how can I get two cameras to aquire at the same time rather than one after the other

[deater]

I've got (2) PCI-1428 cards, Two Uniq Vision cameras with power supplies, cameralink cables, and IMAQ-D6804 cables. Both cameras are being triggered by the same switch, but they are not grabbing images at the same time. Right now it is triggering one camera as desired, but the other doesn't aquire until after the time-sensitive event. On the next test, the two camera will trade these roles. I am using 2 cards, so they should acquire at the same time. How do I change it so that they grab images at the same time? Thank you for your help.

                                                              Deater

[Savageaggie]

Hi Deater,

Thank  you for your post.  Triggering from two cameras at the same time may be a little trickey, but it can be done.  There are multiple ways to tackle this problem.  If you have a RTSI cable, you can RTSI the two PCI boards together internally to lock them in HW.  You should also be able to use the triggering line on each board.

One of the best methods for triggering multiple boards is called GenLocking.  The following Developer Zone page describes GenLocking more fully and has several examples to help you out: http://zone.ni.com/devzone/conceptd.nsf/webmain/a387b5c0ac6f6f4e86256c87005fcddf.

The "HL Grab with two boards.vi" shipping example is also a good example of the code needed to trigger two individual boards in LV.  I found a similar post that may be of some help as well: http://forums.ni.com/ni/board/message?board.id=230&message.id=2691&requireLogin=False

Hope this helps!

Thanks,

Scott Savage

National Instruments

Applications Engineering

www.ni.com/support