Again Grab and Attributes Setup.vi

[Yixiao-uncle]

Hi!.

I tryed to write a vi able to change attribute to my iee1394a cam, display images and save in avi file.

So  I modifies Grab and Attributes Setup.vi to this purposee and the result is "almost" good, but i found some problems.

I went back to original vi and there i found something strange.

When i run the vi and select "grab" button, the camesa runs at the maximim speed, 60fps, even the relative attibute is "640 x 480 30 fps" and also in MAX i saved the same configuration.

Then i stop grabbing and i launch it again: the second and the following runs work properly!

Does anybody can understand what is happening?

The camera is a Guppy F036C,  Labview 8.5, Vision Devellopent Module 8.5.

The vi should run on computer with NI  PCI 8254R board, but actually im performing my test on notebook, using its firewire 1394a input.

Thank You a lot

Antonio

[Yixiao-uncle]

Hi.

Maybe my subject was strange to the community, anyway I tried to work deeply on it, so I changed “IMAQdx Get Image.vi” with “IMAQdx Grab Image.vi”.

After it the complete vi is running properly and the frame rate is that prescribed by video mode set in the panel.

I still cant understand the reason of this behaviour.

Can anybody find the explanation?

Thank You

Antonio

[BlueCheese]

Antonio,

Just a thought, but one of the inputs of "IMAQdx Get Image" is the mode to decide what buffer number to get. If you have this set as "newest" you will potentially get repeats of the buffer numbers (if the "newest" buffer is the same from one iteration to the next). The "processed" frames-per-second in this case would be limited by your CPU, not by the camera. "IMAQdx Grab Image" is equivalent to "IMAQdx Get Image" with a buffermode of "Next".

Eric