Hello,
i have a problem with the compilation on fpga.
I have already compiled this Vi several times and it worked perfectly.
I added an INPUT in a loop and since it displays this error!
What is the problem ??
Thank you,
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LabVIEW FPGA: The compilation failed due to timing violations.
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BPSK modulator and demodulator
I'm new to labview (2017) and I'm trying to implement a basic BPSK modulator and demodulator VI.
I need to compare 2 channel: the first one must be ideal channel and the second have to contain white Gaussian noise.
Can you explain me why it doesn't work?
I've already searched in other thread but I can't find something useful for my problem. Thanks for all your answers
I have another question: Several example can't be opened on my computer. can you explain me how to solve it?
thanks for all
Andrea
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Using Extended Validation (EV) Code Signing Cert with Application Builder
I've used a regular code signing cert with Application Builder before without any problems, except for awhile afterwards you get an annoying message popping up saying basically "The cert is new, are you really sure you want to trust it?" I was thinking of going through the process to get an EV code signing cert, so that the program will automatically be trusted. However, I couldn't find any information on whether or not LabView supports that. I'd hate to waste the money and go through the process only to find I can't use it. Does anybody have experience with this, or know where I can find out if this works?
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Access compressed live video bitstream
Is there a way to access compressed live video bitstream from a USB camera that has on-board video compression (like Logitech c920 or c925e) in Labview? When I use IMAQ Grab or Snap, I can only get the encoded video stream.
If not, is there another camera or driver that I can use with Labview to access compressed bitstream?
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Control with single impulse
Hello,
I am using LabView to communicate with a Voltage Source (50kV) and some in and outputs.
I have an boolean which is true when the system detect a breakdown - voltage. The problem is that this boolean is only for a short time true, otherwise its false (only at the moment of the breakdown)
With the first true impulse, I would like to permanently control a relays with a true value.
Should I try to go with a RS Flip Flop or something like that?
Do you have any other suggestions for me?
Thank you very much!
Andy
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Datatype creation with inside binding
Hello,
I didn't use LabView for quite some time now so I may simply have forgotten how to properly approach the problem...
I want to create some kind of data with Typedef that would kind of bind data inside. Let's say I would create a cluster with Ring control specifying several values. Like "SI, SA, SB" etc.
Then I would like to have a second control inside that would have proper descriptions for each of the SI, SA, SB that I could show to the user at runtime. Also I probably want more data than that. All of them bound so when I select SI I get description about SI, values for SI and such.
What would be a proper approach? Can I create it in controls? I would prefer to skip doing it programatically. Less code, less things to worry about.
I currently use it as on the png file. I could select it from an array of strings but what for?
Regards
@Edit: I guess I am looking for something along a dictionary in normal programming languages. Let's say I have a key by which I find data rather than index. I could connect it to an enum or rather... I'd like that enum to configure what happens.
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Variant data in type specification structure
Hello all,
In the attached VI snippet I have a Type Specification Structure (TSS) that I want to be able to include a case for what to do when wired Variant data as a separate case from 'unknown, use last diagram' data.
As per Manual:
Type Specialization Structure Has one or more subdiagrams, exactly one of which LabVIEW compiles and executes, depending on the order and the compilation result of the subdiagram. LabVIEW declines subdiagrams in order if they have syntax errors.
My problem is caused by all 'unknown datatype' being typecast to the variant case, and never reaching the 'unknown datatype' subdiagram.
Any suggestions on how to get the following behavior out of a TSS?
- If Numeric element is wired, run this subdiagram
- If Boolean element is wired, run this subdiagram
- if Variant element is wired, run this subdiagram
- in all other cases run this subdiagram.
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Store three previous values using shift registers.
Hello, I am using LabVIEW with a MyRio and would like to know how can I store three previous values using shift registers? I already managed to store two previous values, but when adding a third register we get NaN at the ouput of our PID equation. Below are the VI front panel and block diagram.
Thanks for your time,
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Timer vi
Hello
I am trying to run multiple timers together but they are in sync. I want to run them individually, is this possible? Many thanks
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Counter output using DAQ-assistant and NI 6343
Hi,
I am using DAQ assistant in Labview in order to use two counter output.
Firstly, I used one DAQ assistant to produce two counter output. The two counter output showed proper result (20180618_7_work.vi), when I checked the two counter output by using a oscilloscope.
In order to obtain two counter output independently, I used two DAQ assistant in new vi code (20180620_1.vi).
Because of my plan is one counter output continuously works and other counter output works during specific time.
However, when I check the two counter output by using a oscilloscope, time interval between two counter output is not constant (For example, the time interval in 1st measurement was 1ms, but the time interval in 2nd measurement was 5ms.) I don't know exact reason. I think the issue may relate with synchronization.
In order to solve the time issue of the two counter output, how should I do?
Hoping someone may be able to help.
Thank you.
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World Cup 2010 - Filtering the Annoying Vuvuzela Noise
Now we're one week into the World Cup and two things have really annoyed me:
- England's lack of a reliable goalkeeper (I'm an Englishman living in Texas)
- The constant drone of the vuvuzelas (those noisy trumpets that sound like a million angry bees)
I'm a terrible goalkeeper and I wasn't named in the English squad so I can't help with #1 on my list but I am an engineer and I can do something about #2.
Other websites have covered various attempts at filtering the vuvuzela noise but none have offered much in the way of a solution you can use at home. My solution is an application (written with LabVIEW) that detects the fundamental frequency of the vuvuzelas (around 233Hz) and applies a notch filter to it and as many harmonics as you specify. The end result is a significant reduction in the annoying background noise without too much interruption of the commentary and other audio.
Hardware-wise you will need to insert your computer in the audio signal flow. If your TV has an audio output, connect that to your sound card's line in, then connect your sound card output to however you want to listen to the game (speakers or headphones). I stream the game to an old PC I have in the corner of my cube and I have the audio output to my laptop, which applies the filter and then outputs to my headphones (don't tell my boss).
Download an installer that includes both the EXE and the Run-Time Engine (for Windows). [Alternate download link]
A Mac .dmg is also attached for those of you rocking Mac OSX. You'll have to install the Mac Run-Time Engine if you don't already have it (I haven't had a chance to test this build but it should work).
You can download the source code and edit it with LabVIEW 2009 (get an evaluation copy here). If you already have the free LabVIEW 2009 Run-Time Engine you can download just the attached zip file which contains the exe.
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How can I turn off all LEDs on breadboard through DAQ when I click the STOP button?
Dear NI family,
I am new with LabVIEW. I am now designing a program to run the LEDs in sequence, however, when I push the STOP button, always there will be one LED is on.
What should I do if I hope to turn off all the LEDs once I push the STOP button?
The code is in the attachment.
Thanks a lot!
Best,
Jason
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How to output 4 bit of serial digital data through 4 DOs into the DAQ and outside hardware?
Dear NI family,
I am new with LabVIEW.
Could you please guide me on how to output 4 bit of serial digital data through 4 DOs into the DAQ and outside hardware?
Are there any examples? How to code for this demand? How can I control the speed of output?
Thanks a lot!
Best,
Jason
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verification of updates for an application at start
Hi
I have deployed a desktop application in several computers, for different people
When I'm updating it, I'm sending an installer to the network and ask for the users to launch the installer, that will replace the previous version of the program
I wander if there is a way with labview to automatically check existing updates and inform the user
thanks in advance for your reply
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Power saving feature for harddisk in OS
It's a reoccuring problems on various LabVIEW systems I have created, that resource problems arise if the Windows
operating system is set with power saving active on the harddisk, instead of having it set to Never.
Is there any way I can in LabVIEW read and check the status of this feature in the OS, and
hence give a warning if it is set to anything else that Never ?
Martin 
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X-Y plot with different colours
Dear all,
I wanted to plot the x-axis (time details) against yaxis (data). I cant seem to be able to plot them to X-Y graph.
My intention is to split the data into time and data then do some sorting work to plot my graphs. I have attached the data. I have successfully split the data into 2 parts.
Is it possible to plot with different colours for the measurement data range while keeping the timestamp?
Meaning 80 and above - one colour (Blue)
40 to 50 range - one colour (Green)
10 to 30 range - one colour (Red)
All should be plotted on the same graph eventually. I think only X-Y graph can do that right?
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access http stream
I am trying to access a http stream (e.g. this one: websdr.ewi.utwente.nl:8901/~~stream?v=11) but neither the VIs of the 'HTTP Client Palette' (e.g. HTTP get) nor the 'Network Streams Functions' seem to do that...
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Elapsed Time
Hi!
I hope so much you could help me in this simple issue.
I would like to start a boolean as true when another boolean become and stay true for 2 second. How can I do it? Please I am a beginner but it is really important to go on with my work.
Sorry for the annoyng
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"Brothers" property in device manager
Hi everyone,
I need to obtain the "brother" property of an USB device, using LabVIEW. I can have it in the "Details" tab of the property windows from the device manager.
I thought I'll find it in the registry key, but I can't find this particular property.
I used the management object in .NET too, but I can't find this property neither.
Any help is welcomed !
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Problem serial communication with Arduino nano
Hi everyone,
I am using Labview 2017, an arduino nano and a SCD30 CO2 sensor. The Arduino communicates with the sensor using a program written by the manufacture (see attached file). Reading the measuremts using the Arduino interface always works fine.
As the Arduino sends the measurements throught serial communication I have used the Labview Continuous Serial and Write example to retrieve the measurements. Quite often at the first loop, and sometimes later on, I get, this error code : -1073807252 ( (Hex 0xBFFF006C An overrun error occured during transfer. A character was not read from the hardware before the next character arrived.
When I include this labview program into my other one (bigger program that does other things including serial communications with other sensors not using arduino equipment and working fine) i get the code error and much more often.
The only way I have made things work is to include a "Visa Flash I/O buffer" Vi ( as you can see in my VI) when the problem occurs and it seems to have worked ok so far.
Does anybody know what I could try to avoid using this Flash Buffer solution?
Thanks for your help.
User
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