ST_CM_InstantaneousPhase_InitPars

Function block-specific structure with initialization parameters, which are analyzed when the function block is initialized.

TYPE ST_CM_InstantaneousPhase_InitPars EXTENDS ST_CM_Object_InitPars :
STRUCT
    nFFT_Length      : UDINT := 512;                                    (* Length of FFT. *)
    nWindowLength    : UDINT := 400;                                    (* Length of analysis window. *)
    eUnwrapMethod    : E_CM_UnwrapMethod := eCM_ThresholdUnwrapping;    (* Unwrap method for phase values. *)
    fPhaseThreshold  : LREAL := cCM_MinArgDiv;                          (* Minimum value for calculating the instantaneous phase. *)
    nChannels        : UDINT := 1;                                      (* Number of channels. *)
END_STRUCT
END_TYPE

• nFFT_Length is the length of the FFT. It must be greater than one and an integral power of two.
• nWindowLength is the length of the analysis window in samples. The length must be greater than one and an even number.
• eUnwrapMethod defines the method used for phase-unwrapping with regard to the phase in multiples of 2 PI (see E_CM_UnwrapMethod).
• fPhaseThreshold limit value for calculating the instantaneous phase. The value is related to the signal envelope. Interpretation: If the signal level is too low, the calculation of the phase is numerically too uncertain and cannot be evaluated reliably. 0 is then output as the phase.