According to http://www.newark.com/tektronix-tbs2000-oscilloscope (http://www.newark.com/tektronix-tbs2000-oscilloscope) is the waveform update rate 10 000.Nothing in the official datasheet. http://www.newark.com/wcsstore/ExtendedSitesCatalogAssetStore/cms/asset/pdf/common/tektronix/Tektronix-TBS2000.pdf (http://www.newark.com/wcsstore/ExtendedSitesCatalogAssetStore/cms/asset/pdf/common/tektronix/Tektronix-TBS2000.pdf)
I have not used video trigger in thisAnother really useful thing on the KS ( not sure which models can do it) is that it can do two serial decodes simultaneously - same or different types.centurymillennium, have you? The serial decoding is probably just a "insert coin" option. The big question is how usable are the decoding options, the Keysight is very fast and usable on decoding.
Johan-Fredrik
I think the specs are preliminary. The 20MPts memory depth on all channels is interesting (Keysight doesn't even come close to that) and Tek finally put a display with a decent resolution in a low-end scope but what is missing are detailed specs like FFT length and decoding options. Without decoding this scope is just too expensive and also not very suitable for modern education.
Maybe but if it has some options like decoding the long memory sure makes it an interesting competitor for Keysight's offerings. This price for the 100MHz 4 channel model is around 2000 euro. So far the low end Tektronix scopes where plagued by short memory and small, low resolutions screens but it seems they finally addressed those issues.I think the specs are preliminary. The 20MPts memory depth on all channels is interesting (Keysight doesn't even come close to that) and Tek finally put a display with a decent resolution in a low-end scope but what is missing are detailed specs like FFT length and decoding options. Without decoding this scope is just too expensive and also not very suitable for modern education.
I doubt Tek sees this scope as a competitor to Rigol's DS1000z/DS2000/DS4000 Series, or the GW Instek GDS-2000E or the Keysight DSO-X2000, scopes which attract hobbyists and small businesses. The new TBS2000 seems to be designed particularly for that one market where Tek still makes a lot of sales - education.
The overall scope properties remind me a lot of OWON.I thought Hantek. :-//
Place your bets folks.....The overall scope properties remind me a lot of OWON.I thought Hantek. :-//
I don't see any indication from that datasheet that it has intensity graded display. If it hasn't, it's just a sad joke.
Looks nice, but waveform update rate is unspecified.
According to http://www.newark.com/tektronix-tbs2000-oscilloscope (http://www.newark.com/tektronix-tbs2000-oscilloscope) is the waveform update rate 10 000.I think that may be an error - it isn't mentioned at all in the datasheet. Neither are decodes.
I have not used video trigger in thiscenturymillennium, have you? The serial decoding is probably just a "insert coin" option. The big question is how usable are the decoding options, the Keysight is very fast and usable on decoding.
Not much detail yet but no examples of intensity grading in the documents so far, and a shame to not have an integrated signal generator even if it has toy specifications for teaching labs.
1400 Euros for 70Mhz, 2-channel 'scope with very basic features... and people are salivating?It's all in the name - maybe if Keysight were still called Hewlett Packard, more people would realise that Tek haven't been "the scope guys" for many years.
Just because it says "Tektronix" on it?
I don't get it. :-//
1400 Euros for 70Mhz, 2-channel 'scope with very basic features... and people are salivating?Yep, and the RMS measurements can probably be trusted too. :P
Just because it says "Tektronix" on it?
I don't get it. :-//
Information include the comparisons with other scopes and the service manual is now on the Tektronix website.
1400 Euros for 70Mhz, 2-channel 'scope with very basic features... and people are salivating?Yep, and the RMS measurements can probably be trusted too. :P
Just because it says "Tektronix" on it?
I don't get it. :-//
Hi group,It is interesting to see Tektronix made comparison sheets for scopes from Hameg, Rigol, GW Instek, Lecroy and Keysight but no Siglent.
Information include the comparisons with other scopes and the service manual is now on the Tektronix website.
Link: http://www.tek.com/search/apachesolr_search/tbs2000 (http://www.tek.com/search/apachesolr_search/tbs2000)
Hi group,
Information include the comparisons with other scopes and the service manual is now on the Tektronix website.
. Sad because they have loosed road.
Link: http://www.tek.com/search/apachesolr_search/tbs2000 (http://www.tek.com/search/apachesolr_search/tbs2000)
It seems the big thing that they are pushing in the comparisons are:
1) 20M point of record length
2) Wireless connectivity, through a dongle stuck in the back
3) The educational aspects.
4) Faster time base 2ns with 500 MS/s
5) Bigger screen
6) The VXI probe interface. I don't know why you need active probes on an entry level 'scope.
Regards,
Jay_Diddy_B
Found a UK website that have published lots of info on the new Tek TBS2000 - http://www.sjelectronics.co.uk/new-tektronix-tbs2000-series-digital-storage-oscilloscopes/ (http://www.sjelectronics.co.uk/new-tektronix-tbs2000-series-digital-storage-oscilloscopes/)Spot the Tek Troll.
Low cost, and specs look pretty good.
Found a UK website that have published lots of info on the new Tek TBS2000 - http://www.sjelectronics.co.uk/new-tektronix-tbs2000-series-digital-storage-oscilloscopes/ (http://www.sjelectronics.co.uk/new-tektronix-tbs2000-series-digital-storage-oscilloscopes/)
Low cost, and specs look pretty good.
So the 4-channel version is three times the cost of the Rigol 1074Z and no intensity display. What planet are these people on?
Conclusion: They've got their sights set on people who don't spend their own personal money on test gear.
Why is none of these big companies doing real innovation anymore?
A good 4-ch isolated scope doesnt even need to be affordable, we would pay a whole lot for that kind of instrument, if it were to exist. Copy the user interface and frontend from Lecroy (since they do the least crappy ones at the moment), large benchtop form factor is perfectly good as it fits a large display, we dont care for portability.Keysight has some hand-held-ish scopes with isolated inputs. They are not cheap and not really portable but would be useful as a bench scope.
The R&S RTH did look good on paper but did disappoint me pretty hard, lacking even basic features (and having surprisingly crappy CMRR).
So definitely no intensity display then - pathetic, just pathetic. 20M record length is pretty pointless without it.It would surprise me if it doesn't have intensity display; maybe Tektronix deems that so standard they don't even mention it. After all they already had some form of persistence on the monochrome TDS500 series (early 90's).
No mention of it, or update rate and no sign of it in any of the images. One of the dealer pages does use the DPO acronym, another shows an update rate but not seen it in any of the Tek documents.So definitely no intensity display then - pathetic, just pathetic. 20M record length is pretty pointless without it.It would surprise me if it doesn't have intensity display; maybe Tektronix deems that so standard they don't even mention it. After all they already had some form of persistence on the monochrome TDS500 series (early 90's).
Considering how lame it looks you'd expect them to be pushing every possible feature.I wouldn't call the scope itself lame. The way it looks is a result of the current test equipment design style (the Panda look). Let's just wait until the datasheet gets completed. Does Tektronix send scopes to Dave for a review?
The Tektronix TPS2024B looks so much better! Moreover that one comes with 4 isolated channels!
I didn't mean the physical look, I meant the whole product - piss-poor value and lacking features that have become industry standardConsidering how lame it looks you'd expect them to be pushing every possible feature.I wouldn't call the scope itself lame. The way it looks is a result of the current test equipment design style (the Panda look). Let's just wait until the datasheet gets completed. Does Tektronix send scopes to Dave for a review?
The update rate is 10000 times per second. The controls look lively in the demo. It DOES have variable persistence. See the spec sheet. VP is a DISPLAY mode, not an acquisition mode. Beauty is in the eyes of the beholder but the handle is normally flipped down when the scope is in use. Then it matches the case. But seriously do we choose a scope by how it looks?another one shill? (one post)
Guys why do we beat equipment up before we know the facts? The website seems to be barely working I know but give it a chance.
NOTE. The maximum sample rate of 1 GS/s is only available when one channel per channel pair is active (channel 1, 2:-- :--
pair or channel 3, 4 pair).
For two-channel models, only one channel (either channel 1 or 2) can sample at 1 Gs/s. If channel 1 and 2 are both
active, then the maximum sample rate changes to 500 MS/s.
On four-channel models, only two channels can sample at 1 GS/s (one channel from each pair). So if channel 1 or 2, and
channel 3 or 4, are active, the maximum sample rate is available. Turning on a 3rd channel (in either pair) changes the
maximum sampling rate to 500 MS/s.
Rear-panel connectorsOK, I like that there is a Trig Out.
1. Aux Out. Sends a positive pulse
(low-to-high transition) when a trigger
occurs, to synchronize other test
equipment to trigger events.
NOTE. The Aux Out sends out randomWhat the hell is this supposed to be??
pulses when there are no signals connected
to the oscilloscope.
According to the manual, there is no video trigger. This is crap.
Remotely controlling the oscilloscope from a Web browserWell, this is nice. I think that Rigol, Siglent or Owon do not have this feature. At DSOX2002A you have to buy an expensive plug-in LAN module.
(LXI)
The oscilloscope has a built-in LXI-compliant browser interface. The Web browser shows instrument status, configuration,
and controls with which to remotely control the oscilloscope and view waveforms. You can connect to the oscilloscope Web
page by simply entering the oscilloscope’s IP address in the address bar of a Web browser.
In 31 years I sold fewer than 50 video triggers. In the last ten years 0!TBS2000 is probably the first scope without a video trigger in last 25 years or so. Even that basic TDS210 has a video trigger.
But if you need video trigger, then just chose annother scope.
Is this how Tek normally do LAN remote scope control ?QuoteRemotely controlling the oscilloscope from a Web browserWell, this is nice. I think that Rigol, Siglent or Owon do not have this feature. At DSOX2002A you have to buy an expensive plug-in LAN module.
(LXI)
The oscilloscope has a built-in LXI-compliant browser interface. The Web browser shows instrument status, configuration,
and controls with which to remotely control the oscilloscope and view waveforms. You can connect to the oscilloscope Web
page by simply entering the oscilloscope’s IP address in the address bar of a Web browser.
Not a shillsorry for that :) but you know.. the timing.. the content..
Is this how Tek normally do LAN remote scope control ?
Siglent's use the EasyScope interface and NIVISA software to provide the LAN and USB connection drivers.
Why would you want video trigger? Who even uses analogue video signals nowadays? Besides I think you can still do video triggering if the trigger system supports triggering on events.In 31 years I sold fewer than 50 video triggers. In the last ten years 0!TBS2000 is probably the first scope without a video trigger in last 25 years or so. Even that basic TDS210 has a video trigger.
But if you need video trigger, then just chose annother scope.
On the other hand, TBS2000 can be nice for basic school use.
If someone can name one new feature in the new TBS2000 oscilloscope which wasn't already present in all entry-level DSO scopes for the past 3-5 years?That 20Mpoints memory with search and mark capability (in future firmware release) is not common. Active probe support is very uncommon among low-cost scopes.
That teaching capabilities with WiFi are quite new, but not needed IMHO. For school I want real scopes that are used in industry, like HP 54600, Tek TDS2000, DSOX2000 or DSOX3000.So do the instructors but they don't get the budgets and have to make do with what's affordable.
It is funny how all other scopes in comparison sheets have 1GS per channel (at least stated by Tektronix guys) and only TBS2000 has 500MS per channel. The ADCs are apparently expensive even in 2016. Come on, even TDS210 has 1GS per channel.
The update rate is 10000 times per second. The controls look lively in the demo. It DOES have variable persistence. See the spec sheet. VP is a DISPLAY mode, not an acquisition mode. Beauty is in the eyes of the beholder but the handle is normally flipped down when the scope is in use. Then it matches the case. But seriously do we choose a scope by how it looks?VP is not necessarily the same as intensity grading. I see no reference to any intensity control in the UM
Guys why do we beat equipment up before we know the facts? The website seems to be barely working I know but give it a chance.
If someone can name one new feature in the new TBS2000 oscilloscope which wasn't already present in all entry-level DSO scopes for the past 3-5 years?er, wifi.... because everyone needs wifi on a piece of kit that lives on a bench, obviously.... :-DD
1400 Euros for 70Mhz, 2-channel 'scope with very basic features... and people are salivating?Yep, and the RMS measurements can probably be trusted too. :P
Just because it says "Tektronix" on it?
I don't get it. :-//
In fact, those overpriced oscilloscopes targeted for education are neither used in the industry, and are neither used by hobbyists. So you learn to work with a scope that is not used by anybody else except instructors. Not very good IMO!:scared:
They should use oscilloscopes in the labs, which are used in the industry, or at least which are used by many people. In that case, putting a Rigol DS2000A or a Siglent SDS2000X in the university lab wouldn't be such a bad idea at all. Hardware wise it outperforms the Tektronix education line with several miles, and it is used by many people.
So definitely no intensity display then - pathetic, just pathetic. 20M record length is pretty pointless without it.
If that's the best Tek can do years after what KS and Rigol have been doing, it looks like they've pretty much given up trying. I'd be highly surprised if this wasn't a re-badge job from one of the Chinese companies.
Not sure if Rigol DS2000A or a Siglent SDS2000X survive a 8 hour use per day. I have never seen an erratic knob on a Tek at my university. There were some cracked knobs on few 54600 scopes, well, after some 15-20 years after manufacture.:-DD
That's why I was saying that they have to make a 4 channel oscilloscope with an isolated front-end AND with a deep memory! For some reason, no manufacturer can realize that configuration!And why? think back to the discussion in the thread "What is missing in the marketplace".
That's why I was saying that they have to make a 4 channel oscilloscope with an isolated front-end AND with a deep memory! For some reason, no manufacturer can realize that configuration!And why? think back to the discussion in the thread "What is missing in the marketplace".
In order to get the analog data across the isolation barrier there are speed bottlenecks.
::)That's why I was saying that they have to make a 4 channel oscilloscope with an isolated front-end AND with a deep memory! For some reason, no manufacturer can realize that configuration!And why? think back to the discussion in the thread "What is missing in the marketplace".
In order to get the analog data across the isolation barrier there are speed bottlenecks.
Speed bottlenecks are no argument, as the Tektronix TPS2024B can go up to 200 MHz.
It would be the perfect scope, if it only had deep memory!
It is funny how all other scopes in comparison sheets have 1GS per channel (at least stated by Tektronix guys) and only TBS2000 has 500MS per channel. The ADCs are apparently expensive even in 2016. Come on, even TDS210 has 1GS per channel.
You seem awfully sure of this. Is that because you are familiar with the fiber optic options and their price points? Or because you aren't? I haven't spent enough time shopping to have an opinion of my own, but even if I were sure that there was nothing on the market at an appropriate price point, I wouldn't make bets on 6 months from now.That's why I was saying that they have to make a 4 channel oscilloscope with an isolated front-end AND with a deep memory! For some reason, no manufacturer can realize that configuration!And why? think back to the discussion in the thread "What is missing in the marketplace".
In order to get the analog data across the isolation barrier there are speed bottlenecks.
I'm only familiar with the current use of opto isolation for isolated front ends and a fibre optic solution may offer a better solution. :-+You seem awfully sure of this. Is that because you are familiar with the fiber optic options and their price points or because you aren't familiar with them and are repeating old knowledge?That's why I was saying that they have to make a 4 channel oscilloscope with an isolated front-end AND with a deep memory! For some reason, no manufacturer can realize that configuration!And why? think back to the discussion in the thread "What is missing in the marketplace".
In order to get the analog data across the isolation barrier there are speed bottlenecks.
If they want to take the lead, they should come up with a cheap and affordable 4-channel 100 MHz scope with a deep memory and where ALL 4 channels would be isolated. Many universities would buy these scopes for their Power Electronics labs. None of these big companies has real guts to pull of an affordable 4-channel isolated scope!
If someone can name one new feature in the new TBS2000 oscilloscope which wasn't already present in all entry-level DSO scopes for the past 3-5 years?You sure are making a lot of noise without actually checking the details. They specify a CMRR for the channels, separately to crosstalk, and the manual has:
Two ratings are important to know and understand:But these specifications are missing from the available documents at the moment. Its entirely possible the scope has floating inputs and discusses using a probe across a resistor to measure currents (with probe settings to read directly in amperes).
The maximum measurement voltage from the probe tip to the probe reference lead
The maximum floating voltage from the probe reference lead to earth ground
That might be the worst introduction video I've ever seen as well.Not sure why. The video was OK for me.
Looks like they're making good use of the higher resolution screen, the cursors are very tidy and informative.That might be the worst introduction video I've ever seen as well.Not sure why. The video was OK for me.
Little to do with the vid, I've already flagged diesel as a stalker.That might be the worst introduction video I've ever seen as well.Not sure why. The video was OK for me.
It can be seriously argued that TEK never made good digital scopes. The last independent number I saw indicate that TEK had about 50% of the worldwide digital scope market. If that still holds true they sell as many scopes as all other manufacturers put together.
While this does not prove they make the best scopes it does mean that Majority of people who believe they do!
Looks like they're making good use of the higher resolution screen, the cursors are very tidy and informative.That might be the worst introduction video I've ever seen as well.Not sure why. The video was OK for me.
It can be seriously argued that TEK never made good digital scopes. The last independent number I saw indicate that TEK had about 50% of the worldwide digital scope market. If that still holds true they sell as many scopes as all other manufacturers put together.
:wtf:
That's nonsense, at no point had Tek anywhere near 50% of global the DSO market. Tek had a leading position in the market for analog scopes (where if I remember right they managed to reach some 62% at some point) but that changed quickly when digital scopes became increasingly widespread, a market that was (and still is) dominated by HP (then Agilent, then Keysight) and LeCroy.QuoteWhile this does not prove they make the best scopes it does mean that Majority of people who believe they do!
Yeah, like people who believe smoking is good for them. |O
And it's a shame that the belief of all these people doesn't help Tek to increase its dwindling sales, while for some reason despite all this people believing Tek is the best they still rather spend their money scopes made by someone else. :palm:
Be careful with that stuff you're smoking, dude!
Damn that looks good
Look at those cursors, the gui and how it is laid out. that's the attentions to details one expects from tek, this is where a noticeable part of your money went.
Damn that looks good
Look at those cursors, the gui and how it is laid out. that's the attentions to details one expects from tek, this is where a noticeable part of your money went.
Have you looked at the R&S HMO series of 'scopes? They do all that sort of stuff even better and have far more capabilities (eg. Serial decoding).
Looking at that video this Tek seems aimed squarely at education. What University teacher isn't going to be asking for more budget after watching that?
(...and will the next generation of students go straight into their first jobs not knowing that "ground-clip is bad"?)
the point of my post was why would someone spend two, three times the money for an instrument that, from a first glance at the spec sheet, is the same as another oneI can see instructors using the UI features to upload a course wirelessly for students to access in the GUI later then grab all the WiFi dongles and lock them in his/her desk. Often lab scopes are Kensington locked to benches with only a mains supply with no LAN and I find this WiFi feature quite unique.
the point of my post was why would someone spend two, three times the money for an instrument that, from a first glance at the spec sheet, is the same as another oneFrom what little I know it would be a poorly-run educational establishment that paid even half the listed price, for a multi-unit buy.
Their ridiculous list price clearly has a lot of headroom to discount. Their build cost isn't going to be far off similar Chinese models.the point of my post was why would someone spend two, three times the money for an instrument that, from a first glance at the spec sheet, is the same as another oneFrom what little I know it would be a poorly-run educational establishment that paid even half the listed price, for a multi-unit buy.
Judging by your comments you appear to be something of an industry expert.
I didn't represent that TEK currently has 50% DSO market share. I could not possibly know that. What I said was the last time I saw a market share report, and I only saw 1 independent report, that was the number I saw.
I do know there was essentially NO DSOs made at that time except those made by HP, TEK, a few Lecroy some by Gould and some by Nicolet. That tells me this was before Lecroy seriously entered the scope market.
Now the market is loaded with cheap Chinese imports and I would expect that they would dominate the unit volume but probably not the dollar volume.
Since TEK became a part of Danaher in 2007 sales are no longer reported externally so no one outside of TEK/ Danaher really knows what their sales are. Indeed even employees below top management were not provided with sales information except in a general sense. I did hear some numbers from time to time that were " leaked". They seemed lower that what I though they should be. I can tell you that in my territory though I did annual market share analysis. I do not claim absolute precision but I had been in the territory for 31 years so I pretty much knew what everyone had. In my last year (2011) with TEK I estimated scope market share at around 40%. At that time I do not have responsibility for low end scopes- those below about $15K and so my numbers did not include them. My Agilent counterpart agreed with this analysis. He admitted that we were kicking his ass. I did not even know who the Lecroy guy was... Your stated market share in analog agrees with numbers I have heard, but did not see. I do not know how other territories or other parts of the world fared.
If you have current market share estimates those would be interesting.
I think that lecroy does that too
For one man shops the Tektronix scopes are totally uninteresting so far. I did buy a Tektronix scope for a customer a couple of years ago but that was just for political reasons and purely based on brand recognition and me being able to 'drive' it without needing to learn a new user interface. I have owned&used Tektronix scopes (DSOs) for nearly 2 decades but there is nothing in Tektronix' line-up I would buy nowadays. Still if the TBS2000 gets decent protocol decoding for a sane price it will be a very interesting scope compared to what the competition is currently offering.Judging by your comments you appear to be something of an industry expert.
Let's just say I got around a bit. Based on your comments I guess you've been in sales for Tek? If so then I'm the type of person that sits opposite you (customer). Aside other things, I specify and buy test equipment (lots of it, really) for a larger number of technology labs spread around Europe and the US.
We also maintain very good contacts to other labs, facilities and to some extend Universities and technical training schools which are used to gather and process independent market figures for our own use, far away from manufacturers' Kool-Aid. What we don't capture (and don't care for, honestly) are sales to individuals like one-man shops or hobbyists.
The back shot shows it has ethernet socket. I think the wifi dongle is liable to go missing in a classroom. Hopefully generic chinese ones can replace it.
Other interesting features (promised for the future) are the 16 bit high-res mode when most competitors only go to 12 bit (or less).
Other interesting features (promised for the future) are the 16 bit high-res mode when most competitors only go to 12 bit (or less).
R&S offers 16bit (software) HiRes modes for RTE/RTO as option, but even on these scopes with fast ADCs the benefit over 11bit or 12bit modes is miniscule.
Judging by your comments you appear to be something of an industry expert.QuoteI didn't represent that TEK currently has 50% DSO market share. I could not possibly know that. What I said was the last time I saw a market share report, and I only saw 1 independent report, that was the number I saw.
I do know there was essentially NO DSOs made at that time except those made by HP, TEK, a few Lecroy some by Gould and some by Nicolet. That tells me this was before Lecroy seriously entered the scope market.
Which LeCroy did in 1981 and back then there wasn't really a large market for DSOs anyways. My data doesn't go so far back but irrespective of Teks marketshare being 50% or not it's a lot easier to become dominant in an emerging market than in an established one, which is what the DSO market is today.QuoteNow the market is loaded with cheap Chinese imports and I would expect that they would dominate the unit volume but probably not the dollar volume.
I doubt that they dominate the unit volume, at least not for units sold under their own brands. The hobbyist market seems to love them but in the commercial field they are still pretty much non-existent.QuoteSince TEK became a part of Danaher in 2007 sales are no longer reported externally so no one outside of TEK/ Danaher really knows what their sales are. Indeed even employees below top management were not provided with sales information except in a general sense. I did hear some numbers from time to time that were " leaked". They seemed lower that what I though they should be. I can tell you that in my territory though I did annual market share analysis. I do not claim absolute precision but I had been in the territory for 31 years so I pretty much knew what everyone had. In my last year (2011) with TEK I estimated scope market share at around 40%. At that time I do not have responsibility for low end scopes- those below about $15K and so my numbers did not include them. My Agilent counterpart agreed with this analysis. He admitted that we were kicking his ass. I did not even know who the Lecroy guy was... Your stated market share in analog agrees with numbers I have heard, but did not see. I do not know how other territories or other parts of the world fared.
That's pretty much the opposite from what I have seen and also what our data shows. Tek sales have been dwindling since at least 2004, and in 2011 I very much doubt their market share was even close to 40%, much less so for the mid-range and high-end segments, both areas where Tek hasn't really been competitive for ages. Things were a bit better in the low-end, predominantly thanks to the edu segment, which Tek courts in the hope that it hooks more people to their brand.
And frankly, that's not surprising. Unlike their analog scopes, Tek DSOs were rarely anything to write home about. Entry-level scopes with ridiculously low memory, mid-range and high-end scopes that were limited in performance and capabilities compared to its competitors while in general being painfully slow ("like wading through molasses" is a term often associated with TDS5000/6000/7000/70000 scopes, and rightfully so). Then there are some annoying limitations (like the DPO "high-speed" mode where measurements are disabled, or the mentioned memory sizes), and some really daft ideas (like the LCD shutter on early TDS scopes). To make matters worse, instead of coming up with some innovative new products Tek pretty much continued to push their stale products in a warmed-up form.
Tek may have had some interesting scopes like the 11000 Series back in the mid-'80s, and later introduced the lunchbox format and came up with intensity grading (on which HP and LeCroy worked as well), but that was back in the '90s. Technical advances of DSO technologies since then happened elsewhere (which isn't surprising because Tek has long lost most of its talent, not just thanks to the mind-numbing DBS).
Today Tek is widely considered the bottom-of-the-barrel of the big brand scope manufacturers. The only ones buying Tek (aside from the edu market thanks to strong incentives) are people that don't know what else is out there, often with fond memories from back in the analog scope days (or they just spend someoneone else's money and thus don't care). And even then the preferrence only lasts until they have tried a modern Tek scope and scopes from other manufacturers.
Of all the labs we support, only one still buys Tek scopes, and this only for contractual reasons (limited to specific pieces of kit). We occasionally invite Tek for evaluations we do before making a procurement decision, but they regularly don't get the sale simply because their products weren't good enough and the pricing too unflexible.
Mind you that this is limited to scopes, not other categories of test instruments. And not all current Tek products are as poor as their scopes. And in regards to scopes, at least that new TBS2000 looks like a decent and well thought out unit, at least based on the data that is available so far. I'm sure the edu market will love it.QuoteIf you have current market share estimates those would be interesting.
Sure it would be interesting, we're often asked by manufacturers to provide access to our data. But that's not gonna happen.
I'd be wary of putting too must trust into high-res modes other than doing unspecified filtering on the signal. For getting more bits from an A/D converter a lot depends on the linearity of them (and they are probably barely linear enough to support 8 bit resolution) and the amount of noise available to do oversampling. Think about feeding the scope with a very accurate and low noise DC signal. I doubt it can resolve beyond 8 bit. On the Tektronix TDS744A I used to own I could get the weirdest interpolation results in high-res mode with the bandwidth limiting on.I would be surprised if the s/n ratio ratio ever would approach 16 bits also. High res as implement in TEK scopes is really a type of boxcar integrator. It uses the extra samples that the A to D can produce beyond what is necessary for a given sweep speed and record length to compute a sort of a horizontal or spacial average.Other interesting features (promised for the future) are the 16 bit high-res mode when most competitors only go to 12 bit (or less).
R&S offers 16bit (software) HiRes modes for RTE/RTO as option, but even on these scopes with fast ADCs the benefit over 11bit or 12bit modes is miniscule.
Thus at slow sweep speeds you have lots of extra samples and this increases both resolution and s/n a large amount. At fast sweep speeds where 1 GS/s is called for their is no improvement when using hi res.
The back shot shows it has ethernet socket. I think the wifi dongle is liable to go missing in a classroom. Hopefully generic chinese ones can replace it.
At this price you'd think WiFi would be built in - they're really pushing it as a selling point and it's only $1 in extra hardware. Adding the extra USB port at the back probably costs them nearly that much.
Other interesting features (promised for the future) are the 16 bit high-res mode when most competitors only go to 12 bit (or less).
R&S offers 16bit (software) HiRes modes for RTE/RTO as option, but even on these scopes with fast ADCs the benefit over 11bit or 12bit modes is minuscule.
I would be surprised if the s/n ratio ratio ever would approach 16 bits also. High res as implement in TEK scopes is really a type of boxcar integrator. It uses the extra samples that the A to D can produce beyond what is necessary for a given sweep speed and record length to compute a sort of a horizontal or spacial average.
The user is always in charge off his results. Hires in my experience works great. You can think of it as low pass filter. The approximate cut off frequency is sample rate divided by 2. But the response has a sinx/x characteristic. So if you use a 20MHz BW limit the sample rate would have to be around 50Ms/s to produces the best signal to noise ratio. If you signal had frequency components above 20MHz that were really strong this could cause the scope to alias at this low of a sample rate and that could cause the problems you describe. This is because BW limit filters on scopes are NOT brick wall. Once again, most scopes have a manual transmission. You have to shift the gears at the right time or bad things can happen. Judging by your tag line you, like many of us, have had that problem.I'm very well aware of aliasing problems! It is just that you can't create extra bits from an AD converter in a meaningfull way in an uncontrolled environment like an oscilloscope.
Agreed. Isn't the high res filter implemented in hardware so it is essentially processing samples as fast as they come in?The back shot shows it has ethernet socket. I think the wifi dongle is liable to go missing in a classroom. Hopefully generic chinese ones can replace it.
At this price you'd think WiFi would be built in - they're really pushing it as a selling point and it's only $1 in extra hardware. Adding the extra USB port at the back probably costs them nearly that much.
Or they wanted the capability to unambiguously disable wireless access for security reasons or wanted easy upgradability since WiFi standards progress so quickly. I would worry about someone walking off with the WiFi dongle though.
In a classroom environment, I would hope that the wired ethernet is used instead.Other interesting features (promised for the future) are the 16 bit high-res mode when most competitors only go to 12 bit (or less).
R&S offers 16bit (software) HiRes modes for RTE/RTO as option, but even on these scopes with fast ADCs the benefit over 11bit or 12bit modes is minuscule.
How do they handle the INL of the 8 bit digitizer though? I would expect the measurement accuracy to be at best 8 bits and significantly less at higher frequencies where the ENOB drops no matter how the samples are processed into each bin without heroic self calibration. Delta-Sigma ADCs avoid multibit quantization for a good reason if INL is important.
I see that nctnico is asking the same question.I would be surprised if the s/n ratio ratio ever would approach 16 bits also. High res as implement in TEK scopes is really a type of boxcar integrator. It uses the extra samples that the A to D can produce beyond what is necessary for a given sweep speed and record length to compute a sort of a horizontal or spacial average.
The signal to noise ratio is improved tremendously but the nonlinearity of the 8-bit digitizer trashes the SFDR and high resolution measurement accuracy which nctnico observed with his TDS744A.
Boxcar averaging is the worst common FIR filter but it does have the virtue of only using 0 and 1 coefficients making it easy to implement in hardware for maximum performance.
High resolution mode is a great simple feature for lowering noise to produce a clearer display at the cost of bandwidth though. Just do not be fooled into thinking that DC measurements are improved as well.
I would be surprised if the s/n ratio ratio ever would approach 16 bits also. High res as implement in TEK scopes is really a type of boxcar integrator.
I'd be wary of putting too must trust into high-res modes other than doing unspecified filtering on the signal. For getting more bits from an A/D converter a lot depends on the linearity of them (and they are probably barely linear enough to support 8 bit resolution) and the amount of noise available to do oversampling. Think about feeding the scope with a very accurate and low noise DC signal. I doubt it can resolve beyond 8 bit. On the Tektronix TDS744A I used to own I could get the weirdest interpolation results in high-res mode with the bandwidth limiting on.
I agree with some of your points and disagree with others. This is interesting to me. If you you would like to continue the discussion I am up for it
but we should probably take it off line as we are getting off topic.
Tektronix should do an upgrade of DPO2000 / MSO2000 with that 480×240 WQVGA LCD.
http://www.tektronixoverachiever.com/ (http://www.tektronixoverachiever.com/)
The signal to noise ratio is improved tremendously but the nonlinearity of the 8-bit digitizer trashes the SFDR and high resolution measurement accuracy which nctnico observed with his TDS744A.Agreed. Isn't the high res filter implemented in hardware so it is essentially processing samples as fast as they come in?
Boxcar averaging is the worst common FIR filter but it does have the virtue of only using 0 and 1 coefficients making it easy to implement in hardware for maximum performance.
High resolution mode is a great simple feature for lowering noise to produce a clearer display at the cost of bandwidth though. Just do not be fooled into thinking that DC measurements are improved as well.
For schools I prefer DSOX2000 / DSOX3000 series.
These scopes are used in industry, too.
I like that big Multipurpose knob of TBS2000. It is much better than Keysight, Rigol or Siglent.
the DSOX2k comes with a silly 1Mpts memory, and both don't even come with something so basic as a LAN port (and forget about WiFi).This might often be no problem. I did not see any scope with LAN being used at my university.
the DSOX2k comes with a silly 1Mpts memory, and both don't even come with something so basic as a LAN port (and forget about WiFi).This might often be no problem.
I did not see any scope with LAN being used at my university.
Maximum analog channels record length
? 2 GSa/s 4 Mpts half channel interleaved, 2 Mpts all channel
> 2 GSa/s 1 Mpts half channel interleaved, 500 kpts all channel
Maximum digital channels sample rate 2 GSa/s half pods interleaved, 1 GSa/s all pods
Maximum digital channels record length 4 Mpts half pods interleaved, 2 Mpts all pods
How many points are used in the FFT? In the video from Tektronix it says 2000 points.Not for long. ;)
In that respect the FFT functionality isn't better than the one you can find in Siglent or Rigol.
Some notable things on the extracted files:
- There are two monster executables, ULPP and tekapp, totalling over 40MB. Fore some reason, they left the map file for the ULPP binary in the image.
- It really seems to be based on the AM33xx, there's a programm called gpmcdma
- There are many libraries referring to other tek instruments,
- There's a 16MB big Opentype font, seems a bit like an overkill
I caught that on page 1 of the thread.Some notable things on the extracted files:
- There are two monster executables, ULPP and tekapp, totalling over 40MB. Fore some reason, they left the map file for the ULPP binary in the image.
- It really seems to be based on the AM33xx, there's a programm called gpmcdma
- There are many libraries referring to other tek instruments,
- There's a 16MB big Opentype font, seems a bit like an overkill
Found this tidbit on the profile from that business-oriented social networking website of apparently the System Engr/HW Lead of the TBS2000 scope:
Main board?10 layer?, main component: TI CPU (AM3352) + Xilinx FPGA (Kintex7)+
ADI ADC (AD9434)+ Power supply(Buck,Cuk [sic],buck-boost)
Analog front end( TEK ASIC + differential Amplifier, DAC, comparator ),
IO board(Ethernet, USB, UART, external trigger)
1. I wonder if he realises that it is sampling at 500 megasamples in his vid
2. no detents on the multiknob ??
let's see if tek can actually fix things in their updates, it is very lacking at the moment.
It looks like the Rigol DS1054Z performs better than the Tektronix TBS2000.
let's see if tek can actually fix things in their updates, it is very lacking at the moment.
Originally an independent company, it is now a subsidiary of Fortive, a spinoff from Danaher Corporation.https://en.wikipedia.org/wiki/Fortive
Fortive is an industrial company based in North America which focuses on professional instrumentation and industrial technologies.[1][2]I am not sure if anything important changed...
The company was split off from Danaher in July 2016.[3]
exactly the same. i'd love to own a modern tek if it wasn't a complete laugh of an instrument (price/quality/feature ratio)let's see if tek can actually fix things in their updates, it is very lacking at the moment.
What a disappointment. :--
Seeing the video I get the impression that Tek has now solidly arrived in the bottom bin, not just compared to big brands but even to Chinese B-brands. The latter have bugs but at least they don't charge Tek prices for it.
I had really hoped that this would be a sign of a new beginning for Tek (especially since they are apparently no longer owned by Danaher), abandoning the mediocrity in their previous products. But it rather seems its still the same old Tek, selling overpriced junk.
https://en.wikipedia.org/wiki/TektronixQuoteOriginally an independent company, it is now a subsidiary of Fortive, a spinoff from Danaher Corporation.https://en.wikipedia.org/wiki/FortiveQuoteFortive is an industrial company based in North America which focuses on professional instrumentation and industrial technologies.[1][2]I am not sure if anything important changed...
The company was split off from Danaher in July 2016.[3]
Some big companies just loose it.
From innovators, they become second followers.
From second followers, they finally land below Chinese manufacturers.
We have seen this happen at many American companies.
It might be related to overpaid product managers who have no engineering degrees,
and just focus on process and change management. They have no clue about the products they are making. In fact, they might not even care, as long as their pay check keeps rolling in at the end of the month. Probably they remove all the mirrors from their house, as they don't want to see their true identity with their own eyes.
I just watched the video.
Oh, dear...
It's not just worse than a DS1054Z (unlocked), it actually looks worse than the $299 Siglent SDS1102 (which I'm not saying is a bad scope for $299)
All that fuss about being able to connect Tek active probes, etc., .... why would anybody even want to?
PS: I'm not sure I believe it has no AC coupling mode. It simply has to have that somewhere.
urill
You can use the Menu On/Off button instead of a back or escape button
It has AC coupling. It does not have AC coupled trigger.
- There's a 16MB big Opentype font, seems a bit like an overkill16MB isn't especially big for an opentype font. If they are trying to get reasonable coverage they probably have upwards of 10k characters in the font.
Element 14 seems to be doing a big promotion of these scopes. They describe them as basic, and everything looks fine for a basic scope..... until you reach the prices.
It looks like they have taken an Owon scope, added some courseware features, the Tek logo and a higher price tag, and will now market it to those Western universities with adequate budgets.
Board details...Any photos of the power supply PCB?
Some big companies just loose it.
From innovators, they become second followers.
From second followers, they finally land below Chinese manufacturers.
We have seen this happen at many American companies.
Tek had lost it a long time ago, long before when the Chinese started to invade the western T&M markets. Tek pretty much stopped innovating when the DSO replaced the analog scope as general purpose scope. It's like they made DSOs only because they were forced to, and would have happily made analog scopes instead. HP on the other hand, while not being overly successful with analog scopes, embraced DSOs and made the best of it (and LeCroy was pretty much with DSOs right from the start).
I have recently acquired a Tek TDS784A and nothing could be further from the truth. In its day(1995) it was way ahead of the competition and today is still way ahead of the low-end scope market in some of its performance metrics. I bought it because I needed a 4ch scope with at least 1GHz bandwidth and 4Gs/s plus 400,000 waveforms/s acquisition rate for runt pulse detection where my low-end 200MHz Hantek just didn't cut it. It appears that once you go above the 500MHz bandwidth this is still dominated by the big names and most of the low end scopes fall by the way side probably because they don't have the expertise and experience to design ultra high sample rate acquisition hardware .You mean like a WS3000, the HW of which is made by Siglent.
Rigol may have a 1GHz scope but checkout the pricing. No longer the sub $1000 mark is it ;)And nor should it be. :box:
I have recently acquired a Tek TDS784A and nothing could be further from the truth. In its day(1995) it was way ahead of the competition and today is still way ahead of the low-end scope market in some of its performance metrics. I bought it because I needed a 4ch scope with at least 1GHz bandwidth and 4Gs/s plus 400,000 waveforms/s acquisition rate for runt pulse detection where my low-end 200MHz Hantek just didn't cut it. It appears that once you go above the 500MHz bandwidth this is still dominated by the big names and most of the low end scopes fall by the way side probably because they don't have the expertise and experience to design ultra high sample rate acquisition hardware .You mean like a WS3000, the HW of which is made by Siglent.QuoteRigol may have a 1GHz scope but checkout the pricing. No longer the sub $1000 mark is it ;)And nor should it be. :box:
I wouldn't call the SDS2000X series entry level, some might. :-//I have recently acquired a Tek TDS784A and nothing could be further from the truth. In its day(1995) it was way ahead of the competition and today is still way ahead of the low-end scope market in some of its performance metrics. I bought it because I needed a 4ch scope with at least 1GHz bandwidth and 4Gs/s plus 400,000 waveforms/s acquisition rate for runt pulse detection where my low-end 200MHz Hantek just didn't cut it. It appears that once you go above the 500MHz bandwidth this is still dominated by the big names and most of the low end scopes fall by the way side probably because they don't have the expertise and experience to design ultra high sample rate acquisition hardware .You mean like a WS3000, the HW of which is made by Siglent.QuoteRigol may have a 1GHz scope but checkout the pricing. No longer the sub $1000 mark is it ;)And nor should it be. :box:
So siglent should have a scope like this ?? I only see entry level scopes on their website.
I wouldn't call the SDS2000X series entry level, some might. :-//I have recently acquired a Tek TDS784A and nothing could be further from the truth. In its day(1995) it was way ahead of the competition and today is still way ahead of the low-end scope market in some of its performance metrics. I bought it because I needed a 4ch scope with at least 1GHz bandwidth and 4Gs/s plus 400,000 waveforms/s acquisition rate for runt pulse detection where my low-end 200MHz Hantek just didn't cut it. It appears that once you go above the 500MHz bandwidth this is still dominated by the big names and most of the low end scopes fall by the way side probably because they don't have the expertise and experience to design ultra high sample rate acquisition hardware .You mean like a WS3000, the HW of which is made by Siglent.QuoteRigol may have a 1GHz scope but checkout the pricing. No longer the sub $1000 mark is it ;)And nor should it be. :box:
So siglent should have a scope like this ?? I only see entry level scopes on their website.
I'd also be quite confident it'd find your problem with it's 160k wfps, 2Gsa/s sampling and 140 Mpts memory depth.
That's the best they have to offer the western markets at this time.........unless you count the Siglent made LeCroy.
I have recently acquired a Tek TDS784A and nothing could be further from the truth. In its day(1995) it was way ahead of the competition
and today is still way ahead of the low-end scope market in some of its performance metrics.
I bought it because I needed a 4ch scope with at least 1GHz bandwidth and 4Gs/s plus 400,000 waveforms/s acquisition rate for runt pulse detection where my low-end 200MHz Hantek just didn't cut it.
It appears that once you go above the 500MHz bandwidth this is still dominated by the big names and most of the low end scopes fall by the way side probably because they don't have the expertise and experience to design ultra high sample rate acquisition hardware
Rigol may have a 1GHz scope but checkout the pricing. No longer the sub $1000 mark is it ;)
So siglent should have a scope like this ?? I only see entry level scopes on their website.I wouldn't call the SDS2000X series entry level, some might. :-//
I have recently acquired a Tek TDS784A and nothing could be further from the truth. In its day(1995) it was way ahead of the competition
No, it wasn't. It certainly was one of the better scopes back then but with only 500kpts per ch (in single ch mode), only basic triggers, simple maths and FFT (and a floppy as only local storage medium) it was far from "way ahead of the competition". Other manufacturers already offered 1Ghz 4GSa/s with up to 4Mpts/Ch, advanced FFT and maths (plus a ton of other analysis tools), advanced triggers and local storage on a hard disk.
The thing is that in the subsequent years Tek's products haven't really progressed a lot, while other scope manufacturers' products have. The result was that Tek was being left behind even further, until today where pretty much no-one buys Tek unless forced or having a mind being stuck in the analog days.
Basic triggers ?? Are you kidding me.
It's got "InstaVu" which at the time put it way ahead of the competition in catching infrequent events such as runt pulses, glitches setup and hold time violations. Way ahead of its time which saw Agilent and Lecroy desperately trying to play catch-up.
Sure it doesn't have lots of the bells and whistles you get in modern scopes that most will probably never use but then this was a scope of the time and still is relevant in many ways.
My Hantek has got lots of these bells and whistles
Your siglent won't be-able to be used to diagnose problems with high speed memory timing because it just aint got the bandwidth.
Basic triggers ?? Are you kidding me.
No, I'm not. You got:
- Edge
- Logic
- Pulse (includes glitch, runt, width, slew rate)
- Video (PAL/SECAM/NTSC, FlexFormat) if you've got Option 05
That's it.
Even back then that wasn't exactly earth shattering. Other scopes also gave you exclusion trigger, droput triggers, interval trigger and so on.QuoteIt's got "InstaVu" which at the time put it way ahead of the competition in catching infrequent events such as runt pulses, glitches setup and hold time violations. Way ahead of its time which saw Agilent and Lecroy desperately trying to play catch-up.
I'm sorry but that is nonsense. When your TDS came out HP already had its own high waveform rate architecture (MegaZoom) on the market - faster, fully automatic, and without the drawbacks of Tek's InstaVu mode (like the lack of measurements). What's really sad is that the same limitations are even found on modern Tek scopes like the MDO3k Series, which just shows how stale their technology is.
LeCroy back then already had the 9300 Series, which was vastly more powerful than any DSO Tek came up with. Like any high end scope it lacked the high waveform rates but its advanced SmartTriggers made more than up for that. Plus you got more memory (like, a lot), and what were back then the most advanced maths and analysis tools on the market. End of 1996 they then came up with the LC Series, up to 1.5Ghz and 8GSa/s plus an even more powerful architecture, plus an extension of the already very long list of available options.
There wasn't anything in the TDS Series which HP or LeCroy were "desperate to catch up" to - that's really jutst wishful thinking on your part.QuoteSure it doesn't have lots of the bells and whistles you get in modern scopes that most will probably never use but then this was a scope of the time and still is relevant in many ways.
Well, it also lacked many of the features you got in scopes from other brands at the time. Which pretty much contradicts your "far ahead of the competition" statement.QuoteMy Hantek has got lots of these bells and whistles
Actually, it doesn't. Hantek's scopes are as basic as it can get, really. Just have a look at the current crop of entry-level scopes, like the GW Instek GDS-2000E, or even the Rigol scopes.QuoteYour siglent won't be-able to be used to diagnose problems with high speed memory timing because it just aint got the bandwidth.
Not sure what you're talking about as I don't own any Siglent scopes.
Anyways, as someone who has used the TDS Series as well as the various HP scopes extensively back then when they were current I can assure you that the TDS784A was in no way "ahead of the competition". It was a good scope, aimed at engineers converting from analog scopes, but nothing extraordinary.
Look, I know that coming from a Hantek a TDS700 must look like a tool from another planet, but if you think that back then it was extraordinary you're deluding yourself.
Tek's problem was and still is that they saw the DSO as another form of the analog scope, while HP and especially LeCroy understood that the benefit of the digital scopes lies in its analysis capabilities. Tek never made that switch, and this, reflected in their portfolio of lacklustre products, is the reason why they are trailing the big brands and increasingly also the B-brands.
Basic triggers ?? Are you kidding me.
No, I'm not. You got:
- Edge
- Logic
- Pulse (includes glitch, runt, width, slew rate)
- Video (PAL/SECAM/NTSC, FlexFormat) if you've got Option 05
That's it.
Even back then that wasn't exactly earth shattering. Other scopes also gave you exclusion trigger, droput triggers, interval trigger and so on.
you forgot Pattern, State and Setup/Hold time violation triggers so that was not all ;)
In 97 I worked for a company that bought a whole lot of agilent scopes. Can't remember the models but with CRT green screens. Should have seen the single shot trigger :palm: Just a pile of incoherent dots on the screen. No sinx/x interpolation etc. It was woeful but it wasn't a cheap scope either. Perhaps I missed a setting or something but unless it was a repetitive waveform it was pretty much useless on high sample rates. Must have been an entry level scope ;)
[Hantek] does have a whole pile of measurement functionality but I only use a handful of them. These days scopes seem to be a lot about one-upmanship on who can have more measurements modes than the other even when you'll only use a handful of them.
I need raw scope performance and these entry level scopes won't deliver it no matter how many measurements you've got on it. Let me know when your cheap scopes can sample at 4Gs/s with 1Ghz bandwidth and I'll be ready to order one because that is what I need right now ;)
I watched this video on a comparison between the Siglent and Rigol scopes and it appears that the siglent firmware is very buggy whilst the rigol maybe slower in some modes it seems to operate much more reliably. Both scopes achieve update rates from a few hundred to nearly 50,000 at different time-base settings and that seems to be the upper ceiling in terms of performance.That's the problem with OLD videos, they're well out of date. :scared:
I watched this video on a comparison between the Siglent and Rigol scopes and it appears that the siglent firmware is very buggy whilst the rigol maybe slower in some modes it seems to operate much more reliably.
Both scopes achieve update rates from a few hundred to nearly 50,000 at different time-base settings and that seems to be the upper ceiling in terms of performance. If most of these scope features are just firmware then perhaps Tek can step up to the plate with its new low-end scope platforms ;)
Rigol also tends to release gear in an immature state.as this tek wasn't :palm:
QuoteBoth scopes achieve update rates from a few hundred to nearly 50,000 at different time-base settings and that seems to be the upper ceiling in terms of performance. If most of these scope features are just firmware then perhaps Tek can step up to the plate with its new low-end scope platforms ;)
They could, and I really wish they would (we could really use another successful big brand in the market to keep Keysight from squeezing it), but I don't think they will. Tek was part of Danaher, which employed their 'Danaher Business System' (DBS) of excessive cost cutting to maximize shareholder value, which has driven out most of Tek's old talent long ago already. And not too long ago the sad rest of Tek was split off into a Danaher spin-off (Fortive), and they seem to stick to the same methodology as Danaher. As the new TBS2000 shows, sadly.
QuoteRigol also tends to release gear in an immature state.as this tek wasn't :palm:
in the video from the user who got them at his uni you see that there are knobs that don't do anything yet because functions are yet to be implemented, menus grayed out for the same reason.
i get it, they wanted to have tehe product on the benches for the beginning of school year.
still a big fat :palm:
So Dave are you going to get one to have a peak inside ?
Why would you need video trigger nowadays? Analog video has been obsolete for a while now.Yes, but I think that almost all other scopes have a video trigger. And TBS2000 is a school scope. There should be a video trigger.
Why would you need video trigger nowadays? Analog video has been obsolete for a while now.
i was surprised to see dedicated video-trigger hardware in the DSOX1000 -an LM1881 sync seperator.Why would you need video trigger nowadays? Analog video has been obsolete for a while now.
Video triggers also work with analog RGB like from VGA but I agree, it seems odd that oscilloscopes still include them.
Well, Keysight DSOX2000 was designed as a school scope back in 2011 and it stays competitive till nowadays. Yes, it har a small 1Mpoints memory, but at school it is OK.U really need more acquisition memory? U really use more memory day from day in measurement? For what?
U really need more acquisition memory? U really use more memory day from day in measurement? For what?
As for Tek TBS2000, I not understand Tek marketing, I not understand targeting this device.. price starting from 1200 USD, 1 GS/s Sample Rate and TekVPI™ probe interface :-DD Probe from Tek with this interface type cost more that couple of this scopes... For what this interface was added in this scope?
Well, Keysight DSOX2000 was designed as a school scope back in 2011 and it stays competitive till nowadays. Yes, it har a small 1Mpoints memory, but at school it is OK.U really need more acquisition memory? U really use more memory day from day in measurement? For what?
As for Tek TBS2000, I not understand Tek marketing, I not understand targeting this device.. price starting from 1200 USD, 1 GS/s Sample Rate and TekVPI™ probe interface :-DD Probe from Tek with this interface type cost more that couple of this scopes... For what this interface was added in this scope?
As for Tek TBS2000, I not understand Tek marketing, I not understand targeting this device.. price starting from 1200 USD, 1 GS/s Sample Rate and TekVPI™ probe interface :-DD Probe from Tek with this interface type cost more that couple of this scopes... For what this interface was added in this scope?
Well, Keysight DSOX2000 was designed as a school scope back in 2011 and it stays competitive till nowadays. Yes, it har a small 1Mpoints memory, but at school it is OK.U really need more acquisition memory? U really use more memory day from day in measurement? For what?
As for Tek TBS2000, I not understand Tek marketing, I not understand targeting this device.. price starting from 1200 USD, 1 GS/s Sample Rate and TekVPI™ probe interface :-DD Probe from Tek with this interface type cost more that couple of this scopes... For what this interface was added in this scope?
Compared with my old oscilloscope, a Tektronix TDS1012C-EDU with only 2.5k points of record length, it only accelerated a thousand times my debug work in I2C and SPI buses because I can capture all the communication in the bus, turn off the circuit and analyze calmly if the obtained signals correspond what should happen.
My main motivation for buying the TBS2104 was its affordable price, the 20M of record length, the four analog channels and the superb 9" display.
My main motivation for buying the TBS2104 was its affordable price, the 20M of record length, the four analog channels and the superb 9" display.
Compared with my old oscilloscope, a Tektronix TDS1012C-EDU with only 2.5k points of record length, it only accelerated a thousand times my debug work in I2C and SPI buses because I can capture all the communication in the bus, turn off the circuit and analyze calmly if the obtained signals correspond what should happen.I think that TBS2104 has no I2C or SPI decoding... :-(
My main motivation for buying the TBS2104 was its affordable price, the 20M of record length, the four analog channels and the superb 9" display.
Compared with my old oscilloscope, a Tektronix TDS1012C-EDU with only 2.5k points of record length, it only accelerated a thousand times my debug work in I2C and SPI buses because I can capture all the communication in the bus, turn off the circuit and analyze calmly if the obtained signals correspond what should happen.
Not if you want to look at both signal waveform and decoding. From my own experience having an oscilloscope with deep memory AND decoding is definitely better (=more productive). Think about situations where a signal gets distorted every now and then. Deep memory (segmented mode) allows to capture many messages without knowing exactly what is wrong with the signal and when the message with the problem is found you can also check the waveform.Compared with my old oscilloscope, a Tektronix TDS1012C-EDU with only 2.5k points of record length, it only accelerated a thousand times my debug work in I2C and SPI buses because I can capture all the communication in the bus, turn off the circuit and analyze calmly if the obtained signals correspond what should happen.
There are certainly applications where a long record length is required but they are in the minority. In the past, this would have been done with a logic analyser or protocol decoder and those are still better instruments for this.
Compared with my old oscilloscope, a Tektronix TDS1012C-EDU with only 2.5k points of record length, it only accelerated a thousand times my debug work in I2C and SPI buses because I can capture all the communication in the bus, turn off the circuit and analyze calmly if the obtained signals correspond what should happen.I think that TBS2104 has no I2C or SPI decoding... :-(
My main motivation for buying the TBS2104 was its affordable price, the 20M of record length, the four analog channels and the superb 9" display.
... if you can only buy tektronix. i'll give you that. i heard that buying these things is a bit tricky in brazilThe Brazil is a hell for who like Science or Electronics. I hate this country and I will left from here as soon as possible.
Compared with my old oscilloscope, a Tektronix TDS1012C-EDU with only 2.5k points of record length, it only accelerated a thousand times my debug work in I2C and SPI buses because I can capture all the communication in the bus, turn off the circuit and analyze calmly if the obtained signals correspond what should happen.
There are certainly applications where a long record length is required but they are in the minority.
There are certainly applications where a long record length is required but they are in the minority.
Not really. For example, just watch how quickly the sample rate (and thereby the useable BW) drops on scopes with small sample memories when you extend the timebase. A scope with deep memory can sustain a high sample rate even at long timebase settings.
More processing power was also required to allow deep acquisition memories but both were the result of increases integration and processing power has fallen behind making very deep acquisition memories *less* useful in a general sense. Maybe high end DSOs avoid this problem but my experience with the DSO/MDSO5000 series is that they do not; using high record lengths results in waiting for processing of each record which is fine for single shot applications where long record lengths are especially useful but it is aggravatingly slow otherwise.This is kind of a typical Tektronix problem which cannot be extrapolated to oscilloscopes in general. Besides that there are several affordable scopes on the market which have enough processing power to deal with tens of Mpts quickly.
More processing power was also required to allow deep acquisition memories but both were the result of increases integration and processing power has fallen behind making very deep acquisition memories *less* useful in a general sense. Maybe high end DSOs avoid this problem but my experience with the DSO/MDSO5000 series is that they do not; using high record lengths results in waiting for processing of each record which is fine for single shot applications where long record lengths are especially useful but it is aggravatingly slow otherwise.
This is kind of a typical Tektronix problem which cannot be extrapolated to oscilloscopes in general. Besides that there are several affordable scopes on the market which have enough processing power to deal with tens of Mpts quickly.
There are certainly applications where a long record length is required but they are in the minority.
Not really. For example, just watch how quickly the sample rate (and thereby the useable BW) drops on scopes with small sample memories when you extend the timebase. A scope with deep memory can sustain a high sample rate even at long timebase settings.
But not long delay settings as we discovered with the Rigol DS1000Z. (1) In that case, long record lengths are great as long as what you want to see what lies within them and if it does not, the sample rate has to be decreases anyway.
Oscilloscopes with short acquisition memories use features like peak detection and delayed acquisition (sweep) to apply their maximum sample rate exactly where the user wants.
More processing power was also required to allow deep acquisition memories
Maybe high end DSOs avoid this problem but my experience with the DSO/MDSO5000 series is that they do not; using high record lengths results in waiting for processing of each record which is fine for single shot applications where long record lengths are especially useful but it is aggravatingly slow otherwise.
This processing power problem with long record lengths is not new.
(1) The Rigol DS1000Z series brings up another question. Exactly what is the record length of a DS1000Z? Measurements are only made upon the display record which is 600 or 1200 points long yet the specifications say 3 Mpoints/channel. Shouldn't they say something like 600 or 1200 points operating in real time and 3 Mpoints/channel when stopped? How many other DSOs which make measurements on the display record are like this?
More processing power was also required to allow deep acquisition memories but both were the result of increases integration and processing power has fallen behind making very deep acquisition memories *less* useful in a general sense. Maybe high end DSOs avoid this problem but my experience with the DSO/MDSO5000 series is that they do not; using high record lengths results in waiting for processing of each record which is fine for single shot applications where long record lengths are especially useful but it is aggravatingly slow otherwise.
This is kind of a typical Tektronix problem which cannot be extrapolated to oscilloscopes in general. Besides that there are several affordable scopes on the market which have enough processing power to deal with tens of Mpts quickly.
I have played with other DSOs
and I have yet to fine *one* where "quickly" was quick enough. See above about display record length.
Which ones (list some make/models)?
Well, I have no idea if the DS1000z, a bottom-of-the-barrel scope which it's biggest feature being cheap, does something different here but on a decent scope with "deep memory" the sample rate drops a lot later than on a scope with just a few thousand kpts of memory.
Which ones (list some make/models)?
I do not keep an itemized list (and do not get enough opportunities to test DSOs) and the DPO/MSO5000 series were the only memorable ones and no LeCroys.
Often you can tell from a review video that something weird and unspecified is going on.
Well, I have no idea if the DS1000z, a bottom-of-the-barrel scope which it's biggest feature being cheap, does something different here but on a decent scope with "deep memory" the sample rate drops a lot later than on a scope with just a few thousand kpts of memory.
Weren't we talking about affordable DSOs?
After finding about the display record thing in the DS1000Z and other people saying that most modern DSOs make display record measurements, I am not sanguine that the statement "the sample rate drops a lot later than on a scope with just a few thousand kpts of memory" has much meaning.
Lets have a closer look at how both scopes perform at various timebase settings:
Tektronix TDS694C with standard (30k) and "long" (120k) memory Timebase Setting Sample Rate (std memory) Frequency limit (fsample/2) (std memory) Sample Rate (long memory) Frequency limit (fsample/2) ("long" memory) 10ns/div 10GS/s 3GHz (bw limit) 10GS/s 3GHz (bw limit) 20ns/div 10GS/s 3GHz (bw limit) 10GS/s 3GHz (bw limit) 30ns/div 10GS/s 3GHz (bw limit) 10GS/s 3GHz (bw limit) 50ns/div 10GS/s 3GHz (bw limit) 10GS/s 3GHz (bw limit) 100ns/div 10GS/s 3GHz (bw limit) 10GS/s 3GHz (bw limit) 200ns/div 10GS/s 3GHz (bw limit) 10GS/s 3GHz (bw limit) 300ns/div 10GS/s 3GHz (bw limit) 10GS/s 3GHz (bw limit) 500ns/div 5GS/s 2.5GHz 10GS/s 3GHz (bw limit) 1us/div 2.5GS/s 1.25GHz 10GS/s 3GHz (bw limit) 2us/div 2.5GS/s 1.25GHz 5GS/s 2.5GHz 3us/div 1GS/s 500MHz 2.5GS/s 1.25GHz 5us/div 500MS/s 250MHz 2.5GS/s 1.25GHz 10us/div 250MS/s 125MHz 1GS/s 500MHz 20us/div 125MS/s 62.5MHz 500MS/s 250MHz 30us/div 100MS/s 50MHz 250MS/s 125MHz
The table clearly shows that the small memory causes huge 3GHz bandwidth and the fast 10GSa/s sample rate to drop dramatically beyond 1us/div (long memory) or even 200ns/div (std memory), and with it the useful bandwidth, i.e. at 10us it's essentially just a 500MHz (long memory) or even just a 125MHz (std memory) scope.
Lets see how the WP960 performs:
LeCroy WavePro 960 quad channel with standard (250k) and long (16M) memory Timebase Setting Sample Rate (std memory) Frequency limit (fsample/2) (std memory) Sample Rate (long memory) Frequency limit (fsample/2) (long memory) 10ns/div 4GS/s 2GHz (bw limit) 4GS/s 2GHz (bw limit) 20ns/div 4GS/s 2GHz (bw limit) 4GS/s 2GHz (bw limit) 30ns/div 4GS/s 2GHz (bw limit) 4GS/s 2GHz (bw limit) 50ns/div 4GS/s 2GHz (bw limit) 4GS/s 2GHz (bw limit) 100ns/div 4GS/s 2GHz (bw limit) 4GS/s 2GHz (bw limit) 200ns/div 4GS/s 2GHz (bw limit) 4GS/s 2GHz (bw limit) 300ns/div 4GS/s 2GHz (bw limit) 4GS/s 2GHz (bw limit) 500ns/div 4GS/s 2GHz (bw limit) 4GS/s 2GHz (bw limit) 1us/div 4GS/s 2GHz (bw limit) 4GS/s 2GHz (bw limit) 2us/div 4GS/s 2GHz (bw limit) 4GS/s 2GHz (bw limit) 3us/div 4GS/s 2GHz (bw limit) 4GS/s 2GHz (bw limit) 5us/div 4GS/s 2GHz (bw limit) 4GS/s 2GHz (bw limit) 10us/div 2GS/s 1GHz 4GS/s 2GHz (bw limit) 20us/div 1GS/s 500MHz 4GS/s 2GHz (bw limit) 30us/div 1GS/s 500MHz 4GS/s 2GHz (bw limit) 50us/div 500MS/s 250MHz 4GS/s 2GHz (bw limit) 100us/div 250MS/s 125MHz 4GS/s 2GHz (bw limit) 200us/div 125MS/s 62.5MHz 4GS/s 2GHz (bw limit) 300us/div 50MS/s 25MHz 4GS/s 2GHz (bw limit) 500us/div 50MS/s 25MHz 2GS/s 1GHz 1ms/div 25MS/s 12.5MHz 1GS/s 500MHz
The initial bandwidth of the WP960 is of course lower (2GHz vs 3GHz), however the WP960 maintains a fast sample rate for much longer than the TDS694C. Even with the reduced sample rate in 4 channel mode the WP960 with deep memory still captures at full analog bandwidth where a fully spec'd TDS694C only captures less than 100MHz. And this performance distance only gets larger when only two or a single channel is needed as the WP960 can combine sampling and memory sizes.
This also pretty much shows that a scope's performance can't be judged just by looking at two of the main parameters (analog bandwidth and sample rate). There's a lot more to it.
After finding about the display record thing in the DS1000Z and other people saying that most modern DSOs make display record measurements, I am not sanguine that the statement "the sample rate drops a lot later than on a scope with just a few thousand kpts of memory" has much meaning.
But it does. Because with the sample rate your useable BW also drops, and when your sampling BW drops below the (true) analog BW then any frequency component sitting in between will cause aliasing.
My point was that the display record processing makes these DSOs operate more like they are limited by the display record length than the record length given in the specifications which in only available for saved acquisitions. This is a deliberate tradeoff because they cannot process their full record length in an acceptable time.
The TDS694C (and all of the TDS600 models) is more specialized than the typical DSO of that time and has more in common with transient digitizers than oscilloscopes. It uses CCD sampling to achieve 10GS/s on every channel simultaneously.
My point was that the display record processing makes these DSOs operate more like they are limited by the display record length than the record length given in the specifications which in only available for saved acquisitions. This is a deliberate tradeoff because they cannot process their full record length in an acceptable time.
They can, as could even scopes back then (the same M68k that Tek used it its low memory TDS scopes was used by deep memory scopes like the HP 54645A/D with 1Mpts or the LeCroy 9300 Series with up to 8Mpts, and even the latter had no problems processing the full record length in acceptable time).
QuoteThe TDS694C (and all of the TDS600 models) is more specialized than the typical DSO of that time and has more in common with transient digitizers than oscilloscopes. It uses CCD sampling to achieve 10GS/s on every channel simultaneously.
Probably (well, the short memory makes the TDS694C useless for pretty much anything else than short transients), but for this discussion that's completely irrelevant as the same is true for pretty much any low memory scope vs a deep memory scope.
They can, as could even scopes back then (the same M68k that Tek used it its low memory TDS scopes was used by deep memory scopes like the HP 54645A/D with 1Mpts or the LeCroy 9300 Series with up to 8Mpts, and even the latter had no problems processing the full record length in acceptable time).
HP had their Megazoom ASIC doing the heavy processing in the HP 54645A
and I assume LeCroy was doing something similar. If only the 68000 processor had been available, then the performance with long record lengths would have been unacceptable except for a minority of long record length applications.
That is why I gave examples of old DSOs which did not support longer record lengths simply because of processing limitations.
They could not even support their longest record length without reducing their display update rate noticeably so they allowed shortening the record length even further.
QuoteProbably (well, the short memory makes the TDS694C useless for pretty much anything else than short transients), but for this discussion that's completely irrelevant as the same is true for pretty much any low memory scope vs a deep memory scope.
That series of oscilloscopes was intended for applications where bandwidth and real time sample rate were the only considerations. They had a specific market which in earlier time would have been using oscilloscopes like the 519, 7104, and scan converter based instruments.
I get your point that record length limits sampling rate and I have never disagreed. I just think long record lengths which have been enabled by increasing integration have been seized upon by marketing departments in a quest for specsmanship leading to deceptive practices like the Rigol example I gave.
They could not even support their longest record length without reducing their display update rate noticeably so they allowed shortening the record length even further.
Please explain how a scope should maintain the same update rate in small memory (say 4k) as in large memory (say 4M) when by the laws of physics and math at a given sample rate it takes 1000x as long to fill the large memory than to fill the small memory? Of course the update rate will drop when using large memory, unless your scope uses HPAK's trick of using only small memory and only making the last acquisition a long one?
Sample memory sizes haven't really been the prime marketing argument for the best part of a decade, and even before then were rarely so.
Maybe, and it shows that Tek didn't really 'get' digital scopes and was too fixated on their analog past, but as I said the TDS694C was only an example, and Tek has produced many more low memory scopes and not all of them have the excuse of being made for niche purposes.
Just do the math and see how far you'd get with the few K you believe are sufficient for a DSO these days.
Why do you think so many DSOs are making measurements on the display record? It is faster and requires less processing power because it limits the record length. It also sometimes produces deceptive results.
Why do you think so many DSOs are making measurements on the display record? It is faster and requires less processing power because it limits the record length. It also sometimes produces deceptive results.
So many? I know one brand who truly does that.
Then theres some others who use more complex approach, lets say "optimized dataset", but (much) larger than display.
Out of approx 10 scopes tested in auto-measurements thread (https://www.eevblog.com/forum/testgear/testing-dso-auto-measurements-accuracy-across-timebases/) there was only 1 using display record.
Also processing power deficit as of today is complete myth, as latest entry level scope tests show.
Its up to user if stick to CRO-like practices or soak in new possibilities, concentrate on task at hand and let scope processor do the dirty work.
Interesting that this has created situation where more conservative top-dollar tech may get beatings from low-end DSOs in low-freq applications.
Which one is that? We know Rigol is doing it and the Keysight guy at the end says their InfiniiVision DSOs do it which is not the first time I have heard that about them although I did not believe it the first time.
The transition time test is good and I have used it myself but it is not very relevant to practical applications. Someone would naturally zoom in when making this measurement.
The test I have started to use is RMS
QuoteAlso processing power deficit as of today is complete myth, as latest entry level scope tests show.I do not see where that was measured at all.
If the new possibilities include producing the wrong result, then it is hardly an alternative.
Please explain how a scope should maintain the same update rate in small memory (say 4k) as in large memory (say 4M) when by the laws of physics and math at a given sample rate it takes 1000x as long to fill the large memory than to fill the small memory? Of course the update rate will drop when using large memory, unless your scope uses HPAK's trick of using only small memory and only making the last acquisition a long one?
I explained it right here:
This processing power problem with long record lengths is not new. The ancient Tektronix 2230/2232 DSOs support 1k and 4k record lengths which seems laughably short by today's standards but why did they support a 1k record length at all?
See where it says 4M? Hmm, I don't. See where it says anything close to 4M? Hmm, it does not say that either.
Why do you think so many DSOs are making measurements on the display record?
QuoteSample memory sizes haven't really been the prime marketing argument for the best part of a decade, and even before then were rarely so.
For something that is so unimportant for marketing, they sure go out of their way to advertise their long record lengths while avoiding the subject of how those long record lengths do not apply except in specific operating modes.
QuoteMaybe, and it shows that Tek didn't really 'get' digital scopes and was too fixated on their analog past, but as I said the TDS694C was only an example, and Tek has produced many more low memory scopes and not all of them have the excuse of being made for niche purposes.
It shows Tektronix made those oscilloscopes for a specific market where the limit in record length was irrelevant and other considerations like sample rate and bandwidth were more important.
I'm not very familiar with LeCroy's products other than those from companies that they bought. How did the LeCroy DSOs which were contemporaries to the Tektornix TDS600 series compare? Wasn't LeCroy selling a lot of DSOs for high energy physics applications at the time? Maybe there wasn't much overlap with the market Tektronix was catering to.
When I have used modern DSOs which support long record lengths, I set them low enough for maximum performance unless a long record length is needed just like I do with my 20+ year old DSOs.
Yes, there is a fundamental limit to how fast the display can be drawn at slower timebases, but even there many scopes fall far below the theoretical maximum rates. But thats ignoring the faster timebases where there are significant limits to how fast waveforms can be captured and displayed in real time, where there is a wide diversity of scopes optimised for different purposes as was shown here:Please explain how a scope should maintain the same update rate in small memory (say 4k) as in large memory (say 4M) when by the laws of physics and math at a given sample rate it takes 1000x as long to fill the large memory than to fill the small memory? Of course the update rate will drop when using large memory, unless your scope uses HPAK's trick of using only small memory and only making the last acquisition a long one?
I explained it right here:
This processing power problem with long record lengths is not new. The ancient Tektronix 2230/2232 DSOs support 1k and 4k record lengths which seems laughably short by today's standards but why did they support a 1k record length at all?
I'm sorry but you didn't explain. While you think that it's processing which makes deep memory scopes slow, you seem to ignore the basic fact that at a given sample rate it simply takes more time to fill the larger memory. Processing has nothing to do with it.
I've no problem believing that small memory works for you, I guess you're probably used to it (and it seems you didn't really had much contact with any decent modern deep memory scope), and that's fine. It however doesn't invalidate my arguments.You really need to stop going out of your way to tell everyone that scopes with deep memory and advanced post capture analysis are so far superior for all possible uses than scopes with fast realtime analysis or displays. They're both useful for different purposes which the other cannot do, and while they have a lot of overlap where either could solve the same problem not everyone has the budget for multiple scopes or a scope with useful deep memory analysis.
Increasing the memory depth of those rigol scopes further reduces their acquisition rates, same with the Tektronix examples David is talking about, its like this with most scopes and well known.
The entire "argument" about needing memory depth controls is that the user needs it for some reason, in the Agilent/Keysight X series thats not needed because there isneverso rarely a reason for the user to capture a smaller memory depth (even though it could be nice for some applications where the data is being offloaded).
I've no problem believing that small memory works for you, I guess you're probably used to it (and it seems you didn't really had much contact with any decent modern deep memory scope), and that's fine. It however doesn't invalidate my arguments.
You really need to stop going out of your way to tell everyone that scopes with deep memory and advanced post capture analysis are so far superior for all possible uses than scopes with fast realtime analysis or displays.
The DSO-X, like any HPAK InfiniVision scope, is cheating as the only time it acquires a long memory segment in normal acquisition is at the last acquisition made after pressing STOP, otherwise it uses just enough memory to fill the display record. Plus it doesn't even tell you how much memory it uses.That isn't entirely true because what happens if you press stop and there is nothing more to trigger on? You can still use zoom to zoom into the signal. I'm pretty sure HPAK is using a dual acquisition technique which uses a short buffer to draw an intensity graded trace and switches to a deep memory mode when you change the timebase to zoom in. The giveaway is that the intensity graded trace dissapears once you change the timebase to zoom in/out.
The DSO-X, like any HPAK InfiniVision scope, is cheating as the only time it acquires a long memory segment in normal acquisition is at the last acquisition made after pressing STOP, otherwise it uses just enough memory to fill the display record. Plus it doesn't even tell you how much memory it uses.
That isn't entirely true because what happens if you press stop and there is nothing more to trigger on? You can still use zoom to zoom into the signal. I'm pretty sure HPAK is using a dual acquisition technique which uses a short buffer to draw an intensity graded trace and switches to a deep memory mode when you change the timebase to zoom in. The giveaway is that the intensity graded trace dissapears once you change the timebase to zoom in/out.
There is no basic maths you can apply to determine how fast a particular scope will update in realtime, none reach the theoretical ideal and all have some limitations which are not disclosed/revealed by the manufacturer. Lets go back to your point where this started:Increasing the memory depth of those rigol scopes further reduces their acquisition rates, same with the Tektronix examples David is talking about, its like this with most scopes and well known.Thanks Captain Obvious, but the point was not if scopes get slower with larger sample memory (they do) but the why. David seems to believe it's because of processing, but in reality this is simply down to basic math.
Ideally you wouldn't have to compromise on memory depth, it would always be as deep as possible for the horizontal window. You are limited by sample rate for short captures, and memory depth for long captures, but in the in-between where neither is limiting people still choose to have a shorter memory depth than they could capture because it slows down aspects of the scope such as the waveform display rate. You can measure this so I took a rigol 1054 and did the comparison setting both scopes to 50us per division:They could not even support their longest record length without reducing their display update rate noticeably so they allowed shortening the record length even further.Please explain how a scope should maintain the same update rate in small memory (say 4k) as in large memory (say 4M) when by the laws of physics and math at a given sample rate it takes 1000x as long to fill the large memory than to fill the small memory? Of course the update rate will drop when using large memory, unless your scope uses HPAK's trick of using only small memory and only making the last acquisition a long one?
| Waveforms | wfms/s | |||
| Rigol | Memory | Vector | Dots | Sample Rate |
| 1054Z | 12k | 363 | 624 | 10MS/s |
| 120k | 217 | 298 | 125MS/s | |
| 600k | 178 | 192 | 1GS/s | |
| 1200k | 160 | 170 | 1GS/s | |
| 12M | 60 | 61 | 1GS/s | |
| 24M | 35 | 36 | 1GS/s | |
| Keysight | ||||
| 1000/2000X | 500k | 1800 | 1GS/s | |
| 3000X | 500k | 1746 | 1GS/s | |
| 3000X | 2M | 780 | 4GS/s |
If you want to capture a specific length of data sure, its nice to have the controls available and I did mention that is one corner case. But in general what people want to capture is a length of time and they would like to have as much memory and sample rate as possible, but for most scopes thats balancing against realtime waveform update rate. Or the user needs to capture elements with a particular frequency so they are constrained in their lowest possible sample rate, again the tradeoff appears. Or we can take the Keysight X series scopes where they provide no choice, but there are so few cases where you would want to have shorter memory depths on them that that it seems reasonable they left the option out.The entire "argument" about needing memory depth controls is that the user needs it for some reason, in the Agilent/Keysight X series thats not needed because there isneverso rarely a reason for the user to capture a smaller memory depth (even though it could be nice for some applications where the data is being offloaded).
The DSO-X, like any HPAK InfiniVision scope, is cheating as the only time it acquires a long memory segment in normal acquisition is at the last acquisition made after pressing STOP, otherwise it uses just enough memory to fill the display record. Plus it doesn't even tell you how much memory it uses.
That is fine for some tasks but not for others, i.e. sometimes you might want to capture a specific lenght only. After all, there's a reason why pretty much any other newer scope allows for manual setup of sample memory, and that includes even Keysight's own scopes (Infiniium), which indicates that there's some use for this feature.
The DSO-X, like any HPAK InfiniVision scope, is cheating as the only time it acquires a long memory segment in normal acquisition is at the last acquisition made after pressing STOP, otherwise it uses just enough memory to fill the display record. Plus it doesn't even tell you how much memory it uses.They don't cheat, it tells you the sample rate for the current mode clearly and plainly on the UI as do many other scopes:
Daniel from Keysight engaged on this and linked to a video:The DSO-X, like any HPAK InfiniVision scope, is cheating as the only time it acquires a long memory segment in normal acquisition is at the last acquisition made after pressing STOP, otherwise it uses just enough memory to fill the display record. Plus it doesn't even tell you how much memory it uses.
That isn't entirely true because what happens if you press stop and there is nothing more to trigger on? You can still use zoom to zoom into the signal. I'm pretty sure HPAK is using a dual acquisition technique which uses a short buffer to draw an intensity graded trace and switches to a deep memory mode when you change the timebase to zoom in. The giveaway is that the intensity graded trace dissapears once you change the timebase to zoom in/out.
What happens if there's no trigger after pressing STOP is an interesting question. I honestly don't know, and I'll have no access to a DSOX for a while so somebody else would need to test that out.
There is no basic maths you can apply to determine how fast a particular scope will updateIncreasing the memory depth of those rigol scopes further reduces their acquisition rates, same with the Tektronix examples David is talking about, its like this with most scopes and well known.Thanks Captain Obvious, but the point was not if scopes get slower with larger sample memory (they do) but the why. David seems to believe it's because of processing, but in reality this is simply down to basic math.
Lets go back to your point where this started:They could not even support their longest record length without reducing their display update rate noticeably so they allowed shortening the record length even further.
Please explain how a scope should maintain the same update rate in small memory (say 4k) as in large memory (say 4M) when by the laws of physics and math at a given sample rate it takes 1000x as long to fill the large memory than to fill the small memory? Of course the update rate will drop when using large memory, unless your scope uses HPAK's trick of using only small memory and only making the last acquisition a long one?
Ideally you wouldn't have to compromise on memory depth, it would always be as deep as possible for the horizontal window. You are limited by sample rate for short captures, and memory depth for long captures, but in the in-between where neither is limiting people still choose to have a shorter memory depth than they could capture because it slows down aspects of the scope such as the waveform display rate.
You can measure this so I took a rigol 1054 and did the comparison setting both scopes to 50us per division:
[...]
The theoretical zero blind time rate is 2000 wfms/s for the Keysight, and 1667 wfms/s for the Rigol (extra 2 divisions horizontal display). They're all maxing out at 1GS/s for this test but the Keysight gives you no options to change to other memory depths, while the Rigol with all its choices fails to match the realtime performance. It even lets you choose longer depths that are captured outside the display but not shown until you stop and zoom around the capture, at the shorter memory depths the Rigol is dropping its sample rate and not putting 1GS/s data onto the screen which is why comparisons need to be made carefully. Processing (and/or memory bandwidth) is limiting the ability to draw more information to the screen and the reason why many scopes offer the choice of shorter memory depths.
If you want to capture a specific length of data sure, its nice to have the controls available and I did mention that is one corner case.
But in general what people want to capture is a length of time and they would like to have as much memory and sample rate as possible, but for most scopes thats balancing against realtime waveform update rate. Or the user needs to capture elements with a particular frequency so they are constrained in their lowest possible sample rate, again the tradeoff appears.
Or we can take the Keysight X series scopes where they provide no choice, but there are so few cases where you would want to have shorter memory depths on them that that it seems reasonable they left the option out.
I find this is much easier to work with than memory depth as I'm generally concerned about the frequencies being captured, not the specific length of memory being used to do this. Again, when you always get as much memory as possible used in the captures you can forget about that parameter and focus on the ones that matter to your specific situation. Yes, going to a single capture doubles the memory depth in many situations (but not all) but when looking at the signal I can quickly asses if the sample rate is sufficient for the information I want to see and adjust the controls accordingly.
What happens if there's no trigger after pressing STOP is an interesting question. I honestly don't know, and I'll have no access to a DSOX for a while so somebody else would need to test that out.
Daniel from Keysight engaged on this and linked to a video:
https://www.eevblog.com/forum/testgear/new-keysight-scope-1st-march-2017/msg1125192/#msg1125192 (https://www.eevblog.com/forum/testgear/new-keysight-scope-1st-march-2017/msg1125192/#msg1125192)
Its not confusing or magic, while in run mode the memory is halved from maximum (generally)
and when pressing stop the memory is held
and when you press single it uses as much memory as possible for the next trigger.
Its not using the minimum possible to fill the display buffer, the data is aggregated into a 2d histogram (with vectors) at the running sample rate and there is a larger memory available when stopped to navigate/zoom through.
The DSO-X, like any HPAK InfiniVision scope, is cheating as the only time it acquires a long memory segment in normal acquisition is at the last acquisition made after pressing STOP, otherwise it uses just enough memory to fill the display record. Plus it doesn't even tell you how much memory it uses.They don't cheat, it tells you the sample rate for the current mode clearly and plainly on the UI as do many other scopes:
(https://www.eevblog.com/forum/testgear/new-lecroy-scope-waverunner-8000/?action=dlattach;attach=217688;image)
OK, so on a DSO-X3kT with 4Mpts and 5GSa/s, that would mean a best case (single channel) 2Mpts in normal acquisition mode, which at 5GSa/s takes 400us to fill. Even on a perfect scope with zero blind time, 400us per acquisition translate into only 2,500 acquisitions per second. Which means to reach the very high waveforms the DSO-X3kT can achieve it would have to dramatically reduce the amount of memory used, i.e. at 500k acquisitions per second that just leaves 2us for acquisition + blind time, so even that perfect scope with no blind time would have to reduce the sample memory size to 10k.As I wrote before your math is too simplified. You don't have to fill the entire acquisition memory if you know the data is not going to be used. This is the case when a new trigger arrives before the acquisition memory is completely filled. After all at short time/div settings you'll be looking at a fraction of the acquisition memory anyway. The rest is outside the screen.
OK, so on a DSO-X3kT with 4Mpts and 5GSa/s, that would mean a best case (single channel) 2Mpts in normal acquisition mode, which at 5GSa/s takes 400us to fill. Even on a perfect scope with zero blind time, 400us per acquisition translate into only 2,500 acquisitions per second. Which means to reach the very high waveforms the DSO-X3kT can achieve it would have to dramatically reduce the amount of memory used, i.e. at 500k acquisitions per second that just leaves 2us for acquisition + blind time, so even that perfect scope with no blind time would have to reduce the sample memory size to 10k.As I wrote before your math is too simplified.
You don't have to fill the entire acquisition memory if you know the data is not going to be used. This is the case when a new trigger arrives before the acquisition memory is completely filled. After all at short time/div settings you'll be looking at a fraction of the acquisition memory anyway. The rest is outside the screen.
No new trigger means the memory is filled completely and then the data required to show the signal outside the screen will be there. Don't think in terms of fixed memory lengths. It is like starting with a new task and abandoning the old task. new trigger = reset acquisition memory addres counter.No, it's not. It's simply one of the critical limitations in linear sampling systems.OK, so on a DSO-X3kT with 4Mpts and 5GSa/s, that would mean a best case (single channel) 2Mpts in normal acquisition mode, which at 5GSa/s takes 400us to fill. Even on a perfect scope with zero blind time, 400us per acquisition translate into only 2,500 acquisitions per second. Which means to reach the very high waveforms the DSO-X3kT can achieve it would have to dramatically reduce the amount of memory used, i.e. at 500k acquisitions per second that just leaves 2us for acquisition + blind time, so even that perfect scope with no blind time would have to reduce the sample memory size to 10k.As I wrote before your math is too simplified.QuoteYou don't have to fill the entire acquisition memory if you know the data is not going to be used. This is the case when a new trigger arrives before the acquisition memory is completely filled. After all at short time/div settings you'll be looking at a fraction of the acquisition memory anyway. The rest is outside the screen.Yes, you don't have to fill the entire memory, that is clear. But if the scope doesn't then where should it get its data to zoom out from?
We know that the DSO-X uses half memory (2Mpts) in NORMAL/AUTO mode on the *last* acquisition made after pressing STOP.You're once again saying things are fact which you dont understand, every capture in run mode is filling a sample buffer of the same size (the halved memory). It is rendered out to the screen at a smaller resolution without dropping any of the points from every single one of those buffers. As soon as you press stop the last of those complete buffers is available to navigate/zoom through. The case of waiting for the next trigger is when you request that functionality by pressing not stop, but the single button to rearm acquisition.
We know that the DSO-X uses a lot less than the available memory (which would be 2Mpts best case) for all acquisitions in NRM/AUTO except for the last one to maintain its very high update rates (again, it uses the full available memory on the last acquisition after pressing STOP).
So what about when the scope is in NRM and you press STOP and no further trigger appears? The scope will not have made a longer 'last' acquisition as it hasn't been triggered anymore. And the acquisitions made before STOP was pressed would only have used a small part of the available memory as otherwise the update rates would have dropped like a rock (see the formula I stated, for which there is no way around). And with the last acquisition only using a small part of the memory, there simply is no data to zoom out.
I did mention the theoretical maximum capture rates, very few scopes approach those limits, and their peak performance is typically found by drastically reducing the memory depth and/or sample rate as shown in the example I presented. You cannot come up with "simple maths" to determine how fast any particular scope model will update.There is no basic maths you can apply to determine how fast a particular scope will updateIncreasing the memory depth of those rigol scopes further reduces their acquisition rates, same with the Tektronix examples David is talking about, its like this with most scopes and well known.Thanks Captain Obvious, but the point was not if scopes get slower with larger sample memory (they do) but the why. David seems to believe it's because of processing, but in reality this is simply down to basic math.
There's basic math which tells you how long it takes to capture a specific segment, a time that no scope no matter how fast is able to beat, which is
Tcapture [seconds] = sizememory [Samples] / fsampling [Samples per second]
Knowing this, it should really be no surprise why a long memory scope will take more time to complete an acquisition cycle than a short memory scope.
More processing power was also required to allow deep acquisition memories but both were the result of increases integration and processing power has fallen behind making very deep acquisition memories *less* useful in a general sense. Maybe high end DSOs avoid this problem but my experience with the DSO/MDSO5000 series is that they do not; using high record lengths results in waiting for processing of each record which is fine for single shot applications where long record lengths are especially useful but it is aggravatingly slow otherwise.
This processing power problem with long record lengths is not new. The ancient Tektronix 2230/2232 DSOs support 1k and 4k record lengths which seems laughably short by today's standards but why did they support a 1k record length at all? Why wasn't more acquisition memory included? It would have been trivial to do and only moderately expensive. I suspect it was because the limited processing power available at the time could handle 1k records significantly faster so for a *better user experience*, a selectable 1k record length was made available.
My point was that the display record processing makes these DSOs operate more like they are limited by the display record length than the record length given in the specifications which in only available for saved acquisitions. This is a deliberate tradeoff because they cannot process their full record length in an acceptable time.
No new trigger means the memory is filled completely and then the data required to show the signal outside the screen will be there. Don't think in terms of fixed memory lengths. It is like starting with a new task and abandoning the old task. new trigger = reset acquisition memory addres counter.
Quote from: Wuerstchenhund link=topic=71941.msg1281322#msg1281322So what about when the scope is in NRM and you press STOP and no further trigger appears? The scope will not have made a longer 'last' acquisition as it hasn't been triggered anymore. And the acquisitions made before STOP was pressed would only have used a small part of the available memory as otherwise the update rates would have dropped like a rock (see the formula I stated, for which there is no way around). And with the last acquisition only using a small part of the memory, there simply is no data to zoom out.
You're once again saying things are fact which you dont understand
every capture in run mode is filling a sample buffer of the same size (the halved memory). It is rendered out to the screen at a smaller resolution without dropping any of the points from every single one of those buffers. As soon as you press stop the last of those complete buffers is available to navigate/zoom through. The case of waiting for the next trigger is when you request that functionality by pressing not stop, but the single button to rearm acquisition.
David was pretty clear in his articulation about the long memory being counterproductive to update rates.
More processing power was also required to allow deep acquisition memories but both were the result of increases integration and processing power has fallen behind making very deep acquisition memories *less* useful in a general sense. Maybe high end DSOs avoid this problem but my experience with the DSO/MDSO5000 series is that they do not; using high record lengths results in waiting for processing of each record which is fine for single shot applications where long record lengths are especially useful but it is aggravatingly slow otherwise.
This processing power problem with long record lengths is not new. The ancient Tektronix 2230/2232 DSOs support 1k and 4k record lengths which seems laughably short by today's standards but why did they support a 1k record length at all? Why wasn't more acquisition memory included? It would have been trivial to do and only moderately expensive. I suspect it was because the limited processing power available at the time could handle 1k records significantly faster so for a *better user experience*, a selectable 1k record length was made available.
My point was that the display record processing makes these DSOs operate more like they are limited by the display record length than the record length given in the specifications which in only available for saved acquisitions. This is a deliberate tradeoff because they cannot process their full record length in an acceptable time.
It has been a year since they released this scope. The search/marker buttons still do nothing.
If the Keysight scopes achieve higher waveforms/s than they should given the amount of memory versus samplerate then this is what they must be doing.No new trigger means the memory is filled completely and then the data required to show the signal outside the screen will be there. Don't think in terms of fixed memory lengths. It is like starting with a new task and abandoning the old task. new trigger = reset acquisition memory addres counter.That would make sense but is this really what happens? Has anyone tried?
You still think I'm wrong? Fine, prove it.I have so carefully framed the discussion yet you take it off in directions that make no sense, if you wanted to talk about fast sweep times then why not say that originally instead of writing several pages of off topic thread derailment?
Ideally you wouldn't have to compromise on memory depth, it would always be as deep as possible for the horizontal window. You are limited by sample rate for short captures, and memory depth for long captures, but in the in-between where neither is limiting people still choose to have a shorter memory depth than they could capture because it slows down aspects of the scope such as the waveform display rate. You can measure this so I took a rigol 1054 and did the comparison setting both scopes to 50us per division:Its stands as a representative example of two different scopes both of which increase their realtime update rate when showing fewer points despite it being the same acquisition time window.
Waveforms wfms/s Rigol Memory Vector Dots Sample Rate 1054Z 12k 363 624 10MS/s 120k 217 298 125MS/s 600k 178 192 1GS/s 1200k 160 170 1GS/s 12M 60 61 1GS/s 24M 35 36 1GS/s Keysight 1000/2000X 500k 1800 1GS/s 3000X 500k 1746 1GS/s 3000X 2M 780 4GS/s
The theoretical zero blind time rate is 2000 wfms/s for the Keysight, and 1667 wfms/s for the Rigol (extra 2 divisions horizontal display). They're all able to run at 1GS/s for this test but the Keysight gives you no direct options to change to other memory depths, while the Rigol with all its choices fails to match the realtime performance. It even lets you choose longer depths that are captured outside the display but not shown until you stop and zoom around the capture, at the shorter memory depths the Rigol is dropping its sample rate and not putting 1GS/s data onto the screen which is why comparisons need to be made carefully. Processing (and/or memory bandwidth) is limiting the ability to draw more information to the screen and the reason why many scopes offer the choice of shorter memory depths.
You are limited by sample rate for short captures, and memory depth for long captures, but in the in-between where neither is limiting people still choose to have a shorter memory depth than they could capture because it slows down aspects of the scope such as the waveform display rate.There are limits but they are entirely constant with the displayed sample rate. Which leads onto this:
Tl;dr: The scope can impossibly fill 2Mpts at each acquisition while maintaining its excessive update rates in NORM/AUTO mode. So yes, the DSO-X is 'cheating' as normal acquisitions only use a small amount of sample memory and the max available memory (2M) is only used in the last acquisition.The Keysight X series always use as much memory as possible to fill the acquisition time window, at the fastest sample rate possible. Yes when its running at fast sweep speeds then the sample rate limits the amount of memory that can be shown on the screen, and when pressing stop in such a situation you either get no more than that memory depth available or when hit with a repetitive signal the entire 1/2M buffer so there is some mystery around how its managing the acquisition memory and what might be available when you press stop. Contrast this to the rigol example above which you can ask it to sample a buffer much larger than is on the display and it will dutifully do so, continuing to show only whats on the display but capturing a large window to either side into the memory while the auto memory depth mode picked a memory depth to fit the acquisition window and no more.
There is something not obvious happening when you press stop, but its not ever giving less memory depth than the sample rate * acquisition width, sometimes more but never less.If the Keysight scopes achieve higher waveforms/s than they should given the amount of memory versus samplerate then this is what they must be doing.No new trigger means the memory is filled completely and then the data required to show the signal outside the screen will be there. Don't think in terms of fixed memory lengths. It is like starting with a new task and abandoning the old task. new trigger = reset acquisition memory addres counter.That would make sense but is this really what happens? Has anyone tried?
When you press 'stop' triggers which start a new acquisition are blocked so the memory can be filled. Nothing non-obvious happens. BTW I used to own a DSO7104A so I'm quite familiar with how Megazoom based Agilent/Keysight scopes work.There is something not obvious happening when you press stop, but its not ever giving less memory depth than the sample rate * acquisition width, sometimes more but never less.If the Keysight scopes achieve higher waveforms/s than they should given the amount of memory versus samplerate then this is what they must be doing.No new trigger means the memory is filled completely and then the data required to show the signal outside the screen will be there. Don't think in terms of fixed memory lengths. It is like starting with a new task and abandoning the old task. new trigger = reset acquisition memory addres counter.That would make sense but is this really what happens? Has anyone tried?
You still think I'm wrong? Fine, prove it.I have so carefully framed the discussion yet you take it off in directions that make no sense, if you wanted to talk about fast sweep times then why not say that originally instead of writing several pages of off topic thread derailment?
Tl;dr: The scope can impossibly fill 2Mpts at each acquisition while maintaining its excessive update rates in NORM/AUTO mode. So yes, the DSO-X is 'cheating' as normal acquisitions only use a small amount of sample memory and the max available memory (2M) is only used in the last acquisition.
Yes when its running at fast sweep speeds then the sample rate limits the amount of memory that can be shown on the screen, and when pressing stop in such a situation you either get no more than that memory depth available or when hit with a repetitive signal the entire 1/2M buffer so there is some mystery around how its managing the acquisition memory and what might be available when you press stop.
There is something not obvious happening when you press stop, but its not ever giving less memory depth than the sample rate * acquisition width, sometimes more but never less.
There shouldn't be a mystery how the acquisition memory is managed. While I'm not a friend of the auto-only memory management in the DSO-X I can see that it's adequate for most common measurement situations entry-level scopes are normally facing, however I still think the scope should at least show how much memory is A) available and B) actually in use.Keysight will never ever do that because the actual memory depth the scope has available can be over 8 times less than it says on the badge (all analog + digital + reference channels enabled). How to explain that?
You frame "cheating" in a very curious position, cheating is where something is doing an underhanded trick but the scope is showing all the information clearly:You still think I'm wrong? Fine, prove it.I have so carefully framed the discussion yet you take it off in directions that make no sense, if you wanted to talk about fast sweep times then why not say that originally instead of writing several pages of off topic thread derailment?
If this thread derailed then it's because you replied to some postings you didn't even read and argued points that everyone else was in agreement.
But I guess the main trigger was that I said the DSO-X is 'cheating' during normal acquisitions, which as shown it does.
But essentially every scope on the market is limited in its realtime update/throughput rate because none of them hit the theoretical maximums attainable. There is something limiting it, its processing/computing/memory bandwidth.More processing power was also required to allow deep acquisition memoriesActually, no, longer memory doesn't require more processing.
You try and connect display record with the acquisition buffer, which are different lengths and shapes. In the non sample rate limited examples I showed the display record (of note when measurements are derived from it) is much shorter in horizontal samples than the acquisition record, which is maximised under all conditions to the speed of the sweep.The entire "argument" about needing memory depth controls is that the user needs it for some reason, in the Agilent/Keysight X series thats not needed because there isThe DSO-X, like any HPAK InfiniVision scope, is cheating as the only time it acquires a long memory segment in normal acquisition is at the last acquisition made after pressing STOP, otherwise it uses just enough memory to fill the display record.neverso rarely a reason for the user to capture a smaller memory depth (even though it could be nice for some applications where the data is being offloaded).
When zooming out on these long captures there is both pre and post trigger expansion of the memory, it could just be a side effect of the pointers but that would block the pingpong memory allocation which increases memory throughput. So given its related to the frequency of the repetitive signal I think there might be a short timer after pressing stop where it will accept a new trigger and fill out the memory (8Hz and up measured quickly here).When you press 'stop' triggers which start a new acquisition are blocked so the memory can be filled. Nothing non-obvious happens. BTW I used to own a DSO7104A so I'm quite familiar with how Megazoom based Agilent/Keysight scopes work.There is something not obvious happening when you press stop, but its not ever giving less memory depth than the sample rate * acquisition width, sometimes more but never less.If the Keysight scopes achieve higher waveforms/s than they should given the amount of memory versus samplerate then this is what they must be doing.No new trigger means the memory is filled completely and then the data required to show the signal outside the screen will be there. Don't think in terms of fixed memory lengths. It is like starting with a new task and abandoning the old task. new trigger = reset acquisition memory addres counter.That would make sense but is this really what happens? Has anyone tried?
Try a signal with a much longer interval and you'll see it won't wait for a new signal after pressing stop.Yes, there appears to be some maximum time between pressing stop and the next trigger after which it wont make the extra (and sometimes longer) capture.
But I guess the main trigger was that I said the DSO-X is 'cheating' during normal acquisitions, which as shown it does.
You frame "cheating" in a very curious position, cheating is where something is doing an underhanded trick but the scope is showing all the information clearly:
The horizontal sweep time
The sample rate which it is captured at
Yes, its not capturing the data outside the window, but it never claims to be doing that. There are some occasions where it will capture the data around the screen when stopping acquisition of a repetitive signal but its not something which is documented.
If you want that data outside the screen on other scopes you would set the memory depth to instruct it to capture that area, on the X series scopes you would make the acquisition window wide enough to capture that same time period.
Its different ways of working that achieve the same end result, and some of us prefer not having to manually adjust memory depths and would rather use the single horizontal control to do the same. If you don't like working that way its fine but you make out like its some huge deficiency with the product which it simply isn't.
But essentially every scope on the market is limited in its realtime update/throughput rate because none of them hit the theoretical maximums attainable. There is something limiting it, its processing/computing/memory bandwidth.More processing power was also required to allow deep acquisition memoriesActually, no, longer memory doesn't require more processing.
You try and connect display record with the acquisition buffer, which are different lengths and shapes. In the non sample rate limited examples I showed the display record (of note when measurements are derived from it) is much shorter in horizontal samples than the acquisition record, which is maximised under all conditions to the speed of the sweep.
Note that on Auto, some scopes will not utilise the full sample rate and memory depth available because that would degrade the realtime/interactive performance/rate of the scope, because they have limited processing to keep up with the longer memory depths.
Yet you spend several pages trying to disguise this simple point with discussion about the way that the Keysight X series which always maximise the memory depth (even where that is reducing the update/throughput rate) is somehow less ideal.
Again you run in as many different claims as possible into a simple point.If you want that data outside the screen on other scopes you would set the memory depth to instruct it to capture that area, on the X series scopes you would make the acquisition window wide enough to capture that same time period.So essentially if you want to capture a longer segment in NORM/AUTO mode you have to make sure the whole period fits on the screen, i.e. you have to treat a deep memory scope like a small memory scope (i.e. fit the whole period into the few thousand points it uses during repetitive acquisitions), and potentially suffer from the drawbacks (i.e. a drop of sample rate because of the extension of the time base). While on every other decent scope you just set the scope to use more memory, and be done with it, without a drop in sample rate.
So essentially if you want to capture a longer segment in NORM/AUTO mode you have to make sure the whole period fits on the screen,Yes, what would be the value in having information off the screen but still captured? Reading the Lecroy WS3000 manual is says that the maximum memory setting is overridden and shorter memory depths are used at fast sweep speeds, not capturing the extra samples around the sweep window just like the Keysight X series does. But even if you want that its possible to do something similar so its not a lacking feature...
i.e. you have to treat a deep memory scope like a small memory scope (i.e. fit the whole period into the few thousand points it uses during repetitive acquisitions)No, you again jump to the conclusion that there will be some small memory depth used when I'm explaining how to access the full memory depth. Its right there in plain sight if you want to capture the full memory depth available, just keep winding out the horizontal sweep until you've got it all in the acquisition window (or go one step further, watch the sample rate drop and return back to the maximum depth). Its then acquiring that entire memory depth, not "thousands of points".
and potentially suffer from the drawbacks (i.e. a drop of sample rate because of the extension of the time base).The limitations of memory depth and sample rate tradeoff are the same on all scopes, this isn't something particular here. You can access the full memory depth if you wish to, or not. The major limitation is not being able to request a lower memory depth and drop the sample rate for a given time acquisition window, but as discussed above thats a narrow use case where you might want to increase the waveform rate (which you say is already "excessive") or then offload a particular number of samples for processing.
While on every other decent scope you just set the scope to use more memory, and be done with it, without a drop in sample rate.Lengthening the memory depth of the record either a) increases sample rate, or when limited by sample rate b) increases the acquisition window both of these are available on the X series, there is no drop in sample rate. Or are you moving the goal posts once again and trying to make comparisons of unmentioned specific conditions where the shorter maximum memory depth of the X series scopes could be compared to some other scope? More memory is also a nice thing to have for some situations, but thats getting wildly off track again.
The rigol example above (a low end scope being compared in a thread about another competitors low end scope) doesnt use the full memory depth when set to Auto.Note that on Auto, some scopes will not utilise the full sample rate and memory depth available because that would degrade the realtime/interactive performance/rate of the scope, because they have limited processing to keep up with the longer memory depths.That's wrong (if you disagree, name these scopes!). Pretty much every decent scope will of course utilize the full sample rate and the setup memory depth in AUTO mode. And as stated already, scopes don't process the whole memory content during normal acquisitions, just a smaller part required for display content generation and measurements, so there is no processing penalty from longer memory in normal acquisition mode.
Or are you talking about automatic memory management on other scopes? If so, then you're still wrong, as scopes will always maintain the sample rate which is possible at the given timebase setting (based on what the physically available sample memory allows for) and only adjust the used record length to capture enough for screen generation and measurements.
And as stated already, scopes don't process the whole memory content during normal acquisitions, just a smaller part required for display content generation and measurements, so there is no processing penalty from longer memory in normal acquisition mode.You're looping back around and not qualifying this, are you still trying to talk about the fast sweep speeds where most of the acquisition record is off the screen? Because I was clearly talking about auto memory mode where the scope has latitude to pick a memory depth to fill the entire sweep window, where they do need to process all the acquisition memory depth and draw it to the screen, and its well known that increasing the memory depth (increasing sample rate at the same time as the window is a constant width) greatly reduces the update rate of most scopes.
More processing power was also required to allow deep acquisition memories but both were the result of increases integration and processing power has fallen behind making very deep acquisition memories *less* useful in a general sense. Maybe high end DSOs avoid this problem but my experience with the DSO/MDSO5000 series is that they do not; using high record lengths results in waiting for processing of each record which is fine for single shot applications where long record lengths are especially useful but it is aggravatingly slow otherwise.I had some free time to record and chart some of this behaviour, in a Rigol 1104Z and a much older Tek DPO4000. As always the results are interesting.
This processing power problem with long record lengths is not new. The ancient Tektronix 2230/2232 DSOs support 1k and 4k record lengths which seems laughably short by today's standards but why did they support a 1k record length at all? Why wasn't more acquisition memory included? It would have been trivial to do and only moderately expensive. I suspect it was because the limited processing power available at the time could handle 1k records significantly faster so for a *better user experience*, a selectable 1k record length was made available.
DSOX1000 64k point FFT, 3 updates/secondBut the Tek DPO4000 did drop its capture rates when processing its FFTs or maths, and putting its FFT update rates in context:
DS1054Z 64k point FFT, 1 update/second
DSOX1000 1k point FFT, 60 updates/second
DS1054Z 1k point FFT, 3 updates/second
DS4000 1k point FFT, 8 updates/second
[...]
I had some free time to record and chart some of this behaviour, in a Rigol 1104Z and a much older Tek DPO4000. As always the results are interesting.
1.) David and I were discussing if deep memory is actually useful or just a marketing gimmick (David thought it's more of a gimmick, I think it's very useful, as demonstrated on an example used in an older posting of mine).
1.) David and I were discussing if deep memory is actually useful or just a marketing gimmick (David thought it's more of a gimmick, I think it's very useful, as demonstrated on an example used in an older posting of mine).
Interestingly enough Pico has just come up with feature called "DeepMeasure" that will chew up to 1M wfms (100M pts) and format as Excel-style table:
https://www.picotech.com/library/oscilloscopes/deepmeasure?hpc3 (https://www.picotech.com/library/oscilloscopes/deepmeasure?hpc3)
(https://www.picotech.com/images/uploads/library/topics/_med/thousand-cycles-deepmeasure-table-sort-cycle.png)
However I am in deep sadness as auto-measurement aficionado because this feature seems to be limited to USB 3.0 scopes and my 2408B is USB 2.0 :'(
2.) We both are well aware that at a given sample rate more sample memory means lower waveform rates, the point of discussion was about the 'why' (David believed this was due to increased processing, which was wrong as the additional data in a long memory scope is not processed during normal acquisitions; the lower wavform rate comes simply from the fact that more memory needs longer to be filled).Yet you keep only considering the case where adding more memory depth increases the acquisition depth and not the number of those points making it to the screen, and never framed that even when I was explicitly discussing the much more typical operation of an oscilloscope increasing the memory depth where there is sample rate available to keep the entire acquisition on the screen.
And as stated already, scopes don't process the whole memory content during normal acquisitions, just a smaller part required for display content generation and measurements, so there is no processing penalty from longer memory in normal acquisition mode.Its this sort of unqualified statement you keep making that is so obnoxious, during normal acquisitions scopes do process the entire memory depth to the display....
Tek TBS2000 is just strange. There is even no video trigger. https://www.tek.com/oscilloscope/tbs2000-basic-oscilloscope (https://www.tek.com/oscilloscope/tbs2000-basic-oscilloscope)Why would you need video trigger? Analog video has been dead and buried for over 10 years already.