Hi Everybody!
I have attached a VI (Write MAT file.vi - written in LabVIEW 7.1) that takes a waveform and directly converts it to a 2D array where the first column is the timestamps and the second column is the data points. You can then pass this 2D array of scalars directly to the Save Mat.vi. You can then read the .MAT file that is created directly from Matlab.
For more information on this, you can reference the following document:
Can I Import Data from MATLAB to LabVIEW or Vice Versa?
http://digital.ni.com/public.nsf/websearch/2F8ED0F588E06BE1862565A90066E9BA?OpenDocument
However, I would definitely recommend using the Matlab Script node (All Functions->Analyze->Mathematics->Formula->Matlab Script). In order to use the Matlab Script node, you must have Matlab installed on the same computer. Using the MatlabScript node, you can take data generated or acquired in LabVIEW and save it directly to a .mat (Matlab binary) file using the 'save' command (just like in Matlab). You can see this in example VI entitled MathScriptNode.vi - written in LabVIEW 7.1.
I hope this helps!
Travis H.
LabVIEW R&D
National Instruments