Agilent Technologies E1439 manual Age1439frequencysetup, CenterFreqPtr, CmplxDC

Models: E1439

1 246
Download 246 pages 11.5 Kb
Page 138
Image 138

Agilent E1439 Programmer's Reference

Functions listed alphabetically

age1439_frequency_setup

Sets all the zoom center frequency parameters. This description also includes information on the following functions which set or query frequency parameters individually:

age1439_frequency_center sets the center frequency

age1439_frequency_center_get gets the current center frequency age1439_frequency_cmplxdc selects a complex baseband measurement age1439_frequency_cmplxdc_get gets the state of the baseband measurement mode age1439_frequency_sync prepares the module for a synchronous frequency change age1439_frequency_sync_get gets the state of the synchronous change mode

VXIplug&play Syntax

#include "age1439".h

ViStatus age1439_frequency_setup(ViSession id, ViInt16 cmplxDC, ViInt16 sync, ViReal64

centerFreq);

ViStatus age1439_frequency_center(ViSession id, ViReal64 centerFreq);

ViStatus age1439_frequency_center_get(ViSession id, ViPReal64 centerFreqPtr);

ViStatus age1439_frequency_cmplxdc(ViSession id, ViInt16 cmplxDC);

ViStatus age1439_frequency_cmplxdc_get(ViSession id, ViPInt16 cmplxDCPtr);

ViStatus age1439_frequency_sync(ViSession id, ViInt16 sync);

ViStatus age1439_frequency_sync_get(ViSession id, ViPInt16 syncPtr);

 

Description

 

age1439_frequency_setup sets the center frequency of a zoomed measurement. The center of a

 

frequency band of interest is converted to dc with this function. The frequency transition is phase

 

continuous unless the center frequency is set to zero in which case the transition may be selected

 

either to be phase continuous or phase reset. This function may also be used to synchronously

 

change frequency in multiple-module systems.

 

Parameters

id

is the VXI instrument session pointer returned by the age1439_init function.

centerFreq

supplies the center frequency normalized to the sample frequency. It is a number between0.5 and

 

+0.5, which is interpreted as a fraction of the sample frequency. centerFreq is the desired center

 

frequency divided by the ADC sample frequency. For example, selecting 0.25 with a sample

 

clock frequency of 100 MHz yields a center frequency of 25 MHz. When using the IF signal path,

 

the normal range is 0.547 to 0.926 corresponding to 52 to 88 MHz. Your applications should

 

update this parameter when you change signalPath. The ADC sample frequency is returned by

 

the age1439_clock_fs_get function. Negative frequencies select the negative image of the signal,

 

which is spectrally inverted from the input signal.

 

AGE1439_CENT_FREQ_MIN selects the minimum allowable center frequency.

 

AGE1439_CENT_FREQ_MAX selects the maximum allowable center frequency.

 

AGE1439_CENT_FREQ_DEF sets the default center frequency.

centerFreqPtr

points to the current actual value of the center frequency (as a fraction of the sample clock

 

frequency).

cmplxDC

selects either a phase continuous or phase reset transition when freq=0.

128

Page 138
Image 138
Agilent Technologies E1439 Age1439frequencysetup, Age1439frequencycenter sets the center frequency, CenterFreq, CmplxDC