CxMultipleToneSignal
Advanced Analysis Library Only
AnalysisLibErrType CxMultipleToneSignal (NIComplexNumber waveform[], ssize_t waveformSize, double samplePeriodInSeconds, int sortOrder, int exportMode, double threshold, int maxNumberOfTones, int *detectedTones, double frequency[], double amplitude[], double phase[], NIComplexNumber exportedSignal[], double *exportedSamplePeriod, double exportedSpectrum[], double *startFrequency, double *frequencyResolution);
Purpose
Teturns the frequency, amplitude, and phase for each signal tone whose amplitude exceeds a specified threshold. This function also exports the signal and spectrum specified by exportMode.
This function is similar to CxMultipleToneInfo, except that CxMultipleToneSignal exports signal and spectrum values. If you do not need to export signal and spectrum values, you can use CxMultipleToneInfo instead.
A complex multiple tone signal can be expressed as shown in the following equation:
where Ai, fi, and 
i are the amplitude, frequency, and phase, respectively, of the ith tone of a multiple tone signal with N tones and Fs is the sample rate in samples per second of the input waveform signal.
For a complex signal, the frequency range is (min frequency, max frequency) = (–Fs/2, Fs/2).
Parameters
| Input | ||
| Name | Type | Description |
| waveform | NIComplexNumber [] | The input waveform to measure. |
| waveformSize | ssize_t | The size the input waveform. |
| samplePeriodInSeconds | double | Sample period of the time-domain signal, in seconds. |
| sortOrder | int | The sorting order of the detected tones. 0—increasing frequency 1—decreasing amplitude |
| exportMode | int | The source of the exportedSignal and exportedSpectrum to export. You can select one of the following values:
|
| threshold | double | The minimum amplitude that each tone must exceed. |
| maxNumberOfTones | int | The maximum number of tones that this function extracts. |
| Output | ||
| Name | Type | Description |
| detectedTones | int | Detected number of tones; this value is less than or equal to maxNumberOfTones. |
| frequency | double [] | The frequency of the detected tones, in hertz. You must allocate enough memory for this value before calling this function: maxNumberOfTones*sizeof(double). |
| amplitude | double [] | The amplitude of the detected tones. You must allocate enough memory for this value before calling this function: maxNumberOfTones*sizeof(double). |
| phase | double [] | The phase of the detected tones, in degrees. You must allocate enough memory for this value before calling this function: maxNumberOfTones*sizeof(double). |
| exportedSignal | NIComplexNumber [] | The waveform containing the exported time signal as selected by exportMode. |
| exportedSamplePeriod | double | Sample period of the time-domain signal, in seconds. |
| exportedSpectrum | double [] | The magnitude spectrum of the Hanning windowed input signal, in dB. |
| startFrequency | double | The start frequency, in hertz, of the exportedSpectrum. |
| frequencyResolution | double | The frequency resolution, in hertz, of the exportedSpectrum. |
Return Value
| Name | Type | Description |
| status | AnalysisLibErrType | A value that specifies the type of error that occurred. Refer to analysis.h for definitions of these constants. |
Additional Information
Library: Advanced Analysis Library
Include file: analysis.h
LabWindows/CVI compatibility: LabWindows/CVI 2010 and later