MAX Doesn't Retain Camera Settings

[MGould]

So I have a Pleroa U3 HDSDI capture device that is USB3 Vision compliant.  When I plug it in, I set the pixel format to YCbCr422_8_CbCrY. and save my camera configuration file.  Viewing the .icd file with a text viewer confirms this.  If I unplug the U3, and then plug it back in (same USB3 port and everything), then open up MAX, I see MAX has set the pixel format to YCbCr709_422_10p_CbYCrY, which is wrong.  It also happens to be the last one in the pixel format list.  This is on Vision 2016.  This is really annoying because if you restart the computer, MAX loses the configuration and you've got to resetup the U3.  I've talked with Pleroa, and they have recreated the problem as well and it isn't on their end.  Is this a bug in 2016?  Any help or suggestions would be appricated. 

[BlueCheese]

Hi,

It likely has to do with an ordering dependency the camera might have when setting features. I seem to recall that some of Pleora's converters required you set another feature to a specific value before it would let you set PixelFormat. The GenICam standard (that is the foundation for how IMAQdx talks to the camera) has a specific mechanism for resolving these ordering dependencies, but it requires the camera designer to implement things in a specific manner on their end. 

Could you attach the XML file for your device and IMAQdx's ICD file which has your saved settings?

Eric

[MGould]

I did check and make sure that format autoselect was disabled this time :-). Attached are the XML and .icd files.

[BlueCheese]

In the ICD file, PixelFormat is set before SdiInputAutoSelect. This is expected, since there is no "ordering" defined by Genicam that applications can use to restore features in the right order.

IMAQdx uses the DeviceStreamingStart feature to notify the camera that it is loading a bunch of settings and the camera is supposed to turn off any ordering dependencies and validation until we call DeviceStreamingStop. Looking briefly at their XML file, it looks like PixelFormat is locked into a read-only state whenever auto-select is on, but has no connection to the DeviceStreamingStart register, so it fail when written in the order we try. They would need to adjust their XML file (and potentially camera register-level-functionality) to ensure that PixelFormat is unlocked when DeviceStreamingStart is set, regardless of the AutoSelect feature.

As a hacky workaround, you could swap those two lines in the ICD file (though it will be overridden if you ever re-save your configuration).