Local variable behaviour different with panel open?!

Am I going mad?!
We write to a local variable in a subVI, set it TRUE, but when the subVI completes, if the panel is open, it reverts to FALSE. If the panel is closed, it retains its TRUE value as set by the local variable.
The true terminal of the local variable is cased so that it may, or may not, ever be written to.
This behaviour is definitely different from LV5.1.1.
Bug or feature? Any workaround?
TIA
Tom

> Bug or feature? Any workaround?
>
Both.
Indicators that are on the connector pane of a subVI must always return
a value. Problem is that since the diagram can have case statements, it
is possible for the diagram to run and never write to the indicator.
This was deemed a bad thing and it was decided that these "conditional
indicators" should return a default value if they weren't written to.
This writing happens at the last minute, after the diagram completes.
Each conditional indicator has a flag in it that is cleared before the
subVI runs and is set when the indicator is written to. If still clear
at subVI completion, the default is written to the indicator. When
local variables were added, and later when multithreading was added,
there
were some bugs introduced and later fixed. I don't believe the
behavior should be different depending on whether the panel is open.
It would be best if you would email technical support and tell them the
version of LV you are using, list out the steps, and they can tell you
if the bug was already known about and which version it was fixed by.
In the meantime, I'd recommend taking the locals and indicators taken
out of the case statement. Wire a default value of the case statement
or through the case statement and to the terminal or local.
Greg McKaskle

Similar Messages

How to pass local variables between different sequence files?

Actually i want to pass the data (local variable) from my process model file to a client file. The client file only has the callbacks and those callbacks require some parameters as input which is available in local variables of my process model sequence file. I do not want to use Station Globals.
Please tell me any other way by which i can pass that data.

Which Locals do you want from the model. Every sequence has it's own Locals and there are a bunch of sequences in every process model. Do you want the entry point's Locals? A callback's Locals? Just one of the sequence's Locals? Some Models have way more entry points than others. What if your sequence file is ran with a different entry point?
One option is to create your own callback in the model and pass the data to it as parameters. Then add that callback to your client sequence file and get it out of the parameters.
If you simply want the entry point's locals and you are in your Main Sequence then you could use RunState.Caller.Locals.VariableName. This assumes you will use the same entry point every time you run that sequence file. Or assumes that every entry point you run has the same Local variable name.
Maybe there is an API method that exposes what you are looking for. What is your goal?
Regards,
jigg
CTA, CLA
teststandhelp.com
~Will work for kudos and/or BBQ~

Programmatically Open a Remote Front Panel with Panel Open Method

Hi,
I am trying to open the front panel of the VI on my cRIO-9024 through a remote computer. Currently, I am able to run the VI with no problems with the RUN VI method; however, when I try to open the front panel, I receive "Error 1043 - This property or method is not supported in this version of LabVIEW" or the Front Panel is simply not visible. My cRIO is configured to allow TCP/IP protocol, The VI is visible, and I have made my project into a source distribution on my cRIO.
Any help or suggestions regarding this problem would be great. I am very new to LabVIEW.
I have attached a screenshot of my block diagram and project.
Thanks,
Jake
Attachments:
Block_Diagram.PNG ‏12 KB

Project Img
Attachments:
MyProject.png ‏15 KB
MyProject.png ‏15 KB

What is the need to break a VI when a local variable in read mode is unconnected?

What's wrong with an unconnected "read" local variable?
A control terminal (or indicator terminal for that matter) can exist on the BD without issues!
Use case: When I create a new control, I may want to drop a few local variables in different cases of an event structure to be connected later.
If in addition, I am planning to create a few controls, to be used in several cases, this is quicker than dealing with each case one at a time.
I'll just grab the terminal, create a local variable for it, copy it and then paste it in all the cases I need it in.
Then repeat with another control and finally, deal with the bunch of local variables in each case later on.
I would like to be able to run the VI without having to treat all cases, which I can't right nowm because the VI is broken as long as there remains at least one unconnected "read" local variable.
Again, I cannot fathom why the compiler would be unhappy with a "read" local variable unconnected to anything. Generate a copy of the data if you wish, don't use it, that's all!
I can see the problem with a "write" local variable, although I would wish an unconnected "write" local variable would be simply ignored. And probably the same should be done with an unconnected local variable: no copy should be generated.
Of course, a warning would be useful.

Then put it on the IE (assuming it's not already there) and see how it fares. Personally, I think I prefer the current situation for safety (i.e don't forget to use the code you actually put in), but I wouldn't be terribly broken up if it behaved like you want.
Try to take over the world!

Local variables for clean code

A question of style and LV correctness:
I'm quite aware of the risks of these guys, but I see no option here. Right now I have a program with ~35 events in an event structure. I have a wire that contains many device settings that only 2 of these events can change. About 6 events in total require the use of the data on this wire.
Now, I see two choices:
1) I can use a shift register and drag the stupid wire across 35 frames and then remember to do it in any additional frames when I add more
2) I can use a local variable.
This seems much, much cleaner to me, and I see no better way of doing it. My question is, is there? I've looked up feedback nodes, but I think I can only use them in single event cases. Their data doesn't seem accessible beyond one event case. is there some better option? The data on the wire is an array of objects (classes), if that helps.

pobrepablo1 wrote:
Still though, I object on principle to having a wire across every one of my diagrams, it's cluttersome .
I thought of a compromise, how about I use a shift register but wire it around my event structure, through a case structure breaking the wire only when I need to? i.e. see attached
So a single thin 1D object across all event cases is more cluttersome than an additional external 2D case structure, partially wired extra tunnels, and all the extra convoluted logic holding it all together? You priorities seem to be biased.
A nice wire across all cases is much better. It can be read and written in any event case that needs to, and can always be found in exactly the expected location. Remember that a shift register is very efficient. If the data size does not change, it operates fully in place for the duration of the run. It also often contains data that is not directly of interest to the operator so it does not need a display. A local variable requires a front panel object that needs to be updated in the UI thread. In needs a data copy in memory memory for the control/indicator itself as well as another copy for the transfer buffer (because the FP update is asynchronous). Then we have a third copy in the wire itself. Than makes it three copies of your potentially large array. Add another copy for each local variable instance, and you probably end up using 10x more memory compared to a simple shift register. It all adds up!
Local variables can be placed anywhere and keeping track of them is like herding cats. The next programmer to work on your project will have a hard time tracking them all down. In properly designed code, it is just "follow the wire". Much more clear and almost self documenting.
LabVIEW Champion . Do more with less code and in less time .

Final attributes and local variables - performance ??

Hi all,
I and a colleague have done some performance testing regarding the use of final attributes and final local variables, e.g.
with final:
public class MyClass {
private final int i;
public final void myMethod() {
    final int j = 5;
    // do something with i and j
}vs. non-final:
public class MyClass {
private int i;
public final void myMethod() {
    int j = 5;
    // do something with i and j
}I couldn't find any speed differences in a small test program, but my colleague did so in his application. Who is right ??
Still, I will have do some formal testing next week and I will post the results.
I'd prefer the version using final anyway because I find it better readable, but the issue I am having is whether I'll spend 2-3 days going through the program making everything final or not.

I made some tests with final arguments to a method: I could not find any difference between final and non-final arguments. code is posted below
import java.io.*;
import java.net.*;
import java.rmi.*;
import java.util.*;
import javax.ejb.*;
import javax.naming.*;
import javax.rmi.PortableRemoteObject;
import junit.framework.*;
import junit.extensions.*;
public final class FinalVariablesTest extends TestCase /* from junit */ {
     * Constructors
    public FinalVariablesTest(String name) {
        super(name);
     * helper methods/classes
    protected void setUp() throws Exception {
        super.setUp();
    protected void tearDown() throws Exception {
        super.tearDown();
     * Test Suite
    public static void main(String[] args) {
     junit.textui.TestRunner.run(suite());
    public static Test suite() {
        return new TestSuite(FinalVariablesTest.class);
     * Test Cases
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     <p>
     Linux System:
     cat /proc/cpuinfo
     processor       : 0
     vendor_id       : GenuineIntel
     cpu family      : 6
     model           : 8
     model name      : Pentium III (Coppermine)
     stepping        : 1
     cpu MHz         : 501.146
     cache size      : 256 KB
     fdiv_bug        : no
     hlt_bug         : no
     sep_bug         : no
     f00f_bug        : no
     coma_bug        : no
     fpu             : yes
     fpu_exception   : yes
     cpuid level     : 2
     wp              : yes
     flags           : fpu vme de pse tsc msr pae mce cx8 sep mtrr pge mca cmov pat pse36 mmx fxsr xmm
     bogomips        : 999.42
     </pre>
     <p>
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     java version "1.4.0"
     Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.0-b92)
     Java HotSpot(TM) Client VM (build 1.4.0-b92, mixed mode)
     final     non-final
     498     500
     491     494
     491     493
     491     494
     534     494
     492     494
     491     494
     492     493
     491     494
     495     494
     4966     4944 (Totals)
     </pre>
    public final void testIntParametersToForLoop() {
     final int RUNS = 10;
     final int INNER = 1000000;
     final int OUTER = 10;
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     System.out.println("testIntParametersToForLoop");
     for(int i=0; i<RUNS; i++) {
         outerFinalIntParametersToForLoop(INNER, OUTER);
         outerNonFinalIntParametersToForLoop(INNER, OUTER);
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     long start0 = System.currentTimeMillis();
     for(int i=0; i<OUTER; i++) {
         innerFinalIntParametersToForLoop(INNER * i);
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     System.out.println("      final:       " +
                  ( end0 - start0 ) + " milliseconds");
    private final void outerNonFinalIntParametersToForLoop(final int INNER,
                                      final int OUTER) {
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     long start1 = System.currentTimeMillis();
     for(int i=0; i<OUTER; i++) {
         innerNonFinalIntParametersToForLoop(INNER * i);
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     System.out.println(" non final: " +
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         int testVar = i * INNER;
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Keeping at Least One Accordion Panel Open with Variable Heights

Hi -
Is there a way to keep at least one panel open when using {
useFixedPanelHeights: false }?
Here's an example:
http://labs.adobe.com/technologies/spry/samples/accordion/AccordionSample.html#VariablePan elHeights
If panel 4 is open, and you click the panel 4 heading, it
closes and no
panel is open.
Thanks,
Rod

Sorry, I didn't read my full message regarding wanting only
one panel to open.
What I ended up doing was using a PHP conditional to display
a message if a certain variable was not passed in the URL. See my
post on the Friends of Ed forum. Scroll to the bottom for my
solution.
http://friendsofed.infopop.net/4/OpenTopic?a=tpc&s=989094322&f=5283032876&m=3461018571

"Open with" panel items

How do I remove old applications that I no longer have on my Mac from the "Open with" panel the appears when you use the "Open with" command? For example I have Adobe Reader 9.3.4 installed but I'm also given a choice of 2 other Reader versions, in addition to 9.3.4

No. but you can remove duplicates by rebuilding the LaunchServices database with this one-line command run in the Terminal app. Restart after running it:
*/System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/LaunchS ervices.framework/Versions/A/Support/lsregister -kill -r -domain local -domain system -domain user*

Help with menus and variables in different classes.

1) how do I change variables in different classes? My situation..
I have a few tabbed panels/planes, that ask for different user inputs. I want the last tabbed panel/plane to have the inputs on 1 plane. Is that confusing?
Code:
        JTabbedPane tp = new JTabbedPane();
        tp.addTab ("Kitchen", new KitchenPanel());
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        tp.addTab ("Master Bedroom", new MasterBedPanel());
        tp.addTab ("Bedroom 1", new Bedroom1Panel());
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        tp.addTab ("Misc Use", new MiscPanel());
        tp.addTab ("Totals", new TotalsPanel());not the full thing obviously, but just so u see what im working with.
2) How do popup menus work? I have a menu (File -> About | File -> How to Contact)
I want The File->About menu item, to prompt a dialog
The File -> How to to prompt a dialog
Contact Menu(Not Item) to load a webpage
thanks again for the help, and i hope its not to confusing
Edited by: 2point2ek on May 25, 2009 9:51 PM

It's better to think in terms of transferring data between object, rather than between classes.
What you need is for the tab pane objects to have a reference to some common object to which the data is to be sent. This common object might be the total pane. It's generally better design to keep the data in separate objects from the presentation (in this case the totals pane), but at this stage that's probably just going to confuse you.
The simplest way to get this reference in is to the pane objects is as a constructor argument, which the constructor of your pane objects saves in a field. As you create each pane you pass it a reference and it stores that reference for when it needs to save data.
Then, when you click detect the action by which the user tells the program to store the data he's entered the pane class should call a method on the central data object, passing all the data from that pane. If there's a lot of it, wrap it up in an object (typically called a "data transfer object").
The central data object would be responsible for dealing with this data, amending totals etc.. It might delegate responsibility for updating the display to a separate total pane object.

How can I Change data in a type def control containing a Xcontrol with a local variable

Hello
I made a Xcontrol and I inserted this control in a type def.
When I want to change the control's data with a local variable in a VI, the VI change nothing. The change of data isn't perform
How can I correct this issue?
Thanks for your help
Solved!
Go to Solution.

Hello,
What's your LabVIEW version ? Do you have a simple example program which demonstrates this behavior ?
I found another discussions related to your issues with Xcontrols:
updating type defs in Xcontrol Facade
No Data Change event generated for a XControl in a Type Def
XControl facede.vi
Hope this helps.
Regards,
Steve M.
National Instruments France
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>> Vidéo-t'chats de l'été : présentations techniques et ingénieurs pour répondre à vos questions

How come my local variable is not updating it's value with respect to what's happening in the while loop?

Hello,
I am trying to extract data out of a while loop as my declarations update with respect to the iteration number. I have attempted to use both local variables and shift registers, but with no luck.
I have also done the following example: http://www.ni.com/white-paper/7585/en and it works like a charm.
I attached the PNG file with local variable declaration circled in red. Will attach a VI in the next respnose.
Thanks
Solved!
Go to Solution.
Attachments:
Local Variable.png ‏366 KB

OK, looking at the code...
Can you explain what it is supposed to do? What's the purpose of the value property node read which only seems to update an indicator.
The inner while loop should proably be a FOR loop, because the number of iterations is known before the loop starts.
Your use of formula nodes seems overly complicated.
LabVIEW Champion . Do more with less code and in less time .

Sampling local variable and synchronize with DAQmx

Hello,
I made a small change in the set-up I used with labview and now when I wanted to change the code I'm having a rather complicated problem.
In my old set-up I was measuring three variables: x and y with a QPD and the power of a laser with a power detector. I was using the DAQmx and I was getting a matrix with three columns with n (sample rate) values. Now, for various reasons I had to take out the second detector. So now I want to build the same matrix as constructed before, but instead of putting the measured values of the laser power I want to put the theoretical values (they are in a local variable) as I cannot measure them. The problem is that this local variable, in general, changes during the DAQmx acquisition time and I would need to sample it at the same rate as I acquire the data from DAQ and then combine all them. How I could sample this variable and attach it to my DAQ results? DAQmx doesn't accept local variables.
Thanks

A local variable is not something standalone. It is always associated with a control or indicator. Hows is it updated?
From your description, it is not clear what you are doing. Can you show us some code instead?
(Also be more clear when using acronyms. QPD cound mean many things)
LabVIEW Champion . Do more with less code and in less time .

Approval task SP09: Evaluation of approvalid failed with Exception: while trying to invoke the method java.lang.String.length() of an object loaded from local variable 'aValue'

Hi everyone,
I just installed SP09 and i was testing the solution. And I found a problem with the approvals tasks.
I configured a simple ROLE approval task for validate add event. And when the runtime executes the task, the dispatcher log shows a error:
ERROR: Evaluation of approvalid failed with Exception: while trying to invoke the method java.lang.String.length() of an object loaded from local variable 'aValue'
And the notifications configured on approval task does not start either.
The approval goes to the ToDO tab of the approver, but when approved, also the ROLE stays in "Pending" State.
I downgraded the Runtime components to SP08 to test, and the approvals tasks works correctly.
Has anyone passed trough this situation in SP09?
I think there is an issue with the runtime components delivered with this initial package of SP09.
Suggestions?

Hi Kelvin,2016081
The issue is caused by a program error in the Dispatcher component. A fix will be provided in Identity Management SP9 Patch 2 for the Runtime component. I expect the patch will be delivered within a week or two.
For more info about the issue and the patch please refer to SAPNote 2016081.
@Michael Penn - I might be able to assist if you provide the ticket number
Cheers,
Kristiyan
IdM Development

Get if local variable exist with teststand API

Hi,
attach you'll find a sequence file and a VI. This VI should open the Expression Browser and after selection a variable (in this case I select Locals.test) the property object exists should tell me if this local variable exists. This is part of a bigger VI in which help of TS 3.1 API functions I'd like to ensure that the programmer selects a local variable of the type we need (in our case it has to be an array of containers). Some idea to make this work?
thanks
Alex
Attachments:
edit.vi ‏60 KB
GetIfLocalVariableExists.seq ‏23 KB

Alejandro,
I am not sure what you are trying to accomplish.
Why do you want the user to select a specific property?
Could you describe your use case better?
Be aware that the expression browser returns an expression. The user could enter whatever expression he wants.
For your specific example if you select the "test" local variable, the lookup string would be "Locals.test".
Since you are checking if the property exists under Locals, it would return false all the time. If you want to check if the property exists under Locals your lookup string should be "test".
If you want to use "Locals.test" as the lookup string you will have to call 'Exists' on the sequence context.
SequenceContext.AsPropertyObject().Exists("Locals.test")
In order to verify the type of a property object you can use
PropertyObject.GetType() method.
Hope it helps
Antonio Lie.

How to set multple values in cluster with local variable?

Hello all,
Ok, I've made my way through Labview for everyone, and have some basic concepts down. I can see with a cluster, if acting directly upon it, you can unbundle, change values, rebundle, etc.
I'm trying something a bit more complex...and just not sure how to get started on this.
I have a drop down menu ring. I have set this up as a typedef, with 4 values. I have used this typedef 7 times, plus some LED bools, in a cluster. I have made this cluster a typedef.
So, in my main vi I"m starting to design, I've set up an example posted here....and in it, I have two instantiations of the cluster typedef, Left Selector and Right Selector.
I have dropped into this vi, a copy of the menu ring typedef (same typedef as in the clusters, same values)....called reset all tubes.
I'm trying now, to figure out how, with an event on the change of value for 'reset all tubes'....that I can start with the left selector, and change all the tubes (these are the menu ring selector) to the same value as what has been selected with the 'reset all tubes' menu ring.
I've created a local variable for the left selector. It is set to read values. (I'll be doing the same with the right one too, but just starting with the left).
In examples I've seen where directly accessing a cluster, you could unbundle the cluster...loop through and change the values...maybe pull out all of the 'tubes' into an array and move through that to update the values. And when you bundle or unbundle the cluster...you can see the values, etc, when you stretch them out on the block diagram.
With the local variable..I can't see to 'stretch' it out like I was expecting..so I can access the values for the 'tubes'...and set them all to the value of the 'reset all tubes' ring menu value.
Can someone put me on the path on the best way to do this....or is there a structure of component I'm missing here ? Am I on the right track to begin with here?
This would seem pretty basic to me, but I'm just missing something here on how to start...
Thank you in advance,
cayenne
Solved!
Go to Solution.
Attachments:
example_select_dropdown.ctl ‏5 KB
public_selector_cluster.ctl ‏6 KB
laptop_test_public.vi ‏12 KB

nathand wrote:
You can't do this with a for loop the way the cluster is structured, but why make it so complicated? Just bundle the new value into the cluster as shown below:
If you do want to use a for loop, consider restructuring your cluster. Group the ring and a boolean into a cluster, then drop 7 of those into the selector cluster. Then you can use "cluster to array" and "array to cluster" since all elements in the outer cluster will be of the same type.
Also, be careful using rings as type definitions. You probably want to use an enumeration instead. The items in a ring do not update when you update the type definition because they're considered to be cosmetic; the items in an enumeration type definition do update, because the items in an enumeration are considered part of the data type.
Oh my goodness!!
What was MUCH easier than I was trying to make it!!
I was attempting to do this reset, in an incremental fashion, as that later, I'm going to need to change values in this cluster by individual elements....and was using this as a way to try to understand how to iterate between cluster elements, and change the values of each one.
This solution works much better for this 'reset' all solution.
One question on this....with regard to the enum vs the ring menu.
I was actually going to go with the enum, however, I could not find a way to make it LOOK like the ring menu...with the arrow to the side that a user would know to click to present the menu list of choices.
I see with the enum, that you can remove the increment/decrement indicator.....and if the user clicks the control, it will indeed pop up a menu of choices...but there is no 'arrow' on that control to indicate to the user that it is a menu choice there.....
Is there a way to make and enum look like a ring with the "drop down menu" control look?
Again, thank you !!
This helps!
C

Local variable behaviour different with panel open?!

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