Plotting parabolic curve in X-Y graph using 3 or more points ? how to find a,b and c values by using
equation y=ax^2+bx+c
suppose i have 3 points
(50,60)
(80,110)
(150,200)
How do i get values for a,b and c is there any function for that or formula node ?
I have a source that generates between 1 and N (here 5) data points per update. I would like to create a vi that will put generated point 1 in graph 1 generated point 2 in graph 2...ect
I'm not sure why, but my XY Graph clears every few updates. If someone could help me solve/optimize, it would be greatly appreciated.
Hi there,
I am looking for a way to get the .wav header/comment detailed information when reading in a .wav file. I need details like initial time of measurement and scale information that is found in the comment. I am currently using the open/read .wav vis in labview and I need more than sampling frequency, and bits/sample.
Any help would be appreciated!!
Thank-you.
hello to all engineers!!
i found the example mydaqthermistor which converts the Resistance ( from daq) to Tempertaure Polynomial Equation..
i want to modify it and as an input for the resistance to have a 2d array of random numbers and as an input a 2d array ( for every resistance value showing the temperature )
however i cannot find the correct modifications !!! i tried a for loop, i deleted the dynamic data converter i changed the output indicator but it constantly shows errors..
any ideas ???
Dear friends,
In my project, I am using just one USRP RIO 2943 (or 2953). I randomly get this error, but I have no idea the meaning of it. Could you someone teach me the meaning and how to solve it in details? Thank you !!!
Error -1074118627 occurred at niUSRP Configure Signal.vi
Possible reason(s):
A runtime or configuration error occurred.
Code: 312
Details: EnvironmentError: IOError: 0/Radio_0 user_reg_read64() failed: EnvironmentError: IOError: [0/Radio_0] sr_read64() failed: EnvironmentError: IOError: Block ctrl (CE_01_Port_40) no response packet - AssertionError: bool(buff)
in unsigned __int64 __cdecl ctrl_iface_impl::wait_for_ack(const bool)
at P:/Measurements/FlexRIO/SWCode/usrp/niuhd2/trunk/17.0/objects/uhdrepo/host/lib/rfnoc/ctrl_iface.cpp:205
Hello all,
I am trying to fit a lorentzian to my data (see attached for a sample). The peak, is extremely narrow, but it is for sure a lorentzian. I was trying to make the example I found in this post from altenbach work:
https://forums.ni.com/t5/LabVIEW/Lorentzian-Curve-fitting/m-p/208738#M118192
Unfortunately I can't get anything out of this
Can anyone suggest or provide a rough example?
Greetings,
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Since LV2015 it is no longer possible to change a PPL filename after build. My application requires that PPL-based plugins contain the version number as part of the filename ("example 1.2.lvlibp"). I used to handle this with a post-build action.
As a workaround to the new behavior, I created a pre-build action to change the target filename of the build based on the build's version number. The target filename is changed in the build, but the build PPL will have the original file name, not the one modified by the pre-build action.
I had thought that a pre-build action would allow modification of the build specifications, and that these specs would then be used in the build. This appears not to be the case. Thoughts?
Are there other approaches I can take to set the PPL filename programatically at build time?
Hi,
I'm a cell biologist and have no clue about programming/ Labview in general.
Can anybody suggest any coding examples of simple voltage control?
For example, I just need the voltage to stay constant at 2.0V/s for 10 seconds, then speed up gradually to 10.0V within 20 seconds (or within 100 millimeter distance), and maybe after that stay constant or slow down gradually too.
I tried googling things online, but very much hopeless to understand any of them.
I found a file in Labview Forum, prepared in 2010 by a user named Metzer (see attachment). I'm not sure if he/she is still active.
1) Looks very good for 1 pre-set voltage change, but I wish there's multiple pre-sets available for my application. I can't manually stop and key in new numbers, my experiment will be screwed.
2) With this simple code/programme in Labview, can I use it directly? Like open the file in labview, plug-in my computer to the lab power supply-dip coating machine...and magically it works!? Just asking, I do not wish my computer (or me) to explode in any way.
Many thanks in advance for your suggestions/help.
I am using the "call library function node" to make a mouse click with LabView. It works when clicking in some other programs but not in all programs. Is there another mouse clicking function that does work in all programs or an option in the call library function node that can make it possible to click in all programs.
Hey,
So I'm generating a sine wave sweep and taking the FFT of the data I am capturing through microphones. I noticed that the frequency being excited is not the frequency on the FFT. I attached an image of my front panel to show what I just described and I also attached my VI. Does anyone know why this might be happening?
Thanks,
Michelle
Hello,
I updated some vi on a compact Rio, but it seems, it does not take the changes?
What I did, in the Labview project, edit said vi on the cRio, saved. But it seems, when I run the main vi on the PC host, the changes in the subvi did not come through. What to I have to do?
Thanks!
Hello all,
I have a vi that using a lot of Call Library function (same DLL file ) and when i close the vi then the following error is displayed sometimes. Any help? Thanks!
#OSName: Windows Embedded Standard Service Pack 1
#OSVers: 6.1
#OSBuild: 7601
#AppName: LabVIEW
#Version: 15.0 32-bit
#AppKind: FDS
#AppModDate: 6/17/2015 03:53 GMT
#LabVIEW Base Address: 0x00400000
InitExecSystem() call to GetCurrProcessNumProcessors() reports: 2 processors
InitExecSystem() call to GetNumProcessors() reports: 2 processors
InitExecSystem() will use: 2 processors
starting LabVIEW Execution System 2 Thread 0 , capacity: 24 at [3593488142.74428990, (15:09:02.744289875 2017:11:14)]
starting LabVIEW Execution System 2 Thread 1 , capacity: 24 at [3593488142.74428990, (15:09:02.744289875 2017:11:14)]
starting LabVIEW Execution System 2 Thread 2 , capacity: 24 at [3593488142.74428990, (15:09:02.744289875 2017:11:14)]
starting LabVIEW Execution System 2 Thread 3 , capacity: 24 at [3593488142.74428990, (15:09:02.744289875 2017:11:14)]
<DEBUG_OUTPUT>
2017/11/14 下午 03:13:06.000
Crash 0x00000000: Crash caught by NIER
File Unknown(0) : Crash 0x00000000: Crash caught by NIER
minidump id: 224fbd46-6bd8-4c07-b9c8-787f4107ff6d
ExceptionCode: 0xC0000005
</DEBUG_OUTPUT>
0x100011AB - nierInterface <unknown> + 0
0x10005E96 - nierInterface <unknown> + 0
0x1000621C - nierInterface <unknown> + 0
0x7C37FDB4 - MSVCR71 <unknown> + 0
0x77335BE7 - ntdll <unknown> + 0
0x772F98D5 - ntdll <unknown> + 0
0x00000000 - <unknown> <unknown> + 0
Hi, im trying to do a simple project base on Labview software. I wanted to ask how to give a delay like 30 seconds to digital output(LED n buzzer) after my digital input(ir sensor) detect a signal. Im using 6125 daq card.
Thanks
How to correct the following error. I want to connect a waveform Graph to the output as shown, but i got an eror. is there a way to convert to the required data type?. I used merge signal and then connected the graph but nothing shows, what s the problem
Hi,
I have an eken h9 camera, which has wifi. I am able to stream the video live from the VLC media player (my URL is: rtsp://192.168.1.1/MJPG?W=640&H=360&Q=50&BR=3000000), but then I'm unable to get the same video on the labview VI. I tried reading and writing from the same file (the one VLC was writing to, but that didn't work either. I can't find any example code using Find Examples in LV, as there is nothing about RTSP protocol.
Any help regarding this issue will be appreciated.
Hi,
I try to develop an application which based on a .NET dll (builded in LV). In the meanwhile I found a weird behaviour which I can reproduce in a small project (see attached zip). The problem is if I call a dll method, which contains a "wait on asynch call" with a specified timeout, then in case of wait timeout the method will be returned with default value instead of the "real" correct value (of course it works if i dont build and use the dll).
Project structures:
It seems "use case 2" does not behave properly (compare modal window and stingOut values).
Somebody could confirm it that is a bug, or it works as specified and I use the dll wrong?
Thanks for any help,
Balint
I am just attaching a very simple QSM. This is just a Proof of concept to change the User interface language based on a selection. Actually in real time machine controls i have been using the QSM architecture for sequential logic. Just create a TypeDef for the Enumerated Queue states and code. Its working but at times the number of discrete states runs into hundreds and it gets difficult maintaining.
Just thinking aloud if there is any better method in LV to handle Sequential Logic ? There are times when you keep doing the same thing that you miss an opportunity to migrate to new methods !!
Hello all,
I am trying to transmit the received signal with NI USRP 2901. For this, I open an rx session, then configure the signal, initiate niUSRP, and then in a loop I fetch rx data and thus build the waveform. Then I need to transmit the received signal.
First I tried to open a tx session within the rx diagram page, but this gave error saying that the session handling is not alright for Write tx data module.
how should I overcome such a problem?
regards
