02-03-2010 03:19 AM - edited 02-03-2010 03:24 AM
Hi all!
Here is a simple VI containing no controls, functions or libraries in LabView 2009 f3.
WebServer settings are default. After Tools->Web Publishing Tool operation from other PC we are connecting to this panel (IE6 for example) and putting a finger to F5-button not raising it.
Web page with the VI is refreshing continiously.
There are 3 results.
1. In DevEnv: LabView die.
2. In DevEnv: Need to restart LabView so WebServer reloads and connection restores.
3. In App.exe: die
4. In App.exe: LabView interpreter loose some while-cycles in case they exist but connection stored.
5. In App.exe: connection lost but the application working good.
Is it normal? Is there any WebServer settings to avoid this situation.
Solved! Go to Solution.
02-04-2010 10:32 AM - edited 02-04-2010 10:32 AM
Hey kolan,
Is there a reason why your are holding down F5 in your internet browser to try to continuously refresh the page. I am not sure I can think of a used case for doing something like this. Even if you were trying to monitor a VI continuously, it would take time to reload the page and even if everything worked as expected, you wouldn't be able to see your front panel because it would be in a continual state of refreshing. In regards to the outcome of this test, when you say the "DevEnv" are you referring to the development machine running the VI and when you say App.exe are you referring to the instance of internet explorer trying to view the front panel?
If you are looking to view your VI as it is running, you should use the 'Embedded' Video mode. This allows you to view the front panel as it updates so there would be no need to refresh the browser.
02-04-2010 02:06 PM - edited 02-04-2010 02:08 PM
Good evening BCho!
Pressing F5 is just an action which shows a way to achive LabView crash state.
Another way is closing Web-browser on client's PC when it connected to LabView's server.
App.exe - is an executable VI made by an action: Tools->Create an executable
VI may not be downloaded when I press F5 again.
This methods shows that LabView crashes when improper client's request sent.
Does the NI-website die when you close Your browser ?
(DE=DevEnv=Development Environment, App.exe - higher)
No, there are no reasons to do something what wouldn't help to find a solution.
02-05-2010 09:20 AM
02-05-2010 12:21 PM
The result appear not every time.
For a simple panel with no controls it can be reproduced on 20-40 webpage refresh or disconnect from remote panel.
For a panel with 2 buttons, one XY-chart, 2 tab controls and 2 multilists it can appear immediately or on 5-10 reconnect time.
There is a probability which is proportional network speed and number of controls.
LabView does not handle incorrect request and die/hangups/lost connection or begin to behave unexpectedly.
02-08-2010 04:29 AM
Just look at this example (in attach) which reproduces one of the problems... And sorry for my bad english, I hope You understand me...
Now we have to deliver the software to a customer (and register LV9) but this BUG...
02-08-2010 04:45 AM
There are bugs in LabView WebServer EVENTS and PROPERTY code. Not in the LabView engine!!!
LabView developers need to include checkups between WebServer and LabView engine for improper data sending and to reject all unknown data.
02-08-2010 05:37 AM
But if it is too hard to add such checkups into web-server because it may doesn't know anything about send/received data the second way is to realize verifications in the ThEvent.cpp and ThProperty.cpp LabView source code files. But the second way is a bad idea because the error and it's checking must be in one place.
I expect for Developer's reply
02-08-2010 07:54 AM - edited 02-08-2010 07:54 AM
02-08-2010 10:54 AM
Hi Kolan,
I'm still not sure why you would want to continuously refresh the page by pressing F5 repeatedly. Do you see any issues when you are running the VI in "embedded" mode?