Does Labview have Try Catch exception handling?

1) Does Labview have Try Catch functions, exception handling?
2) Can Labview access a file or download a file using http or https?
3) How can labview read data from an ex ternal server http or https?
This is in labview 2009 or 2011

Hi E,
         1. you can chain together your VIs with the error wires, such that if an error occurs in one of them, none of the following VIs will execute. That's like throwing an exception - it interrupts the execution chain. You then "catch" that exception by putting an error handler wherever necessary, but not necessarily in every single VI.Hope You wouldn't put try..catch inside every single .NET function, instead you handle the exception at the level at which is most appropriate. Same thing can be done in LabVIEW.
Also see this.
2. The attached example downloads a picture with http "GET" command.
    Dilbert.Main_LV71.vi 160 KB
3.see this thread:
   http://forums.ni.com/t5/LabVIEW/Read-a-text-file-from-Labview-web-server-http/td-p/267434
Yes!!The same thing pointed out by nijims.
Thanks as kudos only

Similar Messages

Try catch exception handling

Hi there,
Was wondering if you could assist in me getting my head around try catch exception handling? I have this code:
JOptionPane.showMessageDialog(null, "A subject consists of term names and definitions.\nYou should indicate the size and name of the subject");
         inputSubName = JOptionPane.showInputDialog(null, "Enter the Subject Name:");
         inputSubSize = JOptionPane.showInputDialog(null, "Enter the Subject's Term Size:");
         try {
              size = Integer.parseInt(inputSubSize);
              catch (NumberFormatException e) {
                        JOptionPane.showMessageDialog(null, "'" + inputSubSize + " is invalid " + " Please enter digits only");
                        inputSubSize = JOptionPane.showInputDialog(null, "Enter the Subject's Term Size:");
                        size = Integer.parseInt(inputSubSize);
         //create a new Subject object and pass in its name and size
         Subject sub = new Subject(inputSubName, size);
...My query is, if I catch an exception, how do I get the code to repeat the try again until the user inputs a correct data type? If the user above inputs something other than a number, it will catch it once and repeat the joptionpane inputbox, but if they do the same thing twice round - then the program bombs out. Is there a way i can get the code to retry the try until they input correctly?
Cheers.

eg.
int size = 0;
while (true) {
     try {
          size = Integer.parseInt(inputSubSize);
          break;
     catch (NumberFormatException e) {
          JOptionPane.showMessageDialog(null, "'" + inputSubSize
                    + " is invalid " + " Please enter digits only");
          inputSubSize = JOptionPane.showInputDialog(null,
                    "Enter the Subject's Term Size:");
}

Does LabVIEW have support for entering Urdu language script?

Hi All!
My LabVIEW application requires users to enter their observations in a string control which is then stored in an excel file.
Now the issue is that the user wants to enter the data in Urdu language.
Now my question is, Does LabVIEW have support for entering Urdu language script in a string control?
If yes how can I implement this? If no, is there any possibility that National Instruments could extend some help in this regard upon request?
Regards,
Reeves

My experience from Hebrew, which is also right to left, is that it can be done if the operating system supports it, but it will work badly if you include anything in the text which is not an Urdu letter. This causes it to be displayed in the wrong side of the control and is only solved if you add more Urdu text after it.
One option you can try is including an ActiveX control (such as the rich text box) for editing the text and then you can probably get the text from it using a property. I don't remember trying it (my users don't usually need to input Hebrew text themselves), but I think it should work. I wouldn't have any hopes for NI doing anything about this, because it's considered to be a relatively small market.
Try to take over the world!

Does LabVIEW have any kind of source control?

I want to use a source control tool such as git and svn.
Does LabVIEW have such a tool?

Hi icat,
            Yes.See these: (Sorry as GerdW pointed out not embedded in.)
            https://decibel.ni.com/content/docs/DOC-1681
            http://zone.ni.com/reference/en-XX/help/371361D-01/lvhowto/configuring_scc/
Thanks as kudos only

Can we have try/catch in a static block in a class?

hi All
i have a question about put a try/catch block in a static block in a class to catch exceptions that maybe thrown from using System.xxxx(). in my custom class, i have a static block to initialize some variables using System.xxx(). in case of any error/exception, i need to be able to catch it and let the caller know about it. i tried to put a try/catch block in the static block, and tried to rethrow the exception. but it is not allowed, how would i handle situation like this? thanks for your help and advise in advance.

You could just swallow the exception inside try/catch
block, and instead of throwing it out, just set a
static variable to allow checking from outside
whether the initialization succeeded, or check within
the constructor / methods of this class for
successful initialization, and throw the exception
then. You could even save that exception in a static
variable for later.Ouch, ouch, you're hurting my brain. This would allow someone to ignore a (presumably) fatal error. Throw a RuntimeException as indicated. You can wrap a checked exception in an unchecked one if need be.

Doubt on try/catch exception object

why it is not advisable to catch type exception in try catch block. Its confusing me. If i catch exception object then it will show whatever exception occured.
btw, i was just go through duke stars how it works and saw this
http://developers.sun.com/forums/top_10.jsp
Congrats!

Because there are many different kinds of Exception. If you have some specific local strategy for dealing with a particular excepion then you should be using a specific catch block.
If you don't then you should allow the expection to end the program, and ideally you should deal with all the expceptions in one top-level handler, so you should throw, rather than catch the exceptions in your methods. Often at the outer most level of the program or thread you will actually catch Throwable (not just Exception) to deal with any unanticipated problems in a general kind of way.
Also, you should be keeping track of what exceptions might be thrown, so that rather than using Exception in a throws clause or catch block, you should use the particular exceptions. Exceptions, generally, indicate a recoverable error that you really ought to be recovering from rather than just printing a stacktrace.
That's why exceptions are treated differently from runtime errors.

IDocumentQuery.Execute() method throws user does not have edit permissions exception

I'm trying to query a document folder for all of its containing documents. Its a basic query like this:
IPortletContext PortletContext = PortletContextFactory.CreatePortletContext(Request,Response);IRemoteSession PTSession;PTSession = PortletContext.GetRemotePortalSession();IDocumentManager documentManager = PTSession.GetDocumentManager();
IDocumentQuery documentQuery = documentManager.CreateQuery(FolderID); documentQuery.SetSortProperty(ObjectProperty.Name);IObjectQuery queryResults = documentQuery.Execute();
When I'm logged into the portal as an administrator, everything works fine. However if I'm logged in as a "regular" user, I get this exception when calling the Execute() method:
Plumtree.Remote.PRC.PortalException: Exception of type Plumtree.Remote.PRC.PortalException was thrown. ---> System.Web.Services.Protocols.SoapException: Server was unable to process request. --> Access denied: Current user does not have edit permission
I'm sending the Login Token to the portlet. Now I've tried giving the user Edit rights on the document folder as well as Edit the Knowledge Directory rights in the Activity Manager, but neither gets rid of the exception. I'm not sure what other "Edit" permissions to check. I don't even see why the user would need "Edit" permission to anything in the first place since the Execute() method simply returns an IObjectQuery that doesn't have any ability to make changes to any objects. I know that I could use the SearchFactory interface, but I wanted the results to be real time. Any help would be much appreciated. Thanks!
Jimmy

The problem here is that the query is created with default settings to show unapproved documents -- only users with edit access can see unapproved documents. Add the bold line to your code and it will work.
IDocumentManager docManager = prcSession.GetDocumentManager();IDocumentQuery docQuery = docManager.CreateQuery(iFolderID);docQuery.SetShowUnapproved(false);IObjectQuery queryResults = docQuery.Execute()

Problem with a Try/catch exception

Hello everyone here on the forums. I'm brand new to Java and have a bit of a problem with a try catch statement I'm making. In the following code if a user enters a non-integer number the program will display "Sorry, incompatible data." Problem is it gets caught in a loop and continues to display "Sorry, incompatible data." My aim with the try catch was if the user is not quite smart enough to understand quadratic programs don't use symbols and characters it would state it isn't correct and continue running the program.
Heres my code thus far:
package finishedquadraticprogram;
import java.util.*;
* @author Matt
public class quad {
     * @param args the command line arguments
    public static void main(String[] args) {
        boolean verification = true;
        double a, b, c, root1, root2, discriminant;
        Scanner keyInput = new Scanner(System.in);
        while ( verification)
        try
        System.out.println("a: ");
        a = keyInput.nextDouble();
        System.out.println("b: ");
        b = keyInput.nextDouble();
        System.out.println("c: ");
        c = keyInput.nextDouble();
        discriminant = Math.sqrt(b * b - 4 * a * c);
        root1 = (-b + discriminant) / 2 * a;
        root2 = (-b - discriminant) / 2 * a;
        verification = false;
        System.out.println("Root 1 = " +root1+ "\nRoot 2 = " +root2);
        } //try
        catch (InputMismatchException iMe)
          System.out.println( "Sorry. incompatible data." );
}I'm pretty sure the problem is something to do with the keyboard buffer, but I'm not sure what I need to do to either reset it or clear it, whichever one works. (Oh, and how would I go about making the program use complex numbers? I realize Java can't use complex numbers and will just display NaN ... any ideas how to make this work?)
Thanks a lot for all of your help guys, it's appreciated.

this is better:
package finishedquadraticprogram;
import java.util.*;
/** @author Matt */
public class quad
   private static final double TOLERANCE = 1.0e-9;
   /** @param args the command line arguments */
   public static void main(String[] args)
      boolean verification = true;
      double a, b, c, root1, root2, discriminant;
      Scanner keyInput = new Scanner(System.in);
      while (verification)
         try
            System.out.println("a: ");
            a = keyInput.nextDouble();
            System.out.println("b: ");
            b = keyInput.nextDouble();
            System.out.println("c: ");
            c = keyInput.nextDouble();
            discriminant = Math.sqrt(b * b - 4 * a * c);
            if (Math.abs(a) < TOLERANCE)
               root1 = 0.0;
               root2 = -c/b;
            else
               root1 = (-b + discriminant) / (2 * a);
               root2 = (-b - discriminant) / (2 * a);
            verification = false;
            System.out.println("Root 1 = " + root1 + "\nRoot 2 = " + root2);
         } //try
         catch (InputMismatchException iMe)
            System.out.println("Sorry. incompatible data.");
            keyInput.next();
}

Try catch exceptions

I got this:public void fileIO() {
        try {
            File file = new File("aNewFile.txt");
            System.out.println(file.exists());
        } catch (IOException ioe) {
            System.out.println("IOException");
    }which tells me : exception java.io.IOException is never thrown in body of corresponding try statement, if I change the catch to } catch (Exception ioe) {, the error goes away.
My question is why is it giving the error and why is it not giving the error after changing the catch line ?

Read the API!!!!!!!!!
new File(String) may through a NullPointerException
and
file.exists() may through a SecurityException
Neither of those are based on an IOException, hence the error message when you use IOException.
All exceptions are based (somewhere down the line) on Exception, hence no error when you use Exception.

Does labview have a 2D FP high/low pass filter?

After digging through labview for quite a while, and then trying Google I'm starting to think there really is no floating point filter functions in labview for 2D arrays? I tried the IMAQ kit, but even after all the frustration involved in actually getting an array into an "image" it doesn't seem to support floating point (at least as far as I can tell).
Am I missing something or does this really not exist in labview?

Hi, Am not sure whether i understood your question. what does this floating point filter functions means? Have a look that attachment. Different kinds of filters are there in LabVIEW and it accepts floating point input. If you want to pass 2D input pass it thru for loop.
Hope this helps you.
Attachments:
f1.JPG ‏137 KB
f2.JPG ‏150 KB

Does Labview have a Random Number Generator for U16 with a periodicity greater than 64 Million instances of U16words and one with SEED as the connector?

We are doing some testing that requires 64MegaWords be written to our DSP memory with random values to do a validity check and without repeating sequences with using the previous value as the seed for the next and us passing it the initial seed. The dice one doesn't meet that criteria, and I was not sure how the continuous random number generator parameters work and if any of them would meet this criteria. Anyone have any information that might help?
Thanks,
Sue

Hi suem,
There is no reason why you couldn't simply write a pseudo-random number generator by yourself. Simply select a random number algorithm you want to use and implement it in LabVIEW. You do not need to interface code written in another language in order to implement a pseudorandom number generator. If you have a DAQ card or something, you can also use inputr noise or some other hardware soruce to generate real random numbers. For that also LabVIEW is an excellent tool.
Tomi
Tomi Maila

Does Labview have function Mod() ?

Hello, everyone,
I am trying to parse an array only for all its odd/even number elements.
I am thinking of use Mod function upon 'iteration' but labview seems have
nothing there.
Does anyone know something about that?
Thanks in advance,
-Kunsheng
Solved!
Go to Solution.

Stu Turner wrote:
I found my way to this page because I was looking for a modulus function in the mathematical sense, i.e. In mathematics, the absolute value (or modulus) | a | of a real number is the numerical value of a without regard to its sign.
Interesting. I never heard absolute value be called modulus before. I just hit wikipedia to check. In every sense I've heard of modulus (including a few math and cryptography classes), it is remainder (http://en.wikipedia.org/wiki/Modular_arithmetic).
There are only two ways to tell somebody thanks: Kudos and Marked Solutions
Unofficial Forum Rules and Guidelines

Does labVIEW have a function to solve the following math problem?

In Labview what is the easiest way to solve the following problem?
|----             ---|  -1       |--     ---|                |--       --|
| 1   1   0       |            |   a     |                |    x     |
| 1   0   1       |            |   b     |     =         |    y     |
|  0   1   1       |            |   c     |                |    z     |
|__             __|            |_       _|                |_       _|
from the equations:
     a = x + y
     b = x + z
     c = y + z         where a, b, c are know values.    The problem I actually have is a system of 9 equations.
Thank you.

You have a known matrix, a known vector, and a vector you need to solve for given the equation Ax = b. This is exactly the problem this VI is designed to solve:
With the values I made up for a, b, and c, the solution is [2, 3, 4].
Chris M

Does LabVIEW have USB Support?

Can I read/write to a USB port using LabVIEW?

Hi
USB is a bus. You cannot write/read to/from the PCI bus through LV, and the same is with USB. There are no read/write VI's. It's not to compare with RS232, where you have read/write VI's in LV.
Check this link for further informations:
http://digital.ni.com/public.nsf/websearch/42B604435E3F9604862565E20043CD30?OpenDocument
Regards,
Luca

Does LabVIEW have CCITT filter?

Hi
I'm writing a program need CCITT filter. I have sound and vibration toolkit but it doesn't have CCITT filter. Are there anyone tried to use or implement it in LabVIEW?
Bill.

Bill,
You may be interested in this discussion; If I'm not mistaken a psophometric filter is the same as the CCITT filter.
It comes down to having the correct shape of the filter and apply it to the FFT data.
Hope this helps.
Regards,
Juan Carlos
N.I.

Does Labview have Try Catch exception handling?

Similar Messages

Maybe you are looking for