Rigol's New DHO800 Oscilloscope unbox & teardown

[Howardlong]

Zoom.

Is there a quick way to turn horizontal zoom on and off from the control panel, without having to fumble around on the touch screen?

On the DS1000Z, ISTR you pushed the horizontal timebase to toggle zoom. On the DHO800/900 that now toggles the vernier, a nice to have feature, but IME it's far less frequently used than toggling zoom.

[2N3055]

Zoom.

Is there a quick way to turn horizontal zoom on and off from the control panel, without having to fumble around on the touch screen?

On the DS1000Z, ISTR you pushed the horizontal timebase to toggle zoom. On the DHO800/900 that now toggles the vernier, a nice to have feature, but IME it's far less frequently used than toggling zoom.

I belive there is a setting where you can choose what timebase knob press will do: fine/zoom.....

[Howardlong]

Nothing beats real-time data streaming, no segmented memory not any triggering is going to replace grep. Or Python. Or C#. Or <insert your favourite data analysis language>.

I respectfully disagree. As I've said before, it's horses for courses, use the tool for the job that gets you there the quickest considering one's individual experience and skill set.
***
Furthermore, IME near-unlimited streaming of bulk data into a PC from LAs is typically restrictive in terms of sample rate, unless you have a particularly expensive LA. While a reasonably-priced LA might be OK for oodles of I2C traffic, high speed SPI not so much.

Yes but in the context of this thread, we are talking about the DHO900. We have other threads you can argue about PC LA vs MSO that are more relevant.

You are paying $200 (PLUS adapter $50-300) for a LA that:
- takes away from your analog sample rate
- will have limited protocol support compared to sigrok

IMO that ~$300 is better spent toward a known good PC LA or dedicated AWG or something else. Maybe in the future that might change, if rigol puts a lot of effort into the LA (which they have not done in the past).
99% of hobbyist use cases can get away with using a few analog channels for I2C or SPI.

You raise valid points, particularly for hobbyists.

IME a significant limitation of many PC based LAs is the sample rate, particularly for high speed SPI.

For the avoidance of doubt, for PC based LAs I use both the Analog Discovery and the Digital Discovery extensively: while the AD in particular is often deemed a "hobbyist" tool, in practice I wouldn't be without it. Both are worthy of bench positions, or, more accurately, worthy of hand baggage inclusion for field work - in fact I have three ADs for exactly this reason!

And that is my use case for the DHO900, as a field scope. At the moment it's either an AD or an MSO1000Z.

The LA on the DHO900 as it currently stands is almost useless. It's difficult to know where to even start, but not even the threshold values can be relied on.

if rigol puts a lot of effort into the LA (which they have not done in the past).

If they don't put effort into the LA, sadly I can see a lot of units being returned.

[Howardlong]

You mean limitations on the digital decoding due to sampling rate limits on those channels? I understand that the digital part can always sample at 625MSa/s in the DHO900, while the analog channels drop down to 156 MSa/s when all channels are used. Having said that, I do remember discussions about other (Rigol?) scopes which required a surprisingly high sampling rate, relative to the signal clock, to do a decent decoding job.

I checked this last night. The maximum sample rate I was able to achieve from the LA was 312.5MSa/s, even when the scope's saying the sample rate is 625MSa/s. I derived this from observed horizontal granularity of 3.2ns.

On the other side of the coin, when the scope was claiming a sample rate of 156.25MSa/s when all channels were turned on, the observed LA horizontal granularity was still 3.2ns.

[Mechatrommer]

Rigol shall publish the necessary information such the broad community of the talented developers may start to fix and develop new stuff.

maybe in your dream. i just emailed them to ask for the newer wfm file format documentation last week, no reply. and iirc last time too on ds1000z/e. they seems to have no interest at all to support independent developers. what you look like they let the FW "open" or hackable... is probably just because their lazy arse or lack of resources to do anything beyond what is just necessary to turn that HW on and working at minimum..

I checked this last night. The maximum sample rate I was able to achieve from the LA was 312.5MSa/s, even when the scope's saying the sample rate is 625MSa/s. I derived this from observed horizontal granularity of 3.2ns.

so thats still good for 100MHz analog, and probably 20Mbps digital. lack of specification description is common trait of cheapo manufacturers, but Rigol is still the best among them at providing decent capability scope i would say on par with other expensive brand's low end product.

[Fungus]

But we could argue DHO800 should be OK.
OTOH DHO900 is not... You cannot have 200MHz scope with less than 500MSp/s and even that is on the limit..

Do you mean buying the DHO924S model is not a good idea?! DHO914S will be a better choice if I need an LA option?

If you need LA then MSO5000 is probably a better option. It has far more memory, bandwidth, screen area, etc., then the 924 and costs about the same.

[Fungus]

On the DS1000Z, ISTR you pushed the horizontal timebase to toggle zoom.

Look in "Setup", there's an option to enable that.

[Howardlong]

I checked this last night. The maximum sample rate I was able to achieve from the LA was 312.5MSa/s, even when the scope's saying the sample rate is 625MSa/s. I derived this from observed horizontal granularity of 3.2ns.

so thats still good for 100MHz analog, and probably 20Mbps digital. lack of specification description is common trait of cheapo manufacturers, but Rigol is still the best among them at providing decent capability scope i would say on par with other expensive brand's low end product.

The devil is always in the detail! It's the same, if not worse, with things like microcontroller low power specs.

Depending on what you're probing, I'd say 312MSa/s is useful for a lot faster than 20Mbps, over 100Mbps SPI at a push. if only the SPI decoder worked with the LA ;-)

[Howardlong]

But we could argue DHO800 should be OK.
OTOH DHO900 is not... You cannot have 200MHz scope with less than 500MSp/s and even that is on the limit..

Do you mean buying the DHO924S model is not a good idea?! DHO914S will be a better choice if I need an LA option?

If you need LA then MSO5000 is probably a better option. It has far more memory, bandwidth, screen area, etc., then the 924 and costs about the same.

I note that there's still an LA trigger offset display problem on the DHO900, although it's about 350ps rather than the 1ns of the MSO5000.

I quite like the MSO5000, especially having almost all the controls as physical knobs and buttons. Unfortunately mine has just blown its third ISL8203M voltage regulator!

[Fungus]

DHO800 has it at higher (almost 180 MHz) and is also 12 Bit meaning it will alias on signal levels you would not have to worry with 8 bt scope...

So... just like many other oscilloscopes.

eg. Siglent SDS1204X-E has it at 230MHz and a 1GHz sample rate with all channels on.

[Fungus]

Depending on what you're probing, I'd say 312MSa/s is useful for a lot faster than 20Mbps, over 100Mbps SPI at a push. if only the SPI decoder worked with the LA ;-)

You can do SPI on the analog channels until they fix it (and also see the signal integrity).

I always thought the digital inputs were for wider buses than SPI.

[nctnico]

obviously DHO800/900S is not the right tool for you. you are asking too much. you need to step up to > $5K scope range.
(ps: why this kind of basic discussion has to happen sooo many times? )

I don't know ? Maybe if people would not repeat wrong statements all the time that need to be corrected.

Again:

For DHO800 i would accept it is OK. It is not that critcal

But DHO900 : 3 or 4 channels enabled  and digital on : 156.25MSa/s     / 1Mpts memory

On a scope that has 200 MHz BW on inputs feeding the ADC...

Again: With 4 channels enabled on 200 MHz DHO900 you cannot satisfy Nyquist at any timebase or memory setting. If you enable digital, you have sampling enough for a 50Mhz scope...

AFAIK this is not the only scope out there that has such a 'limitation'. It just takes more care from the user. It would be good if the bandwidth is limited automatically or that you can at least set the bandwidth limit.

On my GW Instek 2000E series there is a hack which allows to enable an unofficial 300MHz bandwidth option. However, the samplerate with 3 or 4 channels enabled is not high enough. So in that case the 200MHz bandwidth limit (which comes with the 300MHz option) needs to be set. Sometimes it is nice to have the extra bandwidth for 1 or 2 channels though.

The way Rigol has 'implemented it' ('left it hanging' is a better description) on the DHO900 series is very rough around the edges and you can argue it is not ideal for a beginner to use.

[Fungus]

But DHO900 : 3 or 4 channels enabled  and digital on : 156.25MSa/s     / 1Mpts memory

What is it when you don't turn on that many analog channels?   

AFAIK this is not the only scope out there that has such a 'limitation'. It just takes more care from the user.

Yep. You don't have to turn on everything all the time.

It's like a Swiss Army knife: You don't open all the blades every time you use it, you only open the one you need.

[iMo]

Rigol shall publish the necessary information such the broad community of the talented developers may start to fix and develop new stuff.

maybe in your dream. i just emailed them to ask for the newer wfm file format documentation last week, no reply. and iirc last time too on ds1000z/e. they seems to have no interest at all to support independent developers. what you look like they let the FW "open" or hackable... is probably just because their lazy arse or lack of resources to do anything beyond what is just necessary to turn that HW on and working at minimum..
..

Perhaps the Rigol's CEO reads this thread and takes the action.. 

[Fungus]

Perhaps the Rigol's CEO reads this thread and takes the action.. 

I don't think he's going to sit through this but I started a "requests" thread last week.

I know there's not much chance, but... just in case. 

[iMo]

Perhaps the Rigol's CEO reads this thread and takes the action.. 

I don't think he's going to sit through this but I started a "requests" thread last week.

I know there's not much chance, but... just in case. 

My quick linkedin search shows two managers who would certainly be happy to have a look at this thread (as well as the other threads related to their DHO800/900 series):


Mr. Rico Wang
President at RIGOL Technologies

Mr. Victor Cheng
Chief Strategy Officer at RIGOL Technologies

[Fungus]

I don't know why they aren't already watching.

How hard can it be to get an employee to read a forum for an hour a day and report on bugs as they're found?

[2N3055]

But DHO900 : 3 or 4 channels enabled  and digital on : 156.25MSa/s     / 1Mpts memory

What is it when you don't turn on that many analog channels?   

AFAIK this is not the only scope out there that has such a 'limitation'. It just takes more care from the user.

Yep. You don't have to turn on everything all the time.

It's like a Swiss Army knife: You don't open all the blades every time you use it, you only open the one you need.

You either have trouble with comprehension or you are deliberately trolling here..

There is no scope (including ones from Rigol) that say it is 200 MHz scope and will drop sampling below Nyquist, not mention well below BW frequency....
 
Solution is to call it 70 MHz scope and say it has 100/200 MHz limited mode... And limit BW when it breaks basic sampling theorem..

And Nico's GW Instek was never released that way, it was after unofficial hack. GW Instek was honest there.

What is wrong with you? DHO900 is a bad design. Why don't you want Rigol to fix it? Why do you want that your fellow Rigol users to buy badly designed scope... You're not helping Rigol.. 

[Howardlong]

Depending on what you're probing, I'd say 312MSa/s is useful for a lot faster than 20Mbps, over 100Mbps SPI at a push. if only the SPI decoder worked with the LA ;-)

You can do SPI on the analog channels until they fix it (and also see the signal integrity).

I always thought the digital inputs were for wider buses than SPI.

I'm a mixed signal dude.

I can easily burn up 16 digital channels during a debug session: as well as multiple serial streams, I use multiple GPIOs to debug performance pinch points and monitor software state such as ISR entry and exit. As well as GPIOs, burning up one or two SPI and a couple of UART channels purposed as debugging instrumentation channels to quickly bang out 8, 16 or 32 bit status isn't uncommon because they're both cheap and unobtrusive in performance terms to implement.

The examples below are parts of the guts of a single chip microcontroller based USB PD BMC implementation I'd been working on that I have to hand. As well s software states, multiple interim hardware states are brought out to GPIOs. The BMC signal also requires signal conditioning, so I need the analogue channels too. Unfortunately, much as I like the AD, its Waveforms software doesn't automatically align the LA and analogue channels without some operator jiggery pokery.

[Fungus]

There is no scope (including ones from Rigol) that say it is 200 MHz scope and will drop sampling below Nyquist, not mention well below BW frequency....

I never said there was.

Your memory is like a fish: I've said many, many, many, many, many times in this thread that the DHO924 ought to turn on the 125Mhz limiter (which it already has internally) when there's more than 2 channels enabled.

[2N3055]

There is no scope (including ones from Rigol) that say it is 200 MHz scope and will drop sampling below Nyquist, not mention well below BW frequency....

I never said there was.

Your memory is like a fish: I've said many, many, many, many, many times in this thread that the DHO924 ought to turn on the 125Mhz limiter (which it already has internally) when there's more than 2 channels enabled.

Really ?? You did, right.. But not here... That is my point..
Here, you repeated that same argument again and again, ignoring your own statements..
If lie didn't fly first time, keep repeating it. People might start to believe it..

It is not you manipulating information all the time.. And being insulting, when you have no real information and you want to prove me wrong even when I'm telling the truth...

No, I have bad memory... Which is insulting as heck, because it implies I have a medical condition and you are making fun of it...
Good for you...

Jeez...

[asmi]

For the avoidance of doubt, for PC based LAs I use both the Analog Discovery and the Digital Discovery extensively: while the AD in particular is often deemed a "hobbyist" tool, in practice I wouldn't be without it. Both are worthy of bench positions, or, more accurately, worthy of hand baggage inclusion for field work - in fact I have three ADs for exactly this reason!

That explains a lot. Take a look at DSLogic U3Pro https://www.dreamsourcelab.com/product/dslogic-series/ This is a good example of what modern PC-based LA can do. And that is only using USB3 5Gbps, so with 10 Gbps you can double all numbers.

[2N3055]

For the avoidance of doubt, for PC based LAs I use both the Analog Discovery and the Digital Discovery extensively: while the AD in particular is often deemed a "hobbyist" tool, in practice I wouldn't be without it. Both are worthy of bench positions, or, more accurately, worthy of hand baggage inclusion for field work - in fact I have three ADs for exactly this reason!

That explains a lot. Take a look at DSLogic U3Pro https://www.dreamsourcelab.com/product/dslogic-series/ This is a good example of what modern PC-based LA can do. And that is only using USB3 5Gbps, so with 10 Gbps you can double all numbers.

Do you have it? I was looking at it some time ago.... That one actually have some triggering that seem usable...

[asmi]

Do you have it? I was looking at it some time ago.... That one actually have some triggering that seem usable...

Not (yet) as I'm in a bit of a temporary financial limbo atm so I don't spend money unless I absolutely have to, but I have heard very good things about it, including from people I personally trust. So hopefully in a few weeks once my contract situation gets resolved, I will buy one.

[2N3055]

Do you have it? I was looking at it some time ago.... That one actually have some triggering that seem usable...

Not (yet) as I'm in a bit of a temporary financial limbo atm so I don't spend money unless I absolutely have to, but I have heard very good things about it, including from people I personally trust. So hopefully in a few weeks once my contract situation gets resolved, I will buy one.

Excellent, looking forward to some impressions...
And good luck sorting things out!!