Keysight Technologies N5173B EXG - Page 286

286 Keysight CXG, EXG, and MXG X-Series Signal Generators Programming Guide
Creating and Downloading Waveform Files
Programming Examples
% rms = sqrt(sum(Iwave.*Iwave + Qwave*.Qwave)/points);
% 2.) Save waveform in internal format
*********************************
% Convert the I and Q data into the internal arb format
% The internal arb format is a single waveform containing
interleaved IQ
% data. The I/Q data is signed short integers (16 bits).
% The data has values scaled between +-32767 where
% DAC Value Description
% 32767 Maximum positive value of the DAC
% 0 Zero out of the DAC
% -32767 Maximum negative value of the DAC
% The internal arb expects the data bytes to be in Big Endian
format.
% This is opposite of how short integers are saved on a PC (Little
Endian).
% For this reason the data bytes are swapped before being saved.
% Interleave the IQ data
waveform(1:2:2*points) = Iwave;
waveform(2:2:2*points) = Qwave;
%[Iwave;Qwave];
%waveform = waveform(:)';
% Normalize the data between +-1
waveform = waveform / max(abs(waveform)); % Watch out for divide
by zero.
% Scale to use full range of the DAC
waveform = round(waveform * 32767); % Data is now effectively
signed short integer values
% waveform = round(waveform * (32767 / max(abs(waveform)))); %
More efficient than previous two steps!