web page configuration tool freezes in 8.6 with DSC

[Lenvno]

I am developing a DSC application in LV8.6.   I have no problem with configuring the web page server for small test applications including those using a hypertrend control.  My larger application with shared variables, IO servers etc causes a problem.  When I open the web page server configuration tool, it is practically non functional.  I set any option on the first page and it then freezes and I need to stop LabView using Windows Task Manager to get out of the state.   Are there portions of LabView or DSC that can crash the web page configuration tool?

Thanks for your help.

Len

[Jeremy_B]

Are you referring to the Web Publishing Tool, or the web server configuration in the Tools>>Options menu?

[Lenvno]

Hi Jeremy,

I am refering to the Web Publishing Tool.   I can select the vi to publish or the mode then the page and LabView freeze.

Len

[jpaul]

Hi Len,

There are no know issues of DSC applications freezing the web publishing tool; however, I have seen a large application in LabVIEW 8.5 take a long time to load in the web publishing tool (for which I filed a Corrective Action Request with R&D). I have a few follow up questions in order to try to isolate the issue further:

1- Are you able to narrow it down to specific VIs (using the diagram disable on chunks of your code) ?

2- How long are you waiting before shutting LabVIEW down? I want to try to differentiate between it freezing/crashing LabVIEW or taking a long time.

Thanks!

Jonah P

Applications Engineer

[Lenvno]

Hi Jonah,

Thanks for the reply.  I did not wait very long at all.  There appeared to no disk activity and the items on the screen were not responding so I assumed frozen.  I will do some testing to see if waiting helps.  Do you know the name of the processes that will show up in the Windows Task manager while the web page is being generated?  That would let me know it is working.

Regards,

Len

[NathanK]

Lenvno,

There are only two things that the Web Publishing Tool does that could take any significant time. It loads the VI and generates an image of the front panel. This can take a while if it takes a while to load the VI. If vision is installed it will also scan the front panel to check if the vision control is used. This should be very fast but could conceivably take some time if the front panel was very very large.

I suspect that the problem is that it takes a while to load the VI and acquire the picture of the front panel. Especially as you said that your smaller application does not have the problem. The WPT allows you to select already opened VIs or select unopened VIs from the filesystem. Do you see the same delay (or hang) if the VI is already loaded before opening the WPT?

Unfortunately you would not be able to see any processes in the task manager because the Web Publishing Tool runs inside of the LabVIEW process.

Nathan

Message Edited by NathanK on 03-02-2009 01:53 PM

[Lenvno]

Hi Nathan,

I have only tried using the web page tool with the vi loaded.   I checked the Windows Task Manager and the Labview process is taking almost 100% of CPU time. I did let the thing run for 10 minutes before cancelling and an HTML file was generated but it was not complete.  I will let it run longer to see if it works.   I must have something in my application that is causing a problem with generating the image file for it to take so long.

Len

[Lenvno · Accepted solution]

Nathan,

I now have a working web page. Thank you for your help.  It took a very long time to generate but the result is a webpage that works as expected.  I am still in the dark as to why my application takes so long to start and why the web tool took so long to do its job.  The two things may be related.  Is there an obvious way to debug startup to  identify slow loading components?

Regards,

Len

[NathanK]

I'm glad to hear that you had some success. If you can ever narrow down what it is about the VI that caused the WPT to have issues let us know.

If you have similar issues in the future I would recommend generating the web page with the WPT for a smaller VI. Then manually edit the HTML to replace the name of the simple VI with the name of the actual VI you want to control. The generated HTML is quite simple.

I will take a look at what could slow the WPT down and if it is the image generation we can do something about it. The preview pane is not the most important part of that tool after all.

Nathan

[NathanK]

Lenvno,

Another followup- I had a talk with the DSC developers and they were not aware of anything that could be taking that much time at VI load time.

There were a couple things you could look for-

Try mass compiling your VIs. It may be that they aren't linked correctly and you are searching for pieces.

Similarily, if any parts of your application are on a network share make sure they are in the right place. That is- make sure your VI is loading them from where they really are. Doing a search for missing subVIs over a network share can take a very very long time.

A front panel with a lot of controls bound to variables can take a little while to load. This one shouldn't be as long as what you have described though.

Thanks,

Nathan