Parameters for entire plugin.
Parameter Definitions in NDPluginFFT.h and EPICS Record Definitions in NDFFT.template |
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Parameter index variable | asyn interface | Access | Description | drvInfo string | EPICS record name | EPICS record type |
---|---|---|---|---|---|---|

FFTTimePerPoint | asynFloat64 | r/w | The time interval between samples in the waveforms from the driver. This value is normally updated automatically using the FFTTimePerPointLink record described below. It can also be manually changed if there is no EPICS record available to provide this value automatically. | FFT_TIME_PER_POINT |
$(P)$(R)FFTTimePerPoint $(P)$(R)FFTTimePerPoint_RBV |
ao ai |

N.A. | N.A. | r/w | This record has OMSL="closed_loop" and DOL set to an record that contains the time between points from the driver. The link will normally have the CP attribute, so this record processes whenever the input record changes. The OUT field of this record is FFTTimePerPoint. | N.A. | $(P)$(R)FFTTimePerPointLink | ao |

FFTTimeAxis | asynFloat64ArrayIn | r/o | A waveform record containing the time value of each point in the TimeSeries waveforms. FFTTimeAxis[i] = FFTTimePerPoint * i. Note that this record is useful for 1-D FFTs where the input array is a time-series and the TimePerPoint value is correctly set. | FFT_TIME_AXIS | $(P)$(R)FFTTimeAxis | waveform |

FFTFreqAxis | asynFloat64ArrayIn | r/o | A waveform record containing the frequency value of each point in the FFT waveform records. FFTFreqAxis[i] = FrequencyStep * i, where FrequencyStep is controlled by TimePerPoint and the number of time points in the input array. Note that this record is useful for 1-D FFTs where the input array is a time-series and the TimePerPoint value is correctly set. | FFT_FREQ_AXIS | $(P)$(R)FFTFreqAxis | waveform |

FFTDirection | asynInt32 | r/w |
The FFT direction. Choices are: 0: Time to frequency 1: Frequency to time NOTE: This is not yet implemented because frequency to time requires complex data, and complex data is not yet supported in areaDetector. Currently only Time to frequency is supported, and the frequency output consists of float64 arrays containing the real part, imaginary part, and absolute value of the FFT. |
FFT_DIRECTION |
$(P)$(R)FFTDirection $(P)$(R)FFTDirection_RBV |
bo bi |

FFTSuppressDC | asynInt32 | r/w |
Option to set the zero frequency (DC) value in the output arrays to 0. Choices are: 0: Disable 1: Enable If the signal has a large DC offset then setting the zero frequency component to 0 in the output arrays can make plots look better. This is because the DC component can be much larger than all other frequency components. |
FFT_SUPPRESS_DC |
$(P)$(R)FFTSuppressDC $(P)$(R)FFTSuppressDC_RBV |
bo bi |

FFTNumAverage | asynInt32 | r/w |
The characteristic number of FFTs in the recursive average. The equations for the
FFT averaging are:`Out = ((1-1/NumAveraged) * Old) + (1/NumAveraged * New)` when Old is the previous output and New is the latest FFT calculation. If
NumAverage=1 then there is no averaging. |
FFT_NUM_AVERAGE |
$(P)$(R)FFTNumAverage $(P)$(R)FFTNumAverage_RBV |
longout longin |

FFTNumAveraged | asynInt32 | r/o | The number of FFTs averaged in the current output. This value increases until it reaches the value of NumAverage. See the equations for NumAverage above. | FFT_NUM_AVERAGED | $(P)$(R)FFTNumAveraged | longin |

FFTResetAverage | asynInt32 | r/o | Setting this record to 1 resets NumAveraged to 0, so the averaging process starts over. | FFT_RESET_AVERAGE | $(P)$(R)FFTResetAverage | bo |

N.A. | N.A. | r/w | The name for this signal. | N.A. | $(P)$(R)SignalName | stringout |

FFTTimeSeries | asynFloat64ArrayIn | r/o | The time series data array. | FFT_TIME_SERIES | $(P)$(R)TimeSeries | waveform |

FFTReal | asynFloat64ArrayIn | r/o |
The real part of the FFT.
NOTE: this value is only available as a 1-D waveform. It is not exported as an NDArray. For 2-D FFTs it contains only the first row of the FFT. |
FFT_FFT_REAL | $(P)$(R)FFTReal | waveform |

FFTImaginary | asynFloat64ArrayIn | r/o |
The imaginary part of the FFT.
NOTE: this value is only available as a 1-D waveform. It is not exported as an NDArray. For 2-D FFTs it contains only the first row of the FFT. |
FFT_FFT_IMAGINARY | $(P)$(R)FFTImaginary | waveform |

FFTAbsValue | asynFloat64ArrayIn | r/o |
The absolute value of the FFT.
NOTE: this is exported as an NDArray, either 1-D or 2-D depending on the rank of the input NDArray. However, for 2-D arrays the waveform record contains only the first row of the FFT. |
FFT_ABS_VALUE | $(P)$(R)FFTAbsValue | waveform |