LabVIEW topics

When simulating a siganl, how do you make it continuous without it pulsing?

CJ-89 — Thu, 23 May 2013 11:21:49 GMT

As I increase the temperature I want the duty cycle to increase, which it does. However the simulated PWM signal pulses on and off instead of being a continuous wave. Why is this? And how can I change it?

Thanks

Chris

Cannot terminate LabVIEW application

Hemagopal — Thu, 23 May 2013 10:58:13 GMT

Hello

I am using LabVIEW drivers for Pickering precision resistor card to set the resistance programatically.

I have attached the VI. I am able to set the resistance and the program does not give any errors. I am able to close manually the front panel and block diagram of the VI.

But I cannot close LabVIEW after that. LabVIEW hangs.Please let me know what can be the reason for this.

Regards

Application builder problem

MarkoR — Thu, 23 May 2013 10:30:16 GMT

I am trying to create installer and I get this error message and compiling is unsuccessful:

______________________

Visit the Request Support page at ni.com/ask to learn more about resolving this problem. Use the following information as a reference:

CDK_Build_Invoke.vi.ProxyCaller >> CDK_Build_Invoke.vi >> CDK_Engine_Main.vi >> IB_MSI.lvclass:Build.vi >> IB_MSI.lvclass:Engine_InitializeDistribution.vi >> IB_MSI.lvclass:Report_Preview_Error.vi >> IB_Source_Container.lvclass:Report_Preview_Error.vi

Loading product deployment information

________________________

MAX doesn't find my USB-Scope

Jick — Thu, 23 May 2013 10:21:39 GMT

Cheers!

I am using Agilent DSO1014A USB-scope. If I switch my scope first on and then launch MAX it doesn't see my scope. Refresh doesn't help. Why?

Only way which helps is to launch MAX first then power on scope. That is when NI Signal Express lauches too. I would like to see my scope like other non-USB devices on the Devices and Interfaces list of MAX without restaring scope after MAX launch.

BR,

Jick

FTP & InternetTK folders when building exe

dan_u — Thu, 23 May 2013 10:00:33 GMT

I have an application in LV2012 SP1 that uses both FTP VIs and InternetTK VIs (from the deprecated Internet TK).

When I build the application to an executable, I end up with 2 directories next to the exe: NI_FTP and NI_InternetTK_Common_VIs. Both have 5 VIs with the same names in them (from their corresponding .lvlib, e.g. "Get Case Matching.vi" or "No Time Out Error.vi").

In LV2011 I didn't have any folders with VIs when building the same application.

Why do I get these 2 folders when building the executable in LV2012? Is there any way to have the application builder pack these VIs into the exe? I thought having 2 VIs with the same name in different lvlibs should not be a problem.

How to set the initial time interval of lines in HyperTrend control? Use " ViewMax" and "ViewMin"?

pkusp — Thu, 23 May 2013 09:56:22 GMT

I want to use "ViewMax" after reading the help file, but I can't input any data in "ViewMax" caontrol.

LV OOP - Plugin

Joachim082 — Thu, 23 May 2013 09:49:37 GMT

Hi,

I am trying to implement the plugin example with LV OOP. At the moment if I plugin the ppl in a new project and call an class I get the error 7 - Default Class Values - not found. From the development environment everything is ok - but a calling exe throws this error. I have also attached a screenshot of the calling of the ppl which is embedded in an exe.

Maybe somebody has an hint.

Best Regards,

Joachim

How to find the position of element of a matrix

marmotte — Thu, 23 May 2013 09:28:03 GMT

Hi,

I have a question to ask you.

I have a matrix N x M which contains a large number of zero. I wish to find the position of the element not equal to zero and to classify them in a table of two columns: line of the matrix and the column of the matrix. I do not need the value of the element.

Do you know how I have to proceed?

Thanks for help

Is it possible to decimate or divide down the internal clock PXI 5105

Heidar — Thu, 23 May 2013 07:47:25 GMT

Hi,

Is it possible to decimate or divide down the internal clock of a PXI 5105 ?

Thank you

Heidar

Lambda power supply+labview+current control

arihant — Thu, 23 May 2013 06:28:40 GMT

Hi there,

I want to control the output current from TDK lambda power supply based on input from a pressure sensor. Based on available drivers from Lambda site, I was only able to output certain current and voltage value. But don't know how to control it depending on other input like pressure reading.

Is there any way to do this in labview?

Thanks in advance.

Arihant.

case structure tunnels

Reserved — Thu, 23 May 2013 05:23:49 GMT

Hello all. I seek to populate a Case Structure with 10 cases having DAQ code, located within a While loop. A front panel numeric input establishes how many of the cases will be selected. That input is compared to the While loop index, and the While loop terminates when the loop index matches the number of cases to be selected. The loop index is also delivered to the Case Structure selection portal.

The use of the loop index allows the cases to be selected sequentially, which is what I seek. However, trying to pass the acquired data through Case tunnels to a Build Array outside the Case and Loop results in a broken arrow unless each Case data tunnel has the "Use Defaults if Unwired" selected. Accordingly, since "0" is the default value, every time the loop iterates, all outputs except one send "0" to the Build Array. The array contains the values of interest, with many "0's" interspersed.

After speaking with an Applications Engineer, I tried using a single tunnel in the Case structure, and wired that tunnel to a single element in a Build Array. I was told the output from the various cases would contatenate, and all the data would be available. Sadly, what happened was that the final data value was the only value in the array.

I tried other solutions without success. The broken arrow does not leave without choosing "Use Default..." I've attached a simple example of what I am trying to accomplish. Any suggestions, and thanks in advance for your help.

How to plot the Vibration data against speed

Suraaa — Thu, 23 May 2013 04:52:04 GMT

Hi,

Iam acquiring vibration data from accelero meter during run up condition. same time i am acquiring speed signal also.. i need to plot speed versus vibration level in xy graph... if anybody knows please help me...

Regards,

Vijay

Text Box Value Empty When Reading On LV2012 Development System But Not Production

GeoffF — Thu, 23 May 2013 04:36:16 GMT

Development Platform: 32-bit Windows 7, LV2012 Professional Development System.

Production Platforms: Windows XP.

We have a test application we've developed (in a hurry, I might add) that has a curious issue. As part of the setup for each test, we read a text box with a serial number entry and record it in the log files. Standard enough.

This works fine on the production machines - no apparent problems.

However, on the development machine, when I try to read the text box, all I get is an empty string. I've tried reading it directly from the terminal, as well as using a Value property box. Every time, there is nothing in the string. This is even if I'm looking at the text box and there's data visible in it.

I do clear the text box on several occasions, so I'm looking to see if one of those is occurring at the wrong time. And, indeed, I'm currently looking at a probe value of "" from the Value property node with the string "1234" visible in the text box while NONE of the clearing functions have been hit.

The test application uses a fairly standard user interface event loop model, with one event loop handling user inputs and the other event loop handling the business logic.

Does anybody have any idea what might cause this, or a better search string to find clues?

Thanks,

Geoff

Can anybody explain me the code attached please?what is its purpose?

ayesha_saha — Thu, 23 May 2013 04:33:24 GMT

The refrence icons used,i am not able to realize what is its functioning.kindly letme know.i am attaching the vi.

i have attached the picture in doc file which i want to learn.

kindly help!

read tdm fast

ZIMM — Thu, 23 May 2013 03:47:55 GMT

Hello,

I am trying to read some .tdm data files for a data review tool. My problem is that I find the Read Data Express VI from the storage/data plug in too slow.

I have tried converting these files to TDMS, again using the built in VI, and again very very slow, but the TDMS read function is quite quick in comparison.

Any functions i am missing that I can use to read TDM files faster? Or code snipets?

Thanks for your help!

How do I edit an xControl once it is placed in a vi?

Timmar — Thu, 23 May 2013 01:24:07 GMT

I am hoping that this is a beginners question:

I am evaluating the use of xContols in an application I am developing.

As soon as I place an xControl on a Front Panel, It locks the xControl so that I can no longer edit any of the properties.

Is there a button/menu option I can select to enable me to develop it's functionality?

I get this panel when I as "Why is this library locked" - and this is just on the Dual thermometer example!

At this stage, to edit the funtionality I have to remove the control from my test app, modify the xcontrol and then put it back in. - Not Cool!

Remove fade from tank indicator

KeenanJohnson — Thu, 23 May 2013 00:58:19 GMT

Hello everyone,

When you create a tank indicator or silver boolean, they are colored with a slight fade.

Does anyone know how to remove this?

Thanks.

Instrument reads slow when VI is open

lvuser333 — Thu, 23 May 2013 00:35:54 GMT

I have a top level VI, and in it a subVI where there is an instrument that is continously checking a folder for a text file to be created which tells the instrument to turn on or off. For some reason, the instrument recognizes the text file being created when the subVI is not open and I am only looking at the top level VI. However, if I have the code running with the subVI open, the instrument does not recognize the creation of the text file. Can someone please give me some insight into why they think this is happening. As a follow up, the instrument used to recongize the text file right away, but for some reason it takes 30 seconds or more to recognize it sometimes, and other times it recognizes it right away. The only thing I added in my code was global variables. I know this is a really vague question, but I am just looking for a little guidance

Thanks

labview modbus slave tcp/ip ability to handle multiple master?

Cemach — Thu, 23 May 2013 00:25:34 GMT

Hello,

I have to comunicate my computer (server pc), in slave tcp/ip modbus mode, with differents master in diferentes subnets, can i use a labview modbus library for this? labview modbus slave ability to handle multiple masters? I will use a router to subnetting a masters devices.

Any advice would be appreciated!

César
Lv 8,6
Win Server 2003

Digital Thermometer from One-Wire

augustg — Thu, 23 May 2013 00:18:00 GMT

Im using this device. DS18B20

http://www.pic_examples.byethost3.com/DS18B20.html

and I want to connect it to sbRIO. Since it is in digital, i'll need to connect it into digital input but how do I do that in FPGA?

I connected it into analog input and it gives me negative and positive value interchangeably