Pico Technical Support and Discussion Forum

Guest · Posted: Wed Jul 05, 2006 2:10 pm Post subject: Labview problem

Hi,

I am writing a software such that I am reading the data using the ps3000_get_values by using a while loop. I then save the waveform for each loop. However, whenever it reaches track 78, the ps3000_get_values will not read and the program (labview) will just get stuck. Any help on this one? Is there a limitation on running the function?

p.s I am running the picoscope 3424.

Thanks
Jason

Michael · Posted: Thu Jul 06, 2006 9:20 am Post subject:

Hello,

This sounds like your loop iterations are not being saved correctly. Are you running out of file space?? Has anyone else seen this problem?

Please post your VI so we can have a look for you.

Any other LabVIEW users please offer your suggestions.

Best regards,
Michael

jlamuda · User Joined: 22 Jun 2006 Posts: 2

here's the vi attached.
I dont think it's the loop problem. I checked it again and the program seems to be stuck at the ps3000_get_values

any help will be appreciated.

Thank you

Michael · Posted: Mon Jul 10, 2006 9:13 am Post subject:

Hello Jason,

Thank you for the VI.

OK. A couple of things here. I am guessing you are using the supplied example VI's as standard except a modified "Set_Channel" VI.

The problem appears to lie in the setup data collection portion of your main VI. The Scope is setup for data collection using our standard "setup_data_collection" VI. Then your VI moves on to the "get values" part to retrieve data from the scope. The data collection VI will be setup incorrectly for your application. You will need to cut and paste our VI to suit your main VI.

Do as the following order:
1: At the start of your main VI, open the ps3000(causes the longest wait).
2: Setup your channels and inputs.
3: Set the trigger to sync your test(you only need to call the ETS functions if you need them).
4: Set the sample interval and No of samples.
5: Call the Run Block function.

Now run your motion control side.
6: Call the "stop" function when motion cycle is complete
7: Now call the "get values" function and view the data as you wish.
8: When you have completed your tests, call the "ps3000 close".

During your test, loop steps 5-7.

I hope this helps.

Best regards,
Michael

Guest · Posted: Mon Jul 10, 2006 1:30 pm Post subject:

Hi,

Sorry for the trouble but I have one quick question. I am wondering what do you mean when you call Run Block function. Am I supposed to put the setup_data_collection in the while loop that I am running too?

Thank you so much for the help
Jason

Michael · Posted: Tue Jul 11, 2006 9:07 am Post subject:

Hello Jason,

No need to put the setup data collection in the loop. This would only slow down the converter. You would only need to call this section if you made any changes to the scope settings. Try to avoid this if you are looking for fast data transfer with minimal refresh time intervals.

Best regards,
Michael

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