Inconsistent frame and DAQ rate

Hi,
I have written, LabVIEW 7.0, a code (attached) to read from a DAQ card, 3 Visa's and 2 Firewire cameras. Before I included the cameras, everything worked fine. With the cameras, the performance decreases with time (the longer the acquisition time is, the lesser the frame rate). My questions:
1. How can I optimize the code more, to give me the highest possible frame rate?
2. Is my approach in getting capturing the images an "OK" way, or is there a better way in doing it? This is my first time 'playing' around with IMAQ 1394.
3. I have a hunch that if I save every images once it is in the buffer, instead of capture everything first and save later, would increase the performance. Can this be true?
4. Last, is there a quick and ea
sy way to produce an AVI file from the recorded images? I realize that the elapsed time between the images is different and this cause an additional headache in producing the AVI file.
By the way, the desktop I am using is a P4 2.4 GHz, with 1024 MB of RAM (if I'm not mistaken). I hope what I said make sense here and I highly appreciate all the help I could get Thanks!
Shazlan
Attachments:
NIPost.llb ‏539 KB

Shazlan,
The first thing you can do to optimize your code would be to use only one IMAQ create. In your code the IMAQ create is inside the loop so you will be using more and more memory as the program runs. I have attach an example with 1394 that I wrote. It has only one IMAQ create. The example also has a implemented a save to AVI for saving the images. I hope this help
A. Talley
Applications Engineering
National Instruments
Attachments:
Grab1394_and_Save_to_AVI.vi ‏102 KB

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Here it is! It is not in any form of completion unfortunately.
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Attachments:
rewettin1.vi ‏15 KB

MyRIO memory, data transfer and clock rate

Hi
I am trying to do some computations on a previously obtained file sampled at 100Msps using myRIO module. I have some doubts regarding the same. There are mainly two doubts, one regarding data transfer and other regarding clock rate.
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Hi Sam
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Meanwhile, the other doubt still persists, is it possible to run filter blocks with the derived clock rates? Can we specify clock rates like 200MHz and sampling rates like 100Msps in the filter configuration window? I tried, but obtained zero results.
Thanks and regards
Arya
Attachments:
Dev PC VI.PNG ‏33 KB
FPGA VI.PNG ‏16 KB
Delay text file.PNG ‏4 KB

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Need OID for rxload and input rate

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Thanks Michael -- you've helped me with the project before (back in May of this year).
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Spectrum analyzer with sim and DAQ IV File

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Hi Eldad,
Thanks for posting and welcome to the NI forums!
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FPGA and DAQ card synchronization

Hi, we are controlling and acquiring data from multiple hardware devices (including translational stages and photodetectors). Until last week, we used to peform all control and acquisition using a PCIe 7852R FPGA board. However, we decided to switch the acquisition part to a PCIe 6363 DAQ card to improve the voltage resolution. During testing, I found that the internal clocks in the FPGA and the DAQ cards are slightly mismatched (not just a phase delay, but a difference in time-period).
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Solved!
Go to Solution.

Hi GerdW,
Thank you for your reply.
I understand both solutions you have suggested. I had conceptually thought about the first one (to control the sampling rate). However, I still haven't figured out how to accurately generate a 200kHz square wave - I think I can figure that one out this morning.
However, I am unsure how to implement the second option. I presume the default internal clock inside the DAQ is running at 100MHz or so. Therefore, inorder to obtain the same performance while using an external clock, I would have to generate at least a 80MHz TTL clock-out from the FPGA. Could you please tell me how I can do that? I couldn't find any clock-out capabilities on my FPGA. Or would I have to generate a clock of my own using Single-Cycle-Timed-Loops?
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How can i set the Daq rate on the compactDAQ NI 9237?

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Best regards,

Independent Sample and log rates

I would like to log data at 0.5 second intervals while the daq assistant acquires data at 1KHz,
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Attachments:
logger rates.vi ‏87 KB

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