Author Topic: Keysight MXR 8 channel scope  (Read 9944 times)

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Offline Stranger_danger

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Re: Keysight MXR 8 channel scope
« Reply #25 on: April 28, 2020, 09:24:48 pm »

Min DDC span is 40 MHz, and you can only view a signal as time domain or DDC (or RTSA, which uses DDC). so there is no time correlation. You'd have to use FFT like before. Then it just becomes a question of what RBW you want to figure out the sample rate you'd chew up. We expect the DDC/RTSA option to be popular with more hardcore RF folks who want to stream 8 phase coherent channels of stuff to something like VSA.

I'll stop now before the PR team yells at me :) Expect plenty more after the press event.

Please share more about the DDC and ADC in reference to the signal path?
 
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Offline porker1972

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Re: Keysight MXR 8 channel scope
« Reply #26 on: April 28, 2020, 09:36:48 pm »
RTSA features? CALLED IT!!!  :scared:

16GS/s? CALLED IT!!!  :scared:

Infiniium Model T -- comes in any color you want as long as that's black? Half right  ;D

13GHz? Swing and a miss -- but it's hard to interleave so well that you don't get spurs, so I don't blame them too much.


Now the long wait to get my hands on one begins! I first saw the RTO1024 in 2011 and didn't find one broken/fixable/cheap on ebay until 2019, but it did eventually happen. Dibs on the first broken/cheap/fixable MXR to hit ebay a decade from now!

The way the global economy is going you might be able to make an offer... trade-in maybe?

I an surprised anything is being launched now - it must be killing companies trying to release any kind of product in lockdown- they can't see customers for demos, hold press meetings, attend trade shows... How can you show customers the star features, and how can a customer decide if it works in their application if they can't physically get a unit?
 

Offline Eric_S

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Re: Keysight MXR 8 channel scope
« Reply #27 on: April 29, 2020, 05:32:03 am »
My company is looking to buy scopes for example (Tek scopes, mind you. We have a ton of probes, "people know Tek", bla bla...). People take their work and tools home and do their tings there, so everything keeps flowing. It's so we can have new products to drive sales once the economy picks up.
 

Offline NoisyBoy

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Re: Keysight MXR 8 channel scope
« Reply #28 on: April 29, 2020, 06:37:32 am »
I like it, I may see a Merry Christmas To Me present coming to my hobby lab. 

Can't wait to learn more about it and digesting the datasheet.  At a glance, it has all the features I want, it compare very favorable against the 6000 X-Series and the Infiniium S-Series, and the 15.6" HD screen is the clear winner.

Daniel, remember I asked you about a future scope with a world class display a year ago?  Looks like Keysight have made my wish come true  :-+
 
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Offline snoopy

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Re: Keysight MXR 8 channel scope
« Reply #29 on: April 29, 2020, 07:48:50 am »
https://www.keysight.com/en/pcx-3062392/infiniium-mxr-series-real-time-oscilloscopes?nid=-31731.0.00&cc=US&lc=eng

I saw that Keysight has introduced their MXR 8 channels scopes.  Amazing to see pricing of $108,000 for a 6 GHz scope.  I guess it helps that they are becoming more and more dominant in the scope market and have greater control on price.  Anyone had a demo?

Finally a scope we can all afford :D LOL
 
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Offline Sighound36

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Re: Keysight MXR 8 channel scope
« Reply #30 on: April 29, 2020, 08:51:45 am »
I would be interested in trying one of these for my personal lab, though 2Ghz is sufficient  :-+

If this would be around the £30K mark I could be tempted depending on its full functionality and options costings
Seeking quality measurement equipment at realistic cost with proper service backup. If you pay peanuts you employ monkeys.
 

Offline srce

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Re: Keysight MXR 8 channel scope
« Reply #31 on: April 29, 2020, 10:34:04 am »
https://www.keysight.com/en/pcx-3062392/infiniium-mxr-series-real-time-oscilloscopes?nid=-31731.0.00&cc=US&lc=eng

I saw that Keysight has introduced their MXR 8 channels scopes.  Amazing to see pricing of $108,000 for a 6 GHz scope.  I guess it helps that they are becoming more and more dominant in the scope market and have greater control on price.  Anyone had a demo?

Finally a scope we can all afford :D LOL
Don't forget that's the base price. RTSA, digital and extra memory are all options - you'll need extra probes to work at that frequency that are thousands each - then you get to the s/w options   :scared:

 

Online jjoonathan

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Re: Keysight MXR 8 channel scope
« Reply #32 on: May 02, 2020, 08:15:51 pm »
Quote
I defy anyone to get the R&S scope to achieve the claimed million waveforms per second.
I wasn't reporting marketing material, I was reporting the behavior of the RTO1024 about 5 feet to my left. If I hit PRESET and set trigger to FREE RUN it gets 640k wfm/s and then DISPLAY > DOTS gets it to a smidge over 1M wfm/s. I don't usually bother with dots because 600k is plenty, and it'll do 600k in line mode with noise filling the screen. Cursors don't degrade that, four active channels doesn't degrade that, masks and accelerated measurements send it to 250k, and unaccelerated measurements send it to 30k. It sounds like you had a buggy scope.

As for the UI, I love it, minus a few warts, but every scope has warts. To each their own, but I'm gratified to see that most of my favorite peculiarities seem to be gaining mindshare rather than losing it:
* Signal path diagrams to organize settings
* Good STFFTs (ultra hyped to see MXR take this to its logical conclusion ;D )
* History mode (segmented mode on by default in ring-buffer configuration, press button to see previous acqs, hyped to see this on MXR)
* Configured hysteresis is shown, visually, during trigger adjust, even on crazy triggers
* Single RGB-coded vertical control (so that math, ref, FFTs, MSO, not to mention 8 channels can all share it)
* Window transparency (adjustable with intensity knob)

One feature I love that hasn't experienced growth in mindshare:
* Third timebase knob to adjust memory depth


The way the global economy is going you might be able to make an offer... trade-in maybe?

One can hope, but every time I've quoted out a trade-in in this tier, at both my day job at big co and my personal lab, the trade-in credit wound up being about what I would expect to get on ebay. I suspect that to some degree they really do just turn around and pawn the trade-ins: I bought my Rohde and Schwarz scope from Teledyne Lecroy's ebay shop (yes, really -- pic attached) and that seems like a plausible explanation. I've had much more luck negotiating probes, adapters, and options, but those are much less of a factor for the personal lab.  Of course, there's only one way to find out in these crazy times, and you can bet I'll request a few quotes  :)

You can also bet I'll find an excuse to play with one the moment a MXR shows up on a coworker's bench :)
 
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Offline srce

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Re: Keysight MXR 8 channel scope
« Reply #33 on: May 13, 2020, 09:28:54 am »
Seems the RTSA option is $10k, MSO $5k and ARB $2k.

I was considering buying a Rigol RSA for RTSA functionality, so $10k for this option seems reasonable in comparison. Sensitivity is 5dB worse, but you get 320MHz real-time bandwidth instead of 40MHz and phase noise on the Keysight is 13dB better. Wonder how well it would work as a general purpose SA though? Looks a bit like the standard Infiniium FFT GUI - which I find a bit clunky.

50MHz ARB is silly pricing, when you can pick up a standalone 200MHz unit for a third of the price.

 

Offline JPortici

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Re: Keysight MXR 8 channel scope
« Reply #34 on: May 13, 2020, 10:42:32 am »
i wonder.. use cases?
I sometimes would like to have a 5-6-8 channel scope because of three phase motor driver, or 3PH + DCDC for DC link but i would be satisfied by 350MHz
I wonder what would you do with 8 channel, 6GHz and real time spectrum..
 

Offline pascal_sweden

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Re: Keysight MXR 8 channel scope
« Reply #35 on: May 13, 2020, 11:10:22 am »
Can someone highlight to me why oscilloscopes are used for signals above 1 Ghz?

Bit Error Rate and Eye diagrams. For that you need an oscilloscope that can deal with a high frequency range.

What are the other use cases in this frequency range where an oscilloscope is a better choice than a spectrum analyzer?

Where does the oscilloscope complement the spectrum analyzer?
 

Offline JPortici

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Re: Keysight MXR 8 channel scope
« Reply #36 on: May 13, 2020, 11:14:41 am »
mm.. I'm sure that there are use cases for keeping things "real time" altough i can not see them
 

Offline snoopy

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Re: Keysight MXR 8 channel scope
« Reply #37 on: May 13, 2020, 11:20:47 am »
Can someone highlight to me why oscilloscopes are used for signals above 1 Ghz?

Bit Error Rate and Eye diagrams. For that you need an oscilloscope that can deal with a high frequency range.

What are the other use cases in this frequency range where an oscilloscope is a better choice than a spectrum analyzer?

Where does the oscilloscope complement the spectrum analyzer?

PCI Express is one app where you need lots of bandwidth ;)

Looks good anyway ;)

 

Offline Wuerstchenhund

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Re: Keysight MXR 8 channel scope
« Reply #38 on: May 13, 2020, 11:23:35 am »
R&S has had fast updates in their analysis tier (RTE/RTO/RTP) since ~2010, and there it means: with short 1k acquisitions and all channels, it'll do 1,000,000 Wfm/s in dots mode, 600k Wfm/s in lines, and for longer acquisitions all the way into gigapoints use the rule (1.5 Billion / acq_points) to get Wfm/s. It's extremely nice to have both "modes" of operation in a single instrument, because even when I've got an application that does need the memory, I wind up doing a lot of "low-analysis" probing that benefits from Wfm/s. It's great to see Keysight join this fight in the analysis-class tier after crushing it with InfiniiVision!

Well, some LeCroy scopes could reach up to 1M wfms/s so it's not extraordinary for a more advanced scope being able to achieve higher update rates. But the thing is nobody bought a high end scope for update rates so it wasn't really seen a a major criteria, and still isn't. As long as the update rates are not excessively low (i.e. in the tens of updates/sec) then the update rate doesn't matter because in this class it's all about analysis and triggers. That really hasn't changed.

R&S was the first vendor who actually made a fuss about update rates in the marketing for its lower high-end scope RTO1000, which was R&S' first scope in this class. Back then they were probably looking for something they could use as a differentiator to other high end scopes from established brands, so they marketed heavy with the trigger rate.

Looks like KS wants to play the same game in the high-end segment now. Which is fine as long as the increase in update rate doesn't come with limitations in other areas, as it's the case for the InfiniVision scopes.

I defy anyone to get the R&S scope to achieve the claimed million waveforms per second. We had one on evaluation about 5 years ago: we went through everything and couldn't get the "waveform update rate indicator" above 50k. I even rang them, the sales guy and tech support didn't know. I'm sure it's even worse than the Tektronix "fast acquisition mode" in that's only possible in some obscure settings and by saluting pixies on the way to the office that morning. As for the R&S scope UI and button layout - it was totally un-intuitive, we struggled to use it so didn't buy, no matter how high they offered to discount.

I remember back when the RTO1000 came out and we got some units for evaluation that they indeed reached high trigger rates, even though they didn't go all the way up to 1M (I think we got some 700k out of them which is still better than the majority of analog scopes). Did it matter for what we do or make any of our measurements better? No.

We still decided against them mostly because many of our engineers didn't like the UI, and available probes were limited. In addition, pricing of some options was borderline extortionate, and the heavily marketed 16bit HD resolution which was introduced shortly after was just another oversampling mode which you got with other scopes for free. And like most instruments we got from R&S, the early versions were full of software bugs. 

Which was bit of a shame, as there were some really nice things in these scopes (like being able to change the brightness of the LEDs), it was reasonably compact and not excessively noisy. But so far we haven't seen anything which would be enough to make us move from Keysight and LeCroy.
 

Offline Wuerstchenhund

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Re: Keysight MXR 8 channel scope
« Reply #39 on: May 13, 2020, 11:35:50 am »
Can someone highlight to me why oscilloscopes are used for signals above 1 Ghz?

Because you want to see the waveshape of a signal which has frequency components over 1GHz?

Quote
Bit Error Rate and Eye diagrams. For that you need an oscilloscope that can deal with a high frequency range.

What are the other use cases in this frequency range where an oscilloscope is a better choice than a spectrum analyzer?

We use scopes for wideband applications. A conventional SA is useless because it's swept (i.e. during one 'acquisition' of the set frequency band it will capture a slice at different points in time, which is useless to get a time-coherent spectrum view). The analysis BW (RBW) is usually limited to a few MHz up to a couple of hundred. There are RTSAs of course but even the best one have an analysis BW not exceeding 1GHz or so.

On the other hand, in one application we use a Keysigh Infiniium-S to get an analysis BW of 8GHz.

You can't get that with a SA.

Quote
Where does the oscilloscope complement the spectrum analyzer?

At least for us, it's more a replacement. SAs have their strength when it comes to absolute RF performance. When analysis BW counts however, the scope wins.
 
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Offline nfmax

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Re: Keysight MXR 8 channel scope
« Reply #40 on: May 13, 2020, 11:58:09 am »
Well, some LeCroy scopes could reach up to 1M wfms/s so it's not extraordinary for a more advanced scope being able to achieve higher update rates. But the thing is nobody bought a high end scope for update rates so it wasn't really seen a a major criteria, and still isn't. As long as the update rates are not excessively low (i.e. in the tens of updates/sec) then the update rate doesn't matter because in this class it's all about analysis and triggers. That really hasn't changed.

What has changed is that DSOs are now marching into real-time analyser territory, for which sustained data throughput is one of the key parameters. Fast waveform update rate is a necessary (but not sufficient) condition for such use.
« Last Edit: May 13, 2020, 12:37:13 pm by nfmax »
 

Offline Wuerstchenhund

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Re: Keysight MXR 8 channel scope
« Reply #41 on: May 13, 2020, 12:56:50 pm »
Well, some LeCroy scopes could reach up to 1M wfms/s so it's not extraordinary for a more advanced scope being able to achieve higher update rates. But the thing is nobody bought a high end scope for update rates so it wasn't really seen a a major criteria, and still isn't. As long as the update rates are not excessively low (i.e. in the tens of updates/sec) then the update rate doesn't matter because in this class it's all about analysis and triggers. That really hasn't changed.

What has changed is that DSOs are now marching into real-time analyser territory, for which sustained data throughput is one of the key parameters. fast waveform update rate is a necessary (but not sufficient) condition for such use.

I disagree. The waveform rate isn't really relevant, for two reasons.

One, simply because even if your scope achieves that magical 1M updates/s then you're still blind almost 90% of the time. Which means you still miss most of the information in a dynamic signal.

Secondly, and much more important, for spectral measurements in general, there is no need to rely on the typical scope trigger to look for an specific event to start the acquisition sequence. Because we're no longer in the time domain so the exact point when the acquisition starts is no longer important, as long as the event is somewhere within the acquisition cycle and enough data is captured to perform the FFT. So you don't really need the scope trigger, you don't need time to to re-arm, you can essentially just run the sample memory in an endless cycle, only interrupted long enough to move the sampled data into processing (you might even be able to avoid that short inactive period if your design is dual-ported).

Which is also how many wideband receivers and RTSAs work.

When using a scope for spectral work, what really matters is the size of sample memory, because the memory alone determines how large of spectral sample in time you can capture. Because as soon as the memory is full there will be a very long (in comparison) period where your instrument is completely blind before you can re-acquire data again.
« Last Edit: May 13, 2020, 12:59:53 pm by Wuerstchenhund »
 

Offline Fred27

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Re: Keysight MXR 8 channel scope
« Reply #42 on: May 13, 2020, 01:10:00 pm »
How much is the bottle opener option?
 
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Offline Eric_S

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Re: Keysight MXR 8 channel scope
« Reply #43 on: May 13, 2020, 08:24:36 pm »
If I want to faff arount with a motor and brake system, two arb ports might be nice. Not that any other comparable scope offers that, mind you, but I was half thinking that this one might given its less capable siblings.
 

Offline Someone

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Re: Keysight MXR 8 channel scope
« Reply #44 on: May 13, 2020, 10:39:32 pm »
Well, some LeCroy scopes could reach up to 1M wfms/s so it's not extraordinary for a more advanced scope being able to achieve higher update rates. But the thing is nobody bought a high end scope for update rates so it wasn't really seen a a major criteria, and still isn't. As long as the update rates are not excessively low (i.e. in the tens of updates/sec) then the update rate doesn't matter because in this class it's all about analysis and triggers. That really hasn't changed.

What has changed is that DSOs are now marching into real-time analyser territory, for which sustained data throughput is one of the key parameters. fast waveform update rate is a necessary (but not sufficient) condition for such use.

I disagree. The waveform rate isn't really relevant, for two reasons.

One, simply because even if your scope achieves that magical 1M updates/s then you're still blind almost 90% of the time. Which means you still miss most of the information in a dynamic signal.
Still pushing that horse? You're misleadingly trying to make an equivalence between waveform update rate (drawing things to the screen, like building an eye diagram or histogram) and acquisition rates (dumping data to memory for later retrieval, often separately called segmented or sequenced acquisition to differentiate that).

Its as stark as the difference between "filing" documents to the in-tray, or reading them. The rates of each are radically different measures of performance. Even low cost scopes push big numbers for their sequence acquisitions:
https://siglentna.com/digital-oscilloscopes/
You've never been able to show any substantiated claim of Lecroy scopes achieving high waveform update rates, only fast trigger rates, which they openly and honestly specify:


Also you try and link some arbitrary update rate and blind time together, when that only applies for specific conditions and overheads, this magic 1,000,000 updates/second you seem fixated on does not imply any specific blind time. Yes, the major brands do have a blind time around 90% under the conditions which they hit their peak rates, but that is not applicable across other conditions, and is not some fundamental barrier. If the waveform update rate is 1,000,000 per second, the blind time in undefined, other information is required to determine it.
 

Offline snoopy

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Re: Keysight MXR 8 channel scope
« Reply #45 on: May 14, 2020, 05:20:38 am »
Well, some LeCroy scopes could reach up to 1M wfms/s so it's not extraordinary for a more advanced scope being able to achieve higher update rates. But the thing is nobody bought a high end scope for update rates so it wasn't really seen a a major criteria, and still isn't. As long as the update rates are not excessively low (i.e. in the tens of updates/sec) then the update rate doesn't matter because in this class it's all about analysis and triggers. That really hasn't changed.

What has changed is that DSOs are now marching into real-time analyser territory, for which sustained data throughput is one of the key parameters. fast waveform update rate is a necessary (but not sufficient) condition for such use.

I disagree. The waveform rate isn't really relevant, for two reasons.

One, simply because even if your scope achieves that magical 1M updates/s then you're still blind almost 90% of the time. Which means you still miss most of the information in a dynamic signal.

Secondly, and much more important, for spectral measurements in general, there is no need to rely on the typical scope trigger to look for an specific event to start the acquisition sequence. Because we're no longer in the time domain so the exact point when the acquisition starts is no longer important, as long as the event is somewhere within the acquisition cycle and enough data is captured to perform the FFT. So you don't really need the scope trigger, you don't need time to to re-arm, you can essentially just run the sample memory in an endless cycle, only interrupted long enough to move the sampled data into processing (you might even be able to avoid that short inactive period if your design is dual-ported).

Which is also how many wideband receivers and RTSAs work.

When using a scope for spectral work, what really matters is the size of sample memory, because the memory alone determines how large of spectral sample in time you can capture. Because as soon as the memory is full there will be a very long (in comparison) period where your instrument is completely blind before you can re-acquire data again.

Try viewing a composite video signal with a low acquisition rate scope or a scope with no DPO :( (ok I know, who looks at composite video signals these days but you get my drift ) What does the color burst look like to you ?

Now view it on any Tek scope with DPO because I know how much you hate Tek scopes :-DD

cheers
 

Offline Wuerstchenhund

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Re: Keysight MXR 8 channel scope
« Reply #46 on: May 14, 2020, 10:25:54 am »
One, simply because even if your scope achieves that magical 1M updates/s then you're still blind almost 90% of the time. Which means you still miss most of the information in a dynamic signal.

Still pushing that horse? You're misleadingly trying to make an equivalence between waveform update rate (drawing things to the screen, like building an eye diagram or histogram) and acquisition rates (dumping data to memory for later retrieval, often separately called segmented or sequenced acquisition to differentiate that).

Actually, it yourself who (still, as I remember we had this discussion in the past) gets confused.

You mix the waveform update rate with the screen refresh rate, which are two unrelated things.

The screen refresh rate (i.e. the rate at which the display gets updatd) is usually down to 60Hz on a modern scope (and that includes all these high update rate DSOs such as the DSOX3kT).

The waveform update rate (i.e. the rate at how often the scope can update its waveform record) is different. This is the trigger rate, and contains the whole acuisition as well as the subsequent blind time a scope needs for re-arming and processing.

As to segmented/sequence mode, this is a specific mode where the sample memory is chopped up in small blocks (segments) so the long scope memory can be used for a set of short memory acquisitions, thereby increasing the waveform/trigger rate while being able to make some use of deep memory.

Also, segmented mode is pretty irrelevant when we using scopes for RF work.


Quote
Its as stark as the difference between "filing" documents to the in-tray, or reading them.

Not sure what you're on about "filing documents" here.

It's not just car analogies that suck, that's for sure.  :-\

Quote
You've never been able to show any substantiated claim of Lecroy scopes achieving high waveform update rates, only fast trigger rates, which they openly and honestly specify:

Well, I certainly did before my extended absence, as we had this discussion before (more than once).

And I'm sure I did already present this:



I'm not sure what this is to you, but I can see a LeCroy scope pushing a trigger rate of in excess of 1M waveforms/s in NORMAL mode (although it's in WaveStream mode which is an analog-style persistence mode where update rates are maximized).

Quote
Also you try and link some arbitrary update rate and blind time together, when that only applies for specific conditions and overheads, this magic 1,000,000 updates/second you seem fixated on does not imply any specific blind time. Yes, the major brands do have a blind time around 90% under the conditions which they hit their peak rates, but that is not applicable across other conditions, and is not some fundamental barrier. If the waveform update rate is 1,000,000 per second, the blind time in undefined, other information is required to determine it.

OK, I'll bite one last time.  ::)

The Waveform Update rate (which is identical with the Trigger Rate) is a measure of how many times a scope can update its waveform record. The blind time which follows the acquisition process is a major (actually, the largest) part of the sequence which is the reciprocal of the waveform update rate. It's as simple as that.

I use the 1M wfms/s figure because this is roughly the maximum any scope as of today can achieve (actually, it's slighly higher, but 1M wfms/s is close enough), and it's simpler just taking the max figure when talking about high waveform rate scopes. I thought that was clear, but I guess it's not.

Now as to the blind time: yes, it does vary by scope, and also depends to a certain extend on the memory length and timebase setting used for the acquisition. So you got at least this one right.

There are a couple of things you miss, though.

First, the blind time example I gave was not only rough estimate, i's also a percentage figure. And for a given update rate (like, for example, 1M wfms/s) this percentage figure doesn't vary a lot between scopes. So if you really want to nitpick you can of course argue that it may not be exact 90%, it could well be 93%, 89%, 87% or something else, but at the end of the day the fact remains that at that such high update rates the blind time of any scope available today will always be *vastly* bigger than the acquisition time.

Which means relying on excessively high update rates to capture rare events has roughly a 1 in 10 chance that your scope actually sees it.

Secondly, yes, you can certainly reduce the percentage the blind time presents in the wavform update cycle. You just have to increase the acquisition time, either by lowering the sample rate or by increasing the sample memory. Eventually, your blind time will be smaller than your acquisition time. But then your waveform rate will also have dropped like a rock. And, even when it's smaller, there is still a blind time where your scope will miss events between acquisition cycles.

Which means relying on repeated updates to capture rare events is still a gamble, even your odds may have increased (e.g. 9 out of 10 chance your scope sees it). However, if you can increase the acuisition time to capture your period of interest in one acquisition, and then set a trigger for the event of interest, your the odds of your scope seeing the event will be 100%.
« Last Edit: May 14, 2020, 10:28:27 am by Wuerstchenhund »
 

Offline Someone

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Re: Keysight MXR 8 channel scope
« Reply #47 on: May 14, 2020, 11:21:31 am »
One, simply because even if your scope achieves that magical 1M updates/s then you're still blind almost 90% of the time. Which means you still miss most of the information in a dynamic signal.

Still pushing that horse? You're misleadingly trying to make an equivalence between waveform update rate (drawing things to the screen, like building an eye diagram or histogram) and acquisition rates (dumping data to memory for later retrieval, often separately called segmented or sequenced acquisition to differentiate that).

Actually, it yourself who (still, as I remember we had this discussion in the past) gets confused.

You mix the waveform update rate with the screen refresh rate, which are two unrelated things.

The screen refresh rate (i.e. the rate at which the display gets updatd) is usually down to 60Hz on a modern scope (and that includes all these high update rate DSOs such as the DSOX3kT).

The waveform update rate (i.e. the rate at how often the scope can update its waveform record) is different. This is the trigger rate, and contains the whole acuisition as well as the subsequent blind time a scope needs for re-arming and processing.

As to segmented/sequence mode, this is a specific mode where the sample memory is chopped up in small blocks (segments) so the long scope memory can be used for a set of short memory acquisitions, thereby increasing the waveform/trigger rate while being able to make some use of deep memory.
If you want to roll this back to absolute fundamentals, feel free. But nowhere do I "confuse" display frame rate with waveform update rate. Throwing up more FUD to discredit anyone who dares point out the gaping holes in your nonsense is a transparent attempt at distraction.

The trigger rate and waveform update rate can be completely disconnected. They are not in any way equivalent. Keysight have to clarify this in their marketing material to avoid your sorts of misleading claims:
Quote from: Keysight
When reviewing the update rate process, it seems like trigger rate could be used interchangeably with update rate; however, some oscilloscopes will trigger multiple times while the data is being processed and ignore the newly triggered event, making the trigger rate different than the oscilloscope update rate. The faster the update rate, the more events are being captured and analyzed by the oscilloscope
Waveform update rate is widely understood to be the number of acquisitions per second that are drawn to the screen.

Segmented mode in most scopes doesn't draw all the data to the screen as its assumed you will go back through them after the capture sequence is complete. The MXR scope put this in a rather poetic way for a data sheet:


Its as stark as the difference between "filing" documents to the in-tray, or reading them.
Not sure what you're on about "filing documents" here.
Dumping acquisitions to memory without them being seen, is in no way comparable, to putting their information onto the screen in realtime. One is trivial, the other is resource intensive. Just as pushing through acquisition data without putting it to the screen is not comparable to drawing it there.

You've never been able to show any substantiated claim of Lecroy scopes achieving high waveform update rates, only fast trigger rates, which they openly and honestly specify:

Well, I certainly did before my extended absence, as we had this discussion before (more than once).

And I'm sure I did already present this: [video]

I'm not sure what this is to you, but I can see a LeCroy scope pushing a trigger rate of in excess of 1M waveforms/s in NORMAL mode (although it's in WaveStream mode which is an analog-style persistence mode where update rates are maximized).
You can keep pointing to a video of a scope showing an impressive trigger rate, there is no evidence its drawing or processing the data from those triggers. We could go to the manual for that scope, which nowhere claims anything other than a high trigger rate. They even go as far as this:

Why would they include a special waveform/second optimized mode if the normal mode could outperform it? Note the manufacturer claim, 8000wfms/second.
Competitive comparisons have consistently found very poor updates rates for that model of scope:
https://www.tek.com/document/competitive/tektronix-mso-dpo4000-series-vs-lecroy-waverunner-xi-fact-sheet-0

The Waveform Update rate (which is identical with the Trigger Rate) is a measure of how many times a scope can update its waveform record.
You can keep trying to redefine industry standard terms to suit your misleading arguments, but we'll keep calling it out and pointing to that nonsense. Your emotive rubbish that follows on from that is your "standard" claims which are getting old.

Which means relying on excessively high update rates to capture rare events has roughly a 1 in 10 chance that your scope actually sees it.
Excessively high but still not high enough? Ok, you just want to say its a bad thing no matter if its a high number or a low number.

Secondly, yes, you can certainly reduce the percentage the blind time presents in the wavform update cycle. You just have to increase the acquisition time, either by lowering the sample rate or by increasing the sample memory. Eventually, your blind time will be smaller than your acquisition time. But then your waveform rate will also have dropped like a rock. And, even when it's smaller, there is still a blind time where your scope will miss events between acquisition cycles.
There is no technical barrier to faster update rates than what is currently offered. There are commercial products (but not general purpose oscilloscopes) with zero blind time that guarantee they draw 100% of the samples to the histogram, on sustained XXGsa/s streams. Updates rates are not fixed in stone and imply all the extra conditions you keep claiming they do.

Which means relying on repeated updates to capture rare events is still a gamble, even your odds may have increased (e.g. 9 out of 10 chance your scope sees it). However, if you can increase the acuisition time to capture your period of interest in one acquisition, and then set a trigger for the event of interest, your the odds of your scope seeing the event will be 100%.
Assuming there is a single trigger which you can configure to catch the event. Great, you captured a single event. You can keep falling back to this extreme position which claims everything is solvable with triggers, but its not true for all applications. Some of which require a statistical measure built from an eye diagram. So scopes have specifications for how fast they update the display, waveforms/second or UIs/second (again they can be different and are not equivalent).
« Last Edit: May 14, 2020, 11:26:03 am by Someone »
 

Offline Wuerstchenhund

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Re: Keysight MXR 8 channel scope
« Reply #48 on: May 14, 2020, 11:23:18 am »
When using a scope for spectral work, what really matters is the size of sample memory, because the memory alone determines how large of spectral sample in time you can capture. Because as soon as the memory is full there will be a very long (in comparison) period where your instrument is completely blind before you can re-acquire data again.

Try viewing a composite video signal with a low acquisition rate scope or a scope with no DPO :( (ok I know, who looks at composite video signals these days but you get my drift ) What does the color burst look like to you ?[/quote]

I'm not much into video stuff and may be missing something here, but what do you need a very high waveform update rate for with a signal which changes just some 25 or 30 times per second? :-//

As a side note, CVBS video is still widely used, for example with vehicular cameras and DVRs. So it's not that no-one looks at CBVS signals anymore ;)

Quote
Now view it on any Tek scope with DPO because I know how much you hate Tek scopes :-DD

I don't *hate* Tek scopes (and I do consider attaching emotions to specific brands as something juvenile), it's just my experience that, compared to what we can get from other brands, their digital scopes are simply sub-par (and have been for a long time).

And considering that Tek's scope sales have been declining for years, it appears that many other professional users agree.
 

Online tv84

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Re: Keysight MXR 8 channel scope
« Reply #49 on: May 14, 2020, 11:51:43 am »
How much is the bottle opener option?

Typical prices...  but no options. :)
 
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