Poll

Can you reproduce the Freeze-up Bug as described in this thread?

Yes, can reproduce the freezing.
42 (40%)
No, can't reproduce the freezing.
63 (60%)

Total Members Voted: 100

Author Topic: Rigol DS1054Z Freeze-up Bug Confirmed ??  (Read 136548 times)

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Offline W7NGA

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Re: Rigol DS1054Z Freeze-up Bug Confirmed ??
« Reply #150 on: June 09, 2015, 05:36:03 pm »
Your FFT display is exactly what I would expect.

Why would you not expect the FFT computation to be dependent on the acquired dataset and the filtering/windowing imposed?
« Last Edit: June 09, 2015, 05:40:36 pm by W7NGA »
 

Offline John Coloccia

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Re: Rigol DS1054Z Freeze-up Bug Confirmed ??
« Reply #151 on: June 09, 2015, 05:49:51 pm »
Not entirely sure I really understand the FFT problem either.  I haven't really looked at it yet.
 

Offline alsetalokin4017

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Re: Rigol DS1054Z Freeze-up Bug Confirmed ??
« Reply #152 on: June 09, 2015, 11:08:13 pm »
Your FFT display is exactly what I would expect.

Why would you not expect the FFT computation to be dependent on the acquired dataset and the filtering/windowing imposed?
In the two images I showed, the input signal (from the Calibrator) is exactly the same 1kHz square wave, BW limiting is on in both cases, fft Blackman windowing with Center Frequency at 3kHz is used in both cases, trigger level is set the same in both cases, memory depth is the same in both cases, all other signal and scope parameters are the same, except Acquire Mode. The only difference between the two shots is that in one case the Acquire mode is set to Normal, and in the other case the mode is set to High Precision. The FFT of a 1KHz square wave should consist of peaks at the fundamental (1 kHz) and the odd harmonics (3, 5, 7, etc kHz) without the secondary peaks that show up at the _even_ harmonics that are seen in "normal" acquisition mode. But I'm sure you know this already.
Furthermore, even when High Precision is selected, the resulting FFT display depends on Memory Depth, as Anand noted.

Why would you expect the FFT of a fairly clean 1kHz square wave to show peaks at even-numbered harmonics when a scope is set to "normal" acquisition mode, or indeed at any time? Not arguing, just curious. I'm sure that you probably have a lot more experience with digital scopes than I do, or than most DS1054Z purchasers might have. We just expect to see something that looks like what the textbooks show, I guess!



The easiest person to fool is yourself. -- Richard Feynman
 

Offline John Coloccia

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Re: Rigol DS1054Z Freeze-up Bug Confirmed ??
« Reply #153 on: June 09, 2015, 11:24:40 pm »
His point, I think, is that there's no such thing as a square wave...it's a squarish wave, and it will not be perfect, so you won't see a perfect spectrum. Only way to really know if it's right or not is to download the waveform and run an FFT on your PC, if you're really interested.

You also have to wonder about the various settings, maybe windowing...whatever.  It's definitely something to investigate for someone who has the time and will, but I wouldn't be ready to declare a problem quite yet.
« Last Edit: June 09, 2015, 11:33:13 pm by John Coloccia »
 

Offline miguelvp

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Re: Rigol DS1054Z Freeze-up Bug Confirmed ??
« Reply #154 on: June 09, 2015, 11:44:49 pm »
This is the rise time of the 1KHz test signal on a DS2000 the DS1000z is probably about the same:



That's 11 divisions at 500ns per division so about 5.5us rise time, so the FFT is not going to be perfect.
Fall time is probably as bad.
 

Offline alsetalokin4017

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Re: Rigol DS1054Z Freeze-up Bug Confirmed ??
« Reply #155 on: June 10, 2015, 12:24:58 am »
Sure, but as we asked in another thread... which display is "more correct" then? If you expect to see some "even harmonic energy" due to the slow risetime, why does that show up in the "Normal" mode but not in the "High Resolution" mode? Would one not expect it to be the other way around?

The easiest person to fool is yourself. -- Richard Feynman
 

Offline GlowingGhoul

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Re: Rigol DS1054Z Freeze-up Bug Confirmed ??
« Reply #156 on: June 10, 2015, 12:51:28 am »
I sincerely hope that this bug does not discourage hobbyists from purchasing this scope. I bought the scope last week and immediately put it through the paces of debugging a relatively sophisticated amateur radio application I designed using both SPI and I2C data busses. Never a problem and very impressive performance. I also have an Agilent 7014B right beside it and the only fault I can find is somewhat sluggish operation with everything enabled (triggering/decoding), and the smallish fonts. Yes, there are few other things with persistence (forgetting settings when powered on e.g. measurement font) but for $380 (Tequipment with eevblog discount and free shipping), this thing could lose three channels and I would still be thrilled.

Indeed, it is the best thing going for the hobbyist. I am thinking of purchasing three more for the robotics class I teach. What a bargain!

dan W7NGA

I get the feeling you'll be seeing plenty of used units up for sale soon.
 

Offline miguelvp

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Re: Rigol DS1054Z Freeze-up Bug Confirmed ??
« Reply #157 on: June 10, 2015, 01:04:19 am »
Sure, but as we asked in another thread... which display is "more correct" then? If you expect to see some "even harmonic energy" due to the slow risetime, why does that show up in the "Normal" mode but not in the "High Resolution" mode? Would one not expect it to be the other way around?

Check w2aew's videos regarding this, of course those scopes he uses have more features but higher price scratch that, he is using just the scope features not the spectrum analyzer so it's about in par what the Rigol can do:

Edit: if you don't feel like going through the videos, on Normal mode it's throwing a lot of samples away depending on the sample rate you select, on high res it doesn't.





I get the feeling you'll be seeing plenty of used units up for sale soon.

I doubt that, they can't keep up with inventory.
« Last Edit: June 10, 2015, 01:22:38 am by miguelvp »
 

Offline John Coloccia

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Re: Rigol DS1054Z Freeze-up Bug Confirmed ??
« Reply #158 on: June 10, 2015, 01:11:56 am »
Scopes don't just magically spit out the right answers.
 

Offline W7NGA

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Re: Rigol DS1054Z Freeze-up Bug Confirmed ??
« Reply #159 on: June 10, 2015, 02:44:46 am »
Interesting discussion, and I don't mean to be an apologist for all things Rigol.
In fact, there is some merit to the original posters complaint and I shouldn't dismiss it.

Firstly, the Rigol calibration square wave is better than I thought and there is almost zero energy beyond the expected odd-harmonics and the fundamental.
I show this in the first image, from my conventional spectrum analyzer. The signal is outside the working bandwidth but still provides a good relative indication of harmonic content.
The perfect square wave has discontinuities whereas the real world square wave does not. However, there is such a thing as a distorted (non perfect) square wave with additional FFT terms.

The second image is from the Agilent 7014B where the user has no control of the sampling parameters. Here, Agilent does a better job of memory management.
Rigol has an Auto memory depth mode that still allows sampling artifacts to leak thru. This would be confusing to the beginner and a source of potential measurement error/confusion.

The FFT can be a gnarly beast to tame. Clearly, there are critical relationships between array size, sample-rate, memory depth, truncations and windowing, etc. where the user has to have a firm
understanding of their sampling system. I am a little surprised that Rigol doesn't shield the user better in Auto mode but I don't find it limiting. I will concede that it can be confusing however.

dan W7NGA
 

Offline alsetalokin4017

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Re: Rigol DS1054Z Freeze-up Bug Confirmed ??
« Reply #160 on: June 10, 2015, 04:47:44 am »
Thank you for posting those spectra. Indeed, the spectrum analyzer tells the tale.  The even-numbered peaks in the Rigol's FFT of its Calibrator signal when in "Normal" acquisition mode are spurious.
The easiest person to fool is yourself. -- Richard Feynman
 

Offline miguelvp

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Re: Rigol DS1054Z Freeze-up Bug Confirmed ??
« Reply #161 on: June 10, 2015, 05:18:54 am »
Thank you for posting those spectra. Indeed, the spectrum analyzer tells the tale.  The even-numbered peaks in the Rigol's FFT of its Calibrator signal when in "Normal" acquisition mode are spurious.

In "Normal" acquisition at 5Msps when you are only set to 120Ksps sample rate it means you are throwing away 97.6 percent of the sample data so it's producing peaks where none exists.

You really need to set your scope to high-res for FFTs.

 

Offline Armxnian

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Re: Rigol DS1054Z Freeze-up Bug Confirmed ??
« Reply #162 on: June 10, 2015, 05:34:55 am »
Can reproduce the freeze bug on .04.02 SP4 board 0.1.1 with all options (except 500microvolt/d) enabled. The mem setting is saved with 1 channel on, but reverts to auto if the scope is powered off with 4 channels enabled and set to power on last.

Edit: Just upgraded to .04.03, and somewhat the same problem. Inputting a 1MHz sine wave instantly locks up the scope after switching the persistence. But inputting a 1KHz sine wave does not. I can change the persistence to all the different settings. I can also increase the frequency to 1MHz again and change the persistence around. But if I exit the zoom mode and enter it again at 1MHz it locks up. Basically, if the scope does not initially crash after switching the persistence mode in zoom mode, I can change the frequency to whatever I want, 5Hz and 25MHz for example, and also change the persistence to whatever I want. Tried to enter at 500KHz and it locked up, seems to be a specific frequency and up that it locks up.
« Last Edit: June 10, 2015, 05:56:58 am by Armxnian »
 

Offline alsetalokin4017

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Re: Rigol DS1054Z Freeze-up Bug Confirmed ??
« Reply #163 on: June 10, 2015, 04:04:05 pm »
Thank you for posting those spectra. Indeed, the spectrum analyzer tells the tale.  The even-numbered peaks in the Rigol's FFT of its Calibrator signal when in "Normal" acquisition mode are spurious.

In "Normal" acquisition at 5Msps when you are only set to 120Ksps sample rate it means you are throwing away 97.6 percent of the sample data so it's producing peaks where none exists.

You really need to set your scope to high-res for FFTs.
Well, that's clear enough.... now.  Is that "feature" mentioned in the User's Manual somewhere?  "Thrown away sample data" causing peaks to appear where none exists.... That's interesting. I would have expected that "thrown away data" would cause peaks that _should appear_, to be missing or attenuated, not the other way around. Would you call this an aliasing problem.... which isn't affected by the "anti-aliasing" setting at all.....  ?
The easiest person to fool is yourself. -- Richard Feynman
 

Online ebastler

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Re: Rigol DS1054Z Freeze-up Bug Confirmed ??
« Reply #164 on: June 10, 2015, 04:09:55 pm »
In "Normal" acquisition at 5Msps when you are only set to 120Ksps sample rate it means you are throwing away 97.6 percent of the sample data so it's producing peaks where none exists.
You really need to set your scope to high-res for FFTs.
Well, that's clear enough.... now.  Is that "feature" mentioned in the User's Manual somewhere?

Yes:

Quote
Tips
- You can use HORIZONTAL SCALE to adjust the center frequency
and horizontal scale at the same time.
- Signals with DC components or deviation would cause error or deviation of
the FFT waveform components. To reduce the DC components, set the
“Channel Coupling” to “AC”.
- To reduce the random noise and aliasing frequency components of
repetitive or single pulse, set the “Acquisition Mode” of the oscilloscope
to “Average”.
« Last Edit: June 10, 2015, 04:12:41 pm by ebastler »
 

Offline alsetalokin4017

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Re: Rigol DS1054Z Freeze-up Bug Confirmed ??
« Reply #165 on: June 10, 2015, 04:11:27 pm »
Can reproduce the freeze bug on .04.02 SP4 board 0.1.1 with all options (except 500microvolt/d) enabled. The mem setting is saved with 1 channel on, but reverts to auto if the scope is powered off with 4 channels enabled and set to power on last.

Edit: Just upgraded to .04.03, and somewhat the same problem. Inputting a 1MHz sine wave instantly locks up the scope after switching the persistence. But inputting a 1KHz sine wave does not. I can change the persistence to all the different settings. I can also increase the frequency to 1MHz again and change the persistence around. But if I exit the zoom mode and enter it again at 1MHz it locks up. Basically, if the scope does not initially crash after switching the persistence mode in zoom mode, I can change the frequency to whatever I want, 5Hz and 25MHz for example, and also change the persistence to whatever I want. Tried to enter at 500KHz and it locked up, seems to be a specific frequency and up that it locks up.

Thanks for your report and testing. As I and others have documented, in our scopes the bug can occur with the 1kHz Calibrator signal, or even with no signal applied at all, as long as the horizontal timebase is set to some fast value. See the last video I posted above, where I demonstrate the bug with no signal applied and with no Options unlocked ("unhacked"), stock 50 MHz bandwidth. I have been using 1 us/div in the main horizontal timebase setting for my documentation and testing purposes, but using slower settings can also produce slowdowns and freezes sometimes as well.
The easiest person to fool is yourself. -- Richard Feynman
 

Offline alsetalokin4017

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Re: Rigol DS1054Z Freeze-up Bug Confirmed ??
« Reply #166 on: June 10, 2015, 04:32:34 pm »
In "Normal" acquisition at 5Msps when you are only set to 120Ksps sample rate it means you are throwing away 97.6 percent of the sample data so it's producing peaks where none exists.
You really need to set your scope to high-res for FFTs.
Well, that's clear enough.... now.  Is that "feature" mentioned in the User's Manual somewhere?

Yes:

Quote
Tips
? You can use HORIZONTAL SCALE to adjust the center frequency
and horizontal scale at the same time.
? Signals with DC components or deviation would cause error or deviation of
the FFT waveform components. To reduce the DC components, set the
“Channel Coupling” to “AC”.
? To reduce the random noise and aliasing frequency components of
repetitive or single pulse, set the “Acquisition Mode” of the oscilloscope
to “Average”.

Thank you. This indeed does produce a better FFT display, of the Calibrator signal anyway.

The shot below is using "Average" acquisition mode, 16 averages, Auto memory depth,  AC coupled input with BW limit on, Blackman window for the FFT.   And "persistence time" set to "min" of course.  I hope Anand is reading here! 
« Last Edit: June 10, 2015, 04:34:15 pm by alsetalokin4017 »
The easiest person to fool is yourself. -- Richard Feynman
 

Offline John Coloccia

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Re: Rigol DS1054Z Freeze-up Bug Confirmed ??
« Reply #167 on: June 10, 2015, 05:12:14 pm »
As you've figured out, FFTs are not trivial to get right.  I always take a scope FFT, where you typically don't have fine control over the data and processing, with a grain of salt.  IMHO, it's more useful when you're trying to find some noise injected from somewhere... "Oh, there's a spike around 25kHz...I know what that is!"
 

Offline miguelvp

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Re: Rigol DS1054Z Freeze-up Bug Confirmed ??
« Reply #168 on: June 10, 2015, 05:14:51 pm »
Well, that's clear enough.... now.  Is that "feature" mentioned in the User's Manual somewhere?  "Thrown away sample data" causing peaks to appear where none exists.... That's interesting. I would have expected that "thrown away data" would cause peaks that _should appear_, to be missing or attenuated, not the other way around. Would you call this an aliasing problem.... which isn't affected by the "anti-aliasing" setting at all.....  ?

Well the manual or any other manual for other scopes doesn't go too much into detail. but press the help button and see what it tells you for Hi-res and Normal.

But this is true for all scopes, you should watch those videos by w2aew that I embedded earlier, and by watch I mean actually watch it, not just play it on the background while catching up with the forum.

 

Offline W7NGA

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Re: Rigol DS1054Z Freeze-up Bug Confirmed ??
« Reply #169 on: June 10, 2015, 05:38:02 pm »
This caught me at a bad time since I am leaving for S.E. Asia for 7 weeks and just put most of the test equipment into storage.
I worked for Tektronix and have a dozen (or more) scopes here at the lab. I have a Tektronix TDS2014B, a terrible scope when
compared to the Rigol, and as I recall it cost 4x what the DS1054Z cost but it is similar in performance.

I will retrieve the TDS2014B later in the day and run through these same tests. I am interested in a FFT comparison between it and the Rigol.

Will report back later ...

dan W7NGA
 

Offline W7NGA

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Re: Rigol DS1054Z Freeze-up Bug Confirmed ??
« Reply #170 on: June 11, 2015, 02:18:38 pm »
I retrieved my Tektronix TDS 2014B (100 Mhz, 1 Gs/s) out of storage and ran the FFT tests on the Rigol 1 khz calibrator.
After using this thing for a few minutes, and remembering what I paid for it, I have to tell you that the Rigol DS1054Z is the best hobbyist bargain ever!

What a jewel!

As shown in the photo, even with Auto memory management, there is no getting around the undersampling artifacts.
Using my 'real' spectrum analyzer and narrowing the RBW I can see even-ordered harmonics but they are greater than -50dB down from the fundamental.

The TDS 2014B cleans up as the sampling rate is increased, as does the Rigol.

Enjoy your DS1054Z .. as I said, I am thrilled and will be purchasing a few more for the classes I teach.

Off to Vietnam ... cheers

dan W7NGA
« Last Edit: June 11, 2015, 02:24:06 pm by W7NGA »
 

Offline alsetalokin4017

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Re: Rigol DS1054Z Freeze-up Bug Confirmed ??
« Reply #171 on: June 11, 2015, 04:28:28 pm »
Thanks for doing that comparison. Yes, I agree that the DS1054Z is a great bargain, an excellent scope for beginners like me.

Hopefully you will make up a handout to notify your students about the conditions for lock-up and what settings are "poison" on your new ones, and how to recover from a locked-on-startup condition. Or maybe you can select new ones that don't lock up, from your vendor's stock. After all, you have slightly less than a 50 percent chance of getting scopes that don't show this bug. Or maybe Rigol will have issued another firmware update that fixes this bug by the time you return to your classes.

Just curious ... is it possible to get the Tek TDS 2014B to start up "frozen" and unresponsive to all controls, after being shut down in a running, fully operational state? 
The easiest person to fool is yourself. -- Richard Feynman
 

Online ebastler

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Re: Rigol DS1054Z Freeze-up Bug Confirmed ??
« Reply #172 on: June 12, 2015, 05:45:42 am »
Thanks for doing that comparison. Yes, I agree that the DS1054Z is a great bargain, an excellent scope for beginners like me.

Hopefully you will make up a handout to notify your students about the conditions for lock-up and what settings are "poison" on your new ones, and how to recover from a locked-on-startup condition. Or maybe you can select new ones that don't lock up, from your vendor's stock. After all, you have slightly less than a 50 percent chance of getting scopes that don't show this bug. Or maybe Rigol will have issued another firmware update that fixes this bug by the time you return to your classes.

Just curious ... is it possible to get the Tek TDS 2014B to start up "frozen" and unresponsive to all controls, after being shut down in a running, fully operational state?

Maybe you should consider selling your DS1054Z -- or start using it, to work on some nice, cool projects?
Spending all your electronics hobby time searching for flies in the ointment can't be good for you... ::)
 

Offline alsetalokin4017

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Re: Rigol DS1054Z Freeze-up Bug Confirmed ??
« Reply #173 on: June 12, 2015, 10:10:33 pm »
Thanks for doing that comparison. Yes, I agree that the DS1054Z is a great bargain, an excellent scope for beginners like me.

Hopefully you will make up a handout to notify your students about the conditions for lock-up and what settings are "poison" on your new ones, and how to recover from a locked-on-startup condition. Or maybe you can select new ones that don't lock up, from your vendor's stock. After all, you have slightly less than a 50 percent chance of getting scopes that don't show this bug. Or maybe Rigol will have issued another firmware update that fixes this bug by the time you return to your classes.

Just curious ... is it possible to get the Tek TDS 2014B to start up "frozen" and unresponsive to all controls, after being shut down in a running, fully operational state?

Maybe you should consider selling your DS1054Z -- or start using it, to work on some nice, cool projects?
Spending all your electronics hobby time searching for flies in the ointment can't be good for you... ::)
I use it daily, several hours every day or more. How do you think I found the bug in the first place?  I also apparently use mine for more complex setups and in more ways than ....well... anyone else I've seen reporting on the scope.  I've made several videos showing how to use some of the advanced features of the scope. At the moment I have _eleven_ different experimental setups stored in the scope for working on different projects. Do you think that scopeshots like the one below are somehow deliberately set up to show some severe bug in the instrument? No, this shot is from an actual circuit that I am developing and testing, and when the scope locked up on me, and even started up "locked"... that was from a legitimate combination of settings encountered while trying to get data on an actual circuit.

So I reject your comment and its implied accusation. I am a scope _user_ and I expect a scope--- even a low-end, toy DSO--- to work properly; that is, as claimed by the manufacturer. When it doesn't, I'll make my findings known to other users in an effort to track down the reasons and get them fixed. You may not be aware that this is the second DS1054Z unit that I've had in my possession; the first one turned out to have a bad glitch in the CH4 hardware and so I returned it for replacement. Some people laughed at me then because _they_ never use all four channels, so why should I care if a channel is unusable on such a cheap scope? When I started noticing this present scope freezing up _while testing actual circuits_ on my bench, I started wondering if perhaps I had _another_ bad piece of hardware, so I started this thread. And you, and Rigol, and the other users of this scope, now know, because of MY efforts, that the bug exists in more than 50 percent of scopes tested, and how to avoid it. If you want to "shoot the messenger" or blame me in some way for talking about this severe bug which indicates something wrong at Rigol's production facility... that's fine with me. It won't make the bug go away though.
« Last Edit: June 12, 2015, 10:13:09 pm by alsetalokin4017 »
The easiest person to fool is yourself. -- Richard Feynman
 

Offline tom66

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Re: Rigol DS1054Z Freeze-up Bug Confirmed ??
« Reply #174 on: June 13, 2015, 12:10:23 am »
I am not able to replicate running 00.02.03.SP5. Old version, but DS1074Z, one of the first shipped. have not considered whether I should install latest firmware as current version seems OK (only a spelling error in default USB name and the last sample on the edge of a scrolling screen is wrong)
 


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