HP E4401B, Programmer'S Manual

Page: 144 / 398

3-80 Chapter 3
Programming Examples
Measuring Harmonic Distortion (RS-232)
#include "visa.h"
#define hpESA_IDN_E4401B "Hewlett-Packard, E4401B"
#define hpESA_IDN_E4411B "Hewlett-Packard, E4411B"
ViSession defaultRM, viESA;
ViStatus errStatus;
ViChar cIdBuff[256]= {0};
char cEnter = 0;
int iResult = 0;
long lOpc =0L ;
/*Set the input port to the 50 MHz amplitude reference*/
void Route50MHzSignal()
{
viQueryf(viESA, "*IDN?\n", "%t", &cIdBuff);
iResult = (strncmp( cIdBuff, hpESA_IDN_E4401B,
strlen(hpESA_IDN_E4401B)) && strncmp( cIdBuff,
hpESA_IDN_E4411B, strlen(hpESA_IDN_E4411B)));
if( iResult == 0 )
{
/*Set the input port to the 50 MHz amplitude reference
for the models E4411B, E4401B*/
viPrintf(viESA,"CAL:SOUR:STAT ON \n");
}
else
{
/* For analyzers having frequency limits >= 3 GHz,
prompt the user to connect the amplitude reference output to
the input*/
printf ("Connect amplitude reference output to the
input \n");
printf ("......Press any key to continue \n");
scanf( "%c",&cEnter);
/*Externally route the 50MHz Signal*/
viPrintf(viESA,"CAL:SOUR:STAT ON \n");
}}
void TakeSweep()
{
/*Take a sweep and wait for the sweep completion*/
viPrintf(viESA,"INIT:IMM \n");
viQueryf(viESA, "*OPC?\n", "%d", &lOpc);
if (!lOpc)
{
printf("Program Abort! Error occurred: last command
was not completed! \n");
exit(0);
}