LAVA 1.0 Content

Hi, I've posted this thread which is related to DAQmx, I didn't know in which sub forum I should post it and eventually put it in the "LabVIEW Development Environment" sub forum, I was surprised not to have a DAQ sub forum . What about adding one ?

Hi all, I am acquiring an analog signal with A PCI 6227 board at 40kHz, this signal comes from a microphone that measures the sound of a mechanical watch. As you can see on the graph below, every 166ms we see the same noise pattern that correspond to 3 shocks in the mechanism. I have a DAQmx task to acquire this analog signal. This is basic DAQmx. Now I'd like to go one step further and generate a trigger on a digital output ( to trigger an image acquisition) "as soon as possible" after detecting the first noise of the pattern. I'm not really familiar with DAQmx, and I don't really know what is the best way to go. I've tried to set a trigger generation on the threshold and to set it as automatically retriggerable, but then I get a trigger for the 3 peak of the pattern ; I'd like only one trigger on the first peak. Any ideas ?

QUOTE (bbean @ Jun 18 2008, 03:28 PM) I and my customers have been burned by strings in RT apps running of FP units. Try to avoid strings completely. If you have code that always returns the same string, concider using an enum to display those strings. I have used LV2's set-up as round-robin buffers to do what you are attempting. AS you are developing watch your memory usage over extended periods of time. THe run out of memory issue will sneak up on you if you don't. Ben

QUOTE (limhj @ Jun 18 2008, 04:26 PM) I'm not sure you can uncheck the examples when you install... Anyway, if you did it was a mistake, if you have the CD then install them their worth, specially if you begin with LabVIEW . Hmmm... Maybe IMAQ is not a good search word, try with "1394", if it doesn't work, you're sure that the IMAQ examples are not installed.

QUOTE (limhj @ Jun 18 2008, 02:47 PM) Hi limhj, First, if you are new to LabVIEW, I suggest you have a look at the LabVIEW examples, Help >> Find Example >> go to search tab, dial "IMAQ". Then, I never use it but I know it works well, you can use the "IMAQ express VI" (I have the express VIs disabled on my LabVIEW so I don't even know where it is located). To get the intensity of the pixel, you functions in the IMAQ subpalette and maybe also examples in LabVIEW. Try to do the most you can from the examples and then if you get blocked at some point post your problem + your code. Hope this helps

QUOTE (irpotential @ Jun 17 2008, 01:15 PM) Welcome to LAVA. You will find more physics types here than you will most other places you visit. If you keep your eyes open you'll an entire thread devoted to mis-application of quantum theory. In fact more than one of us can pick out a picture of Maxwell from a collection AND understand what he was getting at. BTW: What school do you attend? Ben

http://www.spreadfirefox.com/en-US/worldrecord

QUOTE (Yen @ Jun 16 2008, 02:33 PM) And I had to work to get a score that low! Thanks for the replies! Ben

QUOTE (crelf @ Jun 16 2008, 01:07 PM) Yes I supose the connection is not obvious. Unfortunately I can't say anything that would help. Try to remember to bring this up again in about ten years. :ninja: Ben

QUOTE (crelf @ Jun 15 2008, 07:43 PM) Have you heard http://en.wikipedia.org/wiki/Artillery' rel='nofollow' target="_blank">MRSI, pronounced Mercy ? It is anything but! Ben

QUOTE (alfa @ Jun 13 2008, 03:03 AM) Maybe I have things mixed up. So a new-born infant is not in an optimal state? It is by interaction with our surroundings that allow some to achieve the higher state? Ben

QUOTE (PaulG. @ Jun 16 2008, 09:26 AM) ... as long as they can do so without mentioning Hitler or the Nazi's. Ben

QUOTE (Yen @ Jun 15 2008, 01:19 PM) No I can't hear it but I seem to be able to sense it somehow. In my "other life" I am surronded by musicians and find myself often bombarded with talk of diminished 7th and pentatonic scales. It is usually about that time that I wonder off into the other room and check the forums because before long they start playing the game of "Lets turn the music way up and start yelling at each other." But back to the topic. I have given more thought to the four vs five finger rendering and am inclined to believe the artist wanted to give the goat guy a greater humanlike nature (hands are supposed to by one of the harder parts to draw). Why would you think goats were chosen to represent the the protagonist? I am curious what you have to say about this Q since goats were used in many interesting passages of scripture. Daniel's "goat with two horns" and one of the apostles wrote of "seperating the goats from the sheep". In the culture I grew up this often taken as seperating the bad (goats) from the good (sheep). But the rebel in me makes me question that meaning. I thought the goats were often kept along with sheep because the sheep were dumb and would follow each other off a cliff, while having a goat around the sheep would follow the goat. So I wonder if that passage really is intended to reference those that blindly follow the masses vs those that question the action of the mob. The card sharkster appers to have morphed into the donkey between scenes, they could be one and the same. OK, that is my last series of comments and observations before you pull back the curtain. Ben

QUOTE (crelf @ Jun 15 2008, 04:23 PM) I did Unfortunately this year I won't be able to come to NIWeek, so not LAVA BBQ either

Is anyone clear on the language of the song? The guteral sound is what made me first think Frnch but if its not french then maybe its hebrew. When I double clciked on Yair's link the YuoTube page had hebrew replies (since (I think) hebrew occationally imbeds words within words I don't know enough to be able to use my hebrew-english lexicon). I had once read that all hebrew music was written in a minor key (is that an over generalization?) so this music passes that test. SO now I want to think this is a story of Isreal. The swimmer represent those that choose the remain in the diaspora and the suit goat represents those that returned. The pursuit by the whale repesnts the persecution by the christian ( water is used to symbolize baptism) (trying to live according to Mosaic law in christian countries). The card sharkster was that counsel by the allies after WWII that decide they would create Isreal. (Side observations: Most cartoons hands are rendered such that they have only four finger (three plus thumb) the goat guys have five. ???) The mule was the US and Great Britain who encouraged the creation of Isreal and fostered the migration. The mule did not aide in the final work and the suit goat had to do it alone. After making the leap into nationhood and then passing by fire (military action) the emerged as a small country. The end scene where the goat and the mule look at each other sorta says "So now what?" Am I getting any closer?

QUOTE (Justin Goeres @ Jun 15 2008, 07:08 AM) Great job lads ! :thumbup: Thank you Chris and Justin :worship:

No CAR available. A future version of LV will give broken wires for this code construct. Ben

I reported this to NI under SR# 1181201. Stand-by for a CAR#. Ben

QUOTE (Eugen Graf @ Jun 12 2008, 05:29 PM) I am involved in the design of many of the applications that come out of my office. I have taught my developers to first evaluate the applications needs before deciding on an architecture. I do not believe any two application have left our house that use the same architecture. App Design in 15 minutes (an obvious oxymoron) 1) Understand the requirements of the app. Create a diagram (model) that illustrates the various responcibilties and the interaction between any cooperative entities. 2) Give the entities descriptive names and list their actions. 3) Define the data used to in the inter process communications. 4) Evaluate the naute of each interaction (these are data paths). 1-to-1 1-to-Many, Many-to-1, etc. Also concider failure scenarios, and performance req's. A high data rate app may require multiple CPU's work cooperatively to keep up with the data stream. 5) For each of the Data paths, identify a comm mechanism that will meet the req's. If possible use built in mech's queue, notifier, etc. If no "out-of-the-box" sync mechanism fits the bill, then design a custom one. In the case of customs I favor AE types but will use others. So I guess the answer to your question is I use all of them and sometimes invent my own. Have fun, Ben

QUOTE (jbrohan @ Jun 13 2008, 01:53 PM) Hi John, This is indeed usefull in LV 7 and previous, it's cool to share it ! If you switch to LV 8 you'll see that the LV project window has great new feature to see where are the VIs called in a project. :thumbup:

QUOTE (PaulG. @ Jun 12 2008, 10:56 PM) And what's about hail? http://en.wikipedia.org/wiki/Hail

Its not French then? Leviathan? Its was involved in both scenarios but only one was pursued by it. The scene were you can see that the one in the suit was the one that choose his card seems signifigant. Ben

It work great. I pass from 20fps 60% of CPU to 30fps 10% of CPU it's much better that way. Thank you all for the reply, and thank you Norm for the hack Dany

Ben's comments remind me a couple of books I read, I don't know if it coud be related to religion or more globaly to spirituality but the wales (or sometimes daulphin) makes me think of something of that kind. My understanding of this video is not clear in my own mind, at first it left me kind of sad and after wiewing it a couple of times I felt chilled out and - not faithfull but - hopefull. I couldn't say why

QUOTE (Yen @ Jun 12 2008, 03:43 PM) Ok i don't saw that Chris have edited is post I take a look at it Thanks Dany