For details on the Camera Link specification and the underlying protocol, see:
CameraLinkSPEC.pdf
and
channellink_design_guide.pdf.

Camera Link is based on the National Semiconductor “Channel Link”. To be a 100% compatible Camera Link device, both the camera transmitter and the interface card receiver must be National Semiconductor devices, specifically, DS90CR2xxx and DS90LV04x chipsets.

Camera Link has 3 basic modes, “base”, “medium”, and “full”. Base uses only one of the Camera Link connectors (most interface cards come equipped with two connectors to be able to run in anyone of these modes), while medium and full use two Camera Link connectors. Since the Andor Xion camera has the potential to only run in base mode, pretty much any card that we get will work.

Latency:
None of the “simple to obtain” brochures and literature have information on latency, they all talk about modes and throughputs, and whether the interface can provide power through the link. That said, the information on the National Semiconductor Channel Link chip lists something that might be useful: “2.5 / 0 ns Set & Hold Times on TxINPUTs”. I interpret this to mean that it takes 2.5 ns to set a word and 0 ns to hold that value. Since the computer DRAM clocking is on the order of 10-40 ns, I suspect most of the latency is going to be in the computer DMA, transfer which is probably why the interface card manufacturers don't list it.

PCI vs PCIe:
Camera Link interface cards come in many different formats, but in only two basic bus interfaces, PCI and PCIe. Base and medium modes can work with a PCI bus, but full mode requires a PCIe. A few of the cards have PCI versions that fit in 3U compact PCI chassis (like the metrology fiber interface in the OPLE rack), 6U compact PCI, and PC104. The AO computer at the telescope has both PCI and PCIe interfaces, so any traditional bus interface PCI/PCIe will work for us. The following table lists typical data rates for the various interfaces.

To begin the search I started with this list of sample framegrabbers. The list is kind of old, so I added more to it, though most of the main players are on the list. Of note, there are a number of entries for a manufacturer called “Coreco”. They have been bought out by Teledyne/DALSA and are listed there, accordingly. Also of note, the entry from “IO Industries” is no longer available. IO Industries is still around, though they only sell digital video editing hardware systems, not individual Camera Link cards.

I would discourage purchase from any of the European-based vendors. I would also discourage getting a 64-bit PCI card (aka PCI-X) – they're significantly more expensive, and we don't have a bus that can take advantage of it.

My recommendation would be the EPIX EB1 (see here), it's only $445 for each board plus $495 for the 64-bit Linux driver (I assume we will only need to buy the Linux driver once). It's been consistently about half the cost of comparably capable cards from other manufacturers.