National Instruments 320571-01 用户手册

Computes the Fast Fourier transform of a
real input sequence X.  If Y represents
the complex output sequence, then:

Y  =  F{X}.

X is a DSP Handle Cluster that indicates the memory buffer on the DSP board that contains the input
signal array.

Notes: The number of elements for input X must be the power of two.

The operation is performed in place and the input array X is overwritten by Re FFT{X}.

The largest FFT that can be computed depends upon the amount of memory in your DSP board.

Im FFT{X} in is a DSP Handle Cluster that indicates the memory buffer on the DSP board that will
contain the imaginary part of FFT{X}.

Re FFT{X} is a DSP Handle Cluster that is identical to X, but with the real part of FFT{X}already
stored in the memory buffer on the DSP board.

Im FFT{X} out is a DSP Handle Cluster that is identical to Im FFT{X} in, but with the imaginary part
of FFT{X} already stored in the memory buffer on the DSP board.

error in (no error) contains the error information from a previous VI.  If an error occurs, it is passed out
error out and no other calls are made.

error out contains the error information for this call.

DSP Reset aborts any currently running
function on the board, stops the library, and
reloads the DSP Library from the directory
specified in the 

WDAQCONF.EXE

 file.

slot is the board ID number.  slot defaults to 3.

error in (no error) contains the error information from a previous VI.  If an error occurs, it is passed out
error out and no other calls are made.

error out contains the error information for this call.