Images have black horizontal lines

[Karen_USGS]

  I'm using a Prosilica GC2450C camera and viewing the camera's output through the Measurements and Acquisitions software.  Nearly every image is covered with black horizontal lines.  (see attached image)  I'm not sure where to begin to address the problem.  I have tried adjusting the frame rates, the packets, StreamBytesPerSecond, and have had no change.  Occasionally the Camera times out (error: 0xBFF6901B).  And now the application is crashing and locking up the computer.

  Images using the SampleViewer from Prosilica are fine.  No lines, no crashes.  

  Does anyone have any suggestions as to what might be causing the trouble? 

  I'm using a brand new Panasonic Toughbook CF-52, Ethernet card: Intel(R) 82577LM Gigbit Network Card, Prosilica GC2450C camera.  (Please let me know if you need more info.)

  Please let me know if this is the correct forum, or if there is a better one to post this message to.

   Thanks

       Karen

[Karen_USGS]

Sorry, I meant Measurements and Automation software....  Thanks

[BlueCheese]

Hi Karen,

That looks like packet loss on the image (you can confirm this via the Ethernet tab). I've seen this before where the default setup of the 82577 using the Intel driver is not well-suited to GigE Vision data. You could try reducing the packet size (down to 4k or 2k) to see if that helps. You may also want to try increasing the number of buffers the Intel driver is using. Unfortunately this chipset is not currently supported by NI's High Performance GigE Vision driver and so the data has to go through the Intel driver and the Windows network stack.

There are several other things you might want to try. Decreasing the data rate would be the easiest option. On the Prosilica there are two methods to do this. There is the StreamBytesPerSecond (Prosilica-specific option) and then the GigE Vision standardized mechanism that is exposed under the Advanced Ethernet->Bandwidth Control settings. I believe the Prosilica camera includes another attribute that switches between which of these two mechanisms is actually throttling the bandwidth. You'll want to change that to match whichever one you are using.

Another option is that from the looks of your missing data, you are receiving RGB images directly from the camera. Switching to a Bayer format would decrease the data rate quite a bit at the expense of slightly more CPU on the host side to decode the image (which may be counteracted by less network data to process).

Lastly, Prosilica installs a filter driver onto the system I believe. You may want to try seeing if you can uninstall or disable it when using IMAQdx. Depending on how they are written, they could cause a performance impact for non-Prosilica applications.

Eric

[Karen_USGS]

Hi Eric.  

  Thanks for your help.  I definitely have packet loss.  I already had the packet size way down (576, it defaulted there once while I was playing around).  Putting it up to 2k didn't change it.  I upped both the transmit and receive bufferes on the 82577 advanced properties tab, but still no change.  I found something in the Proscilia tools called a GvspSocketBufferCount.  (I'm not sure what that is, but I'm going to research it.)  I changed that to 2048 and the lines went away.  But now I can only getting 2 fps, max, but no packet loss.  I can't find in the Meas' & Auto' camera attributes where an equivalent setting might be.  

  Certainly 2 fps with no lines is much better then 15 fps with black lines.  

  You said that this chipset is not supported by NI GigE Vision driver.  Is there a list of chips that are supported?  (Full disclosure, I'm not even sure I know what I'm asking.)

  Karen

[BlueCheese]

Hi Karen,

Yes, 576 would be very taxing on the CPU and network card! You want at least 1500 (non-jumbo frames). Ideally you want 8-9k, but some chipsets can't go that high (either at all or optimally).

I'm a bit confused as you mentioned you changed some option in Prosilica's softwarre and it fixed it. Did it fix it within MAX or within Prosilica's software? I thought you said you didn't see missing lines in their software at all...

I can't point you to a list, but many desktop Intel gigabit cards are supported. There is only one laptop chip supported, but it is an older model that hasn't been on any recent laptops over the past 3 or more years. As far as I know there are no laptops available today that include a chip fully supported by the high-performance driver at the moment.

Eric