Problem with Firewire/1394 speeds

[Jack Brown]

NI-IMAQ for 1394 v2.01
MAX 3.1.1.3004
Vision Development Module

Everything's been update to latest versions.

My problem is that I am limited to 100Mbps data rates, but, only when running through optical repeaters to increase distance. If I connect the cameras by "direct" firewire cables, I get the full 400Mbps bandwidth.

I am using the Opticis Stretch Firewire S800 repeater. These are able to deal with both 1394a and 1394b. As soon as I try to communicate with the camera while connecting via these repeaters, my bandwith is locked at 100Mbps. I've searched through the forums and come across the Win XP SP2 issue. I don't *think* that's my problem since I can talk at full speed without the repeaters. One of my colleagues is able to use the exact same repeaters and gets the full bandwidth, but, he is using software from Cognex, not National Instruments.

I've attempted to duplicate the process described in the fourth post in: <http://forums.ni.com/ni/board/message?board.id=4170&message.id=4538&query.id=15335#M4538>, but, when I try, Windows tells me that the 1394.inf file won't work for my device. (??) I've also tried installing the Microsoft knowledge base KB885222 on the machine, but, it gives me an error saying it can't replace a file that already exists.

I'm stumped at this point. Any suggestions would be appreciated. If more information is needed, I will gladly provide it.

Thanks.

Jack Brown
Controls Engineer
Electroimpact, Inc.
Mukilteo, WA

[David S.]

Hi Jack -

There is no aspect of the NI IMAQ-1394  driver that limits the available bandwidth of a Firewire device.  This bandwidth is reported by Windows, which (I believe) reads it from the device.

As such, the SP2 issue is still most likely the cause of your problem.  Your repeater is a 1394b device and will be affected by the bug, whereas the camera is almost certainly a 1394a device and probably escapes unscathed.  (Which camera are you using, offhand?) Being unable to install the KB885222 Hotfix is also a problem.  Have you tried booting into Safe Mode to install it, as there may be a system process reserving the files?  You may have to contact Microsoft for help with the patch. 

In regard to your colleague's computer, have you verified that this Hotfix wasn't installed on his system?  Perhaps Cognex installed it as part of their software?

[Jack Brown]

Success!

Thanks for the hint, David. For whatever Microsoft reason, the PC wouldn't boot into safe mode. I ended up hitting google and found a solution to the problem about 1/4 the way down on this page:

http://neowin.net/index.php?act=view&id=26338

Once I did that and verified all the SidSpeed settings, it works!

- Jack