HP ESA-E Series - Page 147

Chapter 3 3-83
Programming Examples
Measuring Harmonic Distortion (RS-232)
/*Trigger a sweep */
viPrintf(viESA,"INIT:IMM\n");
/*Check for operation complete */
viQueryf(viESA, "*OPC?\n", "%d", &lOpc);
if (!lOpc)
{
/*Perform a peak search */
viPrintf(viESA,"CALC:MARK:MAX \n");
/*Perform activate signal track */
viPrintf(viESA,"CALC:MARK:TRCK:STAT ON \n");
/*Perform narrow span and wait */
viPrintf(viESA,"SENS:FREQ:SPAN 10e4 \n");
/*Make sure the previous command has been completed */
viQueryf(viESA, "*OPC?\n", "%d", &lOpc);
if (!lOpc)
{
printf("Program Abort! Error occurred: last command
was not completed! \n");
exit(0);
}
/*De-activate the signal track */
viPrintf(viESA,"CALC:MARK:TRCK:STAT OFF \n");
/*Set units to DBM*/
viPrintf(viESA,"UNIT:POW DBM \n");
/*Take a sweep and wait for the sweep completion*/
TakeSweep();
/*Perform a peak search */
viPrintf(viESA,"CALC:MARK:MAX \n");
/*Take a sweep and wait for the sweep completion*/
TakeSweep();
/*Read the marker amplitude, this is the fundamental
amplitude in dBm */
viQueryf(viESA,"CALC:MARK:Y?\n","%1f",
&fFundaAmptdDbm);
/*Change the amplitude units to volts */
viPrintf(viESA,"UNIT:POW V \n");
/*Take a sweep and wait for the sweep completion*/
TakeSweep();
/*Read the marker amplitude in volts, This is the
fundamental amplitude in volts (necessary for the THD