Author Topic: EEVblog #369 - Rigol DS2000 Oscilloscope Playing Around  (Read 58898 times)

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Re: EEVblog #369 - Rigol DS2000 Oscilloscope Playing Around
« Reply #25 on: October 13, 2012, 02:33:23 pm »
I also forgot to try the HiRes mode at 500uV/div, I believe it's much improved over normal mode.
Did John South from Emona show off that in the Electronex show video?
Edit: yes he did, at 1:30


Dave.
« Last Edit: October 13, 2012, 02:35:56 pm by EEVblog »
 

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Re: EEVblog #369 - Rigol DS2000 Oscilloscope Playing Around
« Reply #26 on: October 13, 2012, 02:40:46 pm »
Any chance Dave, or somebody else with DS2000 could investigate that, bit more, Is 500uV real thing or just marketing number... without real backup.

It's the real deal.
In the teardown you could see the extra regulators for the front end circuitry.
Rigol have also said they redesigned the input circuitry to achieve this low noise floor.
Would be interesting to compare directly with my Tek 2225.

Dave.
 

Offline saturation

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Re: EEVblog #369 - Rigol DS2000 Oscilloscope Playing Around
« Reply #27 on: October 14, 2012, 02:15:18 am »
Vertical amp noise increases with bandwidth, so to keep it similar to 50 MHz on 200 MHz scope is noteable.  The vertical amps on the 1052e are used up to 150 MHz [ e.g. on the rarely seen 1152e variant of the 1000 series]  so design wise there is not as big a difference between them on the input section.


I'm interested in that low noise thing of DS2000 series, and have to say that I'm left with bit of disappointment, from Dave "playing with"....

Noise at 500uV being 1 division is hardly good achievement, just by simply comparing to that what DS1052e is doing in that regard, I was clearly expecting much better noise figures.

« Last Edit: October 14, 2012, 02:19:32 am by saturation »
Best Wishes,

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Offline Dread

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Re: EEVblog #369 - Rigol DS2000 Oscilloscope Playing Around
« Reply #28 on: October 14, 2012, 05:53:27 am »
As an owner of Owon 8202V I was shocked as I watched this Video.  Before I go into “why” let me make it clear that I aspire to own a 200MHZ version of the DS2000.  I just don’t like having to choose between a $2500+ scope and my Wife killing me!   I needed to stay Sub $1K in order to live, but if I had ALL the money for a scope like Dave’s I would honestly still buy it even after watching Dave’s video.

Here’s what really bothered me (In Order)

1)  What!! No upgrade for the BW after purchase :o :o  I though that was one of the main upgrades!  I was hoping that one day I could buy the 70 MHz version and save up later for the 200 MHZ upgrade but now all the 70 MHz owners are stuck >:(  This is the number one turn off for me.

2) What no Zoom at all?  Am I missing something here?  I can Zoom with my cheap scope I would expect this one to do that easily.  It was unclear to me if this feature worked before the upgrade or not but I would imagine that it just does not have this feature because Rigol would be asses to fix the XY and at the same time cripple the much more used Zoom Feature.

3)  The whole 50,000 waveform capture thing now seems to me to be more of a gimmick than a real feature.  My Owon which is supposed to have a terrible WC rate has 2Gs at 10M and it does exactly what the Rigol does except in one burst when triggered.   The DS2000 just seems to use a Trigger then Write method.  So each time the unit gets triggered it stores the waveform and stops then waits for the next trigger, etc etc until the memory is used up.    It seems to me that any scope manufacturer could just rewrite their firmware to do the same thing but they instead take one snapshot for the duration of the memory.  Now how fast the DS2000 can reset for the next snapshot may be key but Dave’s video was on a very slow event, I suspect on a fast signal like 100 MHz you would see just about no difference in what you captured on a DS2000 vs any other scope that had the same memory depth and sample rates.


I am no expert on DSO's so please if I am wrong I would like to know what assumptions I made errors on.
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Offline johnboxall

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Re: EEVblog #369 - Rigol DS2000 Oscilloscope Playing Around
« Reply #29 on: October 14, 2012, 01:05:31 pm »

2) What no Zoom at all?  Am I missing something here?  I can Zoom with my cheap scope I would expect this one to do that easily.  It was unclear to me if this feature worked before the upgrade or not but I would imagine that it just does not have this feature because Rigol would be asses to fix the XY and at the same time cripple the much more used Zoom Feature.

You can zoom after sampling. Page 4-5 of manual.

Offline Hypernova

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Re: EEVblog #369 - Rigol DS2000 Oscilloscope Playing Around
« Reply #30 on: October 14, 2012, 03:55:01 pm »
The waveform capture thing looks like a cheap copy of Agilent's Segmented Memory feature, granted it's free (vs buying the SEGMEM license). With SEGMEM you choose how many segments you want and depending on how much sample memory each segment gets the scope drops the sample rate. This IMO is better as you can decide for yourself  the tradeoff between sample rate and segment count.
 

Online taemun

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Re: EEVblog #369 - Rigol DS2000 Oscilloscope Playing Around
« Reply #31 on: October 14, 2012, 04:25:26 pm »
In the first bout of waveform capturing (~20:30), trigger is on Ch1, and set to 150mV and Ch1 to 500mV/div, but it seems to be that it's triggering on nothing - about half of the captured waveforms are dead flat.

Apparently, to Rigol, a rising edge trigger at 150mV is a "something happened near 150mV" trigger.

My DS1052e++ exhibits a similar waveform update problem. Not sure if there is newer firmware available, though.
 

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Re: EEVblog #369 - Rigol DS2000 Oscilloscope Playing Around
« Reply #32 on: October 14, 2012, 06:07:20 pm »
1)  What!! No upgrade for the BW after purchase :o :o  I though that was one of the main upgrades!  I was hoping that one day I could buy the 70 MHz version and save up later for the 200 MHZ upgrade but now all the 70 MHz owners are stuck >:(  This is the number one turn off for me.

Yes, very strange, and quite annoying.

Quote
2) What no Zoom at all?  Am I missing something here?  I can Zoom with my cheap scope I would expect this one to do that easily.  It was unclear to me if this feature worked before the upgrade or not but I would imagine that it just does not have this feature because Rigol would be asses to fix the XY and at the same time cripple the much more used Zoom Feature.

John South at Emona told me he's pretty sure that zoom works as it's supposed to, and there is possibly something wrong with my unit. He will confirm this when back from holiday. Can anyone else with a DS2000 confirm?
He also said there is something wrong with my dim LED's as well.


Dave.
 

Offline drieg

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Re: EEVblog #369 - Rigol DS2000 Oscilloscope Playing Around
« Reply #33 on: October 14, 2012, 07:02:12 pm »
There is a bug in FW 00.00.01.00.02 and earlier (similar to DS4000 units) causing rewritting some areas in memory (trial options for example) when doing Self-Cal, saving setups/ref signal, AND also doing firmware update from the mormal operation (GUI).

This bug has been fixed in FW 00.00.01.00.05 (there are still some bugs, axes in XY mode, trial options get expired after Self-Cal,..), so I suggest anyone with FW 01.00.02  to update to latest version. BUT, it is very IMPORTANT to do this update during boot process, not from the normal operation from the menu. Insert USB stick with the firmware, power-on the unit and pres shortly HELP button (immediately after POWER button before RIGOL logo appears). If it doesn't work, try again. If it still doesn't work, keep tying until it works. After you succeed, the SINGLE button will lights and update process will start shortly (CH1 LED blinks), after it's done, all LEDs light. Power-off, remove USB and power-on again.

Hint: To get full FW version go to trigger menu and set Edge, then press F7-F6-F7-Utility button combination quickly. Check additional info under Utility > System > System Info. To escape from this "special" mode, do again  F7-F6-F7-Utility under trigger menu.

Rigol firmwares starting with 01.xx.. (like in Dave's video 01.00.01.09.00) are testing firmwares.
« Last Edit: December 02, 2012, 07:44:38 pm by drieg »
Bricked Rigol? This thread might be of any help.
 

Online mikeselectricstuff

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Re: EEVblog #369 - Rigol DS2000 Oscilloscope Playing Around
« Reply #34 on: October 14, 2012, 08:06:29 pm »
The waveform capture thing looks like a cheap copy of Agilent's Segmented Memory feature, granted it's free (vs buying the SEGMEM license). With SEGMEM you choose how many segments you want and depending on how much sample memory each segment gets the scope drops the sample rate. This IMO is better as you can decide for yourself  the tradeoff between sample rate and segment count.
Does the Rigol not allow you to select the number of segments? If not this is a major limitation - being able to trade off sample length against number of samples is a very important facility for segmented memory acquisition.
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Re: EEVblog #369 - Rigol DS2000 Oscilloscope Playing Around
« Reply #35 on: October 14, 2012, 09:14:34 pm »
Does the Rigol not allow you to select the number of segments? If not this is a major limitation - being able to trade off sample length against number of samples is a very important facility for segmented memory acquisition.

The Rigol feature is a bit different to Agilent's segmented memory feature.
No, I don't think you can select it on the Rigol, as the sample memory depth is automatically controlled based on timebase like on any scope. And that's the same memory depth regardless of whether the feature is turned on or off. Leave it turned off, and you just waste the memory. Turn it on and you use the wasted memory to capture extra waveforms (at the expense of update speed I presume).
The Agilent 2000X has a relatively slow 20us re-arm time for segmented memory (1us on 3000X), so is more designed for infrequent short-burst waveforms.  Not sure what the equivalent time would be on the Rigol feature.

Dave.
« Last Edit: October 14, 2012, 09:23:21 pm by EEVblog »
 

Offline marmad

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Re: EEVblog #369 - Rigol DS2000 Oscilloscope Playing Around
« Reply #36 on: October 14, 2012, 09:25:32 pm »
3)  The whole 50,000 waveform capture thing now seems to me to be more of a gimmick than a real feature.

I don't think you're understanding waveform update rates. Here are two good explanations of it:

cp.literature.agilent.com/litweb/pdf/5989-7885EN.pdf
www2.rohde-schwarz.com/file/1ER02_1e.pdf

To give you a concrete example of the difference between the Owon and Rigol's rates:

Scope’s blind-time percentage
= 100 x [(1/U) – W]/(1/U)
= 100 x (1 – UW)
where
U = Scope’s measured update rate
and
W = Display acquisition window = Timebase setting x number of divisions (which is 20 on the Owon and 15 on the Rigol).

For example, at a 100ns/div timebase setting:
The 30 wfrm/s update rate of the Owon means a blind-time of 99.994% - in other words, it's only showing .006% of the real-time waveform.
Assuming the Rigol does 50,000 wfrm/s at this timebase setting, the blind-time is 92.5% -  i.e., it's showing 7.5% of the real-time waveform.

What does this mean in terms of glitch hunting? According to the formula, then the average time for catching a repeating signal fault (let's say 10 glitches per second at 100ns/div) with a probability of 99.9%:
Owon: ~3 hours and 12 minutes.
Rigol: 9.2 seconds
 

Offline drieg

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Re: EEVblog #369 - Rigol DS2000 Oscilloscope Playing Around
« Reply #37 on: October 14, 2012, 10:12:49 pm »
Does the Rigol not allow you to select the number of segments? If not this is a major limitation - being able to trade off sample length against number of samples is a very important facility for segmented memory acquisition.
..No, I don't think you can select it on the Rigol, as the sample memory depth is automatically controlled based on timebase like on any scope.

You can select sampling memory depth under Acquire button/menu and see, how the waveform capture rate changes...
« Last Edit: October 14, 2012, 10:17:23 pm by drieg »
Bricked Rigol? This thread might be of any help.
 

Offline rr100

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Re: EEVblog #369 - Rigol DS2000 Oscilloscope Playing Around
« Reply #38 on: October 15, 2012, 12:46:42 am »
When Dave was talking about the trial features and their timelimit was anyone else thinking..  Hm.. i wonder, if i read out the eeprom/flash ICs before i turned it on for the first time, could i then reprogram it every month to get the features back :D
That's clear and if there are more than a few users be sure somebody will find a way to do it.
However I've been thinking something else: they go through all the hoops of making and delivering some features and then they write extra code to actually remove them from the majority of the customers hoping some will come with the cash asking to have them re-enabled. This really rubs me the wrong way. I know is standard practice for med-highly expensive equipment, the one that's more like a computer than like a "normal" tool. But still I can't get rid of this feeling of feeling cheated if I would buy a hammer (or a multimeter or a scope) that wouldn't work as well as it can just because I didn't pay some "extra license to enable all features".
 

Offline cidcorp

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Re: EEVblog #369 - Rigol DS2000 Oscilloscope Playing Around
« Reply #39 on: October 15, 2012, 04:43:58 am »

Ok, I'm lost - where the hell is everyone getting updated firmware for the DS2000 line?

If someone can point me to a copy of the firmware it would be greatly appreciated.

I haven't done a self cal on the device yet cause I'm evaluating the add-on options, so I'd be very concerned the firmware update would reset these trials...

Side note:

The screen update issue that is shown in the video occurs here on my DS2102, same software
and hardware revisions as Dave's 200Mhz model.



 

Offline elbot

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Re: EEVblog #369 - Rigol DS2000 Oscilloscope Playing Around
« Reply #40 on: October 15, 2012, 08:10:28 am »
There is a bug in FW 00.00.01.00.02 and earlier (similar to DS4000 units) causing rewritting some areas in memory (trial options for example) when doing Self-Cal, saving setups/ref signal, AND also doing firmware update from the mormal operation.

This bug has been fixed in FW 00.00.01.00.05, so I suggest anyone with this firmware to update to latest version. BUT, it is very IMPORTANT to do this update during boot process, not from the normal operation from the menu. First, iyou have to nsert USB stick with the firmware file ;), then power-on the unit and pres shortly HELP button. The SINGLE led will light and update process will start shortly (CH1 LED is flashing), after it's done, all LEDs light. Power-off, remove USB and power-on.

Hints: To get full FW version go to trigger menu and set Edge, then press F7-F6-F7-Utility button combination. Check additional info under Utility > System > System Info. To escape from this "special" mode, do again  F7-F6-F7-Utility under trigger menu.

Rigol firmwares starting with 01.xx.. (like in Dave's video 01.00.01.09.00) are testing firmwares.

Please let us know where to get hands on firmware updates, I'm using a DS2102 with the faulty version FW 00.00.01.00.02
and can't calibrate without loosing trial versions, it will help me alot, thanks...

Claus,
 

Offline Rosendorfer

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Re: EEVblog #369 - Rigol DS2000 Oscilloscope Playing Around
« Reply #41 on: October 15, 2012, 08:23:31 am »
Hi

Just to follow with 500uV/div noise and not to go into discussions, if it is really extremely low and can be seen as important feature or is just average at best and 500uV/div is just "marketing function". Interesting would be to compare DS2000 against Hameg HMO series, as both are claiming low noise as their important feature.

Anyway interesting how Dave will follow with full review of DS2000, seems that it is bit more tricky than just showing it is well build 200MHz scope for 1000+USD .
Expectations are pretty high.

Rosendorfer



 
 

Offline Dread

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Re: EEVblog #369 - Rigol DS2000 Oscilloscope Playing Around
« Reply #42 on: October 15, 2012, 01:46:11 pm »
3)  The whole 50,000 waveform capture thing now seems to me to be more of a gimmick than a real feature.

I don't think you're understanding waveform update rates. Here are two good explanations of it:

cp.literature.agilent.com/litweb/pdf/5989-7885EN.pdf
www2.rohde-schwarz.com/file/1ER02_1e.pdf

To give you a concrete example of the difference between the Owon and Rigol's rates:

Scope’s blind-time percentage
= 100 x [(1/U) – W]/(1/U)
= 100 x (1 – UW)
where
U = Scope’s measured update rate
and
W = Display acquisition window = Timebase setting x number of divisions (which is 20 on the Owon and 15 on the Rigol).

For example, at a 100ns/div timebase setting:
The 30 wfrm/s update rate of the Owon means a blind-time of 99.994% - in other words, it's only showing .006% of the real-time waveform.
Assuming the Rigol does 50,000 wfrm/s at this timebase setting, the blind-time is 92.5% -  i.e., it's showing 7.5% of the real-time waveform.

What does this mean in terms of glitch hunting? According to the formula, then the average time for catching a repeating signal fault (let's say 10 glitches per second at 100ns/div) with a probability of 99.9%:
Owon: ~3 hours and 12 minutes.
Rigol: 9.2 seconds

Marmad I have noticed that you really seem to be in love with this feature, which I think is still a bit of a over sell by Agilent to try and make their consumer grade scopes look better than everyone else’s.  Personally I think it's just because so many new DSO makers are now in the market place and this has now become a big push for them because they dominate that area, but hey I am no expert so it's just my opinion.   

BTW I had read that Agilent Document before and it really came off to me as a questionable in the sense that to me as a novice in the world of DSO it seems to only addresses one part of the equation and by that I mean doesn’t it also dependent on how well your scope triggers.   It would seem to me that your scope could be capturing 10M/WFS but if it's trigger does not go off during the glitch then that’s all for naught.  Please let me know if I am wrong but to me that seems logical.

My second comment on all of this comes from 15 years of doing repair work.  For me weird Glitches were very rare in the repair world and when I did come across it; most of the time I could just use my old Analog scope and Tap or twist the board and bingo the glitch would appear or disappear.  If that plus a few other tricks did not work I typically skipped those jobs because I was not going to spend a whole day on those kind of problems, it was never going to be worth my time unless it was a darn expensive piece of gear.   I admit that these new DSO with great waveform capture might have done the trick but as I said before it was a very rare case when I came across a signal fidelity problem that was not looking me straight in the face.
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Offline Dread

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Re: EEVblog #369 - Rigol DS2000 Oscilloscope Playing Around
« Reply #43 on: October 15, 2012, 01:47:15 pm »
1)  What!! No upgrade for the BW after purchase :o :o  I though that was one of the main upgrades!  I was hoping that one day I could buy the 70 MHz version and save up later for the 200 MHZ upgrade but now all the 70 MHz owners are stuck >:(  This is the number one turn off for me.

Yes, very strange, and quite annoying.

Quote

Thanks for the Update Dave.  Please let us know what you find out.
2) What no Zoom at all?  Am I missing something here?  I can Zoom with my cheap scope I would expect this one to do that easily.  It was unclear to me if this feature worked before the upgrade or not but I would imagine that it just does not have this feature because Rigol would be asses to fix the XY and at the same time cripple the much more used Zoom Feature.

John South at Emona told me he's pretty sure that zoom works as it's supposed to, and there is possibly something wrong with my unit. He will confirm this when back from holiday. Can anyone else with a DS2000 confirm?
He also said there is something wrong with my dim LED's as well.


Dave.
The Optimist says the glass is half full, the Pessimist says its half empty, an engineer only see's a glass that’s twice as big as it needs to be!
 

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Re: EEVblog #369 - Rigol DS2000 Oscilloscope Playing Around
« Reply #44 on: October 15, 2012, 05:33:37 pm »
BTW I had read that Agilent Document before and it really came off to me as a questionable in the sense that to me as a novice in the world of DSO it seems to only addresses one part of the equation and by that I mean doesn’t it also dependent on how well your scope triggers.   It would seem to me that your scope could be capturing 10M/WFS but if it's trigger does not go off during the glitch then that’s all for naught. 

Generally, not so.
For example, you are using the infinite persistence function to try and capture an unknown glitch you think might be there but cannot trigger off. You have to know something about the glitch in order to reliably set up the trigger to catch it on trigger, so that's what infinite persistence is for.
If that glitch occurs only once every million cycles, the Agilent 3000X can in theory catch is as quickly as 1 second. Other scopes you could wait an eternity. I have demoed this in an Agilent video.

Of course, if you do know how to trigger from the glitch, then the update rate is essentially irrelevant.

Dave.
 

Offline ejeffrey

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Re: EEVblog #369 - Rigol DS2000 Oscilloscope Playing Around
« Reply #45 on: October 15, 2012, 07:33:00 pm »
My second comment on all of this comes from 15 years of doing repair work.  For me weird Glitches were very rare in the repair world and when I did come across it; most of the time I could just use my old Analog scope and Tap or twist the board and bingo the glitch would appear or disappear.

Repair work is a very different beast than development.  Glitches of the type that a high waveform capture rate helps with are almost exclusively caused by design errors not hardware failures.  If they show up in the field, it means there was insufficient testing for e.g., timing variation vs. temperature and you should just send the board back to the designer.  As a corollary, a glitch that results from a design error cannot usually be fixed by swapping out with a known good board so you really have to find the problem.
 

Offline marmad

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Re: EEVblog #369 - Rigol DS2000 Oscilloscope Playing Around
« Reply #46 on: October 15, 2012, 09:43:24 pm »
Marmad I have noticed that you really seem to be in love with this feature, which I think is still a bit of a over sell by Agilent to try and make their consumer grade scopes look better than everyone else’s.  Personally I think it's just because so many new DSO makers are now in the market place and this has now become a big push for them because they dominate that area, but hey I am no expert so it's just my opinion.   

BTW I had read that Agilent Document before and it really came off to me as a questionable in the sense that to me as a novice in the world of DSO it seems to only addresses one part of the equation and by that I mean doesn’t it also dependent on how well your scope triggers.   It would seem to me that your scope could be capturing 10M/WFS but if it's trigger does not go off during the glitch then that’s all for naught.  Please let me know if I am wrong but to me that seems logical.

Dread: the dead/blind-time (and related waveform update rate) is not a FEATURE of a DSO - it's an inherent fault in them; i.e. the fact that the instrument must spend much more time processing the data for display than it can spend gathering it (whereas an analogue scope only needs to retrace the beam). The scope is effectively dead during this period - so it doesn't respond to triggers at all.

For me weird Glitches were very rare in the repair world and when I did come across it...

The point is this: with a slow wfrm/s rate, you could hook your scope up to a signal and stare at it for 3 solid hours and not realize that there is a glitch in the signal happening once per second.

Of course, if you do know how to trigger from the glitch, then the update rate is essentially irrelevant.

Again, this is only true if the scope is stopped, waiting to trigger from the glitch. If it's running (and has a slow waveform update rate), it will almost certainly miss the glitch. This is easily proved with a Mask test (which is often closely related to the scope's wfrm/s rate).

Edit: BTW, Dave, you mentioned in your vid that the Rigol 1000 series captures around 700-800 wfrm/s. In fact, the E series is somewhere in the 50-200 wfrm/s range, while the CA series is up to 2000 wfrm/s (hence the massive price difference).
« Last Edit: October 15, 2012, 09:55:59 pm by marmad »
 

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Re: EEVblog #369 - Rigol DS2000 Oscilloscope Playing Around
« Reply #47 on: October 15, 2012, 10:03:41 pm »
Again, this is only true if the scope is stopped, waiting to trigger from the glitch.

That's how you usually capture things you are looking for!  ;D

Quote
Edit: BTW, Dave, you mentioned in your vid that the Rigol 1000 series captures around 700-800 wfrm/s. In fact, the E series is somewhere in the 50-200 wfrm/s range, while the CA series is up to 2000 wfrm/s (hence the massive price difference).

I thought I measured it around the 700 mark at one point, but my memory could be wrong.

Dave.
 

Offline marmad

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Re: EEVblog #369 - Rigol DS2000 Oscilloscope Playing Around
« Reply #48 on: October 15, 2012, 10:28:25 pm »
That's how you usually capture things you are looking for!  ;D

Absolutely - when you're looking for a known problem.

I thought I measured it around the 700 mark at one point, but my memory could be wrong.

It's probability theory: you can't find out how fast a scope is (wfrms/s) by running a glitch test a couple of times (as you did in your Agilent review) - you can only prove how fast it isn't.  For example (using the probability formula for a 10/s glitch with a timebase of 100ns), if my scope captures the glitch within 7 seconds - every now and then, or even a few times in a row - it doesn't prove its a 1,000,000 wfms/s scope.  But if one time it takes my scope over 10 minutes to capture the glitch, it does prove (beyond a reasonable doubt) that it isn't a 1M or 100k wfrms/s scope, because the probability of a scope that fast taking that long to capture the glitch is extremely low (99.9999...%).  If you want to try to calculate actual wfrms/s by testing the probability of capturing a random glitch, you have to run many tests - not just a few  ;)
 

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Re: EEVblog #369 - Rigol DS2000 Oscilloscope Playing Around
« Reply #49 on: October 15, 2012, 11:28:52 pm »
If you want to try to calculate actual wfrms/s by testing the probability of capturing a random glitch, you have to run many tests - not just a few  ;)

I ran more tests than what made it into the final edit!

Dave.
 


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