PDA

[lleida]

Hello!

I would like to know that modifications have to make to pass of a labview program from the pc to a pocket pc.  
Do I have to create a new program? Do I have to work inside the panel Pocket Pc Screen.vi? 
And did she also want to know how the data are transferred from the pc to the pda?

Thanks,

Greta 

[ohiofudu]

Hi lleida,
All you need is a PDA module install in you Labview.The decumentation in the PDA module is very simple.In NI website there are  lots of matrials there about PDA.
Hope I am able to help.
All the best.
ohiofudu.

[tst]

You should consider the fact that while you can open your existing VI and convert them to PDA applications, you may run into some comptability problems. The PDA module doesn't support all the features that the desktop version has, so you may have to make some changes to adapt. This is documented fairly well in the manual. You should also consider the smaller screen of the PDA and the fact that only one window can be open at a time.

As for transferring the data, this can be done by using wi-fi (built into many PDAs) and LVs TCP functions. You can search for tutorials and examples about using TCP with LV on this site. If you were refering to transferring the program you built, this is well documented and is done using ActiveSync.

[Bandit]

Here are my observations. I'm fairly new to the PDA module myself, so they may be basic, but as they troubled me they may trouble you.

I'm finding it tricky getting going with LabVIEW PDA (for Pocket PC). tst says above "The PDA module doesn't support all the features that the desktop version has", I would suggest that the library of vi's is substantially less. Whenever I look for something I find usefull in labVIEW for PC, it never seems to be there in LabVIEW PDA. I'm generally working at a lower level.

The PDA module for Pocket PC utilises Microsofts SDK under the hood. The PDA simulator never seems reliable - a NI representative told me they find the same and prefer to use an actual device.

About 1 time in 4 executing code on the device has a problem, the execution fails. Sometimes I have to re-synchronise the PDA and PC, sometimes restart LabVIEW, sometimes both.

There is a documented problem with graphs, for me this shows up when they are on tab panels. Tab away and back again and the graph updates go wrong for a while.

Text on tabs doesn't fit right - descenders on the text (the tails on p, q, etc) isn't shown.

If you commonly fault find by hitting the 'lightbulb' button and watching your code execute on the screen, be aware that doesn't work when you are executing code on the target PDA device - you will have to find another way.

This is I believe the first issue of the PDA module, and it seems rushed out and incomplete to me. But you have to remember it's compared to LabVIEW for PC, which has gone through many versions and as a result is far more polished.

As the PDA module is a much younger product, there are far fewer posts on the user forums - which are normally a very useful place to get support.

Nevertheless I have been able to successfully communicate with measurement instruments via the RS232 serial port, display and chart measurements, and store them in a timestamped log file. Small achievments maybe, but then they are only first steps.

If you go for it - good luck.

[aartjan]

I have been using it quite a bit, and also tried to transform PC applications into PDA versions. It's not been much fun. So far I would blame most of the problems to the cluster datatypes, so my advice is to keep your datatype simple, like strings, numerics and arrays. I still have to proof to myself this solves my problems. At least I know now I will not refactor any more old programs, but always start with a new vi..

[tst]

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@Bandit wrote:

I'm finding it tricky getting going with LabVIEW PDA (for Pocket PC). tst says above "The PDA module doesn't support all the features that the desktop version has", I would suggest that the library of vi's is substantially less.

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I was not refering to supplied VIs, but to features - no support for property and invoke nodes, no display for arrays and clusters and so on. Version 7.0 didn't even have the tab control. All of these are available in the documentation. I wasn't planning on starting a whole PDA bug list, because that would be long (way too long) and unhelpful. You are right that there are a lot less VIs for the PDA than for the PC, but I didn't use a lot of them anyway, so that doesn't bother me usually.

We can only hope that the upcoming version 8.0 will show some significant improvement. The claims are that it should be out soon.

[Bandit]

Less vi's in the library is an additional point, but I tied it to less features as the common theme is less. It's important if you use them a lot, not so for tst who doesn't. However this makes me think - for me, the library of vi's are a feature of the development environment, I use them quite a bit. If your PC code does too, it's one more barrier to porting them to PDA.

This isn't the place for a buglist - I trust NI are keeping that, and when I think I have found one I let them know (but they usually already know anyhow).  But they are things that caused me grief, so I thought them worth sharing. Looking back to the original post maybe I wandered off topic...

To specifically answer the original post...

1. I find porting the code from PC to PDA tends to need a lot of modifications for a variety of reasons

2. You don't have to create a new program, but it often seems easier

3. You don't have to work inside the blank Pocket PC screen .vi, but for any .vi where you will show the front panel it seems best to do so.

4. Programs transfer through active sync. I use that to move other data too (e.g. data log files) as the only connection I have is through the cradle. 

[lleida]

Thank you very much to solve all my doubts.

Thanks. 

[tst]

The popular belief is that LV 8 should come out next week (have a look at NIs home page).

I don't know if the PDA module will be released at the same time, but you should probably ask your local NI office and wait until it comes out before buying.