Hi,
In order to perform the multiple channel acquisition, please take a look at the commands starting with SCAN, such as, SCAN_Start.
And regarding the examples, there are two places I would suggest you to take a look at :
1. In your C:\program files\national instruments\ni-daq\examples\visualc folder
2. Go to www.ni.com, Developer Zone, Development Library and the Measurement Hardware.
Please do let me know if you still have any questions.
Sincerely,
Sastry V.
Applications Engineer
National Instruments.