Picoscope 4226 Scaling

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Alex M
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Joined: Mon Jul 02, 2012 6:54 am

Picoscope 4226 Scaling

Post by Alex M »

Hello Everyone!

I am using Picoscope 4226 for a project which I would like to make in Labview 2011. Based on the streaming example posted here : http://www.picotech.com/support/topic4802.html I am trying to get some data from a device to make a graph. When picoscope scale is set to 50 mV I get for example 7 mV as a measurement (which is right). When I set it to a larger scale I get other measurements like 12mV, 20mV, 35 mV depending on the scale value I use. This happens no matter If I use Labview or Picoscope 6 Software. This wouldn't be a problem but my measurements should be -+2mV accurate and my signal is a 50Hz signal with many spikes. What I really need is to measure the spikes but one spike can be 10mV and the other 200mV or much more. I tried changing the value of "update settings" button on the example given above from True to False when my values exceeded the maximum of each scale but when the picoscope changes a scale, It resets and needs some time until it reads again. Since I am having this overscale and underscale all the time, I get a reset of my picoscope all the time and of course very few measurements which are wrong. Does anyone know how I can avoid this reseting effect?

Thank you in advance,
Alexandros Michas

Martyn
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Re: Picoscope 4226 Scaling

Post by Martyn »

The scope will provide ADC counts which will need to be converted to voltages dependant upon the voltage scale that the scope is set to, is it possible that this adjustment is not being made ?

Post your Labview code and we can take a look, either here or at support@picotech.com
Martyn
Technical Support Manager

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