Amplitude Problems

Post your LabVIEW discussions here
Martyn
Site Admin
Site Admin
Posts: 4491
Joined: Fri Jun 10, 2011 8:15 am
Location: St. Neots

Re: Amplitude Problems

Post by Martyn »

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
Martyn
Technical Support Manager

ulek
Newbie
Posts: 0
Joined: Tue May 28, 2013 8:52 am

Re: Amplitude Problems

Post by ulek »

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

ulek
Newbie
Posts: 0
Joined: Tue May 28, 2013 8:52 am

Re: Amplitude Problems

Post by ulek »

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.

Martyn
Site Admin
Site Admin
Posts: 4491
Joined: Fri Jun 10, 2011 8:15 am
Location: St. Neots

Re: Amplitude Problems

Post by Martyn »

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 479 times
Martyn
Technical Support Manager

Post Reply