Fetches complex, 16-bit signed integer data from the specified channel. To use the niUSRP Fetch Rx Data (I16) VI, you must set the Host Data Type property to I16.

data returns binary values that range from 32,767 to -32,768. The corresponding floating point-values range from 1.0 to ‑1.0. Use the following equations to convert values from binary to floating-point or from floating-point to binary:

floating-point value = binary value/32,768

binary value = floating-point value x 32,767


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Inputs/Outputs

  • cstr.png channel list —

    channel list specifies the channel(s) from which to fetch the data.

  • civrn.png session handle —

    session handle identifies your instrument session.

    session handle is obtained from the niUSRP Open Rx Session VI and identifies a particular receive (Rx) session.

  • ci64.png number of samples —

    number of samples specifies the number of samples to fetch from the acquisition channel. For finite acquisitions, if you specify a value of -1, NI-USRP returns all the remaining samples. NI-USRP returns the samples when the requested number of samples is retrieved from the device or when the timeout is exceeded, whichever happens first.

  • cdbl.png timeout —

    timeout specifies the time to wait, in seconds, before returning an error if the requested number of samples have not been acquired.

    A negative value indicates to the driver to wait indefinitely.

  • cerrcodeclst.png error in (no error) —

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

  • iivrn.png session handle out —

    session handle out passes a reference to your instrument session to the next VI.

    session handle out is obtained from the niUSRP Open Rx Session VI and identifies a particular receive (Rx) session.

  • i1di16.png data —

    data returns the received baseband samples as an array of complex, 16-bit signed integer data. The real and imaginary components of the data correspond to the in-phase (I) and quadrature-phase (Q) data, respectively. I and Q are interleaved [I, Q, I, Q, ...] in the array. The total number of elements returned in the array equals the value of the number of samples parameter x 2.

    The time between samples in the waveform (the sample period) equals 1 divided by the coerced I/Q rate. Determine the coerced I/Q rate by reading the IQ Rate property after you set it or by reading the coerced IQ rate output of the Configure Signal VI.

  • inclst.png timestamp —

    timestamp returns the timestamp of the first receive (Rx) sample returned and indicates the time associated with the first sample of the waveform, according to the onboard device timer.

    timestamp is the time of the clock in seconds, interpreted as whole seconds.fractional seconds.

  • iu64.png whole seconds —

    whole seconds is the integer number of seconds for the time associated with the first sample of the waveform, according to the onboard device timer.

  • idbl.png fractional seconds —

    fractional seconds is the double-precision, floating-point value representing the remaining fraction of a second for the time associated with the first sample of the waveform, according to the onboard device timer.

  • ierrcodeclst.png error out —

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