Chapter 3
141
Programming Examples
Measuring Noise
Measuring Noise
/************************************************************/
/* Measuring Noise */
/* */
/* This example is for the E44xxB ESA Spectrum Analyzers */
/* and E740xA EMC Analyzers. */
/* */
/* This C programming example does the following. */
/* The SCPI instrument commands used are given as */
/* reference. */
/* */
/* - Opens a GPIB session at address 18 */
/* - Clears the Analyzer */
/* - Resets the Analyzer */
/* *RST */
/* - Sets the center frequency and span */
/* SENS:FREQ:CENT 50 MHZ */
/* SENS:FREQ:SPAN 10 MHZ */
/* - Set the input port to the 50 MHz amplitude reference */
/* CAL:SOUR:STAT ON */
/* - Set the analyzer to single sweep mode */
/* INIT:CONT 0 */
/* - Trigger a sweep and wait for sweep completion */
/* INIT:IMM;*WAI */
/* - Set the marker to the maximum peak */
/* CALC:MARK:MAX */
/* - Set the analyzer to active delta marker */
/* CALC:MARK:MODE DELT */
/* - Set the delta marker to 2 MHZ */
/* CALC:MARK:X 2E+6 */
/* - Activate the noise marker function */
/* CALC:MARK:FUNC NOIS */
/* - Trigger a sweep and wait for sweep completion */
/* INIT:IMM;*WAI */
/* - Query the marker delta amplitude from the analyzer */
/* CALC:MARK:Y? */
/* - Report the marker delta amplitude as the carrier to */
/* noise ratio in dBc/Hz */
/* - Close the session */
/************************************************************/
#include <stdio.h>
#include <stdlib.h>