NI RFmx SpecAn Fcnt Configuration Functions

Fcnt Configuration Functions

• RFmxSpecAn_FCntCfgMeasurementInterval
• RFmxSpecAn_FCntCfgRBWFilter
• RFmxSpecAn_FCntCfgThreshold
• RFmxSpecAn_FCntCfgAveraging

RFmxSpecAn_FCntCfgMeasurementInterval

int32 __stdcall RFmxSpecAn_FCntCfgMeasurementInterval (niRFmxInstrHandle instrumentHandle, char selectorString[], float64 measurementInterval);

Purpose

Configures the acquisition time, in seconds, for the frequency count (FCnt) measurement.

Parameters

Input
Name	Type	Description
instrumentHandle	niRFmxInstrHandle	Identifies the RFmx session. You can obtain this parameter from the RFmxSpecAn_Initialize) function.
selectorString	char[]	Comprises the signal name. If you do not specify the signal name, the default signal instance is used. Example: "" "signal::sig1" You can use the RFmxSpecAn_BuildSignalString) function to build the selector string).
measurementInterval	float64	Specifies the acquisition time, in seconds, for the measurement.

Return Value

Name	Type	Description
status	int32	Returns the status code of this operation. The status code either indicates success or describes an error or warning condition. Examine the status code from each call to an RFmx function to determine if an error has occurred. To obtain a text description of the status code and additional information about the error condition, call the RFmxSpecAn_GetError) function. The general meaning of the status code is as follows:

Value	Meaning
0	Success
Positive Values	Warnings
Negative Values	Errors

RFmxSpecAn_FCntCfgRBWFilter

int32 __stdcall RFmxSpecAn_FCntCfgRBWFilter (niRFmxInstrHandle instrumentHandle, char selectorString[], float64 RBW, int32 RBWFilterType, float64 RRCAlpha);

Purpose

Configures the resolution bandwidth (RBW) filter to be applied before measuring the frequency.

Parameters

Input
Name	Type	Description
instrumentHandle	niRFmxInstrHandle	Identifies the RFmx session. You can obtain this parameter from the RFmxSpecAn_Initialize) function.
selectorString	char[]	Comprises the signal name. If you do not specify the signal name, the default signal instance is used. Example: "" "signal::sig1" You can use the RFmxSpecAn_BuildSignalString) function to build the selector string).
RBW	float64	Specifies the bandwidth, in Hz, of the RBW filter used to measure the signal.
RBWFilterType	int32	Specifies the shape of the digital RBW filter.

RFMXSPECAN_VAL_FCNT_RBW_FILTER_TYPE_NONE (5)	The measurement does not use any RBW filtering.
RFMXSPECAN_VAL_FCNT_RBW_FILTER_TYPE_GAUSSIAN (1)	The RBW filter has a Gaussian response.
RFMXSPECAN_VAL_FCNT_RBW_FILTER_TYPE_FLAT (2)	The RBW filter has a flat response.
RFMXSPECAN_VAL_FCNT_RBW_FILTER_TYPE_SYNCH_TUNED_4 (3)	The RBW filter has a response of a 4-pole synchronously-tuned filter.
RFMXSPECAN_VAL_FCNT_RBW_FILTER_TYPE_SYNCH_TUNED_5 (4)	The RBW filter has a response of a 5-pole synchronously-tuned filter.
RFMXSPECAN_VAL_FCNT_RBW_FILTER_TYPE_RRC (6)	The RRC filter with the roll-off specified by RRCAlpha parameter is used as the RBW filter.

RRCAlpha	float64	Specifies the roll-off factor for the root-raised-cosine (RRC) filter.

Return Value

Name	Type	Description
status	int32	Returns the status code of this operation. The status code either indicates success or describes an error or warning condition. Examine the status code from each call to an RFmx function to determine if an error has occurred. To obtain a text description of the status code and additional information about the error condition, call the RFmxSpecAn_GetError) function. The general meaning of the status code is as follows:

Value	Meaning
0	Success
Positive Values	Warnings
Negative Values	Errors

RFmxSpecAn_FCntCfgThreshold

int32 __stdcall RFmxSpecAn_FCntCfgThreshold (niRFmxInstrHandle instrumentHandle, char selectorString[], int32 thresholdEnabled, float64 thresholdLevel, int32 thresholdType);

Purpose

Configures the threshold level for the samples that need to be considered for the frequency count (FCnt) measurement. Enable the threshold when analyzing burst signals or signals with dead time.

Parameters

Input
Name	Type	Description
instrumentHandle	niRFmxInstrHandle	Identifies the RFmx session. You can obtain this parameter from the RFmxSpecAn_Initialize) function.
selectorString	char[]	Comprises the signal name. If you do not specify the signal name, the default signal instance is used. Example: "" "signal::sig1" You can use the RFmxSpecAn_BuildSignalString) function to build the selector string).
thresholdEnabled	int32	Specifies whether to enable thresholding of the acquired samples to be used for the measurement.

RFMXSPECAN_VAL_FCNT_THRESHOLD_ENABLED_FALSE (0)	All samples are considered for the measurement.
RFMXSPECAN_VAL_FCNT_THRESHOLD_ENABLED_TRUE (1)	The samples above the threshold level specified in the thresholdLevel parameter are considered for the measurement.

thresholdLevel	float64	Specifies either the relative or absolute threshold power level based on the value of the thresholdType parameter.
thresholdType	int32	Specifies the reference for the power level used for thresholding.

RFMXSPECAN_VAL_FCNT_THRESHOLD_TYPE_RELATIVE (0)	The threshold is relative to the peak power, in dB, of the acquired samples.
RFMXSPECAN_VAL_FCNT_THRESHOLD_TYPE_ABSOLUTE (1)	The threshold is the absolute power, in dBm.

Return Value

Name	Type	Description
status	int32	Returns the status code of this operation. The status code either indicates success or describes an error or warning condition. Examine the status code from each call to an RFmx function to determine if an error has occurred. To obtain a text description of the status code and additional information about the error condition, call the RFmxSpecAn_GetError) function. The general meaning of the status code is as follows:

Value	Meaning
0	Success
Positive Values	Warnings
Negative Values	Errors

RFmxSpecAn_FCntCfgAveraging

int32 __stdcall RFmxSpecAn_FCntCfgAveraging (niRFmxInstrHandle instrumentHandle, char selectorString[], int32 averagingEnabled, int32 averagingCount, int32 averagingType);

Purpose

Configures averaging for the frequency count (FCnt) measurement.

Parameters

Input
Name	Type	Description
instrumentHandle	niRFmxInstrHandle	Identifies the RFmx session. You can obtain this parameter from the RFmxSpecAn_Initialize) function.
selectorString	char[]	Comprises the signal name. If you do not specify the signal name, the default signal instance is used. Example: "" "signal::sig1" You can use the RFmxSpecAn_BuildSignalString) function to build the selector string).
averagingEnabled	int32	Specifies whether to enable averaging for the measurement.

RFMXSPECAN_VAL_FCNT_AVERAGING_ENABLED_FALSE (0)	The measurement is performed on a single acquisition.
RFMXSPECAN_VAL_FCNT_AVERAGING_ENABLED_TRUE (1)	The measurement uses the averagingCount parameter to calculate the number of acquisitions over which the measurement is averaged.

averagingCount	int32	Specifies the number of acquisitions used for averaging when you set the averagingEnabled parameter to RFMXSPECAN_VAL_FCNT_AVERAGING_ENABLED_TRUE.
averagingType	int32	Specifies the averaging type for averaging multiple acquisitions.

RFMXSPECAN_VAL_FCNT_AVERAGING_TYPE_MEAN (6)	The mean of the instantaneous signal phase difference over multiple acquisitions is used for the frequency measurement.
RFMXSPECAN_VAL_FCNT_AVERAGING_TYPE_MAXIMUM (3)	The maximum instantaneous signal phase difference over multiple acquisitions is used for the frequency measurement.
RFMXSPECAN_VAL_FCNT_AVERAGING_TYPE_MINIMUM (4)	The minimum instantaneous signal phase difference over multiple acquisitions is used for the frequency measurement.
RFMXSPECAN_VAL_FCNT_AVERAGING_TYPE_MINMAX (7)	The maximum instantaneous signal phase difference over multiple acquisitions is used for the frequency measurement. The sign of the phase difference is ignored to find the maximum instantaneous value.

Return Value

Name	Type	Description
status	int32	Returns the status code of this operation. The status code either indicates success or describes an error or warning condition. Examine the status code from each call to an RFmx function to determine if an error has occurred. To obtain a text description of the status code and additional information about the error condition, call the RFmxSpecAn_GetError) function. The general meaning of the status code is as follows:

Value	Meaning
0	Success
Positive Values	Warnings
Negative Values	Errors