KarbonHighSpeed80Bit.fm (July 27, 2011 11:06 am)
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Using High Speed 80-bit (10-tap) Cameras and the BitFlow Karbon
Revision 1.2, 2011-07-27
Introduction
This paper address how to use high speed 80-bit cameras with the BitFlow Karbon. 80-bit cameras out-
put either ten taps of eight bits each, or eight taps of ten bits each. High speed usually means the Cam-
era link Pixel clock is about 75 MHz. Cameras that output these data rates some minor changes how an
application interacts with the BitFlow API. There are some extra examples in the BitFlow SDK that illus-
trate these changes.
For example, The Basler A406K, the first high speed 80 bit camera, is capable of acquiring 2320 x 1726
images at 200 FPS. That results in a data rate of over 800 MB/S. Since this camera was released, many
manufacturers have released similar high speed cameras. These cameras require using the maximum
bandwidth the Camera Link interconnect is capable of, that is, 10 taps with a clock rate of 85 MHz. The
current generation of Karbon frame grabbers can acquire at this rate. However, there is not enough
head room to DMA data at this rate continuously over the PCI Express bus for long term reliable opera-
tion. For this reason, BitFlow has designed the “2x” mode, which shares the DMA responsibility between
two DMA engines. The 2x mode effectively doubles the bandwidth of the Karbon, and provides plenty
of headroom to DMA images from the camera continuously, regardless of system load.
In 2x mode the DMA operations are split up on a line by line basis. One DMA engine is responsible for
all of the odd lines and the other DMA engine is responsible for all the even lines. Both DMA engines
can DMA to the same host buffer simultaneously. Both DMA engines are synchronized because both
Virtual Frame Grabber’s (VFG’s) acquisition engines are synchronized in hardware. The end result is a
seamless end-to-end acquisition system.
Requirements
The following items are required for interfacing to the Basler A406K:
BitFlow Karbon Frame Grabber - Model KBN-PCE-CL4F-IP4
BitFlow SDK 5.20 (or later) - Download from www.bitflow.com, serial number required
Camera Link Cable - Two required
PC with at least on x8 PCI Express slot
Microsoft Windows - 32-bit or 64-bit
Software Installation
Instal the SDK according the Getting started documentation. It is generally recommended that you
install the SDK before installing the Karbon into the system.
After installing the Karbon, make sure that the Karbon works correctly with the synthetic camera file. The
Karbon 4F will appear to Windows as to separate devices, known as Virtual Frame Grabbers (VFGs).
Make sure to test both VFGs with the synthetic camera file before proceeding.
