KEITHLEY kusb data acquisition box input problem (real time plotting and data analysis)

Hi all, I am having some problems with this hardware, more specific with data input and processing. Let me quickly explain a set up. I have a small shaft on which I have small magnet mounted which passes next to a hall sensor. Every time the magnet passes to the hall sensor voltage drops. Constant voltage of 5 volts is applied to the sensor. So this is what I am trying to do. By using daq system I want to receive analog input (voltage) that ranges from 0 - 5 and then plot it in the real time while also extracting that data from the engine. This is the code I tried using:

%create a device object
AI = analoginput('dtol');
ain.inputtype='differential';
%addin a chant(AI, 'Timeout', 60);
duration = 10; %seconds - this can be user input 
set(AI, 'SampleRate', 500);
ActualRate = get(AI, 'SampleRate');
addchannel(AI,0);
%configure 
set(AI,'SamplesPerTrigger',duration*ActualRate)
preview = duration*ActualRate/100;
subplot(211)
P = plot(zeros(preview,10000)); grid on
title('Preview Data')
xlabel('Samples')
ylabel('Signal Level (Volts)')
%acquire data

start(AI)
%while AI.SamplesAcquired < preview
%end
while AI.SamplesAcquired < duration*ActualRate
   data = peekdata(AI,preview);
   set(P,'ydata',data)
   drawnow
end

wait(AI,duration+1)
data = getdata(AI);
subplot(212), plot(data), grid on
title('All Acquired Data')
xlabel('Samples')
ylabel('Signal level (volts)')

delete(AI)
clear all

so by using this code I am trying to plot some samples for 10 seconds and then also store that acquired data in a vector for further analysis. These are the problems that I am having:

The data input never stops by its self. I have to ctrl-c it to stop it. While the program is running this is the message I receive:

Warning: The number of samples requested is not available.
The number of samples returned will be reduced.

Also I don't get any variable containing data. Plot shoes up but there is no data plotting on it, and my axis are x:-1,1 and y:-1,1 even though I specified them differently. Honestly I have no idea what is going on here. This is my first time using this system but I understand the code completely. If someone can help out with this I would be very thankful.

Thank you,

Uros

[Walter Roberson]

Does this imply that you solved the driver and GPIB problems you described in previous questions?

Have you determined that you are able to communicate with the device ?

[Uros]

After rebooting Matlab and creating a new input, channel and run it for 10 seconds I get a plot of correct values which means I can communicate with the device.