Filter (Bandstop » Windowed FIR) (G Dataflow)

Filters a signal using a bandstop windowed FIR filter. Bandstop filters attenuate a certain band of frequencies.

window parameter

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

window type

Type of the smoothing window.

Smoothing windows decrease ripple in the filter passband and improve the ability of the filter to attenuate frequency components in the filter stopband.

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.
Cosine Tapered 12 Applies a Cosine Tapered 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: Rectangle

reset

A Boolean that specifies the initialization of the internal state of the node.

 True Initializes the internal state to zero. False Initializes the internal state to the final state from the previous call of this node.

This node automatically initializes the internal state to zero on the first call and runs continuously until this input is True.

Default: False

signal

Input signal.

This input accepts the following data types:

• Waveform
• Double-precision, floating-point number
• Complex double-precision, floating-point number
• 1D array of waveforms
• 1D array of double-precision, floating-point numbers
• 1D array of complex double-precision, floating-point numbers
• 2D array of double-precision, floating-point numbers

low cutoff frequency

Low cutoff frequency of the filter. low cutoff frequency must be less than high cutoff frequency.

Default: 0.125

high cutoff frequency

High cutoff frequency of the filter. high cutoff frequency must be greater than low cutoff frequency and less than 0.5*f s , where f s is the sampling frequency.

Default: 0.45

number of taps

Number of taps in the FIR filter.

Default: 25

order

Order of the filter.

Default: 2

error in

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.

error in does not contain an error error in contains an error
If no error occurred before the node runs, the node begins execution normally.

If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.

If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.

Default: No error

sampling frequency

Sampling frequency in Hz. sampling frequency must be greater than zero.

This input is available only if you wire one of the following data types to signal:

• Double-precision, floating-point number
• Complex double-precision, floating-point number
• 1D array of double-precision, floating-point numbers
• 1D array of complex double-precision, floating-point numbers
• 2D array of double-precision, floating-point numbers

Default: 1, which is the normalized sampling frequency

filtered signal

Result of filtering the input signal.

This output can return the following data types:

• Waveform
• Double-precision, floating-point number
• Complex double-precision, floating-point number
• 1D array of waveforms
• 1D array of double-precision, floating-point numbers
• 1D array of complex double-precision, floating-point numbers
• 2D array of double-precision, floating-point numbers

error out

Error information.

The node produces this output 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.

error in does not contain an error error in contains an error
If no error occurred before the node runs, the node begins execution normally.

If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.

If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.

Where This Node Can Run:

Desktop OS: Windows

FPGA: Not supported

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