Using control referrences in a subvi
I have an issue and would like to know if someone can make me an example with and explaination. In my main program i have a subvi and in that subvi i have another subvi preforming a calculation. I need to bring the values of the subvi 2 layers up to the main program. I used the link below on another program which worked but I'm having issues doing it on the program with subvis 2 and 3 layers deep. I tried creating a reference then placing the reference on the main program but the values was not propagation upward to the main program. I do not have the file available to view on this forum.
http://www.ni.com/white-paper/3159/en/
duplicate post, continue here…
Best regards,
GerdW
CLAD, using 2009SP1 + LV2011SP1 + LV2014SP1 on WinXP+Win7+cRIO
Kudos are welcome
Similar Messages
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Performance issues using control references in Analog control loop?
My main vi of a tensile tester control application calls a number of sub-vi's, including a analog control loop which controls the test. The control loop must update some boolean and digital indicators and respond to user input on the front panel of the main vi during a test.
To simplify my main vi, I moved the control loop code into a sub-vi, and used control references to access the controls and indicators on the front panel. However, this has dramatically affected my loop performance, and the loop can no longer keep up with the acquisition speed.
Do control references always cause such a slowdown? Is there anything that I can do besides moving the code back into the main vi?
Thank You,
David CreechI have had the same problem. I have discovered other funny things about references also; some kind of memory management (or mismamagement?) is taking place behind the scenes.
Regardless, you can often do away with the references by passing the initial state of a control or indicator into the subvi, changing it inside, and passing the altered state back to the caller. Once back in the caller you update the front panel control or indicator by using a local variable.
One thing to watch out for if using this scenario is the dreaded race condition; this can be avoided using a state machine. Check out
http://www.advmeas.com/goodies/statemachine.html
for a good example. It is a shame that references behave in this way; it limits thier usefulness.
Perhaps someo
ne else will point out a way to utilize them more sucessfully? -
Main VI stops when using control references.
Hi, This is my first question on this forum. I've created an engine simulation VI which uses control references. The main VI has a data acquistion loop and control references. The control references link to another VI that runs an equation loop which continuously calculates engine speed base on data collected in the main VI. The control references work but the main VI data is collected and updated only once when the main VI starts. If I remove the control references from the main VI the daq loop runs fine. Thanks in advance for your help.
MikeJoe,
Thanks for the response. I do not load the subvi dynamically. I have attached a similar vi to show what I'm trying to accomplish. The DAQ vi reads the input and calculates the power. The power is sent to the "engine momentum sub" vi where the speed, as a function of time, is generated and sent back to the DAQ vi. I created the sub vi to clean up and isolate the DAQ vi from the subvi. I wanted the sub vi to run at a certain speed (by adjusting the wait time)and not affect the DAQ vi. If you input a value of 10 into the DAQ vi and then start it you will see the speed ramp up to 100. While the DAQ vi is running, I need to be able to change the input which would cause the power to change and in turn change the speed. I thought the control r
eferences were the way to go. In my real DAQ vi, I have many more inputs, all which do not update after the first reading. I considered putting the DAQ functions in another subvi and reading the outputs through control references but that seemed too cumbersome.
Thanks again,
Mike
Attachments:
DAQ.vi 27 KB
Engine_Momentum_Sub.vi 33 KB -
How to use a event structure in a subVI
I am trying to use an event structure inside a subVI. The subVI has an array builder that builds arrays, and the event structure is used so that when the program is running, it allows you to change the elements of the array. It works, but when I implement it inside a subVI, it does not work properly. This is going into a subVI, because it will be a part of a much larger progrram, so it needs to be modular.
If you're using an event structure, it's not a subVI. if you're worried about modularity, you shouldn't be using the event structure.
You seem to have a fundamental misunderstanding of modularity. An event structure should be placed within a while loop. If you have a while loop within a subVI, you've handed over control of your program to the subVI. You're not modular at this point. Your top level GUI has no control. You'd have to create some asinine system of variables to pass data down to that loop to stop the loop and return to your main VI. That's not a good design decision.
Instead of looking for a way to do something broken, you should spend effort trying to understand what you actually want to accomplish. You should also spend some time learning how event structures work.
This application is small right now and it's already on the path to unreadable. That's a terrible thing to do to yourself. Break these habits now. se variables only when absolutely necessary. Use subVIs to accomplish individual tasks, not run the entire application. With event structures, use a stop button value change event to not be held hostage by the timeout. If your variable has "2" in it, you're doing something wrong. There has to be something different between the setpoints, put that in the name. If you want to make subVIs, create an icon.
But first and foremost, invest time in understanding dataflow -
Using control refnums in srtict typedef cluster
I'm having a small problem using control refnums. I've not used them much so this could just be me doing something wrong!
I'm building an application with a GUI which will need updating with data from within various subVIs and a couple of parallel loops. So, what I wanted to do was "build" a strict typedef cluster of references to the front panel objects I want to update, then I can pass this cluster to any subvi or structure which may need to update a FP object. So far so good...
The problem:
On my main GUI I have a strict typedef'd tab control, which I want to be able to reference. When I build my cluster of refnum's I duly create one for this typedef'd tab control. The problem is, if I modify the tab control in anyway, the cluster of refnum's breaks.
Anyone tell me why this is happening?
I've attached an example VI I created which shows the problem. Basically, open the typedef to the tab control and change anything, you'll see the cluster of refnums break... you can see a video of it here: Video
Any thoughts would be gratefully appreciated!
Thanks
Paul
Attachments:
refnums.zip 15 KBHai,
Just went through the post
The strict typd controls automatically gets updated when the parent control changes. But the refnums that are created out of the strictly typed controls needs manual updation coz there is no linkage between refnum that was created and the strict type control.
You just create a strict type refnum that carries the properties of a strict type control and in no way a linkage exists between these two. Hopefully if there is an option to link the refnum and control with "Update from typedef" will solve the problems
With regards,
JK
(Certified LabVIEW Developer)
Give Kudos for Good Answers, and Mark it a solution if your problem is solved. -
How do get an indicator to appear when using control references
Hi, can anyone help with the following?
I've just managed to resolve the problem of getting indicators of a sub VI to appear on the front panel of my main VI and remain active. This was done by using control references. Basically, I created a reference for the control on the front panel of the main VI. I then dragged the reference in the block diagram of the main VI to the front panel of the subVI to obtain a Control Refnum. Then in the block diagram of the subVI I created a property node and linked the indicator and control refnum to it. Then I wired the subVI's connector pane to the control refnums in the subVi front panel. Finally, I copied the subVI icon into the mainVI block diagram
and wired the references to the relevent renum terminals of the subVI connector pane. However, I'm still having a problem with one of the indicators, which I've called 'time limit reached?'. When the VI has reached the end of the run this indicator in the subVI changes from the word 'No' (surrounded by a red box) to 'Yes' (surrounded by a green box). In the sub VI this was done by using a comparison function and linking the visible property node to the 'time limit reached?' true/false boolean. I would like the same to happen on the front panel of my main VI. In this case where should I put my property node and control refnum? I'm unable to link a control refnum to the current visible property node. When I create a visible property node which can be joined to a control refnum then I don't have the option to link it to the true/false boolean. Any suggestions? I have written a small VI which demonstrates the problem if need be.
Thanks, Adrian
[email protected]I would suggest to use a customized boolean instead of making it visible/invisible, just take a boolean, change boolean text from TRUE/FALSE to YES/NO and change also diferent cases colors, this way, you don't need to play with property nodes. If this can't be done for any reason, using a local / global variable is the only solution that comes to my mind.
Hope this helps -
In alv report can i use control break events? if no .whay?
Hi all,
in alv report can i use control break events? if no .whay?hi,
you can use control break statements in ALV report.
for example: if one PO is having more than one line item, that time you need to display PO only once. -
Can we use control events in smartforms
Hi all,
I am srinivas. can we use control events in smartforms, I mean at new, at end of ..... if these are not used can you suggest me any alternative....
Actually my requirement is like a classical report, for which I need to display subtotal and grand totals based on two fields....
Please help me out in this issue as it is very urgent.
<b><REMOVED BY MODERATOR></b>
Thanks in advance....
Regards,
Sri...
Message was edited by:
Alvaro Tejada GalindoHi Nick,
Thanks for the reply... it is really very useful for me.
As I discussed in my earlier mail regarding the output sequence, which should be in the below format.
number quantity uom unitprice amount curr
plant
material
date
x y z A
e f g h
p q r s
subtotal date..... 1 2 3 4
subtotal material.5 6 7 8
As you said when I using <b>event of Begin</b> its working fine. but while using the <b>event of end</b>, I am specifying date and then matnr (sort) its taking(nodes are created mean first matnr and then date) in the reverse order and when I am taking matnr and date it is placing the events(nodes) in the right order but the order date is not triggering.
can please tell me how to proceed here..
waiting for your reply..
Regards,
Srinivas -
What happen if i use controll break statement in between select & endselect
Hi all,
what happen if i use controll break statement in between select & endselect ?
Thanks in Advance
KRHi for reference u can go through this code example
data:
fs_tab like sflight.
data:
t_tab like standard table of fs_tab.
select * from sflight into table t_tab.
loop at t_tab into fs_tab.
write: / fs_tab-carrid.
endloop.
refresh t_tab.
clear fs_tab.
select * from sflight into fs_tab.
at new fs_tab-carrid.
append fs_tab to t_tab.
endat.
endselect. -
Smartforms, how to use control break events
Please help with this requirement.
Purchase Docu No.111
Pur Item No Mat no Quantity
1 2356 2000
2 1256 2000
3 8556 2000
Purchase Docu No.112
Pur Item No Mat no Quantity
1 9656 2000
2 7356 2000
3 1356 2000
Purchase Docu No.113
Pur Item No Mat no Quantity
1 5356 2000
2 8356 2000
This i have to design for the smartform.
1 header data then its item data.
like is Script i can call the WIndow elements using control break events in the driver prog but how to get this kind of output in Smartforms.???????
ThanksI dont want trigger new page.
In the same page i want like this
I have purchase docu data in only 1 internal table.
So, for every new VBELN, under this i want its corresponding item details.
I have created the command node for the main window with 2 rows, in the 1st row i am giving VBELN and in the 2nd row i am giving in item details like item no, matnr etc etc and in the condition its askng Field name and Comparison Value.
How shold i give condition.??????
Thanks
Edited by: Jalaaluddin Syed on May 1, 2008 5:03 PM -
Key code 24 using control down - no longer works in 10.6
I have a script that should open a dialog box to make a picture using Copernicus. the command I try to invoke is 'Control ='.
here is the script.
tell application "Copernicus"
activate
delay 2
tell application "System Events"
key code 24 using control down
end tell
end tell
or alternative I tried:
tell application "Copernicus"
activate
delay 2
tell application "System Events" to keystroke "=" using control down
delay 5
end tell
However both do not work, it does do nothing on - key code 24 using control down -.
If I do a manual 'Control =' it works regardless if the Application is active or in the background.
Has anything changed in 10.6 that this sort of code no longer works? How do I set it up for this to work?
Message was edited by: ChangeAgentPierre L. wrote:
I have downloaded Copernicus 1.5.2 (Build 15) just to better understand the issue.
is what I use.
However, I am unable to find any “Control =” keyboard shortcut in any menu of that application. Does that shortcut belong to Copernicus, or is it a shortcut that you have added yourself in the Keyboard pane of the System Preferences?
I added it replacing 'F7' for various reasons. however “Control =” works if I do it via the keyboard.
As for me, after assigning a “Control =” keyboard shortcut to a TextEdit menu command, I have no problem invoking it from the following script.
*tell application "TextEdit" to activate*
*tell application "System Events"*
*key code 24 using control down*
*end tell*
OK. as said it works using the keyboard, but not via the script. could it have something to do with Copernicus? I simply do not understand as to why it does not work using a script. -
I captured from mini-dv camcorder to FCP7 using control from my computer. I only find the capture clip in Finder. How do I get the clip in Finder to FCP7.
Also my audio in the capture was not showing up on my audio meters on my computer-is this normal. Thanksyou will not see the audio meters from within fcp move while capturing.
If you only see the captured clip in the finder, not within fcp, there's something wrong. You might try deleting your fcp preferences
https://discussions.apple.com/docs/DOC-2491 -
How can I use control break statement in my requirement
Hi ABAPers,
In my requirement, I have 4 fields in sorted internal table, (audat, prdha, ipnum, netwr). In that i need to do summation of netwr field falling under same prdha(BU) for the same month
internal table fields :
audat prdha ipnum netwr
02 abc 1 100
02 abc 2 200
02 xyz 3 300
03 abc 4 100
03 xyz 5 300
03 xyz 6 200
i need output like this:
audat prdha ipnum netwr
02 abc 1,2 300
02 xyz 3 300
03 abc 4 100
03 xyz 5,6 500
Can anyone suggest me logic for this by using control break statements
Thanks in advance,
Ankita
Moderator Message: Duplciate Post.
Edited by: kishan P on Apr 14, 2011 3:03 PMHi ABAPers,
In my requirement, I have 4 fields in sorted internal table, (audat, prdha, ipnum, netwr). In that i need to do summation of netwr field falling under same prdha(BU) for the same month
internal table fields :
audat prdha ipnum netwr
02 abc 1 100
02 abc 2 200
02 xyz 3 300
03 abc 4 100
03 xyz 5 300
03 xyz 6 200
i need output like this:
audat prdha ipnum netwr
02 abc 1,2 300
02 xyz 3 300
03 abc 4 100
03 xyz 5,6 500
Can anyone suggest me logic for this by using control break statements
Thanks in advance,
Ankita
Moderator Message: Duplciate Post.
Edited by: kishan P on Apr 14, 2011 3:03 PM -
How to load data using Control File in BW 7
Hi All,
I have a requirement to load data in BW using control file. The development is done in in BW 7.0. In BW 3.5 in infopackage, there is an option of FILE IS ( Control File or Data File ). Please suggest how to simulate the same in BW 7.0
Regards,
VikramAny suggestions?
-
Use Control File to load data in BW7.0
Hi All,
I have a requirement to load data in BW using control file. The development is done in in BW 7.0. In BW 3.5 there is an option of FILE IS ( Control File or Data File ). Please suggest how to simulate the same in BW 7.0
Regards,
VikramHi Vikram,
Please have the contents of a sample control file. The file should be saved as ".TXT".
FILENAME = C:\test.csv
FILETYPE = CSV
LOCATION = C
FS = ,
ESCAPE = "
DECIMALPOINT = ,
1000SEPARATOR = .
RECCOUNT = 8
RECSIZE = 53
PACKETSIZE = 1000
Filename should contain the path of the CSV file
Filetype is CSV
location is 'C' for Workstation and 'A' for Application Server
FS contains field seperator ',' in our case
RECCOUNT contain the Rec. Count
RECSIZE is the Max DB size of the a single row ( this can be evaluated by the Total DB Size of a single Line of the Target BW Structure as well ).
The content of my sample test.csv are
1234567890,10,9999999999,,,15,01/01/2005
1234567891,20,9999999999,,,30,01/01/2005
1234567892,30,9999999999,,,0,01/01/2005
1234567893,10,9999999999,,,5,01/01/2005
1234567894,20,9999999999,,,6,01/01/2005
1234567895,40,9999999999,,,10,01/01/2005
1234567896,10,9999999999,,,5,02/01/2005
1234567897,20,9999999999,,,6,02/01/2005
Please let me know if there are any further concerns.
Regards,
Shrey
Edited by: Shrey SAP BI on Mar 8, 2010 4:13 PM
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