Image CRC checkum help

[paubin]

Hi,

I would appreciate your help.

My CVS1458RT is freezing with (1/2) camera  (using same VI) and I think it's because I am receiving corrupted images from that camera.

I'm using a Basler Racer camera and I'm able to read the "IMAQdxChunkData_CameraAttributes::ChunkData::ChunkPayloadCRC16", I would like now to compare it to the received image CRC but I don't really know what to do.. I think I have to calculate that CRC from that image right? How can I do that?

Anyone can help me on that?

thank you 

Patrick

[paubin]

Hi,

Basler mentioned the CRC checksum is calculated using the X-modem method so I tried to calculate the CRC from the image using the "crc 2.vi" (polynomial x1021 and initial value at 0). Basler say the CRC is calculated without the CRC checkksum so I tried different thing, removing the key / not removing the key and I can't get the same CRC has the chunk CRC.

If anyone can help.

Thank you.

Patrick

[AmitShachaf]

Hi Patrick,

I haven't used CRC on CRIO but I do use CRC on my FPGA code.

I am afraid you might have some miss understanding with Basler. Usually USB 3.0 or any USB / GigE communication going in packets. 

CRC is calculated on the packet. Not on the whole image. It is part of the USB standard. 

Seems to me like you are trying to calculate the CRC on the whole image. It shouldn't be the same.

Did Basler told you they calculate CRC on the whole image?

Thanks - Amit

[paubin · Accepted solution]

Finally got it.

I had to remove the chunk part of the crc before calculating the crc of the image.