image acquisition on-board memory

[Gang Pan]

Hi, I have a 1422 card connected to a 1 Mega Pixel camera. The image acquisition runs at 30 fps. I wander if there is any advantage of using on-board memory for ring acquisition? What are the differences between using on-board memory and computer mamory in IMAQ acquisition?

[BruceAmmons]

The main advantage of on-board memory is not being limited by the PCI bus bandwidth during acquisition. If you have a camera that can send data faster than the PCI bus can move it, you can acquire rapidly to on-board memory and slowly transfer it to PC memory after the acquisition.

If your acquisition is slow enough, there aren't many advantages to using on-board memory. I could see acquiring in a ring using on-board memory and waiting for a trigger event to occur and then downloading the image history from the card. This would eliminate a constant use of the PCI bandwidth for storing the continuous images. You would not be able to store a large number of images in the onboard memory, but in most cases it would be enough.

Bruce