Hi Chen,
It looks like the original poster of this forum has not posted to the NI forums in a year so you might get a better response by posting your question with the context of what you are trying to do on a new forum thread.
As far as Sample 1-7, sample 10, etc. When you say sample, do you mean image? So is the read missing images when it is reading from the camera? Are you using the IMAQdx Get Image VI instead of the grab as Vivek_N suggested? Also, have you tried implementing the producer-consumer architecture as mentioned above?
A Johnson
Applications Engineer
National Instruments
