Releasing control of Remote Panel generates Error 1 at property nodes

[Steve2571]

Occasionally when a user using remote panels releases

control of the panel the LabView program crashes with an Error 1 code at some of the property nodes.

Some of the property nodes are writes and some are reads.  Which one it errors on differs each time.

We are currently using Labview 8.2.1.  The program was originally written in Labview 7.0.  We did not

have this problem in 7.0.

I have been progressively removing some of the "offending" property nodes, but LabView just errors out with a

code of 1 on a different property node.

I believe there is a bug in the NI code for the remote panel somewhere.

If anyone knows a good workaround I would appreciate it.

Thanks in advance for any help,

steve

[Nadim R]

Hi Steve,

It may be corrective action request.  Do you get error 1 without using remote front panels and just run your program regularly with LabVIEW?  Woudl it be possible to post the snippet of code that is generating error 1 to this discussion forum (please make it small and compact if possible)?  From there, I will be able to test your VI and remote front panel and verify the results.

Regards,

Nadim
Applications Engineering
National Instruments

[SMeserve]

Steve,

I'm seeing a corrective action request related to the use of property nodes in VIs with the web publishing tool.  A workaround is listed:

"The error doesn't occur if one connects the error output of the property node to an indicator (simply right clicking on output and create an indicator) or if one disable the "Enable automatic error handling dialog" from Tools>>Options>>Block Diagram."

Thanks,

[Steve2571]

The workaround worked great Stephen!  Thanks to both Nadim and Stephen for your quick responses.

I will keep one eye open for the LabView update that will address this.

Thanks,

Steve

[Controls_Engineer]

Stephen,

Has the problem with the property nodes in VIs with web publishing tool been solved?

I am using LabVIEW 8.6 and still seeing the same problem.

Thanks,

Archana

[David_L]

Hello Archana,

I looked up the Corrective Action Request described by the Applications Engineer in the previous posts and this is not a bug.

It is a bad idea to use vi server to interact with front panel controls if the vi will be viewed over remote panels. The vi server properties are trying to access the controls on the panel in the browser that was just closed. The error is a valid error condition and should be reported.

The solution, as mentioned in the workaround, is to handle the legitimate error so the default dialog isn't popped-up.

Hope this helps,

[aleprogman]

Hi everyone,

concerning this topic, does anyone know how to get into the vi on the host machine a kind of signal when the client web browser (controlling the remote panel) is closing?

I just want to use that signal in order to shut down the circuit controlled through the vi to prevent a damage of the system.

Thanks in advance.

Alessio

[Deborah_B]

Hello Alessio,

Is this for a user-controlled web browser closing or for a situation where it closes on it's own, where we want a safeguard? There is a Wait for Front Panel Activity Function and a Remote Panel:Client Connections Method that may be useful to transfer the information necessary to then signal a case structure to shut down the circuit.

Thank you,

Deborah Y.

 

[aleprogman]

Hi Deborah,

the remote panel client connection method was exactly what I needed!

Thanks a lot,

Alessio

[clementw]

Hello all,

sorry for reanimating such an old thread.

I am still hitting this error in LabVIEW 2013. My application is quite big, that's why I have to use Property Nodes in Sub VIs to change Front Panel Elements in my upper VI (I read about this method somewhere in the forums and if I remember correctly, it's the recommend way for such a case).

Also, I can't just clear the error of the Property Nodes, because my Remote Front Panel will just stop refreshing, as the error will occur every time the Property Node is called.

I'm not opening the Front Panel via Browser, just pure LabVIEW.

Attached is a minimal non-working example. I am using LabVIEW 2013 SP1 32 Bit on Windows 7 SP1 x64.

Steps to reproduce:

- Open and run the Main VI on the Local Server.

- Connect to the Server from the Remote Client with "Request Control" enabled.

- Release control on the remote side or just close the remote window.

Main VI:

Sub VI:

Much thanks in advance,

Clement