The General (2nd-Order / Lookup) block gives access to a wide variety of 2nd-order IIR (infinite impulse response) filter algorithms. See General 2nd-Order Filters (in Algorithm Information) for details about the algorithms driving these blocks.
The filters available are:
This block is implemented by a double-precision biquad filter that has multiple sets of coefficients in tables on the DSP. To select curves (lookup), use an Index Lookup Table, a Counter block, or a DC Input block in your design and connect it to the red pin. Using the GPIO blocks you could control the selected responses with a knob, rotary encoder or button.
To open the Filter Control Window:
Enter the number of curves desired in the # Curves field. Enter Boosts, (overall) Gain, and Q in their fields. Enter the desired cutoff or center (peaking filters) frequency in the Frequency fields. Other parameters to enter will vary with filter type.
Note: For n curves, the selected index should not exceed n - 1, i.e., the index range is 0 to n - 1. If you select an n th curve, misbehavior or errors may result.