I am using LabVIEW to operate an ESPEC environmental chamber. In my front panel portion of the program I used multiple tabs due to the amount of graphs and input data the program has. When I run the program hooked up to the system it will not let me switch between tabs. The program runs and I can flip through the tabs to see the data recorded by the graphs once I hit stop. Does anyone know how to fix this? Do tabs not operate fully when a program is running?
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LabVIEW tab control not working
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Performing FFT on data outside while loop
Hi, I am tasked with generating an AC signal with labview and using that signal to output current through a power supply. The power supply then generates a modulating magnetic field. I then measure the magnetic field using another hardware device. On a waveform chart, the magnetic field is a sine wave. I am able to complete all of this under a single while loop and my code is correct. My problem is when I try to take the fourier transform of the magnetic field data I have to index it out through the while loop. The graph I am getting after performing the fourier transform does not have the same frequency as the signal i generated originally and does not match up with the amplitude of the magnetic field data. My goal is to have the amplitude of the magnetic field sine wave appear on my graph at the original frequency I used to generate my signal.I have been using the amplitude and phase spectrum VI and multiplying the output by the square root of 2 to cancel out the rms portion of the amplitude. Does anyone know why I am having this problem and how to fix it? Please let me know if you have a solution to this problem. Thanks!!
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Reading magnitude and phase simultaneously
Hi guys, I need to read data from a lock-in. My VI works fine, but I've just realized that I need to retrieve not only magnitude, but also phase of the signal. I have to idea how to make it and be sure that they are retrieved at perfectly the same time? If you take a look at the picture attached, you can find command "mag" that is sent to the lock-in (and afterwards I save it in a text file). How should I send "pha" for reading phase? I'm afraid that inserting it in series will result in reading the phase of a signal some miliseconds after reading the magnitude. I hope I made it clear and you get what I mean Smiley Happy
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Student myDAQ - audio radar - sync transmit and receive
Hi folks,
I purchased the Student Labview 2016 with the myDAQ device. I want to create an audio imaging radar to teach high school (maybe gifted) kids signal processing, simple Labview programming and some physics. I'm really struggling with the myDAQ device. I'm hoping you can help narrow in on an approach.
As intro, I'll say that I've been programming in Labview for more than 10 years, and am an electrical engineer so I'm well versed in the basics for this task. Most of my Labview programming has been data processing but I have done some data collection with serial devices (compasses, IMUs, rotators).
For this radar to work I need to:
- transmit a 10-20 ms pulse (linear frequency ramp... 100 - 5000Hz)
- simultaneously (maybe within a micro-sec or so... haven't done the math yet) receive the echos for about 30-40 ms (about 20 ft range at speed of sound)
- I'd like to repeat the xmit/rcv paired process ("sweeps") about 10-20 times/sec (50-100 ms period)
So far with the myDAQ I've been able to generate tones and linear ramps, and I can receive signals. I understand setting the sample rates. And, I purchased a cheap function generator to provide an external trigger for the sweeps.... although I'd rather not use this if I don't have to.
But, everytime I go down a path of trying to mix the xmit and rcv in some synchronized form I get errors (start.retrigger, start.digital edge). Here's what I'd like to find out:
- when I "filter" "DAQ MX Trigger" property for my device, it says that start.retrigger is allowable. Is that a lie (I'm seeing other discussions saying it's not available)?
- how about start.digitalEdge... is it allowable for my device?
- how do I find out what features/properties are actually allowable with my device. The manual is of little help for this level of detail, and so far my fingers are raw from Googling/ni info, but I can't tell if it applies to my device... what is the model# of my Student myDAQ device?
- I also see reference to "internal output signals" so that I could generate a clock and just use that output signal as a trigger without actually wiring two pins together (although it wouldn't kill me to wire two pins together)... is that allowable with my Student myDAQ?
- do you think I have enough capability in my student MyDAQ to:
- synchronize a xmit and rcv pulse within a micro-second
- generate 10 - 20 20-40ms sweeps/sec
- control the period between sweeps to within a micro-second
(note: I could postpone all data processing until a full ensemble of 64-128 sweeps were collected; so I'd only be doing data collection during xmit/rcv)
Thanks in advance for any help, advice, or thoughts...
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PAM Tx Labview implementation
Hi,
I am very new to Radio Transmission and USRP and I am trying to make a PAM Transmitter but for taking hints I am taking clue from this ni USRP example. But I am not able to understand few things.Please someone help.
1)I can understand that the pam block below is doing the PAM generation but where is the message signal being generated?
2)Also what is PN Sequence??
3)MOST IMP: DOES ANYONE HAVE AN EASIER EXAMPLE OF PAM OR QAM TO START WITH??
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waveform graph problem
hi,
i need to display a 16 channel in single graph with channel vs channel 2 or Channel 3 vs channel 6 like any channel vs any channel as x and y plot and user should select which plot sould be seen anybody have idea for this
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Modbus TCP Communication to Festo Drive
Hi all,
I'm currently trying to connect LabVIEW to a Festo Drive (CMMP-AS-C2-3A-M0 if that's important) over Modbus TCP. For this I am using the Modbus Driver from this Site: http://forums.ni.com/t5/NI-Labs-Toolkits/LabVIEW-Modbus-API/ta-p/3524019
The Site references multiple options for Modbus TCP communication, so first off: Does anyone know how to get the Modbus communication option that comes with LV RT? This would be interesting only if it is better than the one I am using.
As for my current problem: I am using the Modbus Master Example from the library to communicate with the drive. Connection works out of the box and I have also verified that it's a "real" connection, since it throws an error for all other IP addresses.
When I use the functions I get Error 538181 occurred at <APPEND>Function 15, suggesting that the function is not implemented on the server. This is pretty much expected behaviour.
What I don't get is: If I try the Fetch Basic Objects command, I don't get anything. No error, but no data either.
Because of this, I spoke to my colleague who knows Modbus a bit better than I and he said that my understanding of the architecture is correct: My PC is both Master and Client and the Drive is both Slave and Server.
The functions, of course, are working. When I connect the Master Example to the Slave Example I can send and receive data without problems.
Does anyone have a suggestion what else I can try?
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save strings and time stramps to file
Hi guys,
I have a VI in which I have made a log file containing names and time stramps I would like to save those into a file an excel file would be good having to columns but I face a problem of how to insert the strings into the "write to measurement file " how can I deal with it please help me thank you
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Find a value by its index
Hello,
How can I find a value in a table relative to its index? Imagine a random value array, and I want the index value 3. I can not find a function to do that.
Thank you for your reply.
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Coding suggestion
Hello.
I want to know the method for creating a 'time-delay' before the data is passed. Suppose I have a 'Boolean' switch which is connected to a LED. If I press the switch, there should be some delay (say 30s) before the LED glows. Any help is appreciated.
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The problem of change the value of boolean during the runtime
Hello everyone,
I am making a subvi in a project, here is my subvi. So in my subvi, the program can well automatically stop and the boolean 'Tourner' will turn to false.
But when I delete the loop while and add rest of subvi to my project which is an exemple of stepper motor named '9503 Stepper Drive(Torque Smoothing Coeff)', this part can only stop for a little moment and continue running, I don't know where is the problem, if someone could help me please? Here is also my project vi.
Thanks a lot.
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LABVIEW issue while switching between OS
Hi,
I created a LABVIEW vi from LABVIEW 15.0 in windows 10 OS.With windows 10 on other tablets and laptops no issue.But when i use the same code or .exe of the code in windows 7 laptops with LABVIEW 15.0 its giving issue .the sequence at which different loops is varying between windows10 and windows 7.Can anyone tell me that is it originally because of the way i have written the code or with the LABVIEW itself for different OS'es?
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Scope SFP application
Hello
Is the Scope Soft Front Panel application available?
If one had the free time this application could be created in it's entirety, but I do not have such available time 
. I think that this would be a strong starting point that would provide any user to use the parts that are provided and build it into something that they need faster then starting from scratch.
Thanks
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Control of UR5 Universal Robot Arm
I am working with a Universal Robot arm. I believe it is a UR-5. I was under the assumption that it could be controlled via Modbus, but I found that was incorrect. I need to use URScript commands. I am having a hard time getting started with this. I was wondering if anyone has written a VI that would control the movement of one of these robot arms.
Thanks.
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.NET Month Calendar control and User Events
I am playing around with creating a user event for the .NET MonthCalendar Control. I would like for the user event to fire when a user selects a day on the Month Calendar control, however, I cant seem to even see a list of user events when I select the Register for Events - User Events pick list.
Am I doing something incorrectly here? This is my first time using the User Events portion of LabVIEW (actually, I am looking to enhance one of my existing programs) and I'd figure I'd play in a VI first.
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XNET Database Add Issue
Hi All,
I'm having issues referencing a database file I'm using. I'm using the XNET Database Add Alias.vi to point to the database file that's being used in the test program but I keep getting errors as it's trying to find this file (see screenshot attached). This test program has been updated and has worked before so I'm not sure what's going on. The alias name and filepath were originally hardcoded but I've now added the controls to the UI so that they can be selected prior to the test program being run (see XNET_Error1.jpg attached).
I then tried adding this XNET database through NI MAX but got an error saying the database alias name contains an invalid character (see XNET_Error2.jpg attached).
Any help would be much appreciated. Thanks in advance.
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How can I translate the VI Activation Event Type (a number)?
I am relatively new to LabView (8 months programming a large project). I am trying to better understand events and how the event structure works.
I created a simple example VI which Adds two numbers and provides the result on the front panel. Within the While loop are two events that respond to the user clicking two buttons, Add Numbers and STOP. This VI is a SubVI called by a Top Level or parent VI.
Everything worked fine until I added a VI Activation event to the Event Structure in the SubVI (just to see what it did). Now when I call the SubVI, the VI Activation event is triggered and it is the first thing the subVI processes. I am calling the SubVI inline in the TopLevel VI not with an Invoke Node. The surprising thing to me is that the VI Activation event is triggered over and over once the subVI starts, even though I am NOT doing anything interactive with the Front Panel (yet) and I only call the SubVI once. Essentially the Event Structure goes into an infinite loop. Both the Event Source and Type are numeric data types and my probes tell me that Source and Type are both set to zero when the VI Activation Event is triggered. I can't find a list of Type numbers to know how to translate the numeric value into an event. Is there a list of Type numbers and their corresponding event?
I assume that zero means that nothing specific triggered the VI Activation event, but if the event type is zero, I don't understand why the VI Activation is triggered in the first place, much less repeats. There isn't much information on the VI Activation event in the Forums or NI documentation and I can't find any examples to show how VI Activation is supposed to work. From the meager information I have found, I thought the VI Activation event was triggered only when the user interacted (in some way) with the UI. Can someone provide more insight?
Unfortunately my company does not permit me to upload any code (I am currently signed in with my personal account), but I am including a screen capture of the block diagram.
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Adding a new local variable from VI to a SubVI
I think my title explains the situation decently, current subVI has local variable inputs, and I want to add another but have no idea how (and couldn't find anything concerning local variables with this). I can make a subVI with local variables, but I can't add any in.
Thanks
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Understanding indexing with while loops and building waveforms
I have created 2 separate programs that I want to generate the same result. The first program (whileloop2) generates a sine waveform, performs FFT, and displays it on a graph all under the while loop and outputs the correct result. The second program (whileloop3) generates a sine waveform and sends the array values of the waveform outside the while loop, then builds a waveform and performs FFT outside the while loops and displays it on a graph. The second program is not outputting the same results and i am not sure why. Does anyone know the reason for this and how to fix it? I need to be able to perform the fft outside the while loop correctly for another program that generates values from hardware. Please let me know, thanks.
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LabVIEW connection to Password Protected Access Point with Modbus
Hello. I'm trying to use LabVIEW to control a wireless access point via Modbus. The access point is password protected. How do I enter a password to initiate communication? I have looked at both the vi method and the i/o server method, but I have not been able to initiate communication. I can use a hyperterminal to set up the access point characteristics, after entering the ID and password. Any help or examples would be appreciated.
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