Agilent Technologies N5181A/82A Creating and Downloading Waveform Files Programming Examples

Creating and Downloading Waveform Files

Programming Examples

// Create arrays to hold the I and Q data

int idata[NUMSAMPLES]; int qdata[NUMSAMPLES];

//save the number of sampes into numsamples int numsamples = NUMSAMPLES;

//Fill the I and Q buffers with the sample data for(int index=0; index<numsamples; index++)

{

//Create the I and Q data for the number of waveform

//points and Scale the data (20000 * ...) as a precentage

//of the DAC full scale (-32768 to 32767). This example

//scales to approximately 70% of full scale.

idata[index]=23000 * sin((4*3.14*index)/numsamples); qdata[index]=23000 * cos((4*3.14*index)/numsamples);

}

//Print the I and Q values to a text file. View the data

//to see if its correct and if needed, plot the data in a

//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++)

{

Agilent N518xA, E8663B, E44x8C, and E82x7D Signal Generators Programming Guide 239