ST_FTR_IIRSos
Configuration structure for the function block FB_FTR_IIRSos.
Syntax
Definition:
TYPE ST_FTR_IIRSos :
STRUCT
pCoefficientArrayAdr_Sos : POINTER TO LREAL;
nCoefficientArraySize_Sos : UDINT;
bReset : BOOL := TRUE;
nOversamples : UDINT;
nChannels : UDINT;
pInitialValues : POINTER TO LREAL;
nInitialValuesSize : UDINT;
END_STRUCT
END_TYPE
Parameter
Name | Type | Description |
---|---|---|
pCoefficientArrayAdr_Sos | Pointer to LREAL | Pointer to an array with filter coefficients |
nCoefficientArraySize_Sos | UDINT | Size of the array with filter coefficients in BYTES |
bReset | BOOL | If TRUE, a reset is performed when the filter is configured. |
nOversamples | UDINT | Number of oversamples (greater than zero) |
nChannels | UDINT | Number of channels (greater than zero and less than 101) |
pInitialValues | Pointer to LREAL | Pointer to array with initial values (optional) |
nInitialValuesSize | UDINT | Size of the array with initial values in BYTE (optional) |
An example of a filter with 3 biquads might look like this:
aCoeffs_Sos : ARRAY [1..3] OF ARRAY [1..6] OF LREAL :=
[ [1, 1, 1, 1, 1, 1], // [b01,b11,b21,a01,a11,a21]
[ [1, 1, 1, 1, 1, 1], // [b02,b12,b22,a02,a12,a22]
[ [1, 1, 1, 1, 1, 1]]; // [b03,b13,b23,a03,a13,a23