Interface Via Web

[tolima]

Hi Everyone, I am developing a remote lab which consist: Acquisition of data from a fpga directly to labview through RS232, these data are processed in three graphs to be visualized by the user in real time. My question is: what is the best method for exporting the interface in labview via web to the user without run time engine from labview? I have seen that web service is not recommended for time-sensitive apps. I really appreciate your help.

[nathand]

Where are you seeing that web services are not recommended for time-sensitive applications?  They would not be ideal for time-critical data transfer between computers, but for display of live data to a user they should be acceptable, and you don't have many other options without the run-time engine.  Web services will give the user some control over the application and the data display.  If the user needs only to see the data and does not need to interact with it, you can load the VI's front panel as an image within a web page and refresh it regularly.  Anything else will require either the run-time engine or a lot of custom code.

[tolima]

so, are you saying that the user can view an interface with 2 or 3 graphs like the example in the attachment? My doubt relies in the update speed of the web page for the case of web service.

Now, guessing that the update speed is high to view prefectly the web page; Web Service give me like a .xml which i use it to organize the data in a web page through Html+Javascript (ADOBE FLEX in the NI example ). Is there any advice to take the data in realtime generated by my Graphs Vis and put them in a "dynamic xml" generated by web service of labview?

I am saying this, because i was watching the example "Demo 2 - Function Generator Main" and I think that it doesnt matter if the vi is running, anyway the user will view data preestablished by the web service through the xml, unlike the remote panel option, where if the VI in the web server stop working, the user too.

I dont know if i am clear. Sorry, I am still learning english. 🙂

[nathand]

Yes, you can view an entire front panel as an image.  Look at the Web Publishing Tool under the Tools menu.

I have not used the LabVIEW web services for streaming data, so I cannot provide much help with it.  That said, I don't understand your question.  Where is the demo that you're looking at?  If the VI is generating data, and it stops, the display should stop showing new data as well.

One more option to investigate is WebSockets.  I haven't used this at all, I just remember seeing some posts about using them with LabVIEW:

http://lavag.org/topic/13777-labview-websockets-and-svg/page__view__findpost__p__82819

http://decibel.ni.com/content/docs/DOC-14226