Eye diagrams / dots and vectors

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Iain C

Eye diagrams / dots and vectors

Post by Iain C »

Hi,

Does the Picoscope software have the option to display sample points without the line between them? (ie the "dots" or "vectors" option found on most other oscilloscopes)

The reason I ask is that I'm trying to create an eye diagram type view of a digital signal of around 250Mbit/s on a Pico 3206 (accepting that it will be distorted by the scope's analogue bandwidth).

I've tried using the Digital Colour display with infinite persistence and ETS sampling but as the signal is non-repetitive the scope displays lines between samples of the high and low levels.

If this isn't already an option is there any chance it will be added in the future? It would improve the accuracy of the persistent display with or without ETS. Or does anyone have any other suggestions for this application?

Cheers,
Iain

Michael
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Post by Michael »

Hello Ian,

PicoScope software displays samples with connecting lines. There is no current option to plot only samples. However, if you feel this would be of benefit to you and to others, we will consider including this option in future revisions.

Many thanks,
Michael
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Pico Technology
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Iain C

Post by Iain C »

Hi Michael,

Yes I think adding in the option to display samples only would be of great value in persistent display modes, for the reasons mentioned earlier. I'm sure many electronic engineers would like to use ETS mode for digital signals and this would make it possible - hopefully it's not too hard to implement either!

In non-persistent display mode then the high resolution of a PC screen compared to an oscilloscope's might mean that individual points would be hard to see when spaced out. However when straight lines are drawn between points that are quite spread out the result is a rather jagged waveform which I find harder to interpret visually than a series of dots.

Perhaps a future option could be to offer interpolation based on filtering (blocking frequencies above half the sample rate or even compensating for the scope/probe's analogue characteristics), and highlighting the actual samples in a different colour - this would give the closest representation of the information about the waveform that the scope is recording.

Maybe not - if you need to start doing these things it's probably time to invest in a faster scope! Worth a thought though...

Cheers,
Iain

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