Need a TestStand 2.0.1 global variable with persistence.

I was hoping to use G_DIO_Config_OK, a file global variable, to tell me in the SequenceFileUnload callback sequence whether I could safely try to power off my fixture. The default value is False, and I set it True in a couple of sequences, including the SequenceFileLoad callback. But, even though the sequence file properties are set to have "All Executions Share the Same File Globals", the file global reverts to its default value after the callback has run. Are file globals just not persistent? Do I have to use a station global instead?

Hi gizmogal,
Fileglobals are only available during sequencefile execution.
You will have to use StationGlobals to achieve what you are after.
Regards
Ray Farmer
Regards
Ray Farmer

Similar Messages

How to auto create a global variable with specific variable name in a global vi ?

how to auto create a global variable with specific variable name in a global vi using lv ? Because i need to add a lot of global variable in this global vi. But you know, if i manually add them , it will be a much time-costing work. So i want to use someway to auto generate ? Can i ?? Thanks a lot !

Hi
what aartjan is saying is the way for you. but you can develop an utility which will actually help you create global variables. To get the details on this just have a look at VI Scripting section on LAVA forum.
But i would like you to suggest few things
1. If your programs have so many global variables (Thats why u want utility) then you should take out some time to read about LabVIEW design patterns. I think if programmer follows these practicess he dont need a single global variable.
2. Their are some other ways to achieve similar functionality as of global variables (Uninitialized Shift Registers, Single Element Qs and so on) but they are much faster than global variables.
I am Attaching Whatever Resources i am having I will also attach the template of the design pattern i generaly use in short duration
Message Edited by Tushar Jambhekar on 10-06-2005 07:33 PM
Message Edited by Tushar Jambhekar on 10-06-2005 07:36 PM
Tushar Jambhekar
[email protected]
Jambhekar Automation Solutions
LabVIEW Consultancy, LabVIEW Training
Rent a LabVIEW Developer, My Blog
Attachments:
LabVIEWDesignPatterns.zip ‏1505 KB
Large_Code_Implementation.zip ‏522 KB
Database Tests.zip ‏868 KB

Change a global variable with a function

HI ALL!
I have the following problem...
I would like to change a global variable with a void function so not like this: variable = function(); .
What do you suggest?
Best regards,
Korcs

I have the following problem...
I would like to change a global variable with a void
function so not like this: variable = function(); .
What do you suggest?>
>
I dont quite understand your question but if your variable is a reference to an object then you can certainly have a method to alter the object that the reference is pointing to and/or the reference itself..
otherwise your 'function' will have to return the same type as the variable itself in order to do the assignment as you demonstrated, regardless of wether it's C, C# or Java, AFAIK, WIRNM
HTH

How can I run two different vi's in same project which are accessing same global variable with out effecting the speed of the execution of both the vi's

Hi
I have build an Labview project with FPGA target . I have configured an FPGA VI and an host Vi to acquire data and logged the data to a file and stored the latest data in a global variable simultanously. I have configured one more VI in the same project to access the global variable. I have build a dll to access both the VI as functions in LabWindows/CVI code. My task in CVI is to update configured GUI with latest data periodically and run the host VI continously for a long time and log the data to a file. GUI should update for every one second with latest data for this I am using the second VI in which I am accessing the global varibale in which the latest data has been stored in host VI.

Duplicate Post (go here)

Need features of global variables but want to avoid re-writing to memory

I am making a program with a number of simultaneous loops that will be sharing several variables. Most of the variables are of size 1 or small arrays, so I am not too concerned about the constant re-writings involved. However, I have one rather large data buffer (3D array containing 200Kb+ of data). The buffer will be of a set size. In the various loops, the buffer will be accessed for updates (generally with Replace Array subset), and read from to get average values and such. I'm using semaphores so that none of the loops interact negatively and lose data. In other programs I'd set this up with a shift register in the loop, but since the data is being used in separate simultaneous loops, it's no
t really possible to wire it up that way. I need some sort of memory-space that can be accessed from the various loops.
I guess in sorts, I need to be able to have global variable 'pointers', but of course I was told a couple of years ago at a LabView seminar that pointers was a bad word.

tbob wrote:
> As long as Labview is running, the LV2 style global will automatically
> retain its last value. Of course the very first time it is run, the
> value is undefined, so you should write to it before attempting any
> read.
I have one correction to make. The value of an unitialized shift
register on first load is not undefined but rather contains the
datatype's default default value. This would be False for booleans, 0
for numerics and empty arrays or strings.
Rolf Kalbermatter
Rolf Kalbermatter
CIT Engineering Netherlands
a division of Test & Measurement Solutions

Build stand-alone application with Global variable

Question:
how to build a VI access a global variable into a standalone EXE file?
there are multiple VIs access to one Global variable, one of the VIs need to run in background to update the Global variable, whick i built into EXE file.
the rest VI will be called in from Teststand to retrieve the Global variable.
the global variable is updated if i run the background VI in labview, but after i build it into EXE file, it seems the global is not updated even the EXE running OK.

Hi,
Do you actually need to have an executable.
If you can call your global variable updater VI as a VI form, then your other VI's will still beable to see the Global variable.
You can launch you global variable updater VI in a new thread or execution so that it runs in the background and returns back to TestStand sequence so you can continue on with the rest of your tests.
Remember to close your global updater VI before you complete your test sequence run.
Regards
Ray Farmer

Can F4IF_INT_TABLE_VALUE_REQUEST FM return a value in a global variable?

Hi everybody,
I need to use F4IF_INT_TABLE_VALUE_REQUEST FM because I have to let users select an specific option before choosing another value. The point is that I need to save in a program global variable what the user selects, and decide something with it in the program.
Is it possible that F4IF_INT_TABLE_VALUE_REQUEST FM returns the value in a sinple variable or it has to be paramter?
I look in a lot of previous threads but I didn't find anything, and I don't know if it's possible.
Thanks and kind regards,
MMP.

Hi,
Sure you can. All you need to do is to store what the function returns in your global variable. It don't need to be returned back to screen field.
DATA: BEGIN OF VALUES OCCURS 0,
         CARRID TYPE SPFLI-CARRID,
         CONNID TYPE SPFLI-CONNID,
       END OF VALUES.
DATA: VALUES_TAB TYPE TABLE OF VALUES,
          G_VALUE TYPE SPFLI-CONNID. "global variable to store what is returned
"in PAI first populate your table
SELECT CARRID CONNID
    FROM SPFLI
    INTO CORRESPONDING FIELDS OF TABLE VALUES_TAB
    UP TO 10 ROWS.
"then call the function but don't return the value to screen field
"If you specify the import parameters DYNPPROG, DYNPNR, and DYNPROFIELD, the useru2019s selection is
"returned to the corresponding field on the screen. If you specify the table parameter RETURN_TAB, the
"selection is returned into the table instead.
CALL FUNCTION 'F4IF_INT_TABLE_VALUE_REQUEST'
       EXPORTING
            RETFIELD         = 'CONNID'
            VALUE_ORG        = 'S'
       TABLES
            VALUE_TAB        = VALUES_TAB
            RETURN_TAB      = RETURN_TAB.
"now simply read first row of return tab and store the value returned there in some global var
READ RETURN_TAB INDEX 1.
MOVE RETURN_TAB-FIELDVAL TO G_VALUE.
Regards
Marcin

Global variable in servlet & DBPooling questions

Hello guys,
I used to develop PHP/ASP, and am new to servlet. I have been searching around for a solution ...
With Php, we can get the reference of a global variable in any classes->functions...
How do I do this with servlet ?
And second..I have developed the DB class as below... I set the datasource to be static, so it initializes only once. Is it a good idea? How would you like to improve this class? any comments?
package shop.database;
import javax.sql.DataSource;
import java.sql.*;
import org.apache.commons.dbcp.BasicDataSource;
import org.apache.log4j.Logger;
import shop.admin.exception.GeneralException;
public class DdManager {
     static protected Logger logger = Logger.getLogger(DdManager.class);
     private String userName = "root";
private String password = "";
private String hostName = "jdbc:mysql://localhost:3306/shop";
private String database="shop";
     static private DataSource ds;     // set this to be static so all threads share the same job in JVM
     private Statement stmt;
     private Connection conn;
     private ResultSet rs;
     private CallableStatement cs;
public DdManager() {}
* setup the data source and return it
     public static DataSource getDataSource(
          String sDrvName,
          String sUserName,
          String sPwd,
          String connectURI) {
          BasicDataSource ds = new BasicDataSource();
          ds.setDriverClassName( sDrvName );
          ds.setUsername( sUserName );
          ds.setPassword( sPwd );
          ds.setUrl( connectURI );
          ds.setMaxActive( 15 );
          ds.setMaxIdle( 10 );
          ds.setMaxWait( 10000 ); // 10 seconds
          return ds;
     * static init of the class
     * this class is will be called only once to initialize the DataSource
     static {
          try {
               Class.forName( "com.mysql.jdbc.Driver" );
               ds = getDataSource(     "com.mysql.jdbc.Driver",
                                        "root",
                                        "jdbc:mysql://localhost:3306/shop" );
               if (ds == null) {
                    String msg = "Connection Pool error";
                    logger.error(msg);
                    throw new GeneralException(msg);
               logger.info("DataSource has been initialized");
          } catch(Exception exception) {
               logger.error(exception.toString());
               try {
                    throw new GeneralException(exception.toString());
               } catch (GeneralException e) {
                    logger.error(e.toString());
     * get the connection from the pool (DataSource)
public void openConnection() throws GeneralException {
try {
     BasicDataSource bds = (BasicDataSource) ds;
     logger.info("NumActive: " + bds.getNumActive() + ", " + "NumIdle: " + bds.getNumIdle());
conn = ds.getConnection();
logger.info("Connection of " + database + " has been established");
} catch(Exception exception) {
     logger.error(exception.toString());
     throw new GeneralException(exception.toString());
* close the connection will actually return the connection to the pool (Must)
public void closeConnection() throws GeneralException {
     initResource();
try {
     if (conn != null){
               conn.close();
               logger.info("Connection of " + database + " has been closed");
} catch(SQLException exception) {
     logger.error(exception.toString());
     throw new GeneralException(exception.toString());
* prepare the calling stmt
public void prepareProcedure(String callStatement) throws GeneralException {
     initResource();
try {
     cs = conn.prepareCall(callStatement);
} catch(SQLException exception) {
     logger.error(exception.toString());
     throw new GeneralException(exception.toString());
* set the pass-in parameter for "String"
public void setParameter(int position, String parameter) throws GeneralException {
try {
     cs.setString(position, parameter);
} catch(Exception exception) {
     logger.error(exception.toString());
     throw new GeneralException(exception.toString());
* set the pass-in parameter for "Integer"
public void setParameter(int position, int parameter) throws GeneralException {
try {
     cs.setInt(position, parameter);
} catch(Exception exception) {
     logger.error(exception.toString());
     throw new GeneralException(exception.toString());
* execute the procedure and return the resultset
public ResultSet execProcedure() throws GeneralException {
try {
     rs = cs.executeQuery();
} catch(SQLException exception) {
     logger.error(exception.toString());
     throw new GeneralException(exception.toString());
return rs;
* close the statment and resultset
     private void initResource() throws GeneralException {
     try {
          if(rs != null) {
               rs.close();
          if(stmt!= null) {
               stmt.close();
          logger.info("Statement & Resultset have been free");
     } catch(Exception exception) {
     logger.error(exception.toString());
     throw new GeneralException(exception.toString());
Thanks mates!
myy

Thanks Saish,
Your response is really appreciated. Sorry about that
as i didnt know there is 'code' formatting button,
and I will look into the Singleton pattern.
As I'm still in the learning stage. Therefore, i
still have a lot of thing do not understand.
... use it in a method signature ...What is "a method signature" ?
A method signature is basically the method's parameters, return value, name and any access or other modifiers. The following is a method signature:
static final public void main(final String[] args)Between the braces of the method body is the implementation (or as I already alluded to, the method body).
Consider using an already-developed connection poolimplementation, such as Jakarta Commons DBCP ...
I'm trying to implement the Jakarta DBCP. Did I go
into the wrong way?
Sorry, did not read the imports. Yes, you are. However, I am confused about what you are trying to implement. You have a static method getDataSource(). You also have a static variable 'ds'. Use one or the other. I would be that there are seemingly random errors cropping up based on whether you remember to call getDataSource() or not.
You do not, generally, want the data source to be static. Multiple threads might use the class. And if there is only a static data source, you will either need to synchronize the methods that use the data source (resulting in a scaling bottleneck) or not synchronize them (which will totally destroy any concept of a logical unit of work or database transaction).
.. A static datasource, as in your class, can onlysafely be used by one thread at a time, potentially
introducing scaling bottlenecks (or race conditions)
in your system ...
So, you mean there is no need for the DataSource to
be static ?
No, in fact, IMO, it should not be. That is why you are pooling. Use instances. The pool will manage the connections and their availabilty for you.
Why are you throwing GeneralException everywhere?Here's a question: can someone using your class (a
caller) realistically be expected to handle a
database exception?
When there is a database error, I just want to stop
the process and redirect the user to an error page. I
will look into the unchecked exceptions. Thanks.
Unchecked exceptions do not need to be declared in a method signature or caught within the method body. Checked exceptions do. As such, an added benefit is that unchecked exceptions de-clutter your code.
In your initResources() method, what happens if theclose() on ResultSet throws an exception
Oh, yes. I'm so stupid.
Now I only have ...
     private static DataSource ds;     // set this to
be static so all threads share the same obj in JVM
     private Connection conn;
     private CallableStatement cs;
private void initResource() throws GeneralException
n {
     try {
          if(cs != null) {
               cs.close();
logger.info("CallableStatement has been
as been free");
     } catch(Exception exception) {
     logger.error(exception.toString());
throw new
throw new GeneralException(exception.toString());
You still have issues.
public void initResources() {
   if (rs != null) {
     try { rs.close(); } catch (SQLException ignore) { ignore.printStackTrace(); }
   if (stmt != null) {
     try { stmt.close(); } catch (SQLException ignore) { ignore.printStackTrace(); }
}Normally, this type of method would not be called initResources() but rather closeResources() or freeResources(). It would be called from within the 'finally' block of another method using the CallableStatement or ResultSet.
This is really is problem, would you mind to tell me
how to handle this(close the connection) if the
close() on either CallableStatement or Resultset
throws an exception ?
See above. Simply log the exception (there is usually nothing meaningful you can do if a close() fails, and it is up to you as a developer if this is an error or just a warning). Another option is to 'chain' exceptions. In your own exception, add a method 'addException(Throwable)'. This would add another exception to a List of exceptions. When you print the stack trace, iterate through the chained exceptions to print them all out. One place where I find this useful is rollback() code. If the original SQL statement fails AND the rollback fails, I definitely want to see that rollback() exception as well in my logs.
The DB thing makes me headache. What I actually
wanted is a solution for:
Let say I have a class "HelloAction.class" contains
the code:
public ActionForward XXX() {
     DbManager DB = new DBManager();
     ... do some DB thing here...
     SecondClass SC = new SecondClass();
     SC.doSomeOtherDbThing();
     ... do something else...
     ThirdClass TC = new ThirdClass();
     SC.doMoreOtherDbThing();
}There are some functions in SecondClass.class and
ThirdClass.class that will need database connection.
I consider 'global variable' is because I want these
two classes are able to use the same
connection(DbManager) from the function -
ActionForward XXX().
What is the best way to implement the above situation
(sharing the same connection in different classes &
sub-classes?
I also just realize that the problem of multi-threads
with these two class variables..
     private Connection conn;
     private CallableStatement cs;Really headache. I really appreciate any comments.
Thanks.
- myyPass the Connection or DataSource to each method or constructor. Call commit() or rollback() from the method that created the transaction.
- Saish

Can the output of a Generate Occurrence be passed in Local/Global Variable?

Can the output of a Generate Occurrence function, which is a refnum, be passed in Local/Global Variable so that it does not need to be wired to all parties directly?
Can more than one party be waiting on the same Occurrence and will all waiting function be released together?

dbaechtel wrote:
Answer was not given:
Can the output of a Generate Occurrence function, which is a refnum, be passed in Local/Global Variable so that it does not need to be wired to all parties directly? Is this possible?
I am not worried about whether it is bad form or not, as yet. That is for me to decide on a case by case basis.
Yikes! That is not a very good way to learn.
Anyways, to avoid any more bold emphasis on words, I will answer your question. Locals can only be linked to controls/indicators not individual wires. If you want to get the effect of a local/global variable with a wire value, search the forum for action engines or functional globals. Those will work for passing a wire value between threads.
That said, what are you trying to use occurences for? There may be (and probably is) a more accepted way to implement what you are trying to do instead of using local variables
CLA, LabVIEW Versions 2010-2013

Looking for something more robust than global variables

Hi,
The company I work for makes really big deals based on the Forms we develop,
and it makes me edgy to rely on :Global.variables to assign big amounts of money
to a field or another.
Maybe someone could direct me to a paper about a more robust scheme to run tests deciding what is going to happen next, like calling another form or populating another block?
Many thanks :-)
Message was edited by:
JeanParis

JeanParis,
I did a quick Google search, but didn't find any reference material on you question so I'll give you my personal preference. Bear in mind, it truly was a "quick" search. I'm sure there is information about this topic somewhere.
I use a Global Variable (GV) when a value is needed by significant number of Forms in the application. If the value of the is only needed by a few Forms, then I use a Parameter List. When I do use GVs, I only use them for as long as I need them. In other words, I'll assign the value of the GV to a Forms Block Item (base table or Control Block) or a parameter and then set the value of the GV to NULL. This ensures the value is only available "Globally" for as long as it is absolutely needed. This does cause a little extra work, but it make the Form safer in my opinion.
If I simply need to have access to a "Global Variable" within the scope of a single form, I prefer to use a Form Parameter (FP). I like using using FPs over a Control Block (CB) Item because there is less overhead (attributes of a FP) than with an Item (attributes of the Item) in a CB. I know this is nit-picking, but there is a cost associated with each attribute that is loaded into memory and I like to keep this cost to a minimum. (I suppose if you sub-classed your CB Item then it would share the attributes and reduce the overhead even more). I develop Forms for the web using Forms 10g so any time I can shave off the load-time of my Form is worth it to me.
Hope this helps.
Craig...
Message was edited by:
CraigB
Steve beat me to the punch. I like his option as well and have used this method a time or two. :-)

MetaData Navigator hidding Global Variables

Hello,
In ODI we have several Interfaces that executes MaxL scripts. In these scripts
we need to have a Username Password and thanks to John's help these are now
encrypted. Since we have a bunch of them we created a Global variable with
the Key, Username, Password to be able to easily maintain this.
We are using Oracle MetaData Navigator to execute these using a web browser
which gives use the opportunity to have a Fiscal Year Global variable
and easily change the fiscal year on the fly. Really cool!
Questions:
Since I'm using Global variables for my Key, Username and Password is there
a way to NOT Display these in MetaData Navigator? Since they are Global Variables
they show up in the MetaData Navigator... Which is not what I want... Since
these appear it's almost the same as having them in clear text right?
Any ideas / suggestion where I can have my Key, Username and Password in a
variable without having it show up in MetaData Navigator?
Also can I use the same Fiscal Year Parameter using ODI Operator? Like in the
MetaData Navigator? I've never seen anything about this.
One last thing, where can I find documentation on MetaData Navigator?
Thanks
Eric

Hi,
Here is the thread where John explains how to encrypt username passwords. We are using this now and it works
great so now our username passwords are not in plain text. But since we have so many places using these we decided
to put them in a global variable so when it changes we only need to updated in one place.
Re: Encrypt the Password so that it's not in plain text in a OdiOSCommand.
Since we are using Oracle MetaData Navigator to execute these the global variable show up on the MetaData Navigator web page...
It's no big deal and we will live with this but if I could hide these on the MetaData Navigator then that would be
great.
Eric

Change global variable from symbol

Hi Everyone,
I need help making changes to a global variable. I set a variable up on the creationComplete using the code: sym.setVariable("information", 1);
Later in the project I want to call up that variable and then increase the value on a button click. In the button symbol (onClick) I can call up the variable by using: var paragraph = sym.getComposition().getStage().getVariable("information");
When I use an alert(paragraph), the proper value shows up. But, on the click, I need to change the value of the stageComplete variable "information" to 2.
Can anyone give me some guidance on what I'm not doing right?
Thanks
Randy

Hi,
It seems you want to increment using sym.setVariable() and sym.getVariable().
First step: sym.setVariable("counter",1); // it means: counter = 1;
Second step (another panel): sym.setVariable("counter", sym.getVariable("counter") + 1); // it means: counter = counter +1; or counter += 1
Demo: https://app.box.com/s/dqml4wtbcimtjvlkf2ol

Changing Global variables inside function

Hello all,
Trying to set a global variable in a function that had already been set before the function. For example:
$VariablesAreSame = $false
function CheckIfDifferent ($variable1, $variable2){
If($variable1 -eq $variable2){
$VariablesAreSame = $true
write-host $VariablesAreSame
for($i=1;$i -le 5;$i++){
CheckIfDifferent $i 2
When this is run, $VariablesAreSame is never permanently set within the function, which I would like it to be. Any ideas?

You need to set $VariablesAreSame as a global variable in the function.
$VariablesAreSame = $false
function CheckIfDifferent ($variable1, $variable2){
If($variable1 -eq $variable2){
$global:VariablesAreSame = $true
write-host $VariablesAreSame
for($i=1;$i -le 5;$i++){
CheckIfDifferent $i 2

Global variable readonly

I chose to try/use a global variable to resolve a complex situation I was having. I followed the "Creating Global Variables" from LabVIEW help and everything seemed to work fine. The global stopped working, however, when I checked my files into CM and the xxxGlobal.vi (created by the global variable process) was readonly. I didn't see a runtime error, but the global always returned the default. Then, when I changed the file's attributes (enchecked readonly), I could exercise the other functionality.
Is this a known issue - do I have to make this global.vi read/write for all users, or is there another solution?

I don't think my conclusion (above) is correct. I had a case statement error that made it appear that the readonly was the issue, when it was not. I'm not sure what the deal is now. Here is what I did.
I placed a global variable(gv) in the block diagram of one VI, then double clicked on the gv and got a blank vi. I dropped a text control onto the front panel and named it ReportFormat. I then did a "save as" to save the new (global) VI. I then added some logic (where I originally dropped the gv) to populate the global variable with the user's selection from a drop down (two possible choices) . I then went to another VI and in its block diagram I did a "Select VI", found/selected this global.vi I just created. Since I only have one item on the front panel (in the global.vi), I received an association to ReportFormat. I did a "Change to Read" so I can use the string output to drive a case statement. The default case is always selected, though.

Adding tab to typedef tabcontrol causes class conflict with global variable

Hi,
I am quite new to labview. I have to update an existing program and I have a problem whith a tabcontrol. In attachement, I give you a very simple solution showing my problem.
I have defined a simple tabControl in a typedef ctl. I had it to a VI and in block diagram of this VI, I want to fill a global variable with this control and this global variable is set as "Include Data Type".
When creating my ctl file with a simple tabcontrol, there is no problem but my tabcontrol only contains 2 tabs. When I use "Add page after" in my ctl file to create a third one, after saving, I get a class conflict error on wire to global variable in my block diagram.
If I remove added page, all is OK again. I don't understand why adding a new page causes a class conflict. In my attachement, it is very simple but in program that I have to modify, I already have 15 tabs and I just want to add a 16th one so, I am sure there is a mean, but impossible to fond it after many hours...
If someone can tell me how to make my example works with "Include Data Type" (if I remove it, it always works but that is not what I want) and adding an additional tab, it would hemp me a lot!
Thanks in advance.
Yohann
Attachments:
test2.zip ‏11 KB

The problem is that the tab is an enum, and you can't wire two strictly typed references of two different enums together, because they are considered different data types. What you can do is right click the reference control in the global variable and select Show Control, which will show the data type of the reference. You can then replace the control inside the reference with the typedef, which will cause it to update correctly.
Although that will solve the problem, if you have the reference to a tab control in a global variable, you probably have some issues with your code, but that's not something which can be commented on without more details.
Try to take over the world!

Need a TestStand 2.0.1 global variable with persistence.

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