How to pass a value to TIMER function

Hi, I would like to have the data I obtained from my NI daq board to show on my GUI window in real time while I can still run other things from the GUI. I tried the TIMER function, but not sure how to pass the value to the timer function. Any help and suggestion would be greatly appreciated.

Thanks,

Feng

Answer 1

[dpb]

Create a timer setting type and period initially...

rate=10;    % a repetition rate
ht=timer('ExecutionMode','fixedrate', ...
       'period', rate, ...
       'TimerFcn',@yourcallbackfunction);

Set the rate later...

rate=rate/2;
set(ht,'period',rate);

doc timer % for more details

Not sure how you're trying to do this; you might want a singleshot and restart it from the callback when you've got a new set of data; not sure...

[Feng]

What I was trying to achieve is actually this: t=timer('ExecutionMode','fixedrate', 'period',rate, 'TimerFcn',@callbackfun); Mydata = data;

function data = callbackfun . .

data = 3; . . .

I tried @(data)callbackfun, also t.TimerFcn='data=callbackfun'. it seems that none of them would allow me to access the 'data'. Any suggestion or trick?

Thanks,

Feng

[dpb]

Yeah, you have to follow the rules established for callback functions--see the docs for the timer object for details.

The basic idea is that if you specify the callback commands directly as the value of the callback function property w/ the callback an anonymous function the commands are evaluated in the MATLAB workspace.

OTOH, if instead of specifying MATLAB commands directly as the value of a callback property, when you create a callback function, the first two arguments must be a handle to the timer object and an event structure. Other application-specific arguments must be in a cell array and this function operates in its own space.

It's too involved a subject to try to repeat the help doc's here; read them in their entirety going through the examples of how to create/use callback functions.