Rigol DHO800/900 Oscilloscope Bug Reports + Firmware

[ebastler]

Here pics from 10Mhz, 25Mhz, 100Mhz.
Try this with other scope I have here.

Thanks. I'd say that looks like a constant ~2.5 ns p-p, or 3 sampling intervals. If my theory that it's based on a digital FIR filter is correct, I would expect the spread to become twice as large when a second channel gets activated. Didn't think of trying this on my DHO1000 before I hid it away again. (Don't tell Santa Claus that I had unpacked it...  )

[Serg65536]

I've tested FW 1.02 on my DHO804 with original vendor.bin and activated options:
- "ADC Gain" self calibration option  is enabled by default in FW 1.02
- calibration process fails with "ADC Gain" self calibration option turned on with the native vendor.bin
- oscilloscope could be calibrated successfully and with maximum precision (zero and voltage accuracy), but "ADC Gain" self calibration option should be disabled

Also I've tested FW 1.02 with DHO924 vendor.bin:
- oscilloscope could be calibrated successfully with good zero precision and perfect voltage accuracy, but "ADC Gain" self calibration option should be ENABLED (you can use default calibration options)
- "AFE zero" self calibration option spoils calibration results, but the initial state could be restored by pushing original cal files to the scope

[Fungus]

I found this on the DHO1000 and wonder whether the DHO800 behaves the same:

Couldn't wait until Xmas?

My DHO800 does it.

[Martin72]

(Don't tell Santa Claus that I had unpacked it...  )

You can have the box given to you as a present...

Rigol DS1054Z, Siglent 1104X-E : Both are having no problems with it when setting to AC or LFR.
So it is systemic.

[Fungus]

Thanks. I'd say that looks like a constant ~2.5 ns p-p, or 3 sampling intervals. If my theory that it's based on a digital FIR filter is correct, I would expect the spread to become twice as large when a second channel gets activated.

Yes, it does.

And with three channels it's three times as wide.

[ebastler]

Thanks. I'd say that looks like a constant ~2.5 ns p-p, or 3 sampling intervals. If my theory that it's based on a digital FIR filter is correct, I would expect the spread to become twice as large when a second channel gets activated.

Yes, it does.

And with three channels it's three times as wide.

Thanks for checking! I would expect the jitter to be even four times as wide whith three (or four) channels active, in proportion to the reduced sampling rate. Is that what you see?

[ebastler]

(Don't tell Santa Claus that I had unpacked it...  )

You can have the box given to you as a present...

Rigol DS1054Z, Siglent 1104X-E : Both are having no problems with it when setting to AC or LFR.
So it is systemic.

Sigh... Found the first little disappointment before I even took proper possession of the scope. 

Not a setting I expect to use often, but still -- they might as well have implemented this properly. I hope one does not get the same effect with an AC-coupled signal, or a math channel that uses high-pass filtering, right?

[Fungus]

Thanks for checking! I would expect the jitter to be even four times as wide whith three (or four) channels active, in proportion to the reduced sampling rate. Is that what you see?

Looks like 3 to me:


(count the divisions on the horizontal axis)

[Martin72]

I hope one does not get the same effect with an AC-coupled signal, or a math channel that uses high-pass filtering, right?

Just tested it, AC-coupling makes no problems...

[ebastler]

I hope one does not get the same effect with an AC-coupled signal, or a math channel that uses high-pass filtering, right?

Just tested it, AC-coupling makes no problems...

 

[Fungus]

I hope one does not get the same effect with an AC-coupled signal, or a math channel that uses high-pass filtering, right?

Nope.

[ebastler]

Thanks for checking! I would expect the jitter to be even four times as wide whith three (or four) channels active, in proportion to the reduced sampling rate. Is that what you see?

Looks like 3 to me:
(count the divisions on the horizontal axis)

Right. Actually more than 2.5 ns in single-channel mode, about 5 ns dual-channel, 7.5 or so for three channels and a bit more for four.
There goes my time-discrete filter theory...

[Fungus]

No surprises there... I'm sure somebody would have noticed that one before now.

[rpro]

I've tested FW 1.02 on my DHO804 with original vendor.bin and activated options:
- "ADC Gain" self calibration option  is enabled by default in FW 1.02
- calibration process fails with "ADC Gain" self calibration option turned on with the native vendor.bin

After the default self-calibration failed for me on my DHO804 on the first try, I ran it again (without any settings or file changes) and it worked. (Maybe an exceeded iteration counter was restarted from the last state, or some random reinitialization worked on the second try. I don't know, but it worked...) As found before, the scope retains the "100MHz" and 50M memory enhancements.

Exchanging the vendor.bin file with the 924 version works well without any additional recalibration. No offsets. Hence the vendor.bin files can be switched back and forth in seconds, to increase the BW (to 1.27 ns RT) with the additional decoders and /div features (with better than 24uV/50-Ohm AC-RMS noise floor) as needed, without having to recalibrate...Nice.

[Fungus]

If calibration works using a DHO900 vendor.bin with the new firmware then I'd be interested to know the measured bandwidth of a "125MHz" DHO914.

It would be good if it was near 200Mhz, that way we could have better Nyquist ratios than the DHO924 and the missing 2ns/div horizontal scale on our DHO800s.

Does anybody have a DHO914's vendor.bin to play with?

[JDW]

I've tested FW 1.02...

Ditto my previous post#142 where I say that Firmware version 1.02 does NOT exist, as evidenced by its absence even on Rigol's Chinese language firmware download page for the DHO800 series.

So if indeed you folks citing "1.02" are not in error, please cite the download location for that otherwise undiscoverable firmware version.

Thank you.

[Fungus]

I say that Firmware version 1.02 does NOT exist

Yes it DOES, I've got it. 

It's in the "unbox and teardown" thread... posted on November 22nd.

Unfortunately it seems to have been removed since then.

[JDW]

It's in the "unbox and teardown" thread... posted on November 22nd.
Unfortunately it seems to have been removed since then.

As per your statement above in red, as far as those of us who do not have v1.02 are concerned, it technically does not exist.  Once posted back online for all to download, then we who do not have it can truly say it exists.   

I still don't understand why Rigol isn't publicly posting v1.02 if it is official and good/safe to use.  Or was it created outside Rigol and therefore a questionable update (even if it seems to work fine)?  Or perhaps you don't know who created v1.02.

Anyway, I think these are important and valid questions in light of the title of this thread being focused on FIRMWARE. Some people are testing v1.02, but since it is no longer available for download, that restricts the number of people who are using it to just a few.  Everyone else is stuck with v1.01.

[mwb1100]

I still don't understand why Rigol isn't publicly posting v1.02 if it is official and good/safe to use.

Rigol's firmware release management seems to be haphazard to put it nicely.

[ebastler]

[...]
- "ADC Gain" self calibration option  is enabled by default in FW 1.02
- "ADC Gain" self calibration option should be disabled
[...]
- "AFE zero" self calibration option spoils calibration results, but the initial state could be restored by pushing original cal files to the scope

Are all these checkboxes standard in the DHO 800/900 self-calibration dialog, or do you have to activate some expert/debug mode beforehand? My DHO1000 does not display any options in that dialog, just the "disconnect everything" message.

EDIT: Could you move or copy your post to the Hacking thread?
I think that's the better place, easier to find there for future reference.

EDIT²: Ah, found it. There is indeed a debug mode:

Found a hidden debug mode in the utility menu that can be enabled if you tap the About button several times. This unlocks more options in the Other and the SelfCal tabs and a new Debug tab. Not sure if it has other effects.

[akkk44]

The test signal was provided by a TinySA Ultra.
In the video, I set the simple edge trigger.
The frequency can be seen on the side, as well as the value of Vpp.
and in the pictures you can see it at 4 frequencies.
At 125Mhz and 250Mhz, you can see that the bad triggering zone is larger, that is, the value of deltaY compared to the total Vpp.
I can't reproduce this phenomenon as strongly on another scope.

I have consulted Rigol tech support and here is their reply:

"No, this is not intended behavior."

“We have recently discovered this phenomenon and have watched your video above and it is currently being verified and determined by a dedicated person.”

“We usually have initial conclusions in one to two weeks, and then we will work out a program and plan the timing.”

Sounds hopeful at least.

[ebastler]

I have consulted Rigol tech support and here is their reply:

Do you have a direct contact there, or did you go via the regular support hotline or email?

In either case it looks like a more direct line into the company than going through the European or North American branches. So maybe you could alert them of a few other problems as well -- like the jitter observed with AC and LFR trigger coupling, discussed above? Thanks!

[akkk44]

I have consulted Rigol tech support and here is their reply:

Do you have a direct contact there, or did you go via the regular support hotline or email?

In either case it looks like a more direct line into the company than going through the European or North American branches. So maybe you could alert them of a few other problems as well -- like the jitter observed with AC and LFR trigger coupling, discussed above? Thanks!

I contacted them on their Chinese official website. I will bring that up next time I contact them.

Edit: I tried AC and LFR triggering on my 804(F/W 01.02) from 50Mhz to 120Mhz and did not see the issue. Did I miss something? Video here:
https://youtu.be/ALNmIgmWvGQ

[ebastler]

Edit: I tried AC and LFR triggering on my 804(F/W 01.02) from 50Mhz to 120Mhz and did not see the issue. Did I miss something? Video here:
https://youtu.be/ALNmIgmWvGQ

Hmm, that's intriguing. Could it be that FW 01.02 has fixed this, or maybe (less likely) the upgrade to DHO9xx?

@Martin72, @Fungus -- which firmware version were you running when you confirmed the trigger jitter?

[Fungus]

@Martin72, @Fungus -- which firmware version were you running when you confirmed the trigger jitter?

1.01

There was nothing in the 1.02 release notes that seemed interesting to me.

If anybody desperately wants 1.02 firmware I can send a copy.

I'm more interested in a DHO914 vendor.bin right now.

(Maybe I'll have to synthesize my own but I don't have much free time at the moment)