is obtained from the niRFSA Initialize VI or the niRFSA Initialize With Options VI and identifies a particular instrument session.

/images/reference/en-XX/help/372058U-01/i2di16.gif

data returns the acquired unscaled, complex waveform for each record. Each record occupies a row of the two-dimensional array. A record is composed of interleaved I and Q samples, where the order of the array is as follows:

Array[0] = I(0)

Array[1] = Q(0)

Array[2] = I(1)

Array[3] = Q(1)

/images/reference/en-XX/help/372058U-01/i1dnclst.gif

wfm info contains the absolute and relative timestamps for the operation, the time interval, and the actual number of samples read. Each element of this array corresponds to a record.

/images/reference/en-XX/help/372058U-01/idbl.gif

absolute timestamp returns the timestamp, in seconds, of the first fetched sample that is comparable between records and acquisitions.

Note  The value of the absolute timestamp returned is always 0 for the PXIe-5644/5645/5646, PXIe-5668, and PXIe-5820/5840.
/images/reference/en-XX/help/372058U-01/idbl.gif

relative timestamp returns a timestamp that corresponds to the difference, in seconds, between the first sample returned and the Reference Trigger location.

Note  The value of the relative timestamp returned is always 0 for the PXIe-5644/5645/5646.
/images/reference/en-XX/help/372058U-01/idbl.gif

dt returns the time interval between data points in the acquired signal. The I/Q data sample rate is the reciprocal of this value.

/images/reference/en-XX/help/372058U-01/ii32.gif

actual samples read returns an integer representing the number of samples in the waveform.

Note  The actual number of samples for each record can vary if the Number of Samples property changes per step during RF list mode.
/images/reference/en-XX/help/372058U-01/idbl.gif

offset returns the offset to scale data, (b), in mx + b form.

/images/reference/en-XX/help/372058U-01/idbl.gif

gain returns the gain to scale data, (m), in mx + b form.

/images/reference/en-XX/help/372058U-01/ierrcodeclst.gif

error out contains error information. This output provides standard error out functionality.

niRFSA Fetch IQ (1D I16 Data Ref)

Fetches binary I/Q data inside a data value reference from a single record in an acquisition.

Note  You must call Delete Data Value Reference on any outstanding data value references before calling niRFSA Fetch IQ, niRFSA Close, niRFSA Initialize, or niRFSA Reset. Refer to the LabVIEW Help for more information on the Delete Data Value Reference function and data value references.

Supported Devices: PXIe-5820/5840

Instance Details

niRFSA Fetch IQ (1D I16 Data Ref)

/images/reference/en-XX/help/372058U-01/cio.gif

instrument handle identifies your instrument session. instrument handle is obtained from the niRFSA Initialize VI or the niRFSA Initialize With Options VI.

/images/reference/en-XX/help/372058U-01/ci32.gif

record to fetch specifies the record to retrieve. Record numbers are zero-based. The default value is 0.

/images/reference/en-XX/help/372058U-01/ci32.gif

samples to read specifies the number of samples to fetch. A value of -1 specifies that NI-RFSA fetches all samples. The default value is -1.

Note  Setting samples to read to –1 fetches all remaining samples currently available depending on the Fetch Relative To property and the Fetch Offset property settings.
/images/reference/en-XX/help/372058U-01/cdbl.gif

timeout specifies the time, in seconds, allotted for the VI to complete before returning a timeout error. A value of -1 specifies that the VI waits until all data is available. The default value is 10 seconds.

/images/reference/en-XX/help/372058U-01/cerrcodeclst.gif

error in describes error conditions that occur before this node runs. This input provides standard error in functionality.

/images/reference/en-XX/help/372058U-01/iio.gif

instrument handle out passes a reference to your instrument session to the next VI. instrument handle is obtained from the niRFSA Initialize VI or the niRFSA Initialize With Options VI and identifies a particular instrument session.

/images/reference/en-XX/help/372058U-01/irn.gif

data value reference returns the external data value reference.

/images/reference/en-XX/help/372058U-01/i1di16.gif

data returns the acquired unscaled, complex waveform. The array is composed of interleaved I and Q samples, where the order of the array is as follows:

Array[0] = I(0)

Array[1] = Q(0)

Array[2] = I(1)

Array[3] = Q(1)

/images/reference/en-XX/help/372058U-01/inclst.gif

wfm info contains the absolute and relative timestamps for the operation, the time interval, and the actual number of samples read.

/images/reference/en-XX/help/372058U-01/idbl.gif

absolute timestamp returns the timestamp, in seconds, of the first fetched sample that is comparable between records and acquisitions.

Note  The value of the absolute timestamp returned is always 0 for the PXIe-5820/5840.
/images/reference/en-XX/help/372058U-01/idbl.gif

relative timestamp returns a timestamp that corresponds to the difference, in seconds, between the first sample returned and the Reference Trigger location.

/images/reference/en-XX/help/372058U-01/idbl.gif

dt returns the time interval between data points in the acquired signal. The I/Q data sample rate is the reciprocal of this value.

/images/reference/en-XX/help/372058U-01/ii32.gif

actual samples read returns an integer representing the number of samples in the waveform.

/images/reference/en-XX/help/372058U-01/idbl.gif

offset returns the offset to scale data, (b), in mx + b form.

/images/reference/en-XX/help/372058U-01/idbl.gif

gain returns the gain to scale data, (m), in mx + b form.

/images/reference/en-XX/help/372058U-01/ierrcodeclst.gif

error out contains error information. This output provides standard error out functionality.

niRFSA Fetch IQ (1D I16 Data Ref) Details

Use the In Place Element structure Data Value Reference Read/Write Element to read data and operate on the data within place. Refer to the LabVIEW Help for more information on the Data Value Reference Read/Write Element.

To improve streaming performance, consider the following recommendations:

  • Use LabVIEW (64-bit).
  • Set the Host DMA Buffer Size property to at least 512 MB.
  • Use the TDMS Advanced Asynchronous Write (Data Ref) function to optimize performance when writing data to disk. Refer to the LabVIEW Help for more information about this function.

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