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Chris Davis

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Everything posted by Chris Davis

  1. Well now you've given me a reason to try autotool again! I am one of those people who immediately turn it off, when I run across a machine that doesn't have it turned off.
  2. Why reinvent the wheel, in this kind of case, I usually use Portmon, from sysinternals.com. I does a great job, and best of all, its free!
  3. I've used them to prototype something, as many have listed here. I've also seen them misused, the biggest misuse I remember is using the ExpressVI for a formula node to solve y = x + 2*sqrt(x), inside a loop, and that loop ran thousands of times during one pass of the program's main loop. If you have never looked at the code behind that particular ExpressVI, you will find a work of art, and it is useful when you don't know much about formula nodes or how to solve a nontrivial math equation using LabView. Like I said before, they seem to do a good job of showing us how to prototype something...
  4. Glad to hear that this idea works! It may come in handy in the future. You might try automating the startup of 7.1 and 7.1.1 using a batch file to script the folder name changes you need to make your solution work.
  5. The only suggestion I know that will work, involves Virtual PC. However, you could try installing LV 7.1 on a new machine, copy the LV 7.1 subdirectory to another location, then install the LV 7.1.1 patch and see if you have what you are looking for. I don't know if that would mess up your user.lib and vi.lib directories (which are what gets changed when applying the patch), but it might be worth trying. I also can't say if this "solution" will work, since I haven't tried it myself. You might want to try this on a spare HD or (even better) a spare computer / virtual PC :laugh:
  6. Sounds like you are running into dataflow issues. Message boxes are modal, which means that they stop execution until the OK button is pressed. The easiest way to solve your problem is by using a sequence structure, to ensure that the property node is executed before the message box is displayed. Look at the sequence structure example that ships with labview called Time to Match.vi. I found it by searching for structure in the NI Example Finder.
  7. This sounds more like an excel question than a labview question. Perhaps you should post your question in an excel forum...
  8. Thanks, that was the post I was looking for... :worship:
  9. After reading these posts, I was thinking that NI did a post that tried to answer some of the questions. I can't seem to find it right now, but I remember that they had the paper when they started the LabView Zone. Anyway, it basically stated that you could use LabView as a general purpose language, and that NI always kept that in mind when it wrote LabView, but they also recognize that they make money on the hardware that they sell and integrate into LabView.
  10. You don't have to have the open file and close file outside the while loop, the "read line" vi will open and close the file by itself. You might also setup the read line vi to read 1000 lines of the log file and process those, then read 1000 more and so on, to see if that speeds up your code. Of course you don't mention what speed computer you are trying to process these log files on, and that would make a difference if you are running labview on a resource starved machine.
  11. I've heard of the idea of using a simulated card to "playback" data from a file and I think it would be a good addition to DAQmx. You're idea would take it a bit further than I first thought about, and the only thing I can think of would be that it would be a real headache to program for the people who write the simulated card stuff in max...
  12. A screen shot of your code such as the one below might help. This code uses NI-IMAQ to make an uncompressed 60 frame movie from image source img0.
  13. You can still get all the packages from OpenG without using commander, Jim might chime in here if he can provide a link to help you get them. Then you can use commander to install them from a local disk.
  14. I'm glad you tried something before you posted, and your problem is probably simple to fix just like your last problem, but as one of the posters mentioned, if you don't provide a screen shot or the actual code it is very difficult to help without quoting the manual.
  15. And just so you don't ask what manual you need to read. Look at this ni web page and these dev zone entries 1 2.
  16. The last time I used the NI AVI read / write routines in IMAQ, they had trouble with certain codecs. But it has been awhile since I used those VIs from NI. You might consider changing the codec of the AVI file to one that is more common. One codec that should work without problems is called "Cinepak". It is installed by default on every Windows distribution from 95 to XP SP2, in fact I believe it was on 3.1.1 as well ! Anyway, you may need an AVI converter to recompress the video, in which case I would reccomend VideoMach from Gromada.com. For others on the list they also make a free video player that allows the user to step through a movie frame by frame, (something that windows media player lost a long time ago) and save individual frames as individual images. It also contains no advertisements or liscense restrictions that I'm aware of, and I've found it to be a worthwhile investment :thumbup: BTW, they also claim that thier software runs on linux using wine with no problems.
  17. I don't have LV right in front of me, but if you drop a property node on the block diagram and attach the Imaq 1394 reference to it you should have exposure time in there somewhere. I can probably post a screen shot tomorrow, if I have time.
  18. Are you controlling your camera with NI-IMAQ 1394? If so, exposure time is a property that is controllable in labview. If not, you'll have to control exposure time using a camera vendor supplied DLL or SDK.
  19. I know that IMAQ wasn't designed to do this, but that doesn't mean LabView can't do it. If you are serious, you might want to check out VideoCapX which allows you to deal with a TV tuner (which you will need to get your PVR functionality) with realitve ease using ActiveX. The second part of PVR work is getting the TV schedule, and I'm sure that there is some way to do that with LabView, but I haven't tried it, yet. VideoCapX runs $80 for a single developer liscense with unlimited redistribution. BTW VideoCapX lets you playback video, and can also handle video streaming internally too...
  20. I can't remember from your other posts if you have IMAQ Vision Toolkit. If you do, this should be fairly easy, since there are AVI read / write VIs from National installed with the IMAQ Vision Toolkit. If not you might want to start checking NIs web site for links like this. If you are serious about doing image processing in LabView, but don't want to pay for the IMAQ Vision Toolkit, you might want to check out Irene He's IVision Toolkit which is priced lower, but is still very useful. There are also some other options, but you'll have to work even harder to get them into labview...
  21. I usually post a link to HH's that includes an online (and free) LabView Basics course that NI helped to develop. I've used it at work for when we have summer interns or co-ops who need to learn labview. It covers features in 7.0 and 7.1. I don't think it mentions much about 8.0, but for a general "LabView for Dummies" it works good. Hope it helps. I know I've gotten my monies worth out of it! :thumbup: Chris Davis
  22. Open Office will open .xls files and its free. Although you might be better off with your own .csv format in the long run as yen suggested.
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