ag8753_get_FORM5_binary_data.m

%% Binary Data Read from the 8753/8720 Network Analyzers
%
%   This is the machine generated representation of an instrument control
%   session. The instrument control session comprises all the steps you are
%   likely to take when communicating with your instrument. These steps are:
%   
%       1. Create an instrument object
%       2. Connect to the instrument
%       3. Configure properties
%       4. Write and read data
%       5. Disconnect from the instrument
% 
%   To run the instrument control session, type the name of the M-file,
%   ag8753_get_form5_binary_data, at the MATLAB command prompt.
% 
%   The M-file, AG8753_GET_FORM5_BINARY_DATA.M must be on your MATLAB PATH. For additional information 
%   on setting your MATLAB PATH, type 'help addpath' at the MATLAB command 
%   prompt.
% 
%   Example:
%       ag8753_get_form5_binary_data;
% 
%   See also SERIAL, GPIB, TCPIP, UDP, VISA.
%
%   ojd - 1/12/2009
% 

%% Create a VISA-GPIB object.

%Disconnect and delete all current instrument objects
instrreset;

visa_addr='GPIB5::16::INSTR';

obj1 = instrfind('Type', 'visa', 'RsrcName', visa_addr, 'Tag', '');

% Create the VISA-GPIB object if it does not exist
% otherwise use the object that was found.
if isempty(obj1)
    obj1 = visa('agilent', visa_addr);
else
    fclose(obj1);
    obj1 = obj1(1);
end

% Max out buffer size for largest possible read of 1601 points in FORM5
set(obj1,'InputBufferSize', 13000);

% Connect to instrument object, obj1.
fopen(obj1);

%% Communicating with instrument object, obj1.

% Get and display ID String
data1 = query(obj1, 'OUTPIDEN');
fprintf(1, 'Connected to: %s\n', data1);

% Set data return format and trigger a single measurement
fwrite(obj1, 'FORM5; OPC?; SING');
opc_comp=fscanf(obj1);

%% Read data back from analyzer

%Ask for data
fwrite(obj1, 'OUTPDATA'); 

%Read out #A from binblock
temp=fread(obj1, 2, 'char'); 

%Read out block size
temp=fread(obj1, 1, 'uint16'); 

%Read out trace data
data1=fread(obj1, temp/4, 'float32');

points=temp/(4*2);

%Flush the buffer
clrdevice(obj1);

%Allocate space for data array
data=zeros(points,2);

%Reshape output array into two columns
for i=1:1:points
    data(i,1)=data1((2*i)-1);
    data(i,2)=data1(2*i);
end

%% Calculate Amplitude and Plot

%Allocate space for magnitude array
mag=zeros(points);

%Calculate Magnitude
for i=1:1:points
    mag(i)=20*log10(sqrt(data(i,1)^2+data(i,2)^2));
end

plot(mag);


%% Clean-up

% Disconnect all objects.
fclose(obj1);

% Clean up all objects.
delete(obj1);