Convert local variable to global - labView

I have a sequence with a VI that contains a local variable array. Now I need that data saved for use by a VI in a later sequence. Can locals be converted to globals or must it be re-created and all references to it changed?
Thanks,
jvh

Hi,
If you are using the SequenceContext as the reference, then your lookup string to your variable would need to change.
eg "Locals.MyArray" would become "StationGlobals.MyArray"
Does this help
Regards
Ray Farmer
Regards
Ray Farmer

Similar Messages

Local Variables Versus Global Variables

DATA A TYPE I VALUE 100.
PERFORM PRINT_DATA.
FORM PRINT_DATA.
           DATA A(10) TYPE C 'HELLO'.
           WRITE / A. "Wanted to Print 100 (Global)
           WRITE / A. "Wanted to Print 'HELLO'(Local)
ENDFORM.
Note : Both the times, the Local Variable 'A' is Printed .
?Is there any way to   Differentiate the Local and Global Variables When the Names Are Same.*
*It Might be Possible in Object Oriented But I am Looking for the Same in FORMs.

Hello Gagan,
You want to print the Global as well as the local values of the variable named "A". Here are a couple of approaches:
1.The 'Subroutines' are part of the modularization techniques. There are certain keywords like "using" & "Changing" so that you can work by passing Values.
2. There is a keyword named "LOCAL". Declare data object with the keyword "LOCAL" and then try the 'write" statement. I suppose this should work for you.
Let me know if any one of the above works or if you need more help.
Best Regards,
Chaitanya

How to assign local variable to global variable dynamically in adobe livecycle designer 7.1

Hi All,
i want to assign my textfield value to global variable dynamically.so that where ever i want , i will access my global variable.so it is possible in adobe livecycle designer 7.1. kindly suggest me method.Thanks in advance.
Thanks & Regards
Ganesh

Please remove all adobe livecycle designer versions from your local pc.
restart your pc to be sure, that all temp data is deleted.
download the newest ald version from service.sap.com and install it.
have fun with developing adobe forms with sap transaction sfp.

Using local variables or global attributes

it's been five years now since I learned programming.
But I still have a pretty basic question that isn't answerred yet ...
I'll try to explain it with an example
     //*attributes*
     private int a, b, c;
     private int result
     a =1;
     b =2;
     c=3;
     //first option
     calculate1();
     System.out.println("the result is : " + result);
     //second option
     calculate2(a,b,c);
     System.out.println("the result is : " + result);
     //third option
     result = calculate3();
     System.out.println("the result is : " + result);
     //fourth option
     result = calculate4(a,b,c);
     System.out.println("the result is : " + result);
     private void calculate1(){
          result = a+b+c;
     private void calculate2(int a, int b, int c){
          result = a + b + c;
     private int calculate3(){
          return a+b+c;
     private int calculate4(int a, int b, int c){
          return a+ b + c;
     }what's the best, and why?

Regarding performance:
I tested your example with the code below. I run every test case 10 times: These are the results:
calculate1 = 7567 ms
calculate2 = 8046 ms
calculate3 = 7609 ms
calculate4 = 8047 ms
So, the variants with method parameters are slower. That’s clear, because we have to push and pop the variables to/from stack. I think the ‘huge’ difference between calculate1 and calculate2 results from the unpurified test (Garbage Collector activities, System activities, …).
Regarding style:
It’s up to you, if you like to use your attributes directly or method parameters. That’s OOP :)
As far as I’m concerned:
Your attributes are private. So, within an object I would try to use the attributes directly as often as possible. That’s the reason why I would use calculate1.
Cheers,
Chris
public class TestMe {
     private int a = 1, b = 2, c = 3;
     private int result;
     private int n = 1000000000;
     public void testCalculate1() {
          long t0 = System.currentTimeMillis();
          for (int i = 0; i < n; i++) {
               calculate1();
          long t1 = System.currentTimeMillis();
          System.out.println((t1 - t0));
     public void testCalculate2() {
          long t0 = System.currentTimeMillis();
          for (int i = 0; i < n; i++) {
               calculate2(a, b, c);
          long t1 = System.currentTimeMillis();
          System.out.println(t1 - t0);
     public void testCalculate3() {
          long t0 = System.currentTimeMillis();
          for (int i = 0; i < n; i++) {
               result = calculate3();
          long t1 = System.currentTimeMillis();
          System.out.println(t1 - t0);
     public void testCalculate4() {
          long t0 = System.currentTimeMillis();
          for (int i = 0; i < n; i++) {
               result = calculate4(a, b, c);
          long t1 = System.currentTimeMillis();
          System.out.println(t1 - t0);
     private void calculate1() {
          result = a + b + c;
     private void calculate2(int a, int b, int c) {
          result = a + b + c;
     private int calculate3() {
          return a + b + c;
     private int calculate4(int a, int b, int c) {
          return a + b + c;
     public static void main(String args[]) {
          TestMe t = new TestMe();
          // t.testCalculateX();
}

Store Counter Number in BODS using Global/Local Variable

Hi All,
Anyone done before adding a counter integer field into a table based on key via BODS?
Example:
Table 1 (contains just 1 field) <-Input:
Key 1
Key 1
Key 2
Key 2
Key 2
Table 2(contains 2 fields with INT as the 2nd field) <-Output:
Key 1      1
Key 1      2
Key 2      1
Key 2      2
Key 2      3
I was wondering if populating the Local Variable or Global Variable might work but from my understanding, inside the Data Flow , it's not possible to increase the variable value ($count = $count + 1).

Hi Maurice,
Thats a good idea!!
I had currently implemented a solution where i use Variables and Customize Functions to solve the problem.
Will give a try and see if your solution produce the same result.
Tim

Labview FPGA: Why not have local variable without indicator?

In Labview FPGA, to transfer data among parallel loops, there are three ways or maybe more, local variable, global variable and block memory. The problem with local variable is that it needs an indicator along with, not like global variable. I was thinking why Labview doesn't make a kind of local variable not need indicator? I guess local variable itself doesn't cost resource much compared to global variable, however when it comes into indicator, it will cost more. Just an idea, though. I guess there is a reason NI doesn't do that.

As in Labview document, global variable can be used for transfer data among VIs, which local variable isn't capable of.
Global variable is not always a better solution. From my experience, it is still unclear among different compilations using local vs global in terms of resources. A thread here http://forums.ni.com/t5/LabVIEW/FPGA-global-variables-vs-front-panel-items/td-p/1407282 talks about that too.
Stephen, is there any documents say that global makes timing worse? I didn't see this noticeable.

LabVIEW 2010 local variable behavior

Hi -
I upgraded to LabVIEW 2010 from 2009SP1 and the attached sub VI no longer works correctly. This is a state machine case structure that gets called inside a loop. I'm setting a Boolean local variable true, then on the next call when the case changes the variable has been reset to false. It did not do this in LV2009.
Someone will immediately tell me I have a race condition, but these local variables are not being written anyplace else, just within these separate cases.
See the attached code, specifically, the local variable "Enable" is getting reset when going from case "Enable" to case "Turn on".
Anyone else seen this issue, or can shed any light?
I fixed the VI by writing the value in each case, but this different behavior makes me wonder what other issues are lurking in LV2010?
Thanks
Solved!
Go to Solution.
Attachments:
eq99_cycling.vi ‏42 KB

This code looks more like some sort of an Action Engine than a state machine, but not quite. It gets called repeatedly from a state machine, and it decides what the next state will be depending upon the inputs. Instead of using all those local variables, I would use uninitialized shift registers (nothing wired to the left side). They hold their value from one call to the next. One more case needs to be added in this case. An unnamed, default case that would set the initial values of all the shift registers. Make it the default case and don't even name it. It will be called first automatically because the shift register is uninitialized so the default will be called. Inside the default case, set all the shift registers to desired values. Next time this subvi is called, those values will still be there. That is as long as nothing is wired on the left side, Whatever is wired to the state shift register will be the next case called.
See attached vi. It is broken because I did not wire anything to the indicators.
- tbob
Inventor of the WORM Global
Attachments:
eq99_cycling-4[2].vi ‏33 KB

Global, local variables in SubVI's

Hi,
I'm having a problem with what is probably a 'feature' of labview
(using ver 6.1).
When running multiple SubVI's of the same type, any local variables
declared within the SubVI are globally scoped across all instances of
that SubVI within one VI. Is there any way to prevent this?
I am trying to store the Status of the SubVI in a local, but obviously
each instance of the SubVI ends up with the same status. Currently i
have solved this by having exact copies of the SubVI for each
instance, but obviuosly as far as labview is concerned they are now
different SubVI's, i consider this a bit of a hack and would rather
avoid it.
Any pointers?
Many Thanks,
Ed

If you make the sub-VI reentrant, you will get the type of local you're looking for. On the sub-VI's menus, goto File >> VI Properties >> Category >> Execution >> Reentrant Execution.

How can I use local variable in LabVIEW-Action?

Hi All!
There is local variable (for example "MyVariable") in local scope of project. There is Action-step, created by LabVIEW. One of input terminals step is "Sequence Context".
How can I access to MyVariable by Sequence Context? Unbundle? It does't work.
Thank you.

On the TestStand palette there is a VI called TestStand - Get Property Value.vi. Use that. Attached is an image showing how to use it. The trick is making it produce the correct data type. Do that by right clicking on the VI and selecting Select Type. Then you can choose the type. I think in LV 2010 and TS 2010 it is a polymorphic VI and you can just change it. I wrote an example here for Chaz: http://forums.ni.com/t5/NI-TestStand/How-to-execute-two-steps-in-parallel/td-p/1449874
It's the second example that's attached.
Hope this helps,
jigg
CTA, CLA
teststandhelp.com
~Will work for kudos and/or BBQ~
Attachments:
AccessLocalVar.JPG ‏67 KB

Having Trouble Copy and Pasteing Local Variable in LabVIEW 2010

I am Having Trouble Copy and Pasteing Local Variable in LabVIEW 2010 in s subVI.
I have a VI that has a Local Variable called "Node Addr". I can select it OK, and it appears to Copy OK, But when I go to paste it, nothing appears. It doesn't matter if I use Cntrl-C Cntrl-V or the Copy and Paste from the Edit menu, I get the same results. I tried many times and got the same results. I made sure that I had click a paste location. I can insert the Local Variable if I use the Data Communication panel.
On one of the Paste, I got an error in the error list that said that a Local Variable was not connected to anything. When I clicked on the error, it took me to an insible item in the lower right corner of the block diagram that had nothing but a select box around it. I couldn't select the invisible item, but I could delete it.
Why does the copy and paste of this local variable not work?
Why does the paste cause the insertion of an invisible item?

dbaechtel wrote:
My VI is fairly complicated. In several places in the VI, I am either reading or writing to this variable which is an numeric Indicator on the Front Panel. Using local variables seems to be the best way to handle this situation rather that using wiring all over the VI. Since the VI is mainly a State Machine and there are only 2 Writes to the local variable, I am not afraid of race conditions in this case. NO!! While you may think that using Locals is your solution to wiring, it is not! The fact that you are writing and reading, most likely from several places, will most definitely contribute to a race condition. Depending on your implemetation, you should ALWAYS use wires. The wires are the variable. If you are using a loop (While, For), then using shift registers are appropriate means for routing values so that they are used by other sections of the code, later. One thing you must respect with LabVIEW is the dataflow. That's where Locals often fail.
I am not copying the Local Variable from one VI to another.
I am not copying the Local Variable from one VI to another.
The Data Communication panel is one of the panels that shows up in the Functions pop up list when editing the Block Diagram. It is the panel that includes the Local Variable function.
I don't know if the invisible item that was inserted in my block diagram was hidden or not. All I know is that the Errors List said that it was a Local Variable and that it was not connected to anything. I couldn't select it to get more information. All I could do was delete it.
You did not address my questions about why the Copy and Paste does not work properly for my Local Variable. Maybe it's a sign from the Software Gods not to use them LOL!..
So if I understand correctly, you are trying to copy & paste the Local Variable from within the same VI. How large is your block diagram? Did you try right-click on the variable and select "Find > Local Variables"? If it's a block diagram larger than 1 single screen (which it shouldn't), then it is possible that the Local is hiding beyond the screen. You should find it as I described earlier.
See my comments in red above.

Create local variable using labview scripting

I am trying to use labview scripting to create a control and a local variable for that control. I want both the local variable and the control contained inside a case structure. My problems are twofold:
1. the local variable is left blank/unnamed
2. the local variable is wired outside of the case structure, even though I set it's owner to be the same as the owner for the control (which is placed inside the case structure).
The flat panel is there because I thought that my problem might be a result of the local var being created before the actual control, so this just forces the control to be created first. The other thing I wonder about is the VI Object Class for the local variable. I have tried 'Node' and Control->Boolean, but neither worked.
I have attached a jpg of the code I'm talking about. The picture on thetop is of the code in question. The picture on the bottom is of the resulting code that's created....
Can anyone offer any help?
Thank you...
Attachments:
vi_scripting_lv.png ‏95 KB

The reason your locals aren't tied to a control, is because you didn't make a local variable from any control. Use the Boolean reference wire and wire it to an Invoke Node and select the Create >> Local Variable method.
Unofficial Forum Rules and Guidelines - Hooovahh - LabVIEW Overlord
If 10 out of 10 experts in any field say something is bad, you should probably take their opinion seriously.

How to: Transform Activity: Read global/local variable, execute java code

Could anyone please show me how to do that???

could you please elaborate your usecase? yes you can read global variable using getVariableData( ) xpath function and pass them as an argument to the processXSLT ( ) xpath function.
You can read the global or local variables inside java exec using, please refer samples/references/javaexec sample.

Is This a Global Versus Local Variable Problem?

I intend to use a variable (myselector) with a text value (e.g. roses, Big Sur, Pacific Grove, night, etc.) for the sort criteria of my photography list. Selection of a tab from a Tabbed Panel will appropriately define the variable and the selected thumbnails will display in the Content Panel.
The variable "myselector" is defined in the head section; a function for each tab of the Tabbed Panel will redefine the variable per the selected tab. Within the function, I am not using "var" to call the variable. Though the variable "myselector" should be global, the changes to its value are discarded when the function closes. This indicates that it is functioning like a local variable in the function. After a bit of reading, I've not found the cause of the global/local discrepancy or a fix for it.
Diagnosis History - I generated a simplified code. Variable "myselector" is defined as "abcd"; function "myfilter" is called by onclick of the text "button" and changes "myselector" to "efgh". At the end of the file, I used "document.write (myselector) to output the "myselector" value. The script follows.
The end value of "myselector" does not change. However, when I add "document.write (myselector)" to the function, then the changed value is displayed.
I ask someone to explain what I am doing incorrectly or, at least, guide me to a solution. I thank you for your assistance.
Scott
<script type="text/javascript">
var myselector="abcd";
function MM_callJS(jsStr) { //v2.0
return eval(jsStr)
</script>
</head>
<body>
<div id=text>
<p onclick="MM_callJS('myfilter();')">Button</p>
<script type="text/javascript">
function myfilter() {myselector="efgh"; }
</script>
<script type="text/javascript">
document.write (myselector);
</script>
</div>

Dear Ben:
I thank youfor your patience. This includes the script using Insert - Syntax Highlighting - Java.
The coding needs a lot of clean up but I want it to work, first.
Scott
<script src="SpryAssets/xpath.js" type="text/javascript"></script>
<script src="SpryAssets/SpryData.js" type="text/javascript"></script>
<script src="SpryAssets/SpryTabbedPanels.js" type="text/javascript"></script>
<script type="text/javascript">
var dsphotodata = new Spry.Data.XMLDataSet("EM_photo.xml", "/gallery");
</script>
<script type = "text/javascript">
function MM_callJS(jsStr) { //v2.0
return eval(jsStr)
</script>
<script type="text/javascript">
var dsphoto = new Spry.Data.XMLDataSet("EM_photo.xml", "/gallery/photos/photo");
dsphoto.filter(subjectfilter);
var myselector;
</script>
<link href="SpryAssets/SpryTabbedPanels.css" rel="stylesheet" type="text/css" />
</head>
<body>
This is a test of Scott's efforts to program his website.
<br />
<br />
<div id="TabbedPanels1" class="TabbedPanels">
<ul class="TabbedPanelsTabGroup">
    <li class="TabbedPanelsTab" tabindex="0" onclick="MM_callJS('{myselector=\'animal\'}; subjectfilter(); dsphoto.filter(subjectfilter); ')">Tab 1</li>
    <li class="TabbedPanelsTab" tabindex="0" onfocus="MM_callJS('myselector=\"pgbeach\" subjectfilter(); dsphoto.filter(subjectfilter); ')">Tab 2</li>
    <li class="TabbedPanelsTab" tabindex="0">Blank</li>
</ul>
<div class="TabbedPanelsContentGroup">
    <div class="TabbedPanelsContent" >Content 1
      <br />
<br />
<script> {document.write (myselector)} </script>
      <br />
      <div spry:region="dsphoto dsphotodata"> <img src="{dsphotodata::thumbnail/@base}{@thumbpath}" width = {@thumbwidth}px height = {@thumbheight}px spry:repeat="dsphoto" onclick="dsphoto.setCurrentRow('{ds_RowID}');" /></div>
    </div>
    <div class="TabbedPanelsContent">Content 2
      <script> {document.write (myselector)} </script>
      <br />
      <div spry:region="dsphoto dsphotodata"> <img src="{dsphotodata::thumbnail/@base}{@thumbpath}" width = {@thumbwidth}px height = {@thumbheight}px spry:repeat="dsphoto" onclick="dsphoto.setCurrentRow('{ds_RowID}');" /></div>
    </div>
    <div class="TabbedPanelsContent">Content 3 <script> {document.write (myselector)} </script><br />
<div spry:region="dsphoto dsphotodata"> <img src="{dsphotodata::thumbnail/@base}{@thumbpath}" width = {@thumbwidth}px height = {@thumbheight}px spry:repeat="dsphoto" onclick="dsphoto.setCurrentRow('{ds_RowID}');" /></div>
</div>
</div>
</div>
<div id="Selected_Photo" spry:detailregion = "dsphoto dsphotodata" >
<img src="Photo-Thumbnails/{@thumbpath}" width = {@thumbwidth}px height = {@thumbheight}px /><br />
<img src="Photo-Email/{@path}" width = {@width}px height = {@height}px />
</div>
<script type="text/javascript">
var subjectfilter = function(dataSet, row, rowNumber, criteria) { if (row["@subject"].search (myselector) != -1) return row; return null; };

</script>

Shall I use global or local variables for my program?

Hello,
1) I am using 2 while loops in parallele. One 50 ms timed and the other one 1000 ms. The 50 ms one gets data from a sensor. I want to display that data every 1000ms in the 1000 ms loop. I have used global variables to do that. Should I better use local variables?
2) This question deals with the VI I have attached
a) Shall I initialise the " Quitter programme " global variable in the main VI aswell ? Or is what I have done enough?
b)
I want the sequence to continue ( finishes the last sequence and goes back to the first one without any delay if possible ) until the user presses Quit. I am concerned about the " wait until " icon of the exterior main while loop ( set to be 250 ms at the moment ). This time, 250 ms, is the time it takes between the end of the last sequence and the beginning of the first sequence? Is that right? Once u start the first sequence, the while loop doesn’t do anything until the end of the last sequence ( my 3 sequences can take several minutes ) ?
Hope I am clear… lol
Don’t hesitate to ask any questions if not clear enough
thanks a lot,
David
Attachments:
Example1.zip ‏28 KB

Bonjour Marc. You will definitely have a race condition because you are writing to the global in a parallel loop. You could click the stop button in the quitter program, then before it is read in the main loop, the lower loop writes a false to it, and your click is lost. Why do you want a separate quitter program? You may have a good reason but it isn't clear here. I would not use globals or locals for this, just put your stop button on the main vi. You already have one, so why do you want another one in another vi? If you must do it this way, eliminate both lower loops. They are not necessary. The global default is set to false, so when you run the vi, it is false. The button mechanical action is set to latch when released, so after clicking it will turn true until the main vi reads it, then it will automatically turn false. So you don't need the lower loops to keep writing false to it. If you just eliminate both lower loops, it will work fine. The only purpose I could see for the quitter vi is to have one button cause several vi's to stop. Instead of doing it this way, put one stop button in your main vi, create a reference (right click - create - reference), and wire this reference into all subvi's that the main calls. The subvi's must be changed to accept the reference and use it. This would be a much better method to close all vi's with one button.
You could also get rid of the sequence structure (it hides code and makes it more difficult to read). Just put all your code side by side. The error in/out wire will ensure that the execution order will be fixed, just like in your first sequence with the open file and write file functions. Just wire the error out of the write vi to the second write vi, and then the error out of the second write vi to the close vi. No sequence structure needed, and all your code is viewable on one screen.
- tbob
Inventor of the WORM Global

Lire variable locals de teststand dans labview par activeX

Bonjour,
Dans le cadre d'un projet interne, je crée une application sous labview qui servira d'interface utilisateur et autres choses.
Le problème est que j'ai besoin de lire les variables locals de teststand avec labview sans que le programmeur teststand se soucie de faire appel à une fonction spécifique.
Pour faire simple l'idée est d'utiliser l'activeX sur labview pour lancer les fichiers séquences etc. ça ne me posse pas se soucie à ce niveau-là.
Mon problème est que j'aimerais lire les variables locals de teststand dans labview, j'avais l'habitude de lire les variables StationGlobals par cette méthode mais pas moyens de faire la même chose pour les locals.
En gros, il faudrait que j'ai accès à sequenceContext par activeX mais sans faire un appel d'un VI dans teststand comme dans l'exemple proposé dans teststand.
Cordialement.

Bonjour Steve,
En effet, ceci n'était pas aussi simple qu'il n'y paraissait...
Voici un exemple:
L'astuce étant de récupérer le Sequence Context depuis l'Executionview manager, on notera qu'il faut passer par l'exécution puis le thread car la propriété qui devrait renvoyer le SequenceContext directement ne fonctionne pas et renvoie une erreur...
Rodéric L
Certified LabVIEW Architect
Pièces jointes :
récuperer locales depuis IHM.png ‏14 KB

Convert local variable to global - labView

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