How to get data from two channels simultaneously in PXI-8252

[Imagineer]

Hello All,

Requirement: I need to show live feed in LabVIEW from two cameras interfaced to PXI-8252 over IEEE 1394  [Firewire].

Cam0: res=1392 x 1040; fps=5fps; 8bit Grayscale

Cam1: res=2452 x 2054; fps=5fps; 8bit Grayscale

Problem:  The first camera is able to grab a buffer but the second throws an error "Insufficient Transfer Engine" at o/p of Configure Aquisition Block. Am assuming here that the buffer cannot be split and shared between two or more cameras, and the only solution seems the need to take picture close buffer then switch to next cam and then close it. This will seem quite an inefficient way of doing it, So my question is - Is there an efficient way out? I hope someone must have accross this scenario....Any cues?

Awaiting a response.

Thanks and Regards,

Tirthankar De

[Vladimir_Drzik]

Hi

Try searching the Machine Vision forums for "Insufficient Transfer Engine".

Vladimir

[Imagineer]

Thanks for the search keyword.......I did get some good information but am still stuck with the problem......let me do some more tries and then shall put down my findings....Thanks Vladimir!

[A_Person]

Hi Imagineer:

I know you took a look around using the keyword Vladimir had suggested but I wanted to make sure you saw the following two forum threads:

http://forums.ni.com/ni/board/message?board.id=200&message.id=3574

http://forums.ni.com/ni/board/message?board.id=200&message.id=12460

It appears that the problem can be solved by changing your packet size to reflect your camera speed.  In the second one specifically, there is a post by JohannS that details what the maximum packet size is for a given camera speed.

Let us know if modfiying the packet size resolves your issue!

[Imagineer]

Hello.

The bandwidth of Cam0 [Guppy F146B] is settable to either of the following: 100Mbps/200Mbps/400Mbps ; In accordance with the spec of the manufacturer.

The bandwidth of Cam1 [Pike F505B] is settable to either of the following: 100Mbps ; As per manufacturer it should be 100Mbps/200Mbps/400Mbps/800Mbps.

Any reason why this discrepancy ?

I forgot to attach the snapshot from Max.....so here it is......

Thanks and Regards,

Tirthankar De

Message Edited by Imagineer on 02-25-2009 02:31 PM

[Imagineer]

I re-plugged both cameras and was able to get the specified bandwidth [transfer rate] options, and did exactly as suggested and able to do what I want to do.

Thanks again!!!

[Vladimir_Drzik]

Hi Imagineer

If you ever happen to have problems with the Pike camera running at just 100 Mbps, have a look at this article:

http://digital.ni.com/public.nsf/allkb/2243D57B9EEF22B686256FB7005E23C1

It's a known issue of 1394b cameras under Windows XP.

Vladimir

[oliver.guennel]

In the meantime, we released a package, which replaces the MS stack by a full compatible, but S800 capable driver:

http://www.alliedvisiontec.com/downloads/avt-software/avt-1394-bus-driver-package.html

With the replacement driver, the Pike, but also Stingray cameras will run full 800Mbit on 1394b cards & 400MBit on 1394a cards.

[Imagineer]

Thanks Vladimir and Oliver! After updating the driver am able to use Pike efficiently. 

I have also linked this thread to the other thread where solution by changing packet size is suggested.

Thanks again!