Agilent Technologies E7401A

Chapter 3 123
Programming Examples
Reading Trace Data Using 32-bit Real Format (GPIB)
iDataBytes = (iSwpPnts*iBytesPerPnt);
lNumberBytes = iDataBytes;
while ((iDataBytes = (iDataBytes / 10 )) > 0 )
{
iHeaderBytes++;
}
/*Set analyzer to single sweep mode */
viPrintf(viESA,"INIT:CONT 0 \n");
/*Set the analyzer to 50MHz-center frequency */
viPrintf(viESA,"SENS:FREQ:CENT 50 MHZ\n");
/*Set the analyzer to 50MHz Span */
viPrintf(viESA,"SENS:FREQ:SPAN 50 MHZ\n");
/* Specify dB per division of each vertical division and Units */
viPrintf(viESA,"DISP:WIND:TRAC:Y:SCAL:PDIV 10dB\n");
viPrintf(viESA,"UNIT:POW DBM\n");
/*Set analyzer trace data format to 32-bit Real */
viPrintf(viESA,"FORM:DATA REAL,32 \n");
/*Set the binary byte order to SWAP */
viPrintf(viESA, "FORM:BORD SWAP\n");
/*Trigger a sweep and wait for sweep to complete*/
viPrintf(viESA,"INIT:IMM;*WAI\n");
/*Calculate size of trace record. This will be sum of HeaderBytes, NumberBytes*/
/*(the actual data bytes) and the "/n" terminator*/
iSize = lNumberBytes +iHeaderBytes+1;
/*Get trace header data and trace data */
viPrintf(viESA,"TRAC:DATA? TRACE1\n");
viRead (viESA,(ViBuf)cResult,iSize,&lRetCount);
/*Extract the trace data*/
memcpy(dTraceArray,cResult+iHeaderBytes,(size_t)lNumberBytes);
/*Save trace data to an ASCII file*/
fTraceFile=fopen("C:\\temp\\ReadTrace32Gpib.txt","w");
fprintf(fTraceFile,"ReadTrace32Gpib.exe Output\nAgilent Technologies 2000\n\n");
fprintf(fTraceFile,"The %d trace data points of the
spectrum:\n\n",(lNumberBytes/4));
for ( long i=0;i<lNumberBytes/4;i++)