Rigol's New DHO800 Oscilloscope unbox & teardown

[2N3055]

Thanks, page 55 of the DHO900 user manual for reference (and yes, those are the issues you will encounter..).

Section 7.3... it's all laid out, at least they're open about it. They even detail all the problems, with pictures. 

It's a tough trade: Do you want full bandwidth with one or two channels? How often will a 200MHz signal make it all the way into the system in "All channels mode"? What effect will using the "150MHz" probes have?

Let the testing begin! 

It is really interesting to see this reinvention of physical (and moral) principles every time people want to sell their agenda..
It is probably sign of times, I guess ....

It is NOT all right to deliberately design an instrument that violates basic principles of math and physics.
It is NOT all right to design it deliberately and with full knowledge that it will grossly violate sampling theorem and then say it is all right because you confessed to it in User manual.

Right thing to do would be to sell it as 100MHz scope (that it is) and 100 MHz scope only..
Which would not diminish it's value at all...

But this scope is all about bombastic trailer and lousy movie, like all new Hollywood productions...

[nctnico]

..
It depends on type of antialiasing filter used . If filter is really sharp, 2,5X is starting point where it works. If you are using more traditional filter with Gausian response (slower roll off), then 4X or 5X might be needed.

Yep, would be great to see the real life measurements, as even the "Max" 100MHz BW with 312.5MS/s sampling rate would be something new, imho For 100Mhz BW I would expect at least 2GS/4=500MS per channel

Those days are long gone. A typical, well designed DSO has the maximum bandwidth right up to the samplerate divided by 2.5. That is a little below the frequency where sin x/x reconstruction stops working. This allows the user to choose between maximum bandwidth or a lower bandwidth with a Gaussian roll-off. A decent DSO typically has multiple bandwidth choices to give the user maximum flexibility.

Interesting.. How they do that with 250MHz BW and 312.5MS/s then?

I guess you skipped over: well designed DSO

[mikeselectricstuff]

Have you guys seen this video?

Did you watch it?

That is cool looking display mode. But what it is used for?
If you have any kind of persistence, you can overlay millions of captures to look for existence of the glitch. It is an old technique.
There are no measurements while it is running or displaying it. No decoding..
What will you use it for? It looks cool on on a shelf in a store but what do you use it for?
It is just a marketing gimmick....

Many of those visualization modes are already there on other scopes. With segmented mode you can overlay segments on Keysight, even on older Rigols. With segmented and history mode you can overlay captures on Siglent too.  And they will measure and decode on that data...

What part of your process will it make so better that it will change your life?

The fact that you can immediately see the time distribution of infrequent events, though the 100 trace limit may limit its usefulness.
Persistance will tell you that something happened, but not how often or the distribution over time.
There are also event types that don't display well with persistence which would be much easier to see with the perspective mode.

I can think of a couple of situations where this would have saved me significant debugging time.

[iMo]

I would accept their marketing of the "70MHz models with 4 channels and that 312.5MSa/s per channel with all 4 channels enabled" as that somehow fits the math. My current understanding is they developed their new 12bit ADC ASIC, and it works those 1.25GSa/s single channel max with no chance for an improvement soon.
Now they want to get their R&D ROI back, so they created a new product series - the 800/900 series - where under their traditionally friendly approach to the tech community they allow for hacking, as they know well their highest 800/900 models (with the single ADC inside) in that series are basically still the 70MHz scopes (such the math works somehow)..

[NE666]

we could also ask rigol as a firmware request: to add can bus decode

It couldn't hurt you to ask, true.  Unless you hold breath until it arrives.  It's clearly a commercial decision Rigol have taken, to differentiate it from the more expensive 900/1000/4000 series models.

[Fungus]

What part of your process will it make so better that it will change your life?
That is definition of phrase "game changer".

Not true. You can also change a game by reducing the price to a point where everybody can afford it, not just a few rich people.

[Fungus]

It is NOT all right to deliberately design an instrument that violates basic principles of math and physics.

It doesn't do that with only one or two channels enabled.

Don't point fingers at me though, I'm on record as saying I wouldn't want full 250Mhz bandwidth in my DHO.

I'm also on record saying Rigol should have programmed the 'scope to turn on the 125MHz bandwidth limiter when you enable more than 2 channels.

[Fungus]

I would accept their marketing of the "70MHz models with 4 channels and that 312.5MSa/s per channel with all 4 channels enabled" as that somehow fits the math.

312.5MSa/s is enough for 125MHz.

The 2.5:1 ratio is well established in the industry for sample rate:bandwidth.

[dreamcat4]

No CAN decoding meh  

we could also ask rigol as a firmware request: to add can bus decode

It couldn't hurt you to ask, true.  Unless you hold breath until it arrives.  It's clearly a commercial decision Rigol have taken, to differentiate it from the more expensive 900/1000/4000 series models.

Thanks. Sorry I was not at my computer - indeed then all anybody needs to do is flash their 800 series to 900 series firmwares. To then get the CAN bus decoding. So i don't see this as an issue in that case... sorry for any confusion here. (at least I am fine with that then, not so sure what the other guy was turning his nose up about).

[NE666]

It is probably sign of times, I guess ....

It is NOT all right to deliberately design an instrument that violates basic principles of math and physics.
It is NOT all right to design it deliberately and with full knowledge that it will grossly violate sampling theorem and then say it is all right because you confessed to it in User manual.

HP/Agilent 54600-Series has entered the chat..

54621A/D "60Mhz"   but 100MSa/s both channels
54622A/D "100MHz" but still 100MSa/s both channels

'Twas ever thus, in marketing departments.  It doesn't mean that either weren't useful to those who purchased them, knowing what their limitations were.

[dreamcat4]

My biggest beef in all this:

* because the DHO1000 isn't portable / battery power-able
* then to transplant out the asic out from cheaper 804 --> DHO1000 will then loose those capabilities of a portable scope

To then have to buy either another 800 series scope for that dedicated purpose, or forgoe the higher bandwidths. Since to have both a 1000 + 800 seems a bit naf really.

[iMo]

I would accept their marketing of the "70MHz models with 4 channels and that 312.5MSa/s per channel with all 4 channels enabled" as that somehow fits the math.

312.5MSa/s is enough for 125MHz.

The 2.5:1 ratio is well established in the industry for sample rate:bandwidth.

Let the experts here create some tests scenarios for the users of the 800/900 such we may get some data and analyze them, and we'll see how it performs in reality..
PS: I've shortlisted it and want to know more about it..

[Fungus]

Thanks. Sorry I was not at my computer - indeed then all anybody needs to do is flash their 800 series to 900 series firmwares. To then get the CAN bus decoding. So i don't see this as an issue in that case... sorry for any confusion here. (at least I am fine with that then, not so sure what the other guy was turning his nose up about).

The 900 has CAN decoding and the 800 doesn't?

That'll be hacked in the first day, too. 

[Serg65536]

Delta replacement fan test.

Dave desperately tries to find a good fan for the scope once again . I understand the reason why: my friend can't cope even with a smallest noise in the office also  .

Please anybody donate a good fan to Dave for this scope. Otherwise, I guess, we'll be waiting for him to make the full review forever.

[2N3055]

It is probably sign of times, I guess ....

It is NOT all right to deliberately design an instrument that violates basic principles of math and physics.
It is NOT all right to design it deliberately and with full knowledge that it will grossly violate sampling theorem and then say it is all right because you confessed to it in User manual.

HP/Agilent 54600-Series has entered the chat..

54621A/D "60Mhz"   but 100MSa/s both channels
54622A/D "100MHz" but still 100MSa/s both channels

'Twas ever thus, in marketing departments.  It doesn't mean that either weren't useful to those who purchased them, knowing what their limitations were.

Those has ETS mode. Rigol does not.

[2N3055]

Have you guys seen this video?

Did you watch it?

That is cool looking display mode. But what it is used for?
If you have any kind of persistence, you can overlay millions of captures to look for existence of the glitch. It is an old technique.
There are no measurements while it is running or displaying it. No decoding..
What will you use it for? It looks cool on on a shelf in a store but what do you use it for?
It is just a marketing gimmick....

Many of those visualization modes are already there on other scopes. With segmented mode you can overlay segments on Keysight, even on older Rigols. With segmented and history mode you can overlay captures on Siglent too.  And they will measure and decode on that data...

What part of your process will it make so better that it will change your life?

The fact that you can immediately see the time distribution of infrequent events, though the 100 trace limit may limit its usefulness.
Persistance will tell you that something happened, but not how often or the distribution over time.
There are also event types that don't display well with persistence which would be much easier to see with the perspective mode.

I can think of a couple of situations where this would have saved me significant debugging time.

100 trace limit is exactly the point :it makes it cool but not really useful.

For instance: any scope that has history /segmented mode you can overlay and/or do animation... And can calculate distribution by using measurements...

Don't get me wrong, there are LeCroy scopes that can do these kinds of visualizations but on full data sets and full math. Where you can actually analyze things.  With this Rigol implementation it is maybe just marginally (visually) better than classic infinite persistence.

Fun fact: on MSO3000T  I can get statistics on glitches by capturing representative data and making a mask on it. Then by using mask mode I get count and stat on all anomalies.  I can do same thing with Siglent.
You can also use search to search for anomalous pulse widths, risetimes or else.

On Picoscope you can also show all segments visually but that is useful for only few dozen segments.
If you have 10000 segments, fining something visually is simply punishment.

Breakthrough , a game changer, would be something like WaveScan on sub 2000€ scope.

Don't get me wrong, it is very nice step in right direction for Rigol.

But if you have a Siglent SDS1104X-E for instance, selling it and buying Rigol DHO800 would not be game changer in any case. It would be incremental positive step in analog performance (slightly better noise and 12 bit), touchscreen interface,  and a step backwards in other analytical capacities: no history mode, no FRA, no CAN/LIN decode etc....
If you have MSO5000, unless you absolutely need low noise and 12 bit, it is a serious downgrade....

Fact is, only scope the DHO800/900 really directly competes with is Rigol's own DS1000Z/MSO series
And DHO814 would be upgrade to DS1000Z even if it were 8bit. With 12 bit low noise it is obvious replacement for DS1000Z.
And that is also Rigol's internal placement. You can see it in careful choice of decodes that matches DS1000Z.

[Mechatrommer]

Those has ETS mode. Rigol does not.

whats the point of ETS on ns-risetime GSps scope? if anything, IT IS the marketing gimmick on entry level DSO today.. nitpick!

[2N3055]

Those has ETS mode. Rigol does not.

whats the point of ETS on ns-risetime scope? if anything, IT IS the marketing gimmick on entry level DSO today..

Way to pick a fight over what you did not understand...

I did not claim that Rigol needs ETS. I said that 30 year old scope that NE666 mentioned had 100 MHz BW with 100MSp/s  because IT had ETS.

ETS is not a trick. It is operating principle to achieve super high equivalent sampling rate with slower ADCs. It is VERY useful for repetitive signals.
It is pretty much useless for anything else.
Therefore all general purpose scopes nowadays just use fast real-time sampling...

EDIT:

I see you edited post... Well in 4 ch mode Rigol DHO800 is sampling at 312,5 MSp/s. That is hardly exceptional... An in this instance I'm not the nitpick...

[Howardlong]

Regarding the aforementioned Nyquist bandwidth shenanigans, presumably the scope channels' bandwidths are reduced automatically when three or four channels are enabled?

As the bandwidth for the different models is configured in software, I'd have hoped this was the case.

 

[Fungus]

Regarding the aforementioned Nyquist bandwidth shenanigans, presumably the scope channels' bandwidths are reduced automatically when three or four channels are enabled?

It's definitely possible but the manual seems to indicate it doesn't do that.

Maybe a future hack... 

[dreamcat4]

On Picoscope you can also show all segments visually but that is useful for only few dozen segments.
If you have 10000 segments, fining something visually is simply punishment.

Breakthrough , a game changer, would be something like WaveScan on sub 2000€ scope.

Yes this is what I was thinking about too... to find anomalies after seeing such a feature demo'd an a much more expensive leading modern LeCroy setup. It seemed pretty much... completely effortless to identify intermittent failed logig transisions. You know - glitches that only occurs 1x randomly every few hundred times. That (on a normal / cheaper scopes) you are looking at the live / realtime updating and just see random flashes.

I am not saying that way cannot work either! It's just... maybe a bit less reliable method of detection? And also requiring (for example) that the scope itself can represent that on the display. Which is itself something can be limited by the decisions of the scope design. Of that specific scope. Wheras LeCroy's mathematical based analysis will trawl through the whole buffer for you. And you can then actually select and choose from a whole variety of different conditions to detect specific different types of anomalous behviours. Which could be... well a whole different categories of issues.

So THAT i was impressed with. And no - it's not really expected on such cheap scopes. But you know... would be really cool to see movement towards those general direction here. With newer firmware / platforms. Even not on this scope, but instead on the higher end DHO4000 series.

step backwards in other analytical capacities: no history mode, no FRA, no CAN/LIN decode etc....
If you have MSO5000, unless you absolutely need low noise and 12 bit, it is a serious downgrade....

Fact is, only scope the DHO800/900 really directly competes with is Rigol's own DS1000Z/MSO series

I think this assessment is wrong here because:

a) you can get CAN bus decode by flashing the 900 firmware, it's included there with a bit of hacking
b) this scope might be able to also compete with PORTABLE scopes. And that would be a killer application which the other scopes you are highlighting simply cannot actually do.

[Fungus]

b) this scope might be able to also compete with PORTABLE scopes. And that would be a killer application which the other scopes you are highlighting simply cannot actually do.

Here's one running from a USB powerbank:

[ifonlyeverything]

Has the user interface responsiveness improved over the DS1054Z? I owned a DS1054Z and really liked it... aside from the sluggish UI, which made me sell it for a Siglent.

[Fungus]

Has the user interface responsiveness improved over the DS1054Z?

Yes.

[Fungus]

Can anybody measure the screen precisely?

I'm definitely going to put a matte screen protector on mine. If somebody has the dimensions I can go looking for one today for when it arrives.