Keysight E4428C ESG RF - Page 278

270 Keysight Signal Generators Programming Guide
Creating and Downloading Waveform Files
Programming Examples
// spreadsheet to help spot any problems.
FILE *outfile = fopen(ofile, “w”);
if (outfile==NULL) perror (“Error opening file to write”);
for(index=0; index<numsamples; index++)
{
fprintf(outfile, “%d, %d\n”, idata[index], qdata[index]);
}
fclose(outfile);
// Little endian order data, use the character array and for loop.
// If big endian order, comment out this character array and for loop,
// and use the next loop (Big Endian order data).
// We need a buffer to interleave the I and Q data.
// 4 bytes to account for 2 I bytes and 2 Q bytes.
char iqbuffer[NUMSAMPLES*4];
// Interleave I and Q, and swap bytes from little
// endian order to big endian order.
for(index=0; index<numsamples; index++)
{
int ivalue = idata[index];
int qvalue = qdata[index];
iqbuffer[index*4] = (ivalue >> 8) & 0xFF; // high byte of i
iqbuffer[index*4+1] = ivalue & 0xFF; // low byte of i
iqbuffer[index*4+2] = (qvalue >> 8) & 0xFF; // high byte of q
iqbuffer[index*4+3] = qvalue & 0xFF; // low byte of q
}
// Big Endian order data, uncomment the following lines of code.
// Interleave the I and Q data.
// short iqbuffer[NUMSAMPLES*2]; // Big endian order, uncomment this line
// for(index=0; index<numsamples; index++) // Big endian order, uncomment this line
// { // Big endian order, uncomment this line
// iqbuffer[index*2] = idata[index]; // Big endian order, uncomment this line
// iqbuffer[index*2+1] = qdata[index]; // Big endian order, uncomment this line
// } // Big endian order, uncomment this line
// Open a connection to write to the instrument
INST id=iopen(instOpenString);
if (!id)