Imaq start stop example

[Es-Thomas]

Hi,
Is there an Imaq example available that uses the imaq start/stop function? I want to do a triggered acquisition (3 images a second) and processing of that image. However, the processing of that image takes a lot of CPU power, and I have a time limit. So I want to use the imaq stop function after the "Imaq Extract" to get all the CPU power, then process the image, and then start the acquisition again.

Can anyone help me with this ? (asap?)

Thanks in advance,
Thomas Vandenberghe

[BruceAmmons]

Thomas,

This won't really help you. The CPU is not involved with the acquisition once it has started. It is a background process where the information from the PCI card is directly transferred to memory. I think it is controlled by the MITE chip on the PCI card.

What you should do is make sure you aren't doing any unnecessary acquisition. Use skip frames to only acquire three frames per second, or use Grab to only get the next frame when you need it.

Bruce

[Es-Thomas]

Hi Bruce,

Thanks for your reply.
In which situation can the start/stop VI's then be used?

Thomas

[BruceAmmons]

I have used Start when I am synchronizing with other tasks, such as motion. I set up all the different tasks, which allows all the necessary memory allocation and a few other time consuming activities. Then I use Start to get it going. If necessary, I use a separate signal and triggering to make sure they all start at the exact same time.

I use Stop when I am doing a buffered acquisition, and I am finished with it. Also, if I get an error, sometimes Stop and Start will clear whatever caused the error.

Bruce