Construct Image 3 taps 16-bit Camera Link Camera using NI 1483

[Shazlan]

Hi Guys,

I'm looking for ways on how do I modify the example LabVIEW program to acquire from an Andor camera (monochrome, 3-taps, 16-bit) using NI 1483 (+ FlexRIO)? The roadblock that I am facing is how do I recontruct the image from the 3-taps? I've seen and read explanations on how to do this with 1, 2 and 4 taps. The only explanation I came across a few days ago wa that 3-taps are used for RGB image acquisition, where each tap represents a color. This, however, may not be my case as the image from the camera is supposed to be monochrome from the beginning.

Please advice.

Shazlan

[natmojo]

Shazlan,

Which Andor Camera Model are you using?

i would like to take a look at the datasheet to see how the camera is mapping the 3 taps to the Camera Link Port/Bit assignments.

For Example:

Base Configuration Camera, 16-bit monochrome, 1 tap

Pixel bit 0 is mapped to Port/Bit A0

Pixel bit 1 is mapped to Port/Bit A1

...

pixel bit 7 is mapped to Port/Bit A7

pixel bit 8 is mapped to Port/Bit B0

pixel bit 9 is mapped to Port/Bit B1

pixel bit 15 is mapped to Port/Bit B7

It is also useful to know whether the 3 taps represent bits from a single pixel during each pixel clock cycle, or if they represent separate areas of the sensor.

Regards,

Jeff

[Shazlan]

Hi Jeff,

Thank you for your reply. I am using Andor Neo sCMOS camera. At the end of yesterday, I was informed by them that the camera does not strictly adhere to Camera Link's protocol. I've asked for clarifications and right now, am waiting for their reply.

Shazlan

[natmojo]

Shazlan,

Any luck getting the Camera Link data bit mapping from Andor?  Their specification document did not specifiy any non-standard mapping.

Thanks, Jeff

[Shazlan]

Hi Jeff,

So far, he has yet to come back to me. I'll try to call him up by end of today.

By the way, I'm curious to know what is the standard mapping for 3-taps camera? As far as standard mappings are concern, I could only found information for 2 and 4 taps only.

Thanks.

[natmojo]

Shazlan,

The Camera Link specification does not recommend a bit assignment for any pixel depth greater than 12-bit.

There are many possible ways to map the 16-bit pixels to the camera link ports.  Below is just one example.

16-bit, 3-Tap Camera Link Example (Medium/Full)

Port A0-A7 (Tap 1 bits 0-7)

Port B0-B7 (Tap 1 bits 8-15)

Port C0-C7 (Tap 2 bits 0-7)

Port D0-D7 (Tap 2 bits 8-15)

Port E0-E7 (Tap 3 bits 0-7)

Port F0-F7 (Tap 3 bits 8-15)

I will attempt to get the Camera Link to Tap mapping from Andor.

Regards, Jeff

[natmojo]

Shazlan,

In addition to needing the bit mapping, it appears that you will need to write some LabVIEW in conjunction with the Andor SDK to configure the camera.  It is my understanding that the camera will need to be configured before it will output image data.

Regards, Jeff

[Shazlan]

Hi Jeff,

Thank you for taking the time to reply.

Yes, you are right. The problem with using their SDK is that it may not recognize the frame grabber as I am using PXI FlexRIO. So, I need to actually program the FlexRIO prior it can do anything. The advice that I got from them was to use a CameraLink splitter. One connects to a desktop PC with their supplied PCI framegrabber and the second end of the splitter connects to the PXI. As I am typing this email, it just came across my mind whether it is possible for me to control the camera using USB...

Anyway, I've gotten a reply from them on the pixel mapping (see attached). Do you think I am right to assume that each pixel# & bit# paired columns represents one clock cycle? If yes, the maximum frame rate that I've calculated doesn't match their published rate. What do you think?

Shazlan

[Shazlan]

Hi there,

Referring to this link (http://digital.ni.com/public.nsf/allkb/EA1727D8D620B81F8625797B0072257C), can somebody please explain the purpose of having the feedback node (or delay) in step #5?

Shazlan

[natmojo]

Shazlan,

Yes, you are correct that each column represents 1 pixel clock period.  So, it takes two pixel clocks to transfer the three 16-bit pixels.

It also appears that each camera link connector is used to transfer one half of the sensor data.  Does the camera have two camera link connectors?

Therefore, over two connectors, the effective transfer rate is 3 pixels per clock.

A rough calculation at Full Frame (2560 x 2160) @ 30 fps results and 3 pixels per clock results in a pixel clock rate of a little over 55 Mhz which is reasonable.

Regards, Jeff