Scan start is for scanning multiple channels - acquiring data from each channel in your scan list; DAQ_start is for scanning one channel.
For scan start you can control the time between channels. For example, you can control the tie between channels 0 and 1. You can also control the time between scans - the time between acquire data from channel 0 and 1 and the next time you acquire data from channels 0 and 1. There are several good examples for C and CVI that show off these functions. Look through your example documentation - try C:\Program Files\National Instruments\CVI70\samples\daq\Ai\DAQSingleBufAsynch.c. In the same folder you will find the ScanSingleBuf Asynch.c. Both of these calls are asychronous. They will execute in the background. You
will have to call DAQ_Check to see when the data has arrived.
What are you wanting to do?
