EEVblog #683 - Rigol DS1000Z & DS2000 Oscilloscope Jitter Problems

[EE-digger]

On an MSO1104Z, I saw serious jitter on a 100MHz, clean sine wave.  It seemed to happen after having all 4 channels active and then turning off the other 3.

Nothing would make the jitter go away until I pressed AUTO.  After AUTO was done, I had to turn off channels 1-3 since my sine was on 4.  Now the jitter was gone.

Along with this, I discovered that the frequency counter is BROKEN.  Again, with a clean sine (57.000MHz, 90.000MHz), the frequency will read high or low, by a huge error, as you adjust the trigger level, all the while the sine remained cleanly triggered.

The frequency appears to be correct only when your trigger line is close to the zero crossing of the waveform.

Den

[olewales]

My results attached.

DS1054Z
SW: 00.04.01.SP2
Board: 0.1.1
Date of calibration (on cal certificate): 04-Sep-2014

Let me say that I don't consider this that big of an issue. Good indication of this is that nobody have noticed any of this for a long time. That's especially true for AC trigger issue which seems to also be present on DS2000 series. For me its just another bug that I need to be aware of as a user. Maybe it would be a good idea to start a thread with list of known bugs in DS1000z series. I could contribute to that (rise/fall time rate measurements broken)

[leppie]

My results attached.

DS1054Z
SW: 00.04.01.SP2
Board: 0.1.1
Date of calibration (on cal certificate): 04-Sep-2014

Let me say that I don't consider this that big of an issue. Good indication of this is that nobody have noticed any of this for a long time. That's especially true for AC trigger issue which seems to also be present on DS2000 series. For me its just another bug that I need to be aware of as a user. Maybe it would be a good idea to start a thread with list of known bugs in DS1000z series. I could contribute to that (rise/fall time rate measurements broken)

It seems there are 2 flavours of the jitter issue. Yours is not so bad (I could live with it) but mine is seriously bad, like some others have.

[EE-digger]

When I had the jitter, no scope setting would make it go away.  Reminds me of Windows, when all "accessible" parameters are correct but it doesn't do something correctly.

Maybe a registry problem

[Muttley Snickers]

Wow, a newly found feature on the Rigol 1000z series.

Bonus Epileptic Fit Generator.   

Muttley

[mikeselectricstuff]

Would be interesting to compare results with internal vs. external function gen - something like leakage of an internal clock to the analogue trigger circuitry would probably have a different effect depending on whether or not it was synced to the scope's clock.

[SiC]

On my DS1074Z soft-upgraded/unlock to 100MHz and using the internal source (set at 20MHz), I don't see the 5uS jitter issue at all. However the AC coupling jitter problem is clear as day. 500nS hold-off on AC coupling produces some weird effects too.

Software revision 00.04.00.
Serial number DS1ZB16115xxxx.

[xnaron]

 Fingers crossed it can be fixed in firmware.

[XFDDesign]

MSO4054 at various delays and beyond, sorry for the ultra crappy webcam footage.  (firmware = 2.02.SP1, hardware version = 1.3)

20Mhz, square, 5Vpp, AC/DC coupling has no effect.

Balls. Even the 4000 series has the issue. I've been wanting to get one.

[leppie]

MSO4054 at various delays and beyond, sorry for the ultra crappy webcam footage.  (firmware = 2.02.SP1, hardware version = 1.3)

20Mhz, square, 5Vpp, AC/DC coupling has no effect.

Balls. Even the 4000 series has the issue. I've been wanting to get one.

Thanks for the comment, I never watched the video, and even 90% thru it I though everything was hunky dory, but holy batshit! that is some wack shit going on there!   

[TMM]

Can confirm my DS1054Z looks exactly like rolycat's with DC triggering, 5us offset.

FW 4.02.SP3
HW 0.1.1

External square wave signal from DG4000, 50ohm termination.

[Döner Hawaii]

Can't confirm the 5µs trigger issue on my MSO1104Z-S.
But the AC trigger jitter is also there. 

Tested by measuring the internal signal generator with one of the probes.
Software Version 00.04.00

Images attached.

[nuno]

I see none of the 2 problems on my DS1104Z-S, using the internal sig gen.
Sw version is 00.04.00
No mention of hw version.

Ok, I correct myself, mine has the AC coupling trigger jitter. I actually interpreted the problem wrongly, thinking it was the input channel coupling having the issue. I admit I had never noticed that there was a trigger coupling mode ...

[leppie]

Can't confirm the issue on my MSO1104Z-S.

Tested by measuring the internal signal generator with one of the probes.
Software Version 00.04.00

Images attached.

What hardware version? If 0.1.1 like the rest of us, perhaps it is merely a firmware bug

[SiC]

Can't confirm the issue on my MSO1104Z-S.

Tested by measuring the internal signal generator with one of the probes.
Software Version 00.04.00

Images attached.

What hardware version? If 0.1.1 like the rest of us, perhaps it is merely a firmware bug

How do you determine the hardware version?

[Döner Hawaii]

What hardware version? If 0.1.1 like the rest of us, perhaps it is merely a firmware bug

Sorry, misunderstood the problem.
I did not realize that the ac coupling jitter appears when the trigger is coupled.

Corrected my reply.

[leppie]

What hardware version? If 0.1.1 like the rest of us, perhaps it is merely a firmware bug

Sorry, misunderstood the problem.
I did not realize that the ac coupling jitter appears when the trigger is coupled.

Corrected my reply.

The AC couple triggering is minor to me. At least you have the DC workaround.

The 5us jitter issue is more of my concern which yours dont seem to show.

[mikeselectricstuff]

What hardware version? If 0.1.1 like the rest of us, perhaps it is merely a firmware bug

Sorry, missunderstood the problem.
I did not realize that the ac coupling jitter appears when the trigger is coupled.

Corrected my reply.

Could it be that it accidentally switches in HF and/or noise reject?


Also, assuming there is an issue with an internal clock influencing trigger level, a few things that may shed some light :
Using an external sig-gen, vary the frequency very slightly by a few Hz - see if there is any phasing type effect. This could be why some people see different results (slight differences in xtal freq), and don't see it from the internal siggen.
Try different waveform risetimes  - do you get more jitter on a triangle compared to a square wave - it may be possible to quantify the amplitude of the noise. Also is it consistent across different vertical scale settings & signal amplitudes?

[EE-digger]

When I set an external Agilent source to 25MHz and 1Hz increment, I can adjust the frequency modulation of the jitter band to nothing.  At a 1Hz step away from "no band", I can watch the wave move left to right with a 1Hz period.

All the while, the right most wave remains stable and unaffected.

This is an MSO1104Z received in the past week, latest firmware.  Trigger is AC coupled.

[Muttley Snickers]

Out of curiosity,

Does anybody know what the going hourly rate is worth for freelance beta testers ?.

If you have already got one of these, then add this to your resume.

Muttley

[TMM]

Square/Sine/Triangle all produce the same amount of jitter for me, the slope of the rising edge doesn't seem to affect it.

Changing the frequency of the signal doesn't alter it either, that's the first thing i tried to rules out the possibility of sampling jitter from my function gen.

Also tried changing from edge triggering to slope to no avail.

[EE-digger]

Also note that the memory depth has a definite impact on the jitter band.

As I manually go from AUTO to full memory, the jitter goes from the smooth band to a sweeping movement, similar to a 1Hz offset I mentioned above.

Acts like an errant index into memory but not on DC .

[leppie]

Out of curiosity,

Does anybody know what the going hourly
rate is worth for freelance beta testers ?.

If you have already got one of these, then add this to your resume.

Muttley

Its OK, I already have this on mine 

Other affiliations:
 
United Federation of Planets (46379.1 - 46831.5)
 
Responsibilities:
 
- Cleaning plasma warp coils
- Assist in dylithium crystal alignment
- Replacement of bio-neural gel packs in the Jefferies tubes
 
Contact person: Jean-Luc Picard

Also note that the memory depth has a definite impact on the jitter band.

As I manually go from AUTO to full memory, the jitter goes from the smooth band to a sweeping movement, similar to a 1Hz offset I mentioned above.

Acts like an errant index into memory but not on DC .

That is why I enabled persistence on my screen caps.

[electronic_eel]

MSO4054 at various delays and beyond, sorry for the ultra crappy webcam footage.  (firmware = 2.02.SP1, hardware version = 1.3)

20Mhz, square, 5Vpp, AC/DC coupling has no effect.

Just tried it with exactly your settings on my MSO4000 and now I see it too. But I think it is a bit less on mine. FW=2.02.SP1, hardware version = 1.3. Seems like I didn't zoom in enough the first time.

[tchicago]

Can't confirm neither of these issues on my DS1104Z purchased this spring. Software version 00.02.03.SP5. Hardware version unknown, it is just not displayed on the sysinfo screen.

No jitter at AC coupling at any offset, and no jitter at DC coupling - tried multiple offsets, 0, 0us, 10us, 15us, fractionals of those.

Attached is a screenshot of 15MHz being fed directly from HP 33120A signal gen, shifted 5us from trigger point. The voltage shown is wrong of course because it is expecting the 10x probe divider instead of direct BNC-BNC cable.

There is other issue with this scope that drives me mad: a very slow response from the vertical offset knob. Does anyone know if there is any software update that would fix this problem?