deleted
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[LabVIEW Bug Report] Negative argument of the complete gamma function is not supported
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Abnormal Waveform from myRIO FPGA Audio IN terminal
Hello there!
I am working on Active Noise Cancellation Project on myRIO 1900.
I just figured out the abnormal waveform coming out of Audio IN (FPGA node).
I am using a 1 V amplitude,2 kHz frequency(0.5msec Time Period), 20k sample rate and 80 #samples sinusoidal noise as source.
I just read this noise using microphone on both RT side and FPGA side seperately. On RT side, I used FPGA High throughput mode(Custom FPGA personality) Audio IN terminal @40k sample rate, and 100 samples. The recorded waveform is
Where as on the FPGA side, I can only record 1 sample at a time. MyRIO 1900 has 500 kS/sec ADC, and If I am using both left and right channels of Audio In, I am getting loop rate of 4 micro seconds (250 kS/sec for each channel). i.e If I can process, 1 sample in 4 micro seconds, over the Time period of 0.5 msec of sinusoide , Audio IN terminal should be able to collect 125 samples of data for one cycle of sinusoid. So, It should be able to give close to perfect sinusoid even with little loss of data ! But here I am getting some abnormal waveform which is not at all sinusoid.
I could not understand why is this happening?
Please help me understand what I am doing wrong !
Thank You.
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Executable Export Image - Picture Method - LV Crash - DAbort 0x786DE250 in drawmgr.cpp
Hey guys,
I have a crash showing up in my application when trying to export an image to the clipboard to be pasted in to my Word document. The crash occurs at the Export Image invoke node, but only occurs in the executable and only occurs on the 102nd iteration. If I run the executable with 101 iterations it's fine. If I run with 50 iterations, then run it again at 52 iterations without closing the executable, it crashes.
Code, snippet, executable, crash dialog below. Do any of you have any suggestions or workaround ideas? Is there something that I could change in me executable build settings to fix this?
To run the code, you can change any parameters and then hit Go to run the iterations.
Thanks for the help!
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notifier bug?
So, I think that I may have come across a notifier bug.... or I may just be using it incorrectly. Please see the attached code or the screenshot below:
Essentially, I have an array of notifiers and I want to check for new notifications from this array. However, when I "wait on notification" using a for loop, I get an innacurate response that there is new data from the last notifier in the array... even though that is not true.
Any ideas? Is this a bug, or am I improperly using this tool?
Many thanks!
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database management and RFID interface
hi frnds, i need to know two things
1. can we interface an RFID tag with labview through PC and read the data stored in the RFID tag??'
2.if so, then how can i match the read data with a predefined database present in labview?? and how to create databases in labview?
please provide me suggestons with this
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help
Hi, is anyone in the dublin area available to give a grind over the weekend. Very new to labView and have been given a project to do but cant even get started. Have only completed 3 lectures in labView covering loops and shift registers, and watched plenty of you tube videos but they seem to lose me. Badly need one to one tuition.
Thanks.
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NI-5771
I think there is mistake in the NI-5771 documentation. There appears to be a mistake for Ref In CLK on the FAM. Additionally does anyone know how to setup the clip so that the ADC CLK takes a 10 MHz input on the ADC REF IN SMA port?
Thanks for your help!
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Sending Serial data with Handshake
I am trying to send via Serial @ 9600 Baud a set of about 20 strings each with about 72 characters. It is terminated by a "\n" character.
The receiver is a Microcontroller unit and after it gets each String completely and saves it sends a "OK\n" back to LV.
At the end of 20 such transactions the port is closed.
But i seem to be having timing issues as each string is not transmitted in full. I am running the LV code inside of a while loop and i have tried various delays of 10ms to 200 ms with no significant improvement.
1. So instead of such a while loop with fixed delay is there any method to time these transmissions?
2. Do we need any delay between the WRITE and READ functions assuming there is no delay at the microcontroller end ?
( Attaching the ZIP file with my code in LV2012 and the garbled data received at the microcontroller end. )
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MyRio - run program without PC
Hey Guys,
We are using the NI myRio device as a datalogger for our thesis. Our problem is, that we can't find out how to run the datalogger.vi, without using a PC, on the NI myRIo.
Can anyone help us? Thank you in advance 
Nice greets from Austria!
harisborovina
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Time accuracy of GPS timestamp
Hello,
How accuratecanthe timeof theGPSsignalbe resolved?
If i look at the actual RX timestamp I see a resolution of 10e-8 s.
At the LV Timestamp it will be the same.
Is it possible to reach a higher/ better time resolution?
e.g. 10e-9, 10e-10, ...
Or is the time resolution limited by the USRP?
thx
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Key focus fails as window frontmost state returns slower in LabVIEW 2014 and 2015 than before
If you have key focus on a control, then open a subVI window or dialog to get some input for example - before returning to the original window...it is a well known problem that you have to programatically set the key focus back on the control. However, there seems to have been a change in 2014 (persistent in 2015) that makes the return of focus on the window of the calling VI behave differently/slower - so that it is now possible that the key focus write is ignored if it is run just after the pop-up window has closed itself.
Let's say that you have a listbox for example and if you double-click on an item there you are given a pop-up window where you can input something...but when that window closes you want the user to be able to continue navigating in the listbox from the original location as if key focus on it was never lost. So you add a key focus property and write a True to it as soon as the pop-up subVI returns...Well, that would have worked in 2013 and earlier, but not in 2014...unless you add a 10 ms wait between the subVI-return and the key focus write(!).
Now the fact that the window where you want key focus to be set has to be frontmost is a documentet fact too, it is described here, but in this case the frontmost state is automatic, so that should not be an issue...
However, 2014 introduces a delay it seems to that return to frontmost state.
(It seems that this is even more complex though, because if you happen to *read* the control's key focus state just before opening the pop-up window...the problem disappears, even though that should not really affect what happens later in the program (an more strange this corrective result only happens if you read the value, of the key focus property not if you just read the error out from it)).
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Can I move Add ins?
Hello,
I don't know if I can describethat very well (I am learing LabView at the moment)
Is it possible to "move" the user specific Add ins?
So that they not appear in "right click > User Libarys > Add in" but in "right click > Add in"?
I am Using LV 2011 and 2014 both 32bit and 64bit Versions and Windows 7 Prof. 64 bit.
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fpga
I have SbRio 9642 and LabVIEW 2013 , can i compile with Xilinx14.4 compiler ? if not which one is siutable
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Converting FPGA time to UTC and logging the time along with Sample values onto the TDMS file
Hi,
In my application I am trying to log the data along with the timestamps in microseconds resolution.
The components of the project are
1:NI cRIO 9030 controller
2:NI 9223 ADC
I have used 'NI Time Sync FPGA Timekeeper' VI for timestamping. I am able to log the data with the timestamps in terms of FPGA time onto the PC using Network Streams.
The concern now is to convert the FPGA time into UTC . I am using the 'FPGA to Labview Time.VI' from the 'NI Time Sync FPGA Timekeeper' to obtain the timestamp value and later am converting it into microseconds resolution but the issue is that on the host PC I have values of the sample values in the form of array and the timestamp values are too in the form of array . However, to convert FPGA to Labview time the VI accepts data in the form of individual elements the process of indexing elements using For loop on the PC too causes issues while logging data.
I have enclosed the snapshot of my VI along with the Time keeper VI. In the host VI all the points are not getting logged onto the TDMS file. I think I am using the Queues incorrectly and if this is the correct approach?
Could you please suggest?
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lvalarms.dll crash
Hi everybody
I tried to find a solution for this problem .
When I use a Timeloop , the first time the VI work very well but the second time Labview crash.
This is the error message :
Description:
Stopped working
Problem signature:
Problem Event Name: APPCRASH
Application Name: LabVIEW.exe
Application Version: 12.0.1.4014
Application Timestamp: 522f27d1
Fault Module Name: lvalarms.dll
Fault Module Version: 5.0.0.49154
Fault Module Timestamp: 4fccee09
Exception Code: 80000003
Exception Offset: 00001779
OS Version: 6.1.7601.2.1.0.256.48
Locale ID: 1033
I tried to change the processor (Timeloop paramters ) but I got the same error
This is the VI that I used
Thank you for you help
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Using htaccess to secure front panels
I am trying to secure the LabVIEW web server using simple htaccess. I have tried creating this file as htaccess.txt and .htaccess. I can't get either one to work. Is this feature still supported in the web server that is shipped with 2015?
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M-PSK Modulation and demodulation Sync
Hello,
I have a problem with M-PSK modulation and demodulation. I think its because of sync... but i am not sure. My problem is; when i try to comare my modulators input bit stream and my demodulators output stream they are different . I mean they are so much different it has BER=1 . I export my modulators input bitstream and my demodulators output bitstream to exel, i compare them , they are very very different. How can i fix it? i want to calculate BER and draw its BER-EB/N0 graph. first i need to compare them but i cant. waiting for helps . have a nice day.
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Nonlinear Curve Fit Error 20068?
Trying to do a simple 3-exponential decay nonlinear curve fit. I have a copy of this working in other VIs but it doesn't seem to work in this VI. I'm using Altenbach's "scalablemultiexponentialdecay" as a model VI/template. The data I'm trying to fit is a simple series RC decay, yes I realize that shouldn't have 3 exponential components, it's just model data. I am able to fit it with the built in Exponential Fit function from the Math palette, however that only works if the parameter bounds input is wired and with rational constraints. However, I get an error on the nonlinear curve fit that I don't understand (picture is attached) indicating that an INF or NaN is getting in the parameters. I don't see where that's happening...
Any help or questions is appreciated.
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Possible Bug with Waveform Graph
labview bug Recently while I was going to create a vi to convert labview grapg into trend I find a small bug in labview graph and waveform that is not possible for solve unless national instrument correct it roots codes
bug is that in invert mood of graph if your minimum data is not zero, start point of grid is not work well and then you loos your grids.
any body else have same problem? you can find more explain in my linkdin hatef fouladi
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FPGA C Interface - How to Use NiFpga_AcquireFifoRead and NiFpga_AcquireFifoWrite Methods
I am looking at the new methods here for acquiring write/read elements to avoid an extra copy from user-mode to kernel-mode here:
http://zone.ni.com/reference/en-XX/help/372928G-01/capi/functions_fifo_write_acquire/
Are there any examples of how to use these methods?
thanks,
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