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Two dequeue operations within one consumer loop -Producer consumer Arch.

January 25, 2019, 2:44 am
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Hi All, 


My Application: 

I have two data acquisition devices. 1. A force sensor 2. output from an ESP32 microcontroller. Both are using visa commands for serial COM ports. And then, the data are plotted in a graph and also written to a text file. For a better sny. architecture, I used a Producer Consumer pattern. After many research in NI forum, I found out that the reason for not executing the consumer loops is that there are 2 dequeues. Then I commented those out to see and it works. I'd like to know from the experts, is there a way that I can resolve this issue. (I was thinking of using a FGV or a notifier also... But I'll wait for your expert answers..) 

Thank you very much in advance. Attached is a .7z + vi 

 

Best, 

Shane

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Remote programming of vision cpu (connected 3GigE cameras) in LabVIEW

January 25, 2019, 3:47 am
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Hello All,

            We are using LabVIEW to develop a vision system for detection of components using Basler GigE cameras.

We have only one Laptop with LabView & Vision development module. We cannot connect these Basler cameras to our Laptop, to do programming. Refer to the below image for the block diagram:

 

vision system Block diagram.jpg

 

Can we program the VIs/ Application from Labview laptop targeted for Vision CPU?

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Reading/Writing of DNG files

January 25, 2019, 4:00 am
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Hi,

 

I am trying to read in a bunch of DNG files to do some processing on them. Has anyone done this before? If so, what approach would be best to use?

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Visa serial don't work sometimes.

January 25, 2019, 4:12 am
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Hello.

First of all, I'm not even close to an expert developer, so I apologize in advance for some possible fool mistake.

I'm trying to read the weigth value from a Bel L16001 model scale, like this.

 

I configured to 9600 of baud rate and its manual says parity is not considered.

Sometimes it works perfectly, but sometimes not.

Sometimes even with the yellow simbol besides the COM5 port appearing (what I think means is connected) it doesn't work.
The cable I'm using for comunication is this.

The most significant thing I did was to "uncheck" a "turn port off for savind energy" box at USB Root Hub on device manager.

 

Thank you guys.

 

Hope you could help me!

Best regards...

 

 

 

 

 

 

 

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Scrollbar Customization in LabVIEW

January 25, 2019, 5:00 am
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I am trying to increase the scrollbar width of the array with customization for a touchscreen application. The changes in scrollbar width are not retained when closing LabVIEW and opening it again. I tried making it strict typedef and still, the changes are not retained. Smiley Frustrated I also tried with other types of controls like modern and classic. I have attached the previews for reference.

 

Anyone have any ideas how this can be done? 

 

Thanks!! Smiley Happy

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Some question about the Modbus library

January 25, 2019, 5:30 am
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Dear all,

 

I have some questions about the Modbus library I hope you can answer

 

1) Why there are two versions of the library (one with the yellow header, the other with the blue header)?

2) Which one NI does recommend to use?

3) Why NI packages one library with the base package and the another Modbus library is separately installable?

4) Why there are no methods to read the timeouts of a connection?

4) Why the property node operator can be used to set the timeouts but not to read them?

 

Sincerely,

 

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While Loop inside a Case Structure executes only Once in FPGA Target

January 25, 2019, 6:30 am
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I have a program made by a previous intern that i'm trying to clean up and get it to work properly. This program is just supposed to take data from an RPM sensor and display it on the screen, and write it to a TPMS log. 

 

The problem is from how it's running currently, the main "while" loop in the main program (host_PC_Energy_drone) only runs once (from the looks of it) and then stops updating data. So the data displayed on the screen only displays once and ends. What could be the cause of this? The stop case for the while loop is if the stop button is clicked, which it isnt. I'm at a loss here. 

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Mi ejecutable llama a un subVI que no se ejecuta

January 25, 2019, 6:54 am
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Erroneous input from NI USB 4432 and LabView

January 25, 2019, 7:11 am
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Hi everyone,

recently I had some troubles while acquiring vibrometric and acoustic data through LabView. My virtual instruments seem not to work anymore, despite nothing has been changed in the settings. I attach two screenshots which explain what happened before and what happens now. I don't know if this could be a sw or hw problem. Does anyone know why can it happen? Is it because my acquisition card is broken?

Thank you for your help!

 

Riccardo

 

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Error with loading 'external assembly', goes away 2nd time I open the file, is there another solution?

January 25, 2019, 7:24 am
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I’m having an issue with loading an ‘external assembly’.

I'm using LabVIEW 2018 (32-bit) on a Windows 10 computer (64-bit), and up to date OmniDriver package downloaded from Ocean Optics (version 2.56).

Description of issue:

When I open LabVIEW and click on the simple .vi (just opening and closing the spectrometers) that uses the NETOmnidriver-NET40.dll I get the following error message :

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LabVIEW: (Hex 0x494) A .NET exception occurred in an external assembly. For information about correcting this error, copy the following exception (in bold), and search the Microsoft Developer Network (MSDN) Web site or the Web for a possible explanation.

The file ‘NETOmniDriver-NET40.dll’ could not be loaded.

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I then click OK and click run in the Front panel of the .vi, then as aspected I get an error in running.

However, when I close the file and open it again, I get no error, and I click run, and the .vi works.

Seems like a delay in loading the DLL?

Can this issue be solved?

 

Perhaps related to this, here another issue:

When I click in the .vi on View -> .NET assemblies in memory, I get the following error message:

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Error 1097 occurred at Call Library Function Node in DotNETAssemblyVisualizer.lvlib:GetArrayOfAssemblyInfo.vi->DotNETAssemblyVisualizer.lvlib:AssemblyVisualizationWindow.vi

Possible reason(s):

 

LabVIEW: (Hex 0x449) An exception occurred within the external code called by a Call Library Function Node. The exception might have corrupted the LabVIEW memory. Save any work to a new location and restart LabVIEW.

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LabVIEW: (Hex 0x449) An exception occurred within the external code called by a Call Library Function Node. The exception might have corrupted the LabVIEW memory. Save any work to a new location and restart LabVIEW.

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(This error doesn’t go away by closing it and doing it again.)

We looked in Windows at Dependency Walker and it seems that might be a delay-load issue of the DLL?

Is there a solution for this? That would be greatly appreciated!

Thank you very much in advance,

Everine

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Array issues

January 25, 2019, 8:03 am
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Hi, having a bit of trouble setting up an array .

The readings came out as a string which I converted into an array which appears as:

1.0001 101 1.0002 102 1.0001 103 1.0001 104

Instead i would like it to be 

1 101 1.0001

2 102 1.0002

3 103 1.0001

4 104 ...

 

Once I get more scans id like it to be:

              1           2 

1 101 1.0001  1.0001

2 102 1.0002  1.0003

3 103 1.0001  1.0003

4 104 ...

 

Any help appreciated 

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Two Edge Separation Timeout

January 25, 2019, 8:47 am
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Hey all,

 

I've got a program using the two edge separation as a timer for relatively high speed object (~100ft/s), and it's working well, but sometimes the first sensor gets tripped by the user by accident, which throws off the next measurement, since the system is waiting for the second sensor. Are there any tricks for adding a timeout, where if the program doesn't see the second edge after a certain time, it resets? I'm not seeing anything in the properties, but I'm hoping y'all have a workaround.

 

Thank you!

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Grayed out a button in NXG

January 25, 2019, 9:11 am
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Hello, I am starting to use labview NXG.

I would like to desactivate/activate some button while the code is running. I knew how to  gray out some button with the normal labview but I can't figure it out with NXG

I tried to use "modify variable propertie" function but I can't understand how does it work. Does someone have some info or an example.

 

Thanks,

Vincent

 

 

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LabVIEW built DLLs as a plugin system for a LabVIEW executable

January 25, 2019, 9:27 am
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Hello all,

 

I'm working on a project where we are attempting to package stand alone modules of our code base into LabVIEW built DLLs that will be called from a LabVIEW executable when that portion of the code base needs to be shown to the user.  I've run into issues trying to get more than one LabVIEW built DLL (with a user interface) to show on the screen at a time.  I've attached a zip file with an example project that contains two "plugins" and a calling application.  I'm working in LabVIEW 2018 64 bit on Windows 7.  Please take a look and see if you can replicate my issues and provide any help!

 

Steps to reproduce:

1.  Build exe or dll in each project.

2.  Run executable.

3.  Start Test 1 plugin.

4.  Start Test 2 plugin, notice that Test 1 plugin disappears, and Test 2 plugin appears.

5.  Start Test 1 plugin again.  Test 1 plugin and Test 2 plugin should both be running now.

 

Why won't Test 1 plugin stay up when I start the Test 2 plugin?  Why does Test 1 plugin show after I start it the second time (in step 5)?

 

Thanks!

Chris Davis

 

 

 

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Need to create a refnum of an multicolumn listbox which its data type in array

January 25, 2019, 10:19 am
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I am having an simple issue but for the life of me can't figure out how to create a refnum of an multicolumn listbox where the data type is in array format.  I have created one where the data type is in scalar (defaulted data type), but can't get the array data type version multicolumn listbox to work. 

 

Basically I want to have a refnum in subVI's so I can reuse the VI to adjust the column width, sort columns of the reference, etc.    All of it was working until I decided to change the multicolumn listbox's Selectable mode to be "1 or More Items".  When in that mode, the data type is changed from Scalar to an Array.  Basically it broke my connections and gives me an Class mismatch.

 

I created an example of it as attached.  Thanks for the help.

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Is LabView for Linux available with the SSP

January 25, 2019, 11:13 am
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Hello everyone!

 

The company where I'm working is considering to transfer our labview test platform from Windows to Linux, we know that there is no demo version, so we are considering to renew our expired SSP, we wonder if the SSP included when buying LabView Professional or full will allow to download the Linux version so we will be able to run some tests but at the same time have the Windows version.

 

If possible we may be able and consider to have a source code compatible with both OS with code selected for compile depending on OS.

 

Thanks and Best Regards.

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How do I take a time stamp and get a new time stamp that is a specific time tomorrow?

January 25, 2019, 1:31 pm
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I want to set an alarm. The set time is held in a time stamp. Say I want an alarm for 5:00 AM local time tomorrow. daily event reminder.png

 

This doesn't work. What will?

 

TIA

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Plot electricity usage to Waveform Chart every hour of the day

January 24, 2019, 9:45 pm
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Hi all i would like to know what settings should i do to my waveform graph so i can display hourly electricity usage for a day. I only want 24 markers on the x axis and for this graph to only update once every  hour and reset after 24 hours. The picture bellow is something like what i would like to achieve. 

Image result for hourly electricity consumption data

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IIR filter Nyquist cut off

January 26, 2019, 3:27 am
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I am trying to reproduce a simple RC low-pass filter response for audio processing. A first-order Butterworth filter works except at high frequency where, as the Nyquist frequency is approached, there is an additional fall off. This behaviour is reproduced by the Digital IIR Filter VI: filter information output (below) so it appears to be a theoretical limitation.

 Filter fall off.JPG

I have tried other implementations, including the IIR cascade filter, and the response is the same. I haven't tried a wideband FIR filter as it looks over-complicated - even a "Butterworth" seems overkill for such a simple response.

 

Oversampling reduces the error but doesn't eliminate it.

It is crucial that the filter also has the correct phase response (satisfying the Kramers-Kronig relation, as the Butterworth filter does). Is there a solution?

 

Thanks, David

 

LabVIEW 18.0

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Need help identifying a LabVIEW symbol

January 26, 2019, 11:12 am
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I'm working through Bishop's Modern Control System Design with LabVIEW by reproducing all his samples.  In Ch.1 he shows a Transfer function with a VI "G1(s) + G2(s) Transfer Function".   The picture is attached.G1+G2 Transfer Function.PNG

I cannot find this VI in the pallets.  There is no Help selection when I right-click it but there is a Description:  "<B> Equation</B> draws a picture of the model equation..." 

What is this?  Is it part of the control system or system identification tools?  Is it something that Bishop has created?  And how to I figure this out the next time it happens so I don't have to bother you good folks?

Max

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