Current vs time for fixed voltage controlling Keithley 2400?

Hi,

I'm new to instrument control with matlab and have been trying to make a simple script that sets a fixed voltage and measures current vs time. I'm having a few problems and was wondering if anyone had a sample script on how to measure this? I would really like to get time and current from the keithley rather than defining it here.

This is my script so far (and doesn't work). I think it works up until where I set the fixed voltage value..

Cheers in advance and apologies for noob errors!

CODE:

    serialObject = serial('/dev/tty.usbserial')
    if nargout > 0
        out = [serialObject];
    end
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
    % Model 2400 Specific Functions
    fopen(serialObject)
    fprintf(serialObject,':*RST')

    time = now;
    current = 0;

    figureHandle = figure('NumberTitle','off',...
        'Name','Current Characteristics',...
        'Color',[0 0 0],'Visible','off');

    %%Set the time span and interval for data collection
    stoptime = 60*60*1; %1hr of seconds
    timeInterval = 0.005;

    % Setup Current fixed level and read current.
    fprintf(serialObject,':SOUR:FUNC:MODE VOLT'); % voltage source selection.
    fprintf(serialObject,':SOUR:CURR:MODE FIXED'); % changes voltage mode to fixed
    fprintf(serialObject,':SOUR:VOLT:LEV 5'); % sets voltage to 5V (works)
    fprintf(serialObject,':SENS:FUNC “CURR”');
    fprintf(serialObject,':SENS:CURR:RANG:AUTO ON');
    fprintf(serialObject,':SENS:CURR:PROT 1');

% fprintf(serialObject,':TRAC:COUN 1') fprintf(serialObject,':TRAC:FEED:CONT NEV'); fprintf(serialObject,':OUTP ON');

    %%Collect data
    count = 1;
    tic;
    while count<=stoptime/timeInterval
        fprintf(serialObject,':INIT');
        fprintf(serialObject,':TRAC:FEED: SENS')
        fprintf(serialObject,':TRAC:DATA?'); 
% To measure current the command is MEASURE:CURRENT:DC?
        current(count) = fscanf(serialObject,'%f');
        time(count) = toc;
        set(plotHandle,'YData',current,'XData',time);
        set(figureHandle,'Visible','on');
        pause(timeInterval);
        count = count +1;
    end

    %%Put the instrument in local mode
    fprintf(serialObject,'SYSTEM:LOCAL');

%% Clean up the serial object fclose(serialObject); delete(serialObject); clear serialObject;