Rigol DHO914S Bode plot

[2N3055]

Instrument vendors do actually fix things after release. Not maybe taking every customer wish, but if they find that instrument is not performing properly they fix it. Keysight does it. R&S does it (they sometimes take time but they fix). Siglent fixes things too, actually better than them sometimes.

The monetary relationships between KS, R&S and their customers are of a very different scale. Similar to the service life of the equipment. The fact that Rigol, Siglent, etc. are also providing the fixes is actually a matter of good will. Perhaps it's more profitable to keep releasing new cheap toys frequently making many users happy to play with them. But I think it'll be not fair to assume that the vendors are intentionally evil. Although they may have a more important, actually not commercial customer, the capabilities can also be a factor. The software consumes the majority of man-hours, not the hardware. If you check the Rigol internet site, you can read that in 2024 a new SW development center is set up somewhere in center China, at the former silk road. That probably means that currently the SW development capability of Rigol is not great, while it's now too expensive to continue to order the development from outside than do that work in-house. Let's wait...

I would prefer if you would exclude Siglent in rationalizing why Rigol thinks it is OK to release alpha level products and never fix them. Because Siglent definitelly tries to not do that, and invests significant effort in that.
And talking about cheap toys, Rigol DHO4000 is definitely "Big Boys" price and not an entry level instrument either.
And that on also receives no update form many bugs reported on whole platform, after being released 2 years ago.
I also know that Rigol is investing serious money into developing new products and chipsets etc.
It is their DECISION to deliberately skimp on FW development....
It is their strategy.
As long as users keep buying "half cooked" products and keep "defending" "poor Rigol" for it, they will happily do nothing to increase quality of FW development. That is what "capitalist West" thought them ooh so well..

[Fungus]

I don't get how a company can invest tens/hundreds of millions in bringing a device to market (surely what it costs in making ASICs, software development, etc.) but can't afford a couple of weeks of bug fixes after users start to find them.

Makes no sense.

Rigol is still fiddling with the DHO800 licensing and doing other things in their firmware.

Most of the bugs are minor things so what gives?

Maybe they have stats on how many 'scopes will come back under warranty as "bricked" with every release.

[Martin72]

As long as users keep buying "half cooked" products and keep "defending" "poor Rigol" for it, they will happily do nothing to increase quality of FW development. That is what "capitalist West" thought them ooh so well..

I don't know if rigol still sells many DHOs to people who don't care if and how their device works.
They came onto the market with the 800/900 as very entry 12 bit scopes a while before siglent, so the models sold well at first.
Now the owners can only hope that rigol will change its mind.

[Njk]

I would prefer if you would exclude Siglent in rationalizing why Rigol thinks it is OK to release alpha level products and never fix them. Because Siglent definitelly tries to not do that, and invests significant effort in that.
And talking about cheap toys, Rigol DHO4000 is definitely "Big Boys" price and not an entry level instrument either.
And that on also receives no update form many bugs reported on whole platform, after being released 2 years ago.
I also know that Rigol is investing serious money into developing new products and chipsets etc.
It is their DECISION to deliberately skimp on FW development....
It is their strategy.
As long as users keep buying "half cooked" products and keep "defending" "poor Rigol" for it, they will happily do nothing to increase quality of FW development. That is what "capitalist West" thought them ooh so well..

If you think that everything is fine with Siglent, I've no objections because of no experience. But the facts are:
- they're of the same origin (a communist country, BTW),
- their products are of the same price category,
- they're competing on the same market.
Because of that, I'm not sure their similar products can be as different as day and night. Although Siglent operates a more dealer-friendly policy and that naturally results in more talks about their products on the internet.

Concerning Rigol, the latest crop of products (DHO800/900, DG800/900 Pro, DM858) belongs to the entry-level category (hence cheap toys). Looks like they'd patented a new type of plastic enclosure and the main goal of the release is to get a feedback about that innovation from the market. For that goal, the SW quality does not make a big difference. Some products, e.g. the DGs seems even more undercooked than that of the pervious generation, and Rigol is not in rush to update the SW.
On the other hand, the latest public firmwares for the upscale series (DS7000/8000) are dated 2024 (or late 2023), which is a quite recent date. Notice that there are many series but few hardware ("chipset") generations. Latest upscale models are based on the Ultravision 2 hardware. I don't think there is a significant SW difference between the series that uses the same HW. It's basically a platform code. The fact that there are no upscale series based on the low-noise Ultravison 3 HW suggests that the code is not yet mature enough. So they're releasing an entry-level scopes with the SW as is, making money to fund the development efforts (it definitely can take a time because of complexity of the matter). Note that at the same time, they also have to continue providing maintenance to the Ultravision 2 code.

BTW I was wrong saying that they'd established a new SW development center. Looks like it's just another Rigol facility, not dedicated to SW. Anyway, I'm not defending or blaming them for more and more half-baked products. But sometimes, commenting on what Rigol is doing is like to comment the erratic movements of a drunk man.

[Martin72]

- they're of the same origin (a communist country, BTW),

 
Oh, that must be new, otherwise countless brand manufacturers wouldn't be producing there.
And I thought the McCarthy era had been over for decades.

[Njk]

- they're of the same origin (a communist country, BTW),

Oh, that must be new, otherwise countless brand manufacturers wouldn't be producing there.
And I thought the McCarthy era had been over for decades.

When you work for a brand, you're not free to do whatever you want. But when you're unleashed...

Yes, McCarthy era. Looks like we still have a huge crowds of funboys.

[KungFuJosh]

I'm pretty sure politics aren't supposed to be discussed here. 🤷

[2N3055]

If you think that everything is fine with Siglent, I've no objections because of no experience. But the facts are:

Contradiction in terms....
If you have no relevant informations, all you have is irrelevant facts and misguided generalizations based on "they all come from same XYZ country so they will all be the same..". I find that to be orders of magnitude too simplistic to be relevant.

I don't say everything is perfect with Siglent. Nothing is perfect. But, and pay attention here, they have proven by it's work that they take it much more seriously and professionally. In some occasions Siglent is better than some very famous brands in that regard.... While Rigol is demonstrably worse.

[NullSense]

I couldn't pass up the black Friday deal for the DHO804, I am waiting on a delivery right now. Been browsing the forum regarding hacks, fw updates and etc.
I am interested in using FFT extensively and sometimes bode plots.

I see this thread hasn't been updated in a while, does anyone have info on these features at the current moment? This is my first scope, so I am not aware of all the minor details and gotchas yet. Anyways, even if half broken, are there any caveats to working with these modes on the DHO804?

EDIT: https://www.eevblog.com/forum/testgear/rigols-new-dho800-oscilloscope-unbox-teardown/msg5543385/#msg5543385 I see here this user's saying you actually need a signal generator and this video running bode plots on 804 however it seems you need to modify hardware?

[ebastler]

I couldn't pass up the black Friday deal for the DHO804, I am waiting on a delivery right now. Been browsing the forum regarding hacks, fw updates and etc.
I am interested in using FFT extensively and sometimes bode plots.

I see this thread hasn't been updated in a while, does anyone have info on these features at the current moment? This is my first scope, so I am not aware of all the minor details and gotchas yet. Anyways, even if half broken, are there any caveats to working with these modes on the DHO804?

The current firmware brings no changes to FFT functionality. Also, there are no automated Bode plots at all in the DHO804. (Note that the present thread discusses the DHO914S, i.e. a model variant with a built-in signal generator which does support Bode plots.)

[NullSense]

Thanks for the reply  . Regarding FFT and bode plotting outside your device, are there any solutions I can find on Github or some de facto software that's used? Ideally something over the network to not have to dump .csvs to usb etc etc. I saw mentions of Samba and FTP possibility? Or even just using adb? What would you guys suggest?

[Fungus]

The FTP port is open, just use it. I use WinSCP to access it.

Samba is new in 1.04, I didn't get it working yet (not that I tried very hard).

[TheoB]

If you want a bode plot, you need extra hardware. I have a LiteVNA for that (or NanoVNA). This little device is a bargain and outperforms the Rigol in any way for frequencies above 10kHz. For FFT up to 100MHz the Rigol is fine. But above that a TinySA (Ultra) is better. Lower noise floor and much higher frequency. Do note that these devices are 50 Ohm based. This means very high impedances can be measured but become inaccurate. For LF/audio cases I use a simple LF generator and manual measure the response.

[NullSense]

Regarding native FFT, are there any things to keep in mind or settings I should use to get the most out of this machine while using FFT? I keep reading a bunch of different "recipes" on youtube and on EEVblog on how to get the most out of it, which is self-contradicting often and confusing.

[iMo]

Thanks for the reply  . Regarding FFT and bode plotting outside your device, are there any solutions I can find on Github or some de facto software that's used? Ideally something over the network to not have to dump .csvs to usb etc etc. I saw mentions of Samba and FTP possibility? Or even just using adb? What would you guys suggest?

A solution would be to have an app running in the 804, sending a request to a waveform generator on the network (like "do set XX KHz, YYY mVpp sine), then the 804 will measure the actual amplitude, save the data into a .csv, making nice graphs, and so on.. Perhaps the hw syncing would be needed in order to get the phase properly. But doable, imho..

PS: or to have a DIY generator hanging on the 804's USB port (like a DDS sine chip like the notorious 9850/51 module, or any of its friends, interfaced via an arduino/rpi/whatever, as the simplest Sunday afternoon hw solution.. not talking sw, of course, such an app should be created by the talented android people here )..

PPS: in order to see the "amplitude vs frequency graph only" no special syncing would be required.. Just a plain freq sweep..
Also for "audio only" you may generate the sine via the arduino and a cheapo DAC..
And, you may add an RF mixer->filter and create a Spectrum Analyzer till XX GHz ..

What is the priority is to get the 804 talk with the arduino/rpi/whatever via the USB on its front panel first, and then..

[gf]

A solution would be to have an app running in the 804...
...
Perhaps the hw syncing would be needed in order to get the phase properly.

Not if you measure two channels simultaneously (input and output voltage of the DUT) and calculate the (complex) quotient Vout(f) / Vin(f), for each frequency f.

I just wonder, is there a fast way for an app to access the samples of the captured traces (w/o saving to a file and re-loading from the file)?

[Fungus]

I just wonder, is there a fast way for an app to access the samples of the captured traces (w/o saving to a file and re-loading from the file)?

Sure, just download the data directly via SCPI.

I assume an APP running on the 'scope can do that, too.

A Bode plot app running on a DHO804 and controlling an external Signal Generator would be a neat hack, and seems perfectly doable. There's already an improved FFT app out there.

[TimFox]

A comment from the originator of this thread:
My current belief is that the problem with the DHO914S Bode plot function is that it does not allow anywhere near enough time for the magnitude and phase measurements to settle after changing frequency (in steps).
As can be seen in my posts from October 2023 and later, when I stepped the frequency manually I had to wait for the measured data to settle and it was a very slow process.
Even with that, there were some quantitative errors in the result, measuring a simple and calibrated R-C filter in the vicinity of 10 kHz.
See my "Reply 32" way back then.

[iMo]

A solution would be to have an app running in the 804...
...
Perhaps the hw syncing would be needed in order to get the phase properly.

Not if you measure two channels simultaneously (input and output voltage of the DUT) and calculate the (complex) quotient Vout(f) / Vin(f), for each frequency f.

I just wonder, is there a fast way for an app to access the samples of the captured traces (w/o saving to a file and re-loading from the file)?

What would help immediately a bit is to create a ramdisk (in the android) and force/redirect (how??) the system to write the .csv files there. To process say 20-40 files (the "20-40 freq points") for a typical bode made over 3-4 freq decades cannot be such a problem then, imho..

PS: we should leave this thread with this as it is not directly related to the 914S issue..

[Fungus]

What would help immediately a bit is to create a ramdisk (in the android) and force/redirect (how??) the system to write the .csv files there

Why would you want to convert to ASCII and parse it back again if "speed" is an issue?

Just read binary data with ":WAV::DATA?"

[iMo]

Because we want to process everything in android. No scipi transfers.
Just a click on an icon, entering in "from-to" and after a while you will see the bode graph and get bode.csv.
Basically the same mrisco does with his "new FFT" in his UI.

[Fungus]

PS: we should leave this thread with this as it is not directly related to the 914S issue..

It is if it uses the DHO914S internal signal generator and ends up better than the official Bode plot.

[Fungus]

Because we want to process everything in android. No scipi transfers.

You're going to have to use SCPI to tell it to write CSV files.

And to control the built-in signal generator.

[iMo]

That will be all done by the userspace apps inside android. The only communication outside 804 will be via the front panel USB to/from a small black box - the black box could be anything you would setup during the Sunday's afternoon
There is none built-in generator in 804, therefore the black box with myGenerator.

PS: we cannot help with 9xxS as we do not have access to the stuff (to the internal generator, or do you have the driver sources?). Therefore we should leave this thread with the "myBode" idea and let us start a new thread like "DHO800 myBode"..

[Fungus]

PS: we cannot help with 9xxS as we do not have access to the stuff (to the internal generator, or do you have the driver sources?)

Hint: Use SCPI.

See section 3.25 of this: https://www.batterfly.com/PDF/RIGOL/dho800/DHO800-Series_programmingguide_EN.pdf