alnaimi Posted February 26, 2007 Report Share Posted February 26, 2007 Hi all, Need ur help plzzzz :worship: :worship: , and its appreaciated ... I have my circuit connected with LABVIEW through DAQ card , in labview i just need to draw the current charastrastic and I have done the program ,,, notice that current = (VD-VDD)/R ,, I have problem it doesnot draw it ,,, I have attached the pictures of circuit and the labview program,,,, Plzzzz need ur help .. Thnxxxx sorry forget the program.... this is the program Quote Link to comment
Jeff Plotzke Posted February 26, 2007 Report Share Posted February 26, 2007 QUOTE(alnaimi @ Feb 25 2007, 09:39 AM) I have my circuit connected with LABVIEW through DAQ card , in labview i just need to draw the current charastrastic and I have done the program ,,, notice that current = (VD-VDD)/R ,, I have problem it doesnot draw it ,,, I have attached the pictures of circuit and the labview program,,,, I think you forgot to attach your VI. Quote Link to comment
alnaimi Posted February 26, 2007 Author Report Share Posted February 26, 2007 VI PROGRAAAAM Quote Link to comment
Jeff Plotzke Posted February 26, 2007 Report Share Posted February 26, 2007 QUOTE(alnaimi @ Feb 25 2007, 09:39 AM) I have my circuit connected with LABVIEW through DAQ card , in labview i just need to draw the current charastrastic and I have done the program ,,, notice that current = (VD-VDD)/R ,, I have problem it doesnot draw it ,,, I have attached the pictures of circuit and the labview program,,,, I see three things that you'll want to look at: 1. How many samples is the 'Simulate Signal' Express VI set to generate? If you're generating multiple samples, you're going to run into a problem since you're only reading one sample from your AI. You'll have no way to synchronize your data together. I'd recommend outputing a single value for Vout, then read the AI for Vin, for each iteration of your loop. This way you can synchronize your data points together. 2. Is your 'Build XY Graph' Express VI set to reset every time it's called? (I believe that's the default) I would wire a false constant to the 'Reset' terminal to ensure that it doesn't clear your graph every time. 3. Your math looks wrong in the VI. I agree that Id = (Vout - Vd) / R -- However in your VI it looks like you calculate Id = (Vd - Vout) / R However, this would just end up inverting your results. You look like you're on the right track -- Hope this helps. Quote Link to comment
alnaimi Posted February 26, 2007 Author Report Share Posted February 26, 2007 Yes , I understoos number 3 ,,, you are right thnxxxxxxxxxxxxxxxxxxxxxxxxxxxx but could u plzzzz rexplain number 1?? u mean flat sequence ?? I really apprecaited for you Quote Link to comment
Jeff Plotzke Posted February 26, 2007 Report Share Posted February 26, 2007 QUOTE(alnaimi @ Feb 25 2007, 02:55 PM) but could u plzzzz rexplain number 1?? u mean flat sequence ?? My main concern is that you're generating x samples of a sine wave (I'm assuming x > 1). The 'Generate Signal' VI returns much more than one sample -- It's actually an array of samples -- As you'll see on the graph you have wired up to output of that VI. So, let's say you're generating a complete sine wave during each iteration. You then output that using your Analog Output. Your analog output will output the entire sine wave as it was generated. However, you then read your Analog Input at some point in time (and remember data flow -- You have no wires from your analog output to your analog input, so it's very possible that you're reading from your analog input before you output any signal!) Since you don't know what your analog output was outputing when you took your analog input sample, you really don't know what voltage (Vout) to connect that point to. I've attached a quick VI that shows you a way to generate an entire sine wave, and then output, point by point, each value of that sine wave, while reading your Vd each time. This way, you can accurately synchronize your input and output data and create your graph. Let me know if you're still having problems. Quote Link to comment
alnaimi Posted February 26, 2007 Author Report Share Posted February 26, 2007 oooh u have newer version mine is 8 i can not open it Quote Link to comment
Jeff Plotzke Posted February 26, 2007 Report Share Posted February 26, 2007 QUOTE(alnaimi @ Feb 25 2007, 03:38 PM) oooh u have newer version mine is 8 i can not open it Attached is the VI saved for LV 8.0. Quote Link to comment
alnaimi Posted February 26, 2007 Author Report Share Posted February 26, 2007 THNXXX I will test it ,,,, u r sooooo unique person i really admit for u Quote Link to comment
alnaimi Posted February 26, 2007 Author Report Share Posted February 26, 2007 any other suggest??? Quote Link to comment
siallid Posted February 27, 2007 Report Share Posted February 27, 2007 QUOTE(alnaimi @ Feb 25 2007, 02:39 PM) Hi all,Need ur help plzzzz :worship: :worship: , and its appreaciated ... I have my circuit connected with LABVIEW through DAQ card , in labview i just need to draw the current charastrastic and I have done the program ,,, notice that current = (VD-VDD)/R ,, I have problem it doesnot draw it ,,, I have attached the pictures of circuit and the labview program,,,, Plzzzz need ur help .. Thnxxxx sorry forget the program.... this is the program Hi Noora thanks for this site. I want to ask you did you recive data from your hardware to your program. so I mean that did you check for that data are recieved by digital display. If your program can read data from your measuring circuit then you may have mistake in the way of using the chart display tool. if possible you may send to me an attachment for a picture of your program front panel and diagram to see if you have some mistake but sorry that I use labview v.6.1 so I can not read your vi so that why I askyou to send to me a picturte. .... thanks Quote Link to comment
alnaimi Posted February 27, 2007 Author Report Share Posted February 27, 2007 its still the same !!!!!!!!!!!!!! :headbang: I still really need ur help thnxxxxx Quote Link to comment
Jeff Plotzke Posted February 27, 2007 Report Share Posted February 27, 2007 QUOTE(alnaimi @ Feb 26 2007, 05:17 AM) its still the same !!!!!!!!!!!!!! :headbang: I still really need ur help thnxxxxx What exactly isn't working? Are you not getting data into your VI? Is your data not what you're expecting? Is your graph not showing your data? Quote Link to comment
alnaimi Posted February 27, 2007 Author Report Share Posted February 27, 2007 the graph is not working @ all ,,,??? I have done what u suggested but still not draw the graph Quote Link to comment
Ton Plomp Posted February 27, 2007 Report Share Posted February 27, 2007 Hi Alnaimi, could you add your program (VI), a little documented. And try to use some proper interpunction, this allows us (at least me) to better understand your post. No, I'm not asking for perfect english Ton Quote Link to comment
alnaimi Posted February 28, 2007 Author Report Share Posted February 28, 2007 no one??? Quote Link to comment
Jeff Plotzke Posted February 28, 2007 Report Share Posted February 28, 2007 QUOTE(alnaimi @ Feb 27 2007, 10:04 AM) no one??? As tcplomp suggested, can you post a version of your VI? We can't fully help you until we really see what's going wrong. Quote Link to comment
alnaimi Posted March 1, 2007 Author Report Share Posted March 1, 2007 this is THE VI , ur help is fully needed and I appreciate it 4 u all ,,, coz i am running out of time and i am new 2 labview Quote Link to comment
Ton Plomp Posted March 1, 2007 Report Share Posted March 1, 2007 QUOTE(Jeff Plotzke @ Feb 25 2007, 08:40 PM) 2. Is your 'Build XY Graph' Express VI set to reset every time it's called? (I believe that's the default) I would wire a false constant to the 'Reset' terminal to ensure that it doesn't clear your graph every time. QUOTE(alnaimi @ Feb 28 2007, 07:08 AM) this is THE VI , ur help is fully needed and I appreciate it 4 u all ,,, coz i am running out of time and i am new 2 labview Alnaimi, Jeff was right. Right click on the build-XY graph VI and configure click properties, deselect the mark: http://forums.lavag.org/index.php?act=attach&type=post&id=5054 Ton Quote Link to comment
alnaimi Posted March 1, 2007 Author Report Share Posted March 1, 2007 wil test it and let u know Quote Link to comment
Jeff Plotzke Posted March 1, 2007 Report Share Posted March 1, 2007 QUOTE(alnaimi @ Feb 28 2007, 01:28 AM) IT draws but not real current versus volatge ,,, any help plzzzzzzzzzz??need it plzzz and thnx for ur time Are you getting real values in for your current? Have you probed your analog input to verify? The graph won't show what you're expecting if you don't actually acquire that data. Quote Link to comment
alnaimi Posted March 1, 2007 Author Report Share Posted March 1, 2007 u know , my curent is small coz the resistor is 47 ohm , but i have test the curent , there was ... but why not logical cuve?? do u think i need buffer??? sychronization? Quote Link to comment
Jeff Plotzke Posted March 1, 2007 Report Share Posted March 1, 2007 QUOTE(alnaimi @ Feb 28 2007, 08:39 AM) u know , my curent is small coz the resistor is 47 ohm , but i have test the curent , there was ... but why not logical cuve?? do u think i need buffer??? sychronization? You'll absolutely need synchronization between your output and your input. Otherwise, you'll have no way to accurately build your XY graph. In the VI you posted yesterday, there wasn't any synchronization -- You output 100 samples of a 10Hz sinewave and read the input each iteration. There's also no guarantee that you'll read your input after you set your output. For this reason, you need to think about these issues in this VI. Quote Link to comment
alnaimi Posted March 1, 2007 Author Report Share Posted March 1, 2007 i dont know how 2 sychronize it :$ :$ n that case :headbang: :headbang: :headbang: Quote Link to comment
Ton Plomp Posted March 1, 2007 Report Share Posted March 1, 2007 LabVIEW examples..... (directory structure) DAQmx\Synchronization\Multi-Function.llb\MultiFunction-Synch AI-AO.vi Ton And please don't PM Quote Link to comment
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