image acq. problem w/ progressive scan camera -- split image

[bowes@physics.utexas.edu]

I would like to repeatedly acquire a dynamic image from a Sony XC-56
progressive scan camera. The image acq. VIs are to be placed into a loop
that controls a servo motor. For each itteration of the motor loop I want to
grab an image and save it with a file name that contains the servo motor position.
The VI that I have developed can take an image with each loop itteration, but
the grabbed image is split -- part of one image and part of the previous. The
attached ZIP file contains the VI that both controls motors and grabs
images spiralZ_NI-help.vi), a VI that only grabs images in a loop
(image_grab_loop-NIhelp.vi -- I get the same results with this simple VI)
and a sample image showing the split frame (example-picture.bmp). The split
"line" isn't stationary -- it will move up and down in different frames, but it is
always horizontal. Also in the ZIP file is the technical manual for the
Sony XC-56 camera, which is different that the Sony XC-55 referenced on NI help
pages.

PS: The VIs are saved as "development-version" so it should contain the necessary sub-VIs.

[BruceAmmons]

I can't open your file because I am not using LV 7.1, but I think I know your problem.

The image you are getting is a partially acquired image that is overwriting the previous buffer. Most likely, you have the "Immediate?" input set to true. This tells the vi to immediately return whatever image it has instead of waiting until acquisition of the current buffer is complete. If you set this input to false, you should get complete images.

If this isn't the problem, you have your program set up with the same buffer for acquisition and analysis.

Bruce

[bowes@physics.utexas.edu]

Hi,

Thank you very much for the suggestion. You're right -- I had not set "Immediate?" to false. With that set now each image is clean with no horizontal line, although the image updating is a bit slower.

If I wanted to set up two buffers, how would I do that? Just use two IMAQ_Create.vi, one wired to display and one wired to save?

Sincerely,

Ben Bowes
bowes@physics.utexas.edu