ni5660 Fetch IQ

This VI returns the IQ waveform acquired by the RF Signal Analyzer during a previously initiated acquisition. This VI returns IQ data computed through a process of filtering, decimation, and downconversion. Use this VI with the ni5660 Initiate VI when continuously acquiring data.

Note  Continous IQ acquisition is only possible for bandwidths smaller than 1.25 MHz. Refer to Small Span Signals and Sample Rates for more information.

receiver info in is the instrument handle that you obtain from the ni5660 Initialize VI. The handle identifies a particular RF Signal Analyzer session.

samples to read specifies the number of samples to fetch. A value of –1 fetches the actual record length. Default Value: –1

timeout (sec) specifies the maximum amount of time in seconds to wait for the acquisition to finish. After this amount of time, the VI returns an error if the acquisition is not complete. If this parameter is set to 0, it returns immediately without checking the acquisition status. If this parameter is set to –1, the function waits forever. Default Value: 5 seconds

error in accepts error information wired from previously called VIs. The pop-up option Explain Error (or Explain Warning) gives more information about the error displayed. status boolean is either TRUE (X) for an error, or FALSE (checkmark) for no error or a warning. The pop-up option Explain Error (or Explain Warning) gives more information about the error displayed. code input identifies the error or warning. The pop-up option Explain Error (or Explain Warning) gives more information about the error displayed. source string describes the origin of the error or warning. The pop-up option Explain Error (or Explain Warning) gives more information about the error displayed.

receiver info out passes a reference to your instrument session to the next VI. receiver info was obtained from the ni5660 Initialize VI. Note  Do not modify the contents of this wire manually.

IQ waveform contains the baseband (downconverted) time-domain waveform for demodulation. This cluster contains the following elements: t0 returns the trigger (start) time of the acquired signal. dt returns the time interval between data points in the acquired signal. The IQ data sampling rate is the reciprocal of this value. Y returns the complex-valued 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. Note  To calculate the instantaneous power of a sampled IQ point, use the equation: where R is the input impedance in ohms. For the RF Signal Analyzer, R = 50Ω.

error out passes error or warning information out of a VI to be used by other VIs. The pop-up option Explain Error (or Explain Warning) gives more information about the error displayed. status is TRUE (X) if an error occurred, or FALSE (checkmark) for no error or a warning. The pop-up option Explain Error (or Explain Warning) gives more information about the error displayed. code identifies the error or warning. The pop-up option Explain Error (or Explain Warning) gives more information about the error displayed. source describes the origin of the error or warning. The pop-up option Explain Error (or Explain Warning) gives more information about the error displayed.