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Dalsa Spyder gigE linescan camera - image overwriting

Hi,

 

I'm using a 4k Dalsa Spyder gigE linecan camera. The problem I'm seeing seems to occur only for images greater than about 4000 lines. Above this value the image starts to wrap round on itself. I've tried setting the image size to match the number of lines explicitly, but this doesn't seem to have any effect. I've tried the LabView IMAQdx low level snap and grab routines in the examples section, but none of these seem to work properly either. 

 

I've used e2v and Basler linescan cameras in the past and never seen this problem. Consequently I'm wondering if there could be an issue with this particular camera / manufacturer.

 

Any suggestions would be welcome.

 

Also a little puzzled about when to use continuous, one shot modes and how the number of buffers comes into play. I usually start with a LabView example - usually snap - and go from there, but I can't say that I fully understand what's going on.  If somebody could enlighten me I'd be grateful.

 

Lightworker

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LightWorker contacted the camera supplier and found that the 4K SG-11 camera he is using has an on board memory limitation of 3960 lines worth of acquisition data. This problem was deemed to be localised to the Dalsa camera after using the software he was provided with on purchase and found that the same error persisted.

 

With GigE compliance, the IMAQdx drivers implicitly buffer images transparently to the LabVIEW developer; although an explicit number of buffers can be configured to prevent data loss during application execution alongside specific property configuration for the IMAQ Image.


Alex Thomas, University of Manchester School of EEE LabVIEW Ambassador (CLAD)

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For anyone interested, a work around is to capture successive images of  less than 3960 lines in separate buffers and then use the Image2 image function with appropriate offsets to create a single image.

 

Lightworker

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