Vision + data acquistion

[Eki]

Hi,
I measure 8 channels (1000 Hz each) with a PCI-6036E card contiously. I have
software trigging. When one seconds RMS from some channel is over the
limit, I stream to disk 30seconds (binary) sample of each channel. I need to
take four fotos with my PCI-1411 card when trigging happens. Does this work
with an other loop (with occurrances or something ) programmately. Can I use
RTSI cable between the cards which is already there. The problem is not to
disturb the writing to disk at the same time. The delay between the four
pics is about one second. I use LV 7 and the newest ImaqVision.

Thanks for hints
Eki

[Yusuf C]

Hello,

I think the best way to approach this would be by doing a buffered acquisition utilizing onboard memory. Check out the following shipping example called LL Sequence in onboard memory.vi (located by default in C:\Program Files\National Instruments\LabVIEW 7.0\examples\IMAQ\IMAQ Low Level.llb\). This example acquires a sequence of images and displays them in an image control using the low-level acquisition VIs. A sequence is appropriate for applications that process multiple images. This example acquires the images into onboard memory and copies them into system memory. Since you're acquiring your images into your onboard memory they will be there until the OS has resources to grab them and write them into a file.
Anything you do with the 1411 can be tr
iggered by the RTSI lines. Check out the triggering examples in the C:\Program Files\National Instruments\LabVIEW 7.0\examples\IMAQ\IMAQ Signal IO.llb\ folder to see demonstrations of this.
Note that there still may be some limitations to this such as the write speed of your hard drive, write buffer size, other programs trying to access the harddrive, etc.
Hope this helps!

Best regards,

Yusuf C.
Applications Engineering
National Instruments