niTuner_setFreq

Function Prototype

niTuner_setFreq (int taskID, double desiredRFFrequency, double span, double *actualIFFrequency, double *actualRFTunedFrequency, double *freqShift);

Purpose

This function sets a single frequency in the scan list with a specified span and triggers the PXI-5600 downconverter to settle on that frequency.

Note  If new center frequencies of less than 15 MHz are specified after a call to this function, attenuation is automatically adjusted. This may add an additional 20 dB attenuation. See the attenuation page for more information.

Parameters

Name	Type	Description
taskID	int	The Task ID obtained from niTuner_init that identifies the session of a particular device.
desiredRFFrequency	double	The desired frequency between 9 kHz and 2.7 GHz to which the PXI-5600 downconverter will tune.
span	double	The expected bandwidth of the RF input signal. You can specify a span value between 0 and 20 MHz. Span values affect phase noise and downconverter tuning step size, as shown below: span setting phase noise tuning step size <= 10 MHz best 5 MHz > 10 MHz good 1 MHz Default Value: 20 MHz Note  The NI 5600 RF downconverter module hardware always downconverts a 20 MHz bandwidth. Software span settings are used to determine optimal phase noise/tuning step size combinations.
actualIFFrequency	double *	The actual IF center frequency. This frequency will be near or equal to 15 MHz, depending on the frequency step size determined from the span.
actualRFTunedFrequency	double *	The actual adjusted RF center frequency, based on the frequency step size determined by the span.
freqShift	double *	The difference between the actual RF center frequency and the actual IF center frequency.

Status

Returns the status of the function. To see an explanation of common error and warning codes, see Error and Status Codes. To see a text explanation of the status code, call niTuner_errorHandler.