MATLAB real time serial data plot

Hi all,

I am trying to use this code to plot the serial data comming from my serial port

But I am having this error

??? In an assignment A(I) = B, the number of elements in B and
I must be the same.

Error in ==> real_time_data_serial at 80
voltage(count) = fscanf(s,'%f');

What should I do ?

Regards