%% MATLAB ICT DPO/MSO2000/B Get Waveform
% Date:  May 30, 2017
% This script demonstrates how to pull waveform data off of a DPO/MSO2000/B
% and scale it for a simple plot.

% Tektronix provides the following example "AS IS" without any guarantees
% or support.  This example is for instructional guidance only.

%% variables
visa_brand = 'ni';
visa_address = 'USB0::0x0699::0x0378::QU100010::INSTR';
buffer = 2000 * 1024; %20 KiB

%% open instrument
dpo2k = visa(visa_brand, visa_address, 'InputBuffer', buffer, ...
    'OutputBuffer', buffer);
fopen(dpo2k);

query(dpo2k, '*IDN?')

%% configure output
fwrite(dpo2k, 'wfmo:byt_n 1');
record = str2double(query(dpo2k, 'hor:reco?'));
fwrite(dpo2k, 'header 0')
fwrite(dpo2k, 'data:encdg rib') %signed integer, msb first
fwrite(dpo2k, 'data:source CH1')
fwrite(dpo2k, 'data:comp singular_yt') %see Appendix B of programmer's manual
fwrite(dpo2k, 'data:resolution full') %DPO/MSO2000/B series only. See Appendix B
fwrite(dpo2k, 'data:start 1');
fprintf(dpo2k, 'data:stop %i', record);

%% request sample data
fwrite(dpo2k, 'curve?');

%% read binary block header
waste = fread(dpo2k, 1); %discard '#' character
a = char(fread(dpo2k, 1));
bytes = char(fread(dpo2k, str2double(a))');

% read digital values into sample matrix
samples = fread(dpo2k, str2double(bytes), 'int8');
fread(dpo2k, 1); %discard linefeed character

%% get scaling values
x_incr = str2double(query(dpo2k, "wfmo:xincr?"));
x_zero = str2double(query(dpo2k, "wfmo:xzero?"));
y_incr = str2double(query(dpo2k, "wfmo:ymult?"));
y_off = str2double(query(dpo2k, "wfmo:yoff?"));
y_zero = str2double(query(dpo2k, "wfmo:yzero?"));

%% close instrument
fclose(dpo2k); % close connection
delete(dpo2k); % remove the ICT object
clear dpo2k; % remove the local MATLAB variable

%% scale samples for plot
x_range = record * x_incr;
x_max = x_range + x_zero;
time_base = linspace(x_zero, x_max, record);

scaled_samples = (samples * y_incr) + y_off;

%% simple plot
plot(time_base, scaled_samples);
%plot(samples);