Loosing camera while doing grab

[Dreamer]

Hello,

I'm getting crazy with a serious problem.

I made an application with LBV 85 and Vision Acquisition 85, running under Vista Business on Dell  Intel dualcore machine. I acquire from two AVT Guppys camera in parallel a 640*480 image, with a triggered acquisition and pattern matching control.  The system works very well and I get 2-3 images/second by each 1394 camera.

The problem is that in a random way, after minutes or several hours one of the camera disappers from the system (also from MAX)...If a unplug or reset the pc, everything starts well again until the next stop..

I set the band to maximum 200Mb and the packet to 1280, but nothing changed..  The grabber is NI-PCI-8254R. I tried using both Legacy and ImaqDx drivers but same story...

I'm really off... I already changed grabber, cable, cameras and the PC is under UPS..

What it could be?   Any help is highly appreciated.

Thank you very much.

[Vladimir_Drzik]

Well, I'd just like to stress this issue a bit more. We've been experiencing exactly the same problem for quite a long time in several of our systems. It happens with PCI-8254R, it happens with PXI-8252, it happens in multiple systems with different PC or PXI configurations. We are also using AVT Guppy cameras. Sometimes the problem stops if we stop using a firewire hub or if we use a different type of firewire interface adapter.

Moreover, there is another problem we had when using PCI-8254R. There were two Guppys connected to the adapter, each set up for packet size 2048 bytes. Absolutely common situation, utilizing the whole firewire bandwidth. But when the cameras were run together in live mode, the images were scrambled - as if the data packets coming from the cameras were mixed. We also tested a different PCI-8254R card (coming from a different manufacturing batch), but no change. The situation could be solved by going down to 200 Mbps speed and 1024 packet size, but that was just not enough for the application. Finally, we bought a second firewire adapter (not from NI), which works absolutely fine.

Currently, we are using Vision Acquisition Software 8.5, but the problem happened with version 8.2 as well. All the systems run on Windows XP Professional. Could this be a compatibility problem of IMAQdx drivers with AVT Guppy cameras, maybe combined with a specific NI hardware?
Vladimir

[Dreamer]

Thank you very much Vladimir,
more or less it's the same for me.

Actually I'm trying to reduce the bandwidth..I went down to 200Mbps and 1024 packet size..I'm monitoring the situation right now. Fortunately for my process this limit is fine.

I got also the same issue of mixing the images and getting the images as if always it was coming out of CAM0 even it was CAM1...
I switched out from Vista to XP Pro and looking for better results.. 

I also got notice from NI staff that maybe the Imaqdx driver is more unstable as they put inside a lot of news to manage gigabit camera too and something needs to be readjusted..
They suggested me to switch back to legacy driver, but I couldn't manage yet to reconvert my software back to old (???)...

I'm a strong NI support, but in ths case may I ask you which 1394 card brand are you using without troubles??

Thank you very much indeed
Marco

[Vladimir_Drzik]

Hi Marco

Sorry I just can't remember the brand of the 1394 card we used as a replacement. It was just an ordinary PCIExpress 1394 adapter bought in a local store.

Vladimir

[oliver.guennel]

Hi together,

the described mixed-up images are typical for bandwidth issues. The image data can be mixed together when bandwidth bottlenecks exist.
We have seen similar issues (too less bandwidth) when connecting camera interface cards to PCI together with e.g. I/O cards. The bandwith, allocated for the I/O card is often high enough to prevent using one 1394a bus parallel.
Beside the mixed-up images, bandwidth issue can also cause bus resets, which might lead to loose the cameras.
Seeing, that a standard 1394 card solves the issue, looks like a similar issue, but on the card (the PCI Express bus will improbable be an bottleneck).

Anybody, using this card together with other cameras and bandwidth > 200Mbit? What happens, if the I/O board is disabled in the device manager?

As the MS 1394 driver is not very debug-friendly, you might use the AVT FirePackage for testing with the Guppies. It provides logging of bus & interface events, which might show the one or more insight. If you need more advice, please don't hesitate to ask your AVT seller for assistance.

Message Edited by oliver.guennel on 06-20-2008 02:36 PM

[Vladimir_Drzik]

Hi Oliver

This sounds very interesting. For some of our problems, I really could imagine that they might have been caused by bandwidth issue. However, for others, I don't think so.

Anyway, do you know about any good workaround to stop those problems from happening? I mean in the situations when you just have to stay with PCI or PXI bus. Usually, if there is actually a congestion on the interface, I wouldn't mind if the driver just delayed the image transfer a bit, that wouldn't do any harm to our systems. But if it disconnects the cameras or scrambles the images, that's fatal.

Vladimir

[oliver.guennel]

Hi Vladimir,

the best workaround, if you have 2 PCI (Express) or PXI slots free: one separate 1394 card + one separate I/O card (if necessary at all).
This should solve all bandwidth issues, the distrubed images + the busresets, causing disapearing cameras.

Oliver

[Vladimir_Drzik]

Hi Oliver

Thanks for all the information you provided. I've recently noticed a new FireWire bus driver at AVT:

http://www.alliedvisiontec.com/corporate/press/pressarticle/article/new-firewire-bus-driver-package-...

Does it address some of the issues mentioned in this thread? Is it worth trying also for 1394a cameras?

Vladimir

[JohannS]

Vladimir,

While the AVT FireWire bus driver will address S800 capability problems on XP/Vista, it does not address the limitations of PCI bandwidth. PCI bandwidth is limited to 133 MB/s. A NI PCI-8254R or PCI-8252 using all FireWire bandwidth can use in excess of 32 MB/s. If your system has a PCI network and video card, then you will soon notice lost packets (in the form of streaked images or lost connection).

In order to prevent PCI bandwidth issues, the only fix I know is a PCIe FireWire interface card like the NI PCIe-8255R.

Hope this helps,

JohannS

[Rick_vd_Z]

But have you in the end solved your problem with the disappearing camera in the device manager? Because I'm having exactly the same issue at the moment.  See: http://forums.ni.com/ni/board/message?board.id=170&message.id=396474#M396474