Webservice development for LabView PDA Module

[peter-biomed]

Webservice development for LabView PDA Module

I recently looked into web services integration in LabView and was quickly able to get something working in an application following some of the instructions available in Developer Zone. As my end goal, I want to have a web service working in a LabView Windows Mobile application, I ported the vi's created for my web service into the PDA vi, but when I built it, I got an error:

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WinMain is a missing VI or C file.

There was an error building the executable.  Please check the VI's or C files that were added.

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Given how the webservice vi's work (with the dll's and .NET), I wasn't surprised that it wasn't able to run in a LabView PDA application. Is there any way to get this type of routine to work? (beyond of course trying to work from straight TCP/IP routines)

Thanks for any advice!

ps. On another note, though still relating to the PDA module, does anyone know how to get transparencies working on a PDA module application? I've noted that all numeric and string controls and indicators always have a thin black border around them whether you like it or not.

[DanRichards]

Hi Peter,

I just want to clarify what your main goal is. Do you want to use webservices to access your PDA front panel across the network? How does that tie in to your application?

About the transparencies issue, you might have better luck creating a new thread for that one or search for others who have dealt with the issue. Although, I'll look into it if you bring it up again after we figure this one out.

Thanks,

Dan Richards

[DanRichards]

Also, which PDA are you using and with which OS? Thanks.

Dan Richards

[peter-biomed]

In my proposed application the PDA will be acquiring data and then passing it on to one of our servers, and the primary mode of receiving data on our server right now is through a webservice.

Currently, I am developing on a Dell Axim x51v for testing purposes, but will likely be moving on to the Motorola Symbol MC50 and MC70, and other devices when we get on to further development. These are working on Mobile 5.0 right now, but may have 6.0 running on them soon.

Thanks for looking into this Dan.

Regards,

peter

[DanRichards]

Hi Peter,

Webservices requires a Web server be hosted on the device. That would take up too much space on the PDA. I believe the best way for you to get data to/from your PDA would be through shared variables.

I recommend learning more by reading through the following article: Creating and Using Shared Variables in the LabVIEW PDA Module.

The link is http://zone.ni.com/devzone/cda/tut/p/id/5547.

Does this help?

Thanks,

Dan Richards

[peter-biomed]

Dan,

To clarify, I don't intend to host a webservice on the PDA. I see that LabView has the webservices vi's, but those aren't the ones I'm trying to use. I'm trying to use vi's I created using Tools>Import>Web Service. This creates a project and vi's for a particular webservice. When I try to use these vi's it gets the aforementioned errors. I do have other ways of getting data to the server, and I imagine the shared variables might be another one, but I wanted to see if there would be a way to call webservices from the PDA (as that is what is already setup on our servers).

Thanks for your help,

peter

[DanRichards]

Hi Peter,

Sorry for the slow reply. The advantage of Web Services is that you can stream data over a network in a standard HTML format so that any program, whether written in C++, Flash, or LabVIEW can access it and parse it for the appropriate information. Therefore, any computer system, including the PDA, that has access to the internet can acces the Web Service. The Web Services VI's will not run on the PDA because you'll need to create a custom program (of any format you choose) to get the data from the service and then parse that data to pull out the information you want. That parsing cannot be handled automatically on a PDA.

If you need further help setting up that custom program, I might suggest creating a new post with a title like, "parsing HTML data in LabVIEW PDA," and you'd be more likely to get more responders. Let me know if I can answer any more questions.