DAQ session error within a guide interface

I am currently building a gui that contains controls for both image acquisition and national instruments data acquisition (sometimes simultaneously). I successfully built the controls for the image acquisition part. I can preview, capture, and process images from my video stream, and view them in real time. I went on to add the daq code and ran into the following error:

No appropriate method, property, or field preview for class daq.ni.Session

This occurs when I try to access any part of the handles structure after issuing a daq command. I check handles and all the fields appear to be present. I created the daq session as handles.s = daq.createSession('ni'). I am sure I am using the handles structure incorrectly but I cannot figure it out.

Answer 1

[Sean de Wolski]

preview is an option to preview an image, it'll be different for daq. I don't have access to any hardware right now but you'll be able to find your method of choice in here, perhaps startbackground?

http://www.mathworks.com/help/releases/R2014a/daq/acquire-data.html

[Edward]

I was trying to preview the video object after the daq command was complete, I was not trying to look at any of the acquired daq data. If I try to access some other variable, for example handles.foo, in the program, I get the same error but it would read

No appropriate method, property, or field foo for class daq.ni.Session