Last Modified: January 12, 2018

Computes the averaged power spectral density of a time-domain signal.

A value that affects the output coefficients when **window type** is Kaiser, Gaussian, or Dolph-Chebyshev.

If **window type** is any other type of window, this node ignores this input.

This input represents the following information for each type of window:

**Kaiser**—Beta parameter**Gaussian**—Standard deviation**Dolph-Chebyshev**—The ratio of the main lobe to the side lobe,*s*, expressed in decibels

**Default: **NaN—Causes this node to set beta to 0 for a Kaiser window, the standard deviation to 0.2 for a Gaussian window, and *s* to 60 dB for a Dolph-Chebyshev window

Time-domain window to apply to the signal.

Name | Value | Description |
---|---|---|

Rectangle | 0 | Applies a rectangle window. |

Hanning | 1 | Applies a Hanning window. |

Hamming | 2 | Applies a Hamming window. |

Blackman-Harris | 3 | Applies a Blackman-Harris window. |

Exact Blackman | 4 | Applies an Exact Blackman window. |

Blackman | 5 | Applies a Blackman window. |

Flat Top | 6 | Applies a Flat Top window. |

4 Term B-Harris | 7 | Applies a 4 Term B-Harris window. |

7 Term B-Harris | 8 | Applies a 7 Term B-Harris window. |

Low Sidelobe | 9 | Applies a Low Sidelobe window. |

Blackman Nutall | 11 | Applies a Blackman Nutall window. |

Triangle | 30 | Applies a Triangle window. |

Bartlett-Hanning | 31 | Applies a Bartlett-Hanning window. |

Bohman | 32 | Applies a Bohman window. |

Parzen | 33 | Applies a Parzen window. |

Welch | 34 | Applies a Welch window. |

Kaiser | 60 | Applies a Kaiser window. |

Dolph-Chebyshev | 61 | Applies a Dolph-Chebyshev window. |

Gaussian | 62 | Applies a Gaussian window. |

Force | 64 | Applies a Force window. |

Exponential | 65 | Applies an Exponential window. |

**Default: **Hanning

A Boolean that specifies whether the node restarts the selected averaging process.

True | Restarts the averaging process. |

False | Does not restart the averaging process. |

When you call this node for the first time, the averaging process restarts automatically. A typical case when you restart averaging is when a major input change occurs in the middle of the averaging process.

**Default: **False

Settings that define how this node computes the averaging.

The mode this node uses to compute the averaging.

Name | Description |
---|---|

No averaging | Does not use averaging. |

Vector averaging | Uses vector averaging. |

RMS averaging | Uses RMS averaging. |

Peak hold | Uses peak hold averaging. |

**Default: **No averaging

Weighting mode for RMS and vector averaging.

Name | Description |
---|---|

Linear | Uses linear weighting. |

Exponential | Uses exponential weighting. |

**Default: **Exponential

Number of averages to use for RMS and vector averaging.

If **weighting mode** is Exponential, the averaging process is continuous. If **weighting mode** is Linear, the averaging process stops after this node computes the specified number of averages.

**Default: **10

Error conditions that occur before this node runs.

The node responds to this input according to standard error behavior.

Standard Error Behavior

Many nodes provide an **error in** input and an **error out** output so that the node can respond to and communicate errors that occur while code is running. The value of **error in** specifies whether an error occurred before the node runs. Most nodes respond to values of **error in** in a standard, predictable way.

**Default: **No error

Averaged power spectral density of the input signals.

This output can return a cluster or a 1D array of clusters.

Start frequency, in Hz, of the spectrum.

Frequency resolution, in Hz, of the spectrum.

Magnitude of the averaged power spectral density.

A Boolean that indicates whether the number of averages this node completed is greater than or equal to the specified number of averages.

True | The number of averages this node completed is greater than or equal to the specified number of averages. |

False | The number of averages this node completed is less than the specified number of averages. |

** averaging done** is True if **averaging mode** is No averaging.

Number of averages this node completed.

Error information.

The node produces this output according to standard error behavior.

Standard Error Behavior

**error in** input and an **error out** output so that the node can respond to and communicate errors that occur while code is running. The value of **error in** specifies whether an error occurred before the node runs. Most nodes respond to values of **error in** in a standard, predictable way.

This node completes the following steps to compute the power spectral density:

- Computes the FFT of the input signal.
- Forms the power spectral density of the input signal.
- Averages the current power spectral density with the power spectral densities computed in previous calls to the node since the last time the averaging process was restarted.
- Returns the averaged power spectral densities.

**Where This Node Can Run: **

Desktop OS: Windows

FPGA: Not supported

Web Server: Not supported in VIs that run in a web application