IEEE 1394 multiple cameras

[WTOR]

Is there any example VI's available showing of how to use 2or more cameras using Ieee1394 Grab?

[Logic]

Hi,

I dont find any examples, But its simple, each camera will use a seperate session. So you have to just have a multiple copy of ur current code with different interface name img0,img1 etc.,

Thanks,
Logic

[RManion]

Hi,

Like Logic said, there are no example programs that will do two camera grab acquisitions. Despite this, it is very easy to make your own. If you look at the HL Grab Example that ships with Labview, you should be able to copy the majority of the program and paste it below the original. You can configure the grab to be in the same loop, or in a parallel process.

Here is an example that I made very quickly.



Hope this helps,

Robert

[WTOR]

Thanks for the help.

[Max_Comtois]

Hi Logic and RManion,

I have looked at Rmanion's example, which basically implements Logic's solution to grab images with multiple cameras. However, RManion's vi is for IMAQ, not IMAQ for IEEE 1394.

I have made a similar vi using IMAQ for IEEE 1394 funcitons. I am using 2 point grey resarch greyscale digital video cameras. The cameras are plugged in a 2 input PCI card (a point grey acquisition device). I can't just copy the grab example code in parallel for use with 2 cameras. The "IMAQ 1394 Grab Setup.vi" can't run for 2 cameras at the same time (even if I have linked each "IMAQ 1394 Grab Setup.vi" to 2 different sessions and cameras).

Can anyone help me on how to grab and display (not snap, GRAB) the images from 2 IEEE 1394 cameras at the same time?

I am using Labview 8.2 and the latest verison fo the vision toolkit.

Regards,

Maxime Comtois
Grad Student, Sherbrooke University, QC, Canada

[Jasper S]

Hello Maxime,

Acquiring from multiple firewire cameras concurrently is supported in the IMAQ for 1394 driver.  The only limitation you will face is with the data-width of the FireWire bus.  The DevZone document linked here describes this issue and offers many considerations.  As for an example of this functionality, as the previous posters noted, there are no shipping examples that come with the driver that perform this operation.  However, you should take a look at another forum post, linked here, in which a user has attached a VI to do this.

Regards,

Jasper S

[Max_Comtois]

Hi Jasper,

As I mentioned in my previous post:

"I am using 2 point grey resarch greyscale digital video cameras. The cameras are plugged in a 2 input PCI card (a point grey acquisition device). I can't just copy the grab example code in parallel for use with 2 cameras. The "IMAQ 1394 Grab Setup.vi" can't run for 2 cameras at the same time (even if I have linked each "IMAQ 1394 Grab Setup.vi" to 2 different sessions and cameras)."

I have fixed the problem by using two acquisition cards (thus, 2 seperate frame grabbers). I haven't figured out how to use only one 2 input card (but only one frame grabber) without external triggering... However, I'm ok with using 2 cards for now.

Thanks for your help guys 🙂

Max

[falkpl]

I am also interessted in this.  I cant cet both cams working using the same firewire card.  2 cards 2 cameras or only 1 session at a time.  What is the fix.  I dont have enough PCI slots for multiple cards.

Paul

[Jasper S]

Paul,

There is no reason why you should not be able to acquire from both of these cameras simultaneously.  I would suggest ensuring that you can acquire from both cameras separately, and that they have distinct identifiers in MAX (cam0, cam1).  You should also set the rate for each camera to 200, which half of the bus width, which will allow both cameras to acquire at the same time.

Regards,

Jasper S

[falkpl]

I am currently acquiring both cameras seperatly with no problem, it is more of a firewire card issue, the bandwidth seems not to set on the card, I set coth cameras to 100MB and each work independently but never both together. 

Paul