Undesireable "split frames" using the NI-PCI-1426

[versh]

Using an Indigo 9803 camera and the NI-PCI-1426 camlink, I occasionally get undesireable "split frames" where the live image contains a horizontal dividing line.  The position of the line will persist for a given acquisition (it doesn't move frame-by-frame), but relocates on subsequent acquisitions.  What causes this and how can I eliminate it?

[The_Chancenator]

Hi Versh,

Do you see the problem when acquiring in Measurement and Automation Explorer?  What version of the IMAQ driver are you using?  This was seen in earlier versions of the driver and with ring acquisitions: Why Do I See Parts of Multiple Frames in the Same Buffer?

Try doing a grab in MAX.  If this does not work, open up a ring acquisition example program from LabVIEW, and see if you see the issue there.   Post back with some more details and we can take a further look into this.

Cheers, 

[versh]

I see the problem no matter what camlink software interface I use (MAX, MATLAB IMAQ Tool & command line, FLIR Rdac, etc.) or acquisition I set up (single-frame or ring).  For a given acquisition (single-frame or ring), if the "split frame" is present (sometimes it isn't), the horizontal dividing line stays in the same place.  For a given acquisition, I can get it to vertically scroll by changing the image height from 513.  The camera is an Indigo Phoenix 9803 DTS system.    My camera config file is attached (oddly, it appears to be setup for a linescan camera but it works).

Regards,

Versh

[versh]

I forgot to ask - when you say "ring acquisition" I assume you mean grabbing multiple frames, correct?  Also, I am not currently running LabVIEW (sacrilage, I know).

[BlueCheese]

If the camera file is configured for a linescan camera then that is likely your problem. With linescan it won't be looking for a frame valid signal to signify the start of a frame. If the acquisition starts mid-frame then you will be forever out-of-sync with the start of the image and see a split frame for each image.

Eric 

[versh]

I thought that having ScanType(LineScan) in my config file was odd, but when I use the Indigo Phoenix 640x512 config file from NI's site, which contains ScanType(Area), it results in a timeout (even after increasing the allowed time in MAX to several seconds).  I hope the problem is in the config file, because then it can be fixed - but I am not certain what lines of code I would need to change to make it work.  Might you have any suggestions?

Eric

[The_Chancenator]

Hi Eric,

You're probably getting the timeout with that Phoenix 640x512 configuration file because it is for a digital camera, not a CameraLink camera.  I'm actually kind of surprised that the other camera file doesn't also do this since it also seems to be for a digital camera.  However, try just changing the "LineScan" token to "Area" in the camera file that you have working. 

If this doesn't work, we can look into using the Camera File Generator to create a camera file that would work for you. 

Cheers, 

[Andrey_Dmitriev]

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versh wrote:
Using an Indigo 9803 camera and the NI-PCI-1426 camlink, I occasionally get undesireable "split frames" where the live image contains a horizontal dividing line.  The position of the line will persist for a given acquisition (it doesn't move frame-by-frame), but relocates on subsequent acquisitions.  What causes this and how can I eliminate it?

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Common problem for low-quality camera link cable / electrical noise in environment. Brand name camera link cables for industrial environment are pretty expensive. Try to replace cable with possible shortest length or install camera link repeater between two short camera link cables. Be sure that camera link cable not places together in parallel with other power cables.

Andrey.

[versh]

I tried several different cables and kept them away from sources of possible interference, but to no avail.  The shortest cable was 5' long. 

I reduced the camera file down to the minimum lines of code that still work (attached).  The code only works when I specify ScanType(LineScan), not when I change it to ScanType(Area).

I'm going to give you guys kudos for helping me narrow this down, although the problem persists!

-Versh

[BlueCheese]

Check that your camera is outputting proper FVAL signals... Also try reducing the image size. if it is trying to acquire too many pixels in an image you'll get a timeout in the non-linescan configuration since it will never get a full image before starting on the next.

Eric