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Property is supported in RT but will always return an error

So I'm relatively new to LabVIEW RT.  I got a few relatively simple projects working and I wanted to play around a bit more to learn.  One of the things I'm aware of is that on RT not all things like property nodes and invoke nodes are supported.  If you open a property node's context help and get more help it will say something like Available in Real-Time Operating System - Yes/No.  So in writing code I make sure that the nodes I use are going to be supported.  

 

I've found several nodes that say they are supported on RT but are clearly not supported.  Basically anything using the front panel aren't going to be supported.  This is because there really isn't a front panel on an RT system.

 

But what I don't understand is why all these property nodes that are of the panel class claim to be supported on RT.  Like this property which returns all the control references on a front panel.

 

http://zone.ni.com/reference/en-XX/help/371361H-01/lvprop/pnl_ctrls/

 

How is this supported on RT?  Shouldn't these say they aren't available on RT?


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Hooovahh wrote: Basically anything using the front panel aren't going to be supported.  This is because there really isn't a front panel on an RT system.

Remote Front Panels are supported in RT.  And if you have an active connection to a RFP, then the front panel property nodes do not throw an error.  I am currently (grudgingly) doing this now with two different types of cRIOs.


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A lot of properties work on RT in the development environment, then return an error in an executable. Is that the case for the properties you're referencing, or do those return an error even in the development environment (when there is a front panel)? There are also front-panel properties that work in RT only when a remote front panel is connected (development or executable); I don't know if they return an error or just have no effect when there isn't a front panel connected.

 

I completely agree with your frustration about this, and I posted a related idea (which NI thinks is completed because they added a VI analyzer check for it; not sure I believe that solves the problem): http://forums.ni.com/t5/LabVIEW-Real-Time-Idea-Exchange/Warn-about-front-panel-property-node-use-whe...

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I would guess the FP properties would work on a RIO with embedded UI which may be why they are listed as supported
Matt J
National Instruments | CLA
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Hey thanks guys for opening my eyes a bit.  I often forget about all the different perminatations of RT systems.  I suspected the newer designs with a monitor might support these methods, but these properties pre-date that hardware so I didn't think that was it.  Remote front panels is one I didn't really think about.  I'm going to want to learn up on this technology and what it can mean for VI Server properties.


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@crossrulz wrote:

Remote Front Panels are supported in RT.  And if you have an active connection to a RFP, then the front panel property nodes do not throw an error.  I am currently (grudgingly) doing this now with two different types of cRIOs.


I'm not seeing this at the moment.  I have an RT system that is vxWorks.  I wrote a VI that would update a graph with random numbers, and it would also try to read the front panel property, and get a reference to all controls then return those control labels.  When running the VI on my Windows host it returns an error as expected.  I then setup Remote Front Panels and connected to it in a browser.  I even had control, but error 1013 still was returned. Is there some other trick you used to get this to work?


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If you run your RT VI directly from the project (which basically deploys the VI to RT and makes the front panel connection to the VI running in RT), you would be able to see your front panel running and showing the data from RT.  Here, you should be able to make use of property nodes.  I have used waveform chart property node to set its x-axis time intervals dynamically.

 

Thanks,

Ajay.

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@Ajayvignesh_MV wrote:

If you run your RT VI directly from the project (which basically deploys the VI to RT and makes the front panel connection to the VI running in RT), you would be able to see your front panel running and showing the data from RT.  Here, you should be able to make use of property nodes.


This is not true.  I have a project with one VI, in that VI I read the front panel reference, then get a reference to all controls in that front panel, and then read their labels.  When I run the VI from the project it deploys it to the RT and runs it showing the running VI in the host, but the first property node which is supposed to return the front panel reference returns an error 1013 Cannot load front panel.  I've also got this error after making a remote front panel connection.  Basically I'm asking when would this property node which states it runs on RT, actually work, and not return an error on RT?


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From what I remember - UI-related property nodes do not work in remote front panels.

 

The reason for some properties being supported on RT is for things like the embedded touch displays / touch panels that you can connect to some RT cRIOs. In this case - I think you can specify one VI (??) for the user interface - any properties that rely on the front panel being open/loaded (and are supported on RT) will work for that VI. All other VIs have their front panel removed during the build process.

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@Sam_Sharp wrote:

 

The reason for some properties being supported on RT is for things like the embedded touch displays / touch panels that you can connect to some RT cRIOs. In this case.


 


@Hooovahh wrote:

I suspected the newer designs with a monitor might support these methods, but these properties pre-date that hardware so I didn't think that was it..


Here is help from LabVIEW 2011 where it states the Front Panel property is supported in real time.  Which is before the RT hardware with video out, was released.

 

http://zone.ni.com/reference/en-XX/help/371361H-01/lvprop/vi_fp/

 

Oh and earlier I stated my RT system was vxWorks, I was mistaken it is Pharlap.


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