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Amplitude Problems

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Re: Amplitude Problems

Postby Martyn » Wed Jun 26, 2013 10:51 am

Before running the code can you try going in to the sub vi and changing the default range to the actual range you require (say 5V rather than 100mV) and save it. It is possible the scope is always set up according to the default value in the settings vi and your changes are not being acted upon.

I can't check at the moment as the Labview PC is in use by a colleague
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Re: Amplitude Problems

Postby ulek » Wed Jun 26, 2013 11:37 am

I don't think that is an issue of the defeault values as the channel setting overrides it and does't change anything when I change the defaults at the channel settings.

Maybe pictures will calrify more what is happening better
First I check whether my FG is set correctly using the original software.
https://www.dropbox.com/sm/create/picoout.PNG
So I get 5V which is what i want

Then I go to lab view and this is what happens
https://www.dropbox.com/sm/create/labview100mv.PNG
https://www.dropbox.com/sm/create/labview200mv.PNG
https://www.dropbox.com/sm/create/labview500mv.PNG
https://www.dropbox.com/sm/create/labview1v.PNG
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Re: Amplitude Problems

Postby ulek » Wed Jun 26, 2013 2:20 pm

Ok. This is probably the most stupid thing that was overlooked but, the probes are x10.
Thus my votage reading of 5V will be read as 500mV thus it will not saturate at 500mV.

Simple x10 after the buffer will fix it.
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Re: Amplitude Problems

Postby Martyn » Tue Jul 02, 2013 8:09 am

I have just tried your Prototype vi, I had to tidy up the Channel A settings wire links to the PS6000Settings block, as far as I can see it is all working correctly.

I am feeding in a DC voltage which I can adjust up to 2V, I have set the Channel Settings Voltage 2V and the range cobo just above it to 2 and I am seeing the correct ADC count in Graph 3 and the correct DC value in Graph 1

I have attached the modified vi
Attachments
Prototype_Rev_4_a (2).vi
Ammended Vi
(66.68 KiB) Downloaded 111 times
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