voltage waveform changes shape with time despite constant settings

August 13, 2020, 7:41 am

≫ Next: PICKERING DRIVER ISSUe

≪ Previous: How can I get DBL from an array cluster/get the phase of a waveform

$

0

0

Hello,

 

I am using USB 6366 to measure a superimposed voltage (50 Hz + harmonics) and current simultaneously, the measurements seem to work fine and the results are plausible, but thre's a problem that I don't understand:

I noticed that when I start my measurements my waveforms do not resemble the ideal waveform - to be exact, they aren't symmetrical >> for example my 50Hz + 550Hz voltage waveform in black  

 

However, as time passes (5 minutes ish, I just let my programm run and I observe the shape), my waveforms slowly resembles their 'ideal' shape and become symmetrical >> see black colour waveform below

Does anyone have any idea why? Software, hardware? The phase of the signals do not happen to have an influence of the shape, phases of both signals aren't similar even if I get my 'ideal' waveform.

 

Would appreciate it if someone has an idea! My vi is attached below.

 

Jun

---

PICKERING DRIVER ISSUe

August 13, 2020, 8:12 am

≫ Next: LabVIEW REAL TIME MODULE INSTALLER

≪ Previous: voltage waveform changes shape with time despite constant settings

$

0

0

I am Having issues in calling ClearSub.vi and OpenCards.vi while trying to open my VI. I am using a pickering card " 40-745-511 " on My Labview 2012 SP1 installed on Windows 7 Pro.

 

Which is the driver i need to install and what could be reason i was not able to load it.

LabVIEW REAL TIME MODULE INSTALLER

August 13, 2020, 8:33 am

≫ Next: Conflict when using a SubVI twice in a VI

≪ Previous: PICKERING DRIVER ISSUe

$

0

0

Hello, 

 

I have LabVIEW 17.0 version installed on my system and I wish to evaluate a real time target My-rio 1900  but I don't have LabVIEW real time and LabVIEW FPGA modules installed. While searching for these module installers, I found out that these are not available (the download button remains disabled). Where can I find the 17.0 RT and FPGA installers for evaluation purpose ?

Please help. 

Kind regards.

Arijit

Conflict when using a SubVI twice in a VI

August 13, 2020, 9:39 am

≫ Next: Dequeue the last element?

≪ Previous: LabVIEW REAL TIME MODULE INSTALLER

$

0

0

Hi,

I'm trying to understand how a subVI works in this case:

I create a subVI, like in the picture below. Where the "Numeric" control replace 1st value in the "Array" control, and move the result to "Array 2" indicator.

Then I create a VI, attach the subVI above:

What I want is, every 2 seconds, the array's 1st value is replaced by a number that I enter (numeric).

The problem is, while running this VI, only the second block works.

Is there any way that I can make 2 blocks work at the same time?

 

The .vi files are attached below.

 

 

Dequeue the last element?

August 13, 2020, 10:27 am

≫ Next: Getting a reference to a specific scrollbar

≪ Previous: Conflict when using a SubVI twice in a VI

$

0

0

 

 

I want to continuously take measurements to monitor operating conditions (100mS update) and safely shutdown if safe operating limits are exceed. If a shutdown occurs I need to dump the measurements from a few seconds before the shutdown to a file.

 

So I imagine using a fixed size queue to keep the last few seconds of measurements in memory so I can dump them to a file if needed. (Will this work? Will a fixed queue remove the oldest element and add the new one once the size limit is reached)

 

But I also need to log measurements at regular intervals. 

 

Is there a way to dequeue the last element in a queue so I have the most recent measurement when a log interval occurs? 

 

Or is there a better way?

Getting a reference to a specific scrollbar

August 13, 2020, 11:27 am

≫ Next: How to review an NI I/O Trace file (.nitrace)?

≪ Previous: Dequeue the last element?

$

0

0

I am able to use a property node in order to get a list of references to all objects on a pane, and then I am able to cast the reference to a scrollbar to find which references are scrollbars. But once I have a reference to the scrollbar, I have been unable to find a property that would tell me if I have a horizontal or vertical scrollbar reference. Is there any property that exists, or something that would help me distinguish them?

 

Just realized the all objects property on a pane doesn't give me a the scrollbars. So my question now becomes, how do I get a reference to a pane's scrollbar, and how do I tell which direction it is (horizontal/vertical)?

 

Thanks!

How to review an NI I/O Trace file (.nitrace)?

August 13, 2020, 12:51 pm

≫ Next: Strain Gauge/Write to text file

≪ Previous: Getting a reference to a specific scrollbar

$

0

0

A colleague provided me an NI I/O Trace file in the .nitrace format, not the exported txt file.  If I launch NI I/O Trace and open the file with it, nothing happens.  What am I doing wrong or is a different tool required to look at the file.  Thank you.

 

Cheers,

JMA_eng

Strain Gauge/Write to text file

August 13, 2020, 1:23 pm

≫ Next: NI845x Driver 20.0 removes LV2013 files

≪ Previous: How to review an NI I/O Trace file (.nitrace)?

$

0

0

Why is my text file not displaying my data that is being shown in my charts?

I'm only getting data from my "Strain" values every 10secs and not the others. It probably has to do with decimals shown.

 

Please help. Thanks. 

 

PS. if you have any suggestions on how to improve my strain gauge readings, it would be a big help. Not much experience using these.

 

---

NI845x Driver 20.0 removes LV2013 files

August 13, 2020, 2:54 pm

≫ Next: how to diagnose an out of memory error

≪ Previous: Strain Gauge/Write to text file

$

0

0

I am trying to migrate to LV2019. I use LV2013 and sometimes it gets a little hinkey. I migrated one of my test programs to 2019 and had minimal problems.Today I tried to move a second one that uses an NI SPI interface. When I loaded it into LV2019 of course the NI845x files were missing. So I downloaded NI-845x 20.0 from NI.com and installed it. When I went back to my LV2013 the NI845x files are now missing from the <vilib> folder. I can't reload them since the 15.0 version driver won't run be a "newer version is installed".

 

Can I just copy the files from another PC into the C:\Program Files (x86)\National Instruments\LabVIEW 2013\vi.lib folder?

 

Norm

how to diagnose an out of memory error

August 13, 2020, 4:01 pm

≫ Next: Error 1498 occurred when I tried to build an EXE

≪ Previous: NI845x Driver 20.0 removes LV2013 files

$

0

0

We have a client running our LabVIEW 2018 program (compiled) on W7, 32bit. They run 24/7, and every 4 months they get error 2, out of memory from our program. (There are two other programs running as well, written in an older version of LV that don't exhibit problems.) Our program is very modular, and except for a couple of custom modules, we've run it on numerous other systems without seeing any such error. So I set up a computer here to run just those two modules. No obvious memory leak. Also, when LV start reporting Error 2, Windows still says that our program is only taking up about 140MB, and there are 600MB free memory! So it really doesn't look like a traditional memory leak out-of-memory error.

I'd like them to try replacing the memory chips, but the system is remote, with limited physical access.

My questions are:

Does anyone have experience with similar symptoms in which it turned out to be the memory hardware was bad, not the software?

Stated another way: Do the symptoms described sound like they could be due to bad memory chips?
Also, any recommendations for a diagnostic program we could run that could check the chips?

Thanks,

    DaveT

Error 1498 occurred when I tried to build an EXE

August 13, 2020, 6:00 pm

≫ Next: An HTTP server implemented using LabVIEW basic functions

≪ Previous: how to diagnose an out of memory error

$

0

0

When I tried to build an exe for my project yesterday, an error occurred straightly after I pressed the button of New Applicaiton(EXE). The project can run without error. Moreover, I didn't get this error on my own laptop unless I use the computer in the company. The complete error information is as below: Error 1498 occurred at Get LV Class Default Value.vi. Possible reason(s): LABVIEW: Library has errors. Fix the errors before attempting this operation. Complete call chain: Get LV Class Default Value.vi AB_UI_Initialize_Framework.vi AB_UI_FRAMEWORK.vi AB_CreateNewWizard_Invoke_CORE.vi EBUIP_CreateNewWizard Invoke.vi EBUIP_CreateNewWizard_Invoke.vi.ProxyCaller Labview attempted the load the class at this path： C:\program Files\National Instruments\LABVIEW2010\vi.lib\AppBuilder\AB_Classes\Build\UI\AB_UI_Frmwk_Build.lvclass

An HTTP server implemented using LabVIEW basic functions

August 13, 2020, 7:10 pm

≫ Next: How to create arbitrary waveform with PXI-5412 Arbitrary Waveform Generator in LabVIEW VI?

≪ Previous: Error 1498 occurred when I tried to build an EXE

$

0

0

When using LabVIEW for network programming, There are two problems: 1. Web Service cannot be created under Linux(x86) version; 2. The Web Application developed with LabVIEW NXG is deployed on NI Application Server(port 8080), and the loading speed is slow due to the large size of individual files (such as \ Ni-Webvi-resource-v0 \ Deployedrun.min.js, 3.34MB). In order to solve the above problems, LabVIEW was used to write an HTTP server, and the Web Service Service program based on the basic TCP/IP function was implemented. The program also realized the function of sending static files. It compresses deployedrun.min.js file with GZIP and returns the compressed content, which improves the loading speed of the page file.

How to create arbitrary waveform with PXI-5412 Arbitrary Waveform Generator in LabVIEW VI?

August 13, 2020, 8:42 pm

≫ Next: NI 6008 USB with Debian Linux

≪ Previous: An HTTP server implemented using LabVIEW basic functions

$

0

0

I am attempting to use the PXI-5412 to create an arbitrary waveform based on a .csv with 1048576 values, all of which are between 1 and -1. I am able to create the waveform fine in the NI-FGEN Soft Front Panel and then read the waveform with a PXIe-5122 oscilloscope. However, when I attempt to generate the waveform in a LabVIEW VI using the same csv file I get an error saying "File size is not a multiple of 8 bytes." I am trying to use the "niFgen Create Waveform From File (DBL)" vi to import the data from the file, is it because the data is not double-precision floating-point? If so how would I convert the data to that format? I'm not 100% clear on the differences. I have attached a screenshot of my VI and of a small portion of the data.

 

Edit: When I adjust the data to make the file a multiple of 8 bytes I then get the error "Requested waveform length is invalid, because the number of samples is not an integer multiple of the waveform length increment. Requested Value: 20315462 Waveform Length Increment: 4" 

NI 6008 USB with Debian Linux

August 13, 2020, 10:59 pm

≫ Next: Questions about Write to Binary File Function

≪ Previous: How to create arbitrary waveform with PXI-5412 Arbitrary Waveform Generator in LabVIEW VI?

$

0

0

Hi,

I was wondering if & how the NI 6008 USB device can be accessed with Linux Debian ?

On the support site there is a driver for other Linux distributions:

CentOS
RedHat
SUSE
Ubuntu

 

but not for DEBIAN

 

https://www.ni.com/cs-cz/support/downloads/drivers/download.ni-linux-device-drivers.html#350003

 

Best regards,

V. Alina

 

Questions about Write to Binary File Function

August 13, 2020, 11:18 pm

≫ Next: USB6216M - How stable ?

≪ Previous: NI 6008 USB with Debian Linux

$

0

0

I am trying to make some test programs.

One of them is to use the Write to Binary File Function to save 1-D data as shown below.

[1,1,1,1,2,2,2,2,3,3,3,3,1,1,1,1,2,2,2,2,3,3,3,3,3 ......]

However, after the contents of [1,1,1,1,1,1,1,1,1,1......] are first written in this file,
The contents of [1,1,1,1,2,2,2,2,1,1,1,1,2,2,2,2......] are written,
Finally [1,1,1,1,2,2,2,2,3,3,3,3,1,1,1,1,2,2,2,2,3,3,3,3 It should be written as .....].

 

The reason I try to write data this way is that the data I'm actually trying to use is much larger than that, and I can't load all of it into my RAM and process it.

 

Therefore, I want to refer to the byte index of the file and push the data after the offset.

Please comment on the above.

 

Thank you.

---

USB6216M - How stable ?

August 13, 2020, 11:28 pm

≫ Next: error loading niimaq.dll

≪ Previous: Questions about Write to Binary File Function

$

0

0

I have a application coming up and the hardware setup I have in mind is as follows :

 

Industrial PC / WIN 10 Pro / Intel i3 processor

USB6216M DAQ module 1 No.

USB6001 DAQ module 2 No 

( Being an Industrial PC, all DAQ hardware will directly plug into native USB ports and no Hub is involved )

 

The system will need to have about 12 Analog Inputs / 6 Analog Outputs / 10 Digital Inputs / 10 Digital outputs.

 

In terms of code complexity its a simple State Machine architecture and enough to run at about 50mS rate. ( 5khz with 250 samples ) 

 

Question :  Is the USB DAQ modules as listed above a reliable choice for this application ? I have read some articles where they mention about a not so stable performance for main line test stands which are 24/7.  But then they also talk about reasons as passive USB hubs and like. 

 

( Left to myself I would have gone with a PCI-6229 and PCI-6518 combo which are proven workhorses. But in this case we have the USB DAQ in stock and can thus save on a 3000 USD investment ) 

error loading niimaq.dll

August 14, 2020, 12:09 am

≫ Next: How to set number of lines in a string indicator

≪ Previous: USB6216M - How stable ?

$

0

0

"error loading niimaq.dll -a dll initialization routine failed". Does anyone have a solution? It was working perfectly until Windows 10Pro crashed and I had to rebuild. After the rebuild I keep getting this error. I have tried a repair of Imaqdx and Vision Acquisition Software using the NI Package Manager, but get the same result. I'm using the latest NI Dev Suite 2020: LabVIEW 2020 /Vision 2020 /VisionAcqSoftw 2020. The niimaqdx.dll files are present in Sys32 and SysWOW64.

How to set number of lines in a string indicator

August 14, 2020, 12:38 am

≫ Next: Certificates

≪ Previous: error loading niimaq.dll

$

0

0

Hello,

i am using a string indicator to log messages.

How can i set a number of maximal possible lines? In the attached example it logs forever.

How can i set that ist like a FIFO with 1000 lines?

Thanks

Certificates

August 14, 2020, 4:05 am

≫ Next: superimpose two waveforms into one signal

≪ Previous: How to set number of lines in a string indicator

$

0

0

Hello Sir, i am not able to access the certificate at NI LabView core 1,2,3 course. Let me know whats the problem.

 

superimpose two waveforms into one signal

August 14, 2020, 4:44 am

≫ Next: Publisher subscriber example

≪ Previous: Certificates

$

0

0

Hello,

 

I have a 50Hz voltage with harmonic content generated experimentally, i separated the signals using multiple tone vi, then for both signals I aligned them and resampled, so that they have the same phase. My question is, is it possible to 're-superimpose' my signals? By using building array I just get my separate waveforms into one chart, which is not the point. I would like my end signals to be one waveform consisting of my 50Hz and harmonics. Is it possible to do that?

The whole reason I am doing this alignment and resampling is because my real life waveform do not have an ideal shape (asymmetrical)- if anyone is interested or has an idea, i posted my question here:

 

https://forums.ni.com/t5/LabVIEW/voltage-waveform-changes-shape-with-time-despite-constant/td-p/4074929

 

Thanks in advance!

Jun