EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: Athanasis on May 27, 2016, 06:34:27 am
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Hi guys. This is a broad thread, but I would really like to ask if I can use some math functions to plot graphs (simple X-Y axis) with RIGOL DS1054Z.
In particular, I am looking into plotting the graph of dependence of Frequency coming from Channel 1 (X-axis) on Voltage coming from Channel 2 (y - axis).
e.g Provided that input values change, is it possible to produce something similar to this with this oscilloscope in real time ?
(http://www.fhwa.dot.gov/publications/research/infrastructure/pavements/12072/images/fig058.gif)
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If your oscillator frequency is controlled by a voltage, you could use that voltage for the X axis instead of the frequency. In that case the scope can measure and display the two voltages directly, in X/Y mode. (The DS1054Z is not great for X/Y mode though, since it always reserves part of the display for the time trace.)
If you need to measure the frequency and use that in the plot, I don't think the scope can generate such a plot on its own. This would be a typical task for a PC-controlled automated measurement setup: Have the PC control your oscillator and scope, e.g. using LabView, and collect and plot the results on the PC.
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Hi ebastler. Yes thanks for giving light on the X/Y mode function of oscilloscopes. It is not a big deal that frequency has to be voltage on the X axis :bullshit:. I can construct a simple Voltage to Frequency circuit (there are a couple of ICs around that can do this) and then perform the measurements :-DMM.
My main concern is that as you said, the DS1054Z is not great in X/Y mode, but I will try to test this my self to see how it shows. :-BROKE
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You can get frequency-to-voltage converters...
http://www.ti.com/lit/ds/symlink/lm2907-n.pdf (http://www.ti.com/lit/ds/symlink/lm2907-n.pdf)
But yes, it's a little bit outside what oscilloscopes are designed to do out-of-the-box (and not just the DS1054Z).
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... I can construct a simple Voltage to Frequency circuit (there are a couple of ICs around that can do this) and then perform the measurements :-DMM.
Yes, that should work well.
Not sure how you had originally planned to obtain the scanned frequency signal? If you have an old-fashioned frequency generator with sweep function, it might have a sweep reference output which also supplies a voltage that is proportioal to the frequency. (For use with your favorite analog chart recorder ;).) I don't know how modern function generators implement this, since all I have ever used are older analog models, but would assume that they also offer this kind of reference output?
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There is Amplitude by frequency
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What you are basically looking for is a Network Analyzer - amplitude versus frequency. This is one of the features built in to the Digilent Analog Discovery. See what I did there? I got a plug in for what I consider the most useful gadget on my bench. And I have the DS1054Z... Different tools for different applications, I guess.
On the 1054, XY mode appears to be an afterthought and the display is rather limited. I haven't pushed all the buttons but I was able to plot a circle from a sin(t) and cos(t) pair of inputs. I really didn't need the YT display at the top of the screen but I didn't find a button to get rid of it and expand the XY display. Still, it worked.
I plan to use XY quite a bit. I may not be doing it on the DS1054Z.
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There is Amplitude by frequency
???
Could you elaborate, please? Are you referring to an operating mode of the DS1054Z, or of frequency generators?
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Thank you friends.
Point is that frequency to voltage converters would not combine perfectly with the X-Y mode of any oscilloscope. X-Y mode spits out only a dot at any particular moment. It does not make whole graph curves on linear (one off) DC fluctuations between 2 points of a circuit. !
I was thinking, If I could export the X & Y voltage Values into 2 respective columns in an Excel spreadsheet, then I could easily construct a graph (in Excel). I don't know if anyone knows how to do this e.g. using DS1054Z USB to PC connection !
There is Amplitude by frequency
I don't get you ebclr. What do you mean? Where?
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(http://www.medicao.com/rigold105401.PNG)
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[FFT screenshot]
Ah -- but that is very different from what the OP wants to measure. What Athanasis is looking for (I understand) is a graph showing how a system reacts to different input frequencies which are applied sequentially, one after the other. In contrast, the FFT shows what frequencies are present simultaneously in an input signal which is a complex mix of different frequency components.
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Yes, FFT is a different thing. It is like a spectrum analyzer of a single input. I was talking about graphical representation of 2 inputs on Y and X axis ! :-+
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(photograph of fft screen display)
What you really have to ask yourself.... ;) .... is how to get a _useful_ FFT display (and image thereof) from your DS1054z:
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Yes, FFT is a different thing. It is like a spectrum analyzer of a single input. I was talking about graphical representation of 2 inputs on Y and X axis ! :-+
DSOs, especially low-end ones, are just not very good at displaying X-Y mode. The DS1054z is especially frustrating since you can't even show the X-Y display in a fullscreen window. But by fooling around with the settings you can usually get a semi-reasonable X-Y mode display. Still not as good as what you can get from a decent analog scope though.
You can always dump your trace data to a spreadsheet-readable file and then make your graphs from that. But to do it in realtime on the scope screen.... that will take some doing, such as using the frequency-to-voltage converter mentioned above, and then you will still be limited by the x-y display mode functionality of whatever scope you are using.
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In particular, I am looking into plotting the graph of dependence of Frequency coming from Channel 1 (X-axis) on Voltage coming from Channel 2 (y - axis).
What you're describing is not unlike aligning a radio using a sweep generator and an oscilloscope. The sweep generator produces a sweeping frequency to drive the device under test, as well as a voltage signal to drive the X axis of a scope. The output of the device under test then goes to the scope's Y input.
I tried doing this using the XY mode on my DS1054Z, but quickly realized my old analog BK precision scope buried in a box in the garage would be more suitable and switched to that. If you want to see a really good demo of radio alignment on an analog scope, see w2aew's video, https://www.youtube.com/watch?v=-A_DxsxPdeI. (https://www.youtube.com/watch?v=-A_DxsxPdeI.) The good news is that you can pick up sweep generators and analog scopes pretty cheap on ebay if you desire.
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Is there a WAV file out there for that scope clock?
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What you really have to ask yourself.... ;) .... is how to get a _useful_ FFT display (and image thereof) from your DS1054z:
Here we go... the Rigol bashers have arrived in the thread. :scared:
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What you really have to ask yourself.... ;) .... is how to get a _useful_ FFT display (and image thereof) from your DS1054z:
Here we go... the Rigol actual users have arrived in the thread. :clap:
Fixed that for you.
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Is there a WAV file out there for that scope clock?
The scope clock display is generated in realtime by a kit available (sometimes) from Dutchtronix.
http://www.dutchtronix.com/ScopeClock.htm (http://www.dutchtronix.com/ScopeClock.htm)
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Buying a kit is a bit overkill to just text/play with XY mode.
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The scope clock display is generated in realtime by a kit available (sometimes) from Dutchtronix.
http://www.dutchtronix.com/ScopeClock.htm (http://www.dutchtronix.com/ScopeClock.htm)
Thanks. Now that $30 isn't burning a hole in my pocket anymore.
Buying a kit is a bit overkill to just text/play with XY mode.
That's what Lissajous patterns are for! A couple of frequency generators is all it takes.
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I bought my DS1054Z for the purpose of using the 4 channels to display the SPI bus AND for the single trigger digital storage features that I can use with my Analog Computer. I have attached a screenshot of Damped Harmonic Motion (a second order differential equation) as well as a snapshot of the front panel of my tiny AC. Next up, track down the noise and, once that is understood, I want a larger AC.
The DS1054Z will be perfect for my applications. Absolutely perfect!
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What you're describing is not unlike aligning a radio using a sweep generator and an oscilloscope............
I ve got this, which has a sweep generator function.
(https://i.ytimg.com/vi/zSJtyfc2Kqg/maxresdefault.jpg)
Point is that I don't know how I can get a frequency to voltage out of this thing.
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.....You can always dump your trace data to a spreadsheet-readable file and then make your graphs from that.....
Wonderful clock view on the analogue screen !!!!
Thank you for your advice. The best way is to dump the data into spreadsheet and then make the graphs in excel. There is a USB port in front of my DS1054Z. I bet I can use a USB memory stick to dump the data...
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What you really have to ask yourself.... ;) .... is how to get a _useful_ FFT display (and image thereof) from your DS1054z:
Here we go... the Rigol bashers have arrived in the thread. :scared:
Those who bash the rigol on FFT are missing something here. Even Dave made an unfair comparison in this video:
https://www.youtube.com/watch?v=07VkEUUd0eo (https://www.youtube.com/watch?v=07VkEUUd0eo)
This is because Dave in his comparison didn't use the Deep Memory feature (switching the mode from "Trace" to "Memory") available in new Rigol DS1054Z firmware versions (Dave you were unfair and many people believed in your review). This is how you get the real FFT on the DS1054Z
https://www.youtube.com/watch?v=dD-3ni7tYM4 (https://www.youtube.com/watch?v=dD-3ni7tYM4)
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This is because Dave in his comparison didn't use the Deep Memory feature (switching the mode from "Trace" to "Memory") available in new Rigol DS1054Z firmware versions (Dave you were unfair and many people believed in your review). This is how you get the real FFT on the DS1054Z
Little bit better than it was but still a completely useless joke.
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This is because Dave in his comparison didn't use the Deep Memory feature (switching the mode from "Trace" to "Memory") available in new Rigol DS1054Z firmware versions (Dave you were unfair and many people believed in your review). This is how you get the real FFT on the DS1054Z
Little bit better than it was but still a completely useless joke.
Let's see: The cheapest spectrum analyzer on Batronix is over $1000
http://www.batronix.com/shop/spectrum-analyzer/index.html (http://www.batronix.com/shop/spectrum-analyzer/index.html)
But somehow you want that included as standard in a $400 oscilloscope? :palm:
Hey, don't let that stop you wrecking another DS1054Z thread though. Gotta keep the standards up.
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But somehow you want that included as standard in a $400 oscilloscope? :palm:
Hopefully this tread won't be derailed but GW instek somehow offers 1 million point FFT in their <$400 GDS-1054B. Which is proven to work very well. And after the firmware update, it became much easier to use than on Daves's video where he admits it works well but don't like clunky control.
Hey, don't let that stop you wrecking another DS1054Z thread though. Gotta keep the standards up.
Frankly you should be the last person saying this, because you are bashing every other scope other than Rigol in non Rigol treads. Or bringing other manufacturers in treads about Rigol issues and derailing them in this way.
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Gentlemen, can we please stop turning yet another thread into a useless argument about the value or non-value of Rigol's FFT implementation? As already confirmed by Athanasis, the application he is interested in has nothing to do with FFT.
Thanks!
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This guy is selling a Keisight on ebay, and try to blame the best performance value on the market ( rigol ) to help he find buyers interested this expensive crap time bomb
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Frankly you should be the last person saying this, because you are bashing every other scope other than Rigol in non Rigol treads. Or bringing other manufacturers in treads about Rigol issues and derailing them in this way.
Really? Examples please. :-DD
No don't bother. I already know what you're thinking. It's true I did mention "Rigol" in both of the threads about Keysight failures - but only to point out that people like you were defending Keysight where you'd be attacking Rigol. Outside of those two threads? Not a chance. Why on earth would I go into a thread about more expensive scopes and say anything about Rigol. I freely admit that more expensive scopes are better - why wouldn't they be?
But somehow you want that included as standard in a $400 oscilloscope? :palm:
Hopefully this tread won't be derailed but GW instek somehow offers 1 million point FFT in their <$400 GDS-1054B. Which is proven to work very well. And after the firmware update, it became much easier to use than on Daves's video where he admits it works well but don't like clunky control.
Sure, but the $400 GW-Instek is only 50Mhz, no serial decoders, less memory... it loses out to the Rigol on other ways.
Besides, not everybody is obsessed by FFTs. The fact that the DS1054Z's FFT is a weak point doesn't mean that people shouldn't buy them
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This guy is selling a Keisight on ebay, and try to blame the best performance value on the market ( rigol ) to help he find buyers interested this expensive crap time bomb
LOL, really? Guess who is topic starter: https://www.eevblog.com/forum/testgear/agilent-u1272a-crappy-soldering/ (https://www.eevblog.com/forum/testgear/agilent-u1272a-crappy-soldering/)
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Sigh.
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Sigh.
+1 or :-DD I don't know what came out first.
What did you expect other than another pissing competition. :scared:
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Back to the topic. If you manage to sweep CH1 so the whole frequency range fits inside the screen (roll mode could be useful for this) and measure the voltage with CH2 then you can get something like what asked in the first post. There won't be any frequency divisions on the screen, however if you want to check precisely, you can later zoom in (acquisition stopped) and check the frequency at particular part with automated measurement. And you can check actual voltage at this frequency in this part with automated voltage measurement on CH2.
(https://www.eevblog.com/forum/testgear/what-else-can-i-do-with-rigol-ds1054z-appart-from-measuring-waveforms/?action=dlattach;attach=228237;image)
(https://www.eevblog.com/forum/testgear/what-else-can-i-do-with-rigol-ds1054z-appart-from-measuring-waveforms/?action=dlattach;attach=228239;image)
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Another solution would be to use segmented recording (trigger on the sine wave) and read the values from automatic measurements while scrolling through the segments.
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Thanks for your suggestions guys but they all sound pain in the ass. The best solution is exporting into Excel of lets say 100 different Values on 2 columns (CH1 and CH2) and let Excel plot the curve. I haven't tried it out yet but I read that Rigol can write Data on a USB memory stick.
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Yes, you can write the waveform data in CSV format to a USB stick. Then, load it into your favorite spreadsheet and make graphs.
(No brands were harmed in the production of this forum post.)