Reading real-time data in Excel

Hello,

I have a simple question. When I try read to real-time Excel data, xlsread doesn't work, meaning every new request does not give me real-time data.  However, the following 2 lines do ...

s = ddeinit('Excel', 'q.xlsx');
t = ddereq(s, 'r1c1:r1c2');

 So, I'm just curious, why doesn't xlsread work?  And why does ddeinit etc. work?

 Thanks
 Damo