DVR accessing a Front Panel Control

Can somebody explain to me why this does not work or how to make something like this work.
Thanks in advance,
Eldon

Your definitely trying to optimize the wrong thing here. There is no way to get a free and cheap reference access to a user interface control on the front panel.
The DVR doesn't link to an UI control for one thing, so it falls off your list already.
The Control Refnum has to deal with race condition protection and all that, so it is indeed slow.
The local indicator is not available in a subVI.
The User Event Refnum is the logical choice here, but you don't like it.
Leaves no other option than abandoning LabVIEW and start programminig in assembly again
Even in C you can't just go and access a GUI at will through a pointer reference. Any well designed GUI framework will require you to call object methods passing the data explicitedly, or sendinig some form of message to the control. Such is life. GUIs are not meant to update Megabtyes of data several times every second anyhow. Humans are only able to grasp a very small number of data points per second so any GUI trying to transport more data to a user is usually pretty misdesigned.

Similar Messages

Bind a front panel control to an item

Hi all,
I have a problem with selecting DataSocket in "Data Binding Selection" when I want to bind a front panel control to an item in another server such as an OPC Server. I want to know whether we connect to that item via OPC Server or DataSocket Server after specifying an OPC URL. The LED_DataSocket near the front panel control planned to bind to an OPC Server's causing this doubtfulness for me.
And I want to know in a big application what the difference between these two is:
Connecting a front panel control to an OPC Item selecting:
NI_PSP\network Items\then selecting the item from an OPC client instance currently created or,
DataSocket\browse\ finding the item we want through Servers listed.
Please advice.

I'm working on a big HMI application with more than 200 I/Os. if I want to read/write these data items from an OPC server, do you mean it's better to use shared variables bound to OPC data items, then read/write directly the shared variable from a front panel object, connecting a shared variable node to it?
I want to know if I bind my all front panel objects to shared variables or OPC items via NI-PSP or Datasocket, for this number of I/Os, it works. And what are the differences between these two technologies?
I 'm for the best way of gathering data from an OPC Server.
Message Edited by Maryam on 04-20-2006 11:41 AM

How do I get the Label for a Front Panel Control to appear in the Block Diagram but not on the Front Panel?

How do I get the Label for a Front Panel Control to appear in the Block Diagram but not on the Front Panel? On the Front Panel I am making a complex control that consists of a Slider and a Numerical Input box. Both Controls display the same information and either can be used for Input. When one changs, the other is made to display the same value.
But I only want the Slider to display the Label on the Front Panel, to avoid confusion. On the Block Diagram however, I want both controls to display their Labels so that I know what they are. How do I display the Label for a Control on the Block diagram, but not display its Label on the Front Panel?

No. The Label Visible property is separate for the front panel control label and the block diagram terminal label.
How did you start out with the block diagram's label not being visible? Whenever I drop a control or indicator, the label is always visible on both the FP and BD by default. Maybe there is a LabVIEW option that causes new controls/indicators not to have their labels visible by default, but I have yet to find it. I don't think an item should ever be dropped without the label visible, good LabVIEW coding practice demands that the labels for control terminals on the block diagram be visible so that you know what control or indicator a wire is going to.
That being said, I have seen a lot of VI's posted where the label for the terminal on the BD is not shown (against good programming practice.) I've gone to the BD and right clicked to show the label. Sometimes, the people have an empty label (which will turn off the visibility for both the FP and BD) and I'm forced to add some text of my own into the label so I can figure out what their code is doing. When I add some text to the label, at that time, I find both the BD and FP labels become visible.
Are you dealing with controls that have empty labels to start?
Good programming practices:
1. Always have a name for all of your controls, never use and empty label by deleting the text in the label.
2. Make the labels unique. For example, don't have two controls both called Stop. How do you know quickly know which terminal relates to which control?
3. Always show the labels on the block diagram, so you know the function of a control's terminal. If you want to hide the label on the FP, that's okay.
4. If you want a different label to appear on the FP than whatever you actually called the control, then use the caption. You can hide the label and show the caption. This is useful if you need to programmatically change what the "label" is on the front panel such if you are making an application that needs to change its user interface such as for a foreign language.

How to make the LV front panel controls the current value through the program is set as the default value when the next time you open?

How to make the LV front panel controls the current value through the programis set as the default value when the next time you open?
1110340051

Try this: Re: How to make a VI remember the latest control value?
Jim
You're entirely bonkers. But I'll tell you a secret. All the best people are. ~ Alice

How to run my vi from a front panel control without using even structure in the vi

Hello, I would like to run my vi from a front pannel control instead of the tool bar RUN botton. I am using LV6.1 without the even structure feature, so I can't do as proposed by a previous posting by setting the vi to run at open in a "do nothing state" then taking the front panel control event and switching the vi into another ("running") state. I wonder is there some other type of solutions to this problem. Your help is greatly appreciated.
Bryan

Hi Dennis, thank you for the reply. I tried with the attached vi. It can only run once (also not in the correct state I want), as the control i placed on the front pannel will stop the VI. I want to have the vi do nothing when it is opened and start counting when the start botton is pressed. Then i want it stop counting when the botton is pressed again...and so on... I must need a different structure to get it work, or did I miss something simple? Thanks again.
Attachments:
StartVI.vi ‏16 KB

Detailed Help on Front Panel Controls

I can't get Context Sensitive Help or Detailed Help on LabVIEW Front Panel Controls. Why doesn't this work in LabVIEW?
I am trying to find detailed Help on Text Ring.
Solved!
Go to Solution.

Where can I find description of example usage for Text Ring?

MAX communicates fine with GPIB Instrument, LV Standalone Exe Front Panel Control Does Not See It.

I have succesfully created a LV standalone EXE which communicated with external GPIB instruments. I used LV 7.1 for this. I upgraded DAQMx to 8.0 on the development machine and also the target which runs the Exe. The EXe runs fine on the development machine but when run on the target laptop, the front panel control fails to see the GPIB instrument. On the target, in MAX I successfully setup communication with the GPIB instrument. Is there some incompatibilty with DAQMx 8.0 and LV7.1? An additional piece of info here: when upgrading to DAQMx 8.0, I selected the installation support for LV 7, 7.1 and also 8. Could this be where the problem lies?
Thanks
Peter

The GPIB code is actually an IVI driver made for a Rhode and Schwarz TRMS meter. Its the standard VISA Read/Write, nothing out of the ordinary. I'm using a USB-GPIB-HS adapter to communicate with it. Like I mentioned, the VISA instrument control drop down list on the front panel of the Exe does not list any GPIB instruments, all that is listed is ASRL...1, ASRL...4, and ASRL...10. In the EXE that used to work, there were no ASRL... references listed. What was listed was the GPIB0...INSTR...20, COM1, and the parallel port. So something weird is going on now, somehow effected with the load of DAQMx 8.0.
Pete.

Help!!! I cannot access to the panel control

Help, please. I cannot access to the panel control, he ask me the user and password but I don't remember to have change them! I tried with admin/admin but nothing, I tried to reset it with buttom for 5 sec. but nothing... I'm desperate!
Linksys WAG320N
Solved!
Go to Solution.

I did the test you said, I can not! I tried with Safari and Firefox, I also deleted the cache. Although I do the reset for 20 seconds, it will not reset. O don't understand... I'm not a dummy
Your last option is to do the hard reset. That's done by pressing the reset button for 30 seconds while the device is powered on. Once done release the button and power off the device. After a while, plug it back in and reinstall the settings from scratch.

Disabling Front Panel Controls

Hello,
Currently I am working on trying to disable/gray out between 10-20 front panel controls when a start button is pressed, and then enabling them at the completion of the test. Currently I am using property nodes which all are wired to a constant of which state I want which works perfectly. My question lies with there being another way other than having a bunch of property nodes filling up my event structure. Ive read where people had subVI's that used references to do this same function, but is there a way to do this right in the block diagram of my current VI? Thank you!

So you have to create references of your front panel controls, this can be quick, since you can select multiple, and with right click you create references.
I have attached a version LV2010.
edit: another advice:
You have to create only once these references. Usually it is comfortable to bundle all the references into a cluster, and use this wire through your whole code. In this way you can just unbundle those references which at the actual location you need to play with, put them into an array, and use the above FOR loop to change their properties...
Like this:

How can I use multiple front panel controls to be mirrors of each other?

Hi All:
I know this is going to be a strange question, but I have multiple inputs that control one output. This in itself not necessarily difficult, but I have a strange need. If one of the control inputs change I would like this to be indicated by the other controls. For example, I have a slider, numeric and dial controls on the front panel that control RPM. If the slider changes to 1000 RPM I would like the numeric and dial controls to see that change. Is this possible. If so, can you give me advice on doing this. I am using 7.1. Thanks for the help.
John Honnold

What you want is not that hard, but asked for a rather limited times.
Here's a how to:
Drop a slider
Right click Visible items-> Digital display
Right click on the slider Advanced-> Customize
Right click on the Digital display Replace select the control you want to replace it with (a gauge for instance)
Right click on the Gauge Visible items -> Digital Display
Now you have one control with three control options:
This was done in 8.2 but I think the same goes for 7.1
Ton
Message Edited by TonP on 04-06-2009 09:52 AM
Free Code Capture Tool! Version 2.1.3 with comments, web-upload, back-save and snippets!
Nederlandse LabVIEW user groep www.lvug.nl
My LabVIEW Ideas
LabVIEW, programming like it should be!
Attachments:
Example_VI.png ‏7 KB

Front panel controls show up one at a time

When I first open my main vi the controls on the front panel appear one at a time over 20-30 seconds. The problem was compounded when a second front panel was made switching between the two the controls for the second panel pop up one at a time and after they all appear the first panels controls go away one at a time. Any ideas on why this ocurs and how do I fix it so the transition happens quickly?

BenThe code is modeled on a vi that was done under LV5 and was also ported over to new computers and LV8. We had to install the traditional drivers to get that code to run on the new systems. The original vi transitions fairly quickly. The new vi is modeled on the original code with efforts being made to strip it of the overhead bagage. ie.the sequence structures and controls no longer needed..... The new code from the begining has sequentially brought up each control with each new control being added it progressively gets worse. With the addition of the second front panel in the same vi the protracted transition of the controls became a significant issue.
Bob
Attachments:
20060817.zip ‏2692 KB

My front panel controls are disappearing after the vi starts. Anyone one know how to fix this?

I have some vis that ran fine on an older machine, but with the new computer controls on the front panel dissappear after awhile and can be made to reappear after closing and reloading the vi. I am not doing any programmatic hiding of any controls. The controls can also be made to reappear by stopping the vi and selecting them with a tool, but then they disappear again when you run the vi again. I played around with "bring to front" but that doesn't fix the problem and read a post about OpenGL problems associatted with 3D controls. Any ideas on what to try to fix the disappearing controls?
I

If you right-click on the terminal and choose 'show control' and then the control can be seen, then it is not hidden behind other controls, decorations, etc. Just to ask a dumb question: have you right-clicked on the terminal and tried Find --> Property nodes to make sure that the control(s) is not being hidden somewhere in your code? Are you passing any control refnums to any subvi's?
"There is a God shaped vacuum in the heart of every man which cannot be filled by any created thing, but only by God, the Creator, made known through Jesus." - Blaise Pascal

How can i access remote front panel in RT with LabVIEW run time engine in client PC

Hi to all,
I have developed the RT application with cRIO 9075 integrated chassis. And i have access its remote front panel in client PC. Now i want to access the remote panel in the client PC without having LabVIEW runtime engine. If i connect the remote panel with that client, it shows only the vi border. i doesn't downloads the front panel.
How Can i access its remote front panel without LabVIEW runtime engine in the client PC?

You cannot view a remote front panel without the LabVIEW runtime - the LabVIEW runtime is what makes the remote front panel possible. What you will want to do instead is likely create a Web Service that you can access from a remote PC without requiring the LabVIEW runtime. However, this will require you to develop a web-based HTML or similar UI to interact with the VIs running on your system - NI hasn't yet created a way to export a LabVIEW front panel as an HTML'ish page.
-Danny

Auto save and auto recover of front panel controls/indicators values

i just want that when i exit from the VI's front panel all controls and indicators current values get saved automatically and when i get back into this vi,those values get recovered automatically.
Like if i incremented numeric control value from 1 to 5 , when i exit from the vi the value 5 get saved automatically and when i get back into the vi ,it shows the recovered value 5 to me automatically.
best regards

I'm Back
I was mistaken when I said the you could select to save either the controls or indicators or both in the Open G Vi's, They are hard wired for both. I made minor changes to these VI's for my app., because I only needed the controls to be saved. The example I am providing uses the Modified VI's, but I've also included the originals.
Modified
Read Panel from INI.vi
Write Panel to INI.vi
Originals
Read Panel from INI.vi
Read Panel from INI__ogtk.vi
The ability to select either or both could easily be implimented into these Vi's using a case selector and an enum wired as an input
Controls only
Indicators Only
Both
Incase you don't have the OpenG toolkit I've provided the necessary files for this example to function
Extract the zip file to your User.lib directory then open Usage.vi
Hope this helps you
Georges Janveau
Attachments:
Config File Usage.zip ‏861 KB

Error accessing Remote Front Panel on RT Target after upgrade to LV2011

I'm upgrading a real-time application (target is a desktop PC running the LabVIEW real-time) from LabVIEW 2009 to 2011. Under 2009, it was possible the view the main VI remotely by browsing to a static HTML page that embedded the front panel. After upgrading to LabVIEW 2011, instead of the front panel image I get an error saying "Server does not support Remote Panels." I have already gone through the list of possible causes from "Server Does Not Support Remote Panels" Error When Connecting to Remote Front Panel, and none of these resolved the problem. I am using the standard LabVIEW web server, there is a direct ethernet cable connecting my computer with the real-time system, and I have recreated the web page to reference the correct plug-in version. I reformatted the RT system and then did a clean install of the components from LabVIEW 2011 (using the Add/Remove Software feature in Measurement and Automation Explorer). I also created a new test project with a new simple VI; I was able to access that VI remotely on port 8000, but not on the default port 80 (which used to work under LabVIEW 2009). What changed in the web server between LabVIEW 2009 and 2011? Can I use the standard HTTP port 80 to serve a static page with an embedded VI, or does this now only work on other ports (and if so, why)? Will I need to recreate my entire project in LabVIEW 2011 in order to get this working at all?

Got it working, after much experimentation. Seems to require installing exactly the right combination of items on the RT target, as some items (web services? web configuration? the "application web server"?) apparently run a separate web server - or instance of the web server - on port 80, which prevents remote front panels from being served on that port.

DVR accessing a Front Panel Control

Similar Messages

Maybe you are looking for