Author Topic: New Rigol DS1054Z oscilloscope  (Read 1483284 times)

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Offline Fungus

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Re: New Rigol DS1054Z oscilloscope
« Reply #4325 on: September 16, 2018, 11:59:23 am »
Neither should happen in a properly designed oscilloscope.  Rigol screwed up.

Rigol put a 4-channel, $399 oscilloscope with the performance shown on the market three years ago. That's hardly a screw-up.
« Last Edit: September 16, 2018, 12:02:07 pm by Fungus »
 
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Online xrunner

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Re: New Rigol DS1054Z oscilloscope
« Reply #4326 on: September 16, 2018, 12:33:42 pm »
Neither should happen in a properly designed oscilloscope.  Rigol screwed up.

Rigol put a 4-channel, $399 oscilloscope with the performance shown on the market three years ago. That's hardly a screw-up.

Every time someone says things like that I say - What do you want for $399 $349?  :-//

They are $349 now!  :clap:
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Offline realitycomputer

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*Very* weird DS1054z problem
« Reply #4327 on: September 16, 2018, 11:53:53 pm »
Hi all,

I have an extremely strange issue with my DS1054z, whereby it is not displaying any trace at all on any of the 4 channels.
I have started a thread here: https://www.eevblog.com/forum/testgear/ds1054z-no-waveform-on-any-channel/msg1828157/#msg1828157
But then I wondered if I ought to mention it in this 1054z "De Facto" thread!?

 

Offline David Hess

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Re: New Rigol DS1054Z oscilloscope
« Reply #4328 on: September 17, 2018, 10:49:56 am »
Neither should happen in a properly designed oscilloscope.  Rigol screwed up.

Rigol put a 4-channel, $399 oscilloscope with the performance shown on the market three years ago. That's hardly a screw-up.

Every time someone says things like that I say - What do you want for $399 $349?  :-//

I expect this sort of shortcoming to be documented as part of the specifications.  I expect the documentation not to deliberately mislead.  I expect their customer service not to lie when I ask questions.
 

Offline Adrian_Arg.

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Re: *Very* weird DS1054z problem
« Reply #4329 on: September 17, 2018, 01:11:50 pm »
Hi all,

I have an extremely strange issue with my DS1054z, whereby it is not displaying any trace at all on any of the 4 channels.
I have started a thread here: https://www.eevblog.com/forum/testgear/ds1054z-no-waveform-on-any-channel/msg1828157/#msg1828157
But then I wondered if I ought to mention it in this 1054z "De Facto" thread!?

I got in touch with rigol china if it is in warranty, I was delayed almost a month, but they advised me to correct the problem, that if I sent them as 10 mail, they asked for images and videos which I uploaded to youtube. Today more than 5 months of the problem (humidity) I am 100% satisfied with the oscilloscope, for $ s319. I have a very good product.
 

Offline Fungus

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Re: New Rigol DS1054Z oscilloscope
« Reply #4330 on: September 17, 2018, 01:15:43 pm »
I expect this sort of shortcoming to be documented as part of the specifications.

How would they word that, exactly?
 

Offline MrW0lf

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Re: New Rigol DS1054Z oscilloscope
« Reply #4331 on: September 17, 2018, 01:39:12 pm »
I expect this sort of shortcoming to be documented as part of the specifications.

How would they word that, exactly?

From random scope spec:
Quote
Bandwidth* (-3 dB): 250 MHz (200 MHz ±50 mV range)
*Quoted bandwidth is with supplied probes or at BNC when 50 Ω impedance selected.

BTW There is old but very interesting thread about DS1000E:
https://www.eevblog.com/forum/chat/rigol-ds1000e-series-possible-errorfail-in-sin(x)x-interpolation/
Interestingly this one had both linear interpolation and Sinc. Sinc=ON had huge bw drop in relation to linear and did not cross actual data points. Somehow it reminds very much of Sinc=OFF on DS1000Z which still look like Sinc but much suppressed. Did they downgrade old Sinc=ON code to Sinc=OFF :-//

 

Offline Fungus

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Re: New Rigol DS1054Z oscilloscope
« Reply #4332 on: September 17, 2018, 02:15:22 pm »
From random scope spec:
Quote
Bandwidth* (-3 dB): 250 MHz (200 MHz ±50 mV range)
*Quoted bandwidth is with supplied probes or at BNC when 50 Ω impedance selected.

I think D.Hess is referring to this image:



Something about the input amplifier overloading a tiny bit when the DS1054Z clicks down below 500Mv mode and you then fine tune the range up to to 400mV manually (ie. towards the limits of the low-range input amplifier).

And if that is what he's referring to, how would it be worded in a manual so that he wouldn't feel "deliberately mislead"?


« Last Edit: September 17, 2018, 02:24:02 pm by Fungus »
 

Offline David Hess

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Re: New Rigol DS1054Z oscilloscope
« Reply #4333 on: September 18, 2018, 12:37:38 pm »
I expect this sort of shortcoming to be documented as part of the specifications.

How would they word that, exactly?

Tektronix did decades ago when bandwidth commonly decreased at the highest sensitivities; they simply specified the bandwidth where it was different for each range.  Many oscilloscopes had a small drop in bandwidth at their highest vertical sensitivity for the reason I mentioned and it was sometimes considered a feature if there was not.  (1) One of the most extreme examples that I know of is the 11A52 which was unusual for a 600MHz vertical amplifier for having a sensitivity down to 1mV/V:

>=10mV/div   600MHz
5 to 9.95mV/div   400MHz
2 to 4.98mV/div   250MHz
1 to 1.99mV/div   200MHz

I think D.Hess is referring to this image:

Something about the input amplifier overloading a tiny bit when the DS1054Z clicks down below 500Mv mode and you then fine tune the range up to to 400mV manually (ie. towards the limits of the low-range input amplifier).

And if that is what he's referring to, how would it be worded in a manual so that he wouldn't feel "deliberately mislead"?

Some instruments might specify full power bandwidth but I have never seen it applied to an oscilloscope.  (2) Such a limitation is just broken.  If they had specified full power bandwidth, then people would have asked embarrassing questions.  I would not want to advertise such a limitation but I sure would not want to mislead people either.

Note that there are actually two separate problems here.  TurboTom's test results here show a significant change in small signal bandwidth with different vertical sensitivities like some oscilloscopes which I mentioned.  The overload leading to non-linearity I spotted (3) produces a change in full power bandwidth which depends on both frequency and amplitude.  Measuring just bandwidth at high signal levels (5 vertical divisions or greater ) will show contributions from both.

(1) The 7A13 listed constant bandwidth as a feature but it was unusual for having 1mV/div sensitivity at 100MHz at a time when most vertical inputs were limited to 5mV/div or 10mV/div where they often had a slightly lower bandwidth.  My guess is that someone had a similar 1mV/div "100MHz" amplifier which was actually significantly slower; Tektronix might even have been comparing it to one of their earlier vertical amplifiers.

(2) Many analog CRT oscilloscopes actually do specify bandwidth under specific large signal conditions but this is due to non-linearity of the CRT itself.  This is typically about 5 divisions (the same amplitude used for rise and fall time measurement) except for some very old oscilloscopes which did not even have 5 vertical divisions.  This shows up in the low frequency trace compression test used verify proper vertical amplifier operation and CRT geometry.

(3) This is not a transient response problem because it disappears at lower signal levels.
 

Offline alsetalokin4017

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Re: *Very* weird DS1054z problem
« Reply #4334 on: September 18, 2018, 03:26:24 pm »
Hi all,

I have an extremely strange issue with my DS1054z, whereby it is not displaying any trace at all on any of the 4 channels.
I have started a thread here: https://www.eevblog.com/forum/testgear/ds1054z-no-waveform-on-any-channel/msg1828157/#msg1828157
But then I wondered if I ought to mention it in this 1054z "De Facto" thread!?

I got in touch with rigol china if it is in warranty, I was delayed almost a month, but they advised me to correct the problem, that if I sent them as 10 mail, they asked for images and videos which I uploaded to youtube. Today more than 5 months of the problem (humidity) I am 100% satisfied with the oscilloscope, for $ s319. I have a very good product.

I'm having trouble understanding this post.

Does it mean that Adrian_Arg had the same problem with no traces, but everything else working on his DS1054z? Did the problem turn out to be high humidity? Did the cure simply involve opening it up and gently drying with warm air?

The easiest person to fool is yourself. -- Richard Feynman
 

Offline iainwhite

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Re: *Very* weird DS1054z problem
« Reply #4335 on: September 18, 2018, 03:40:29 pm »
I'm having trouble understanding this post.

Does it mean that Adrian_Arg had the same problem with no traces, but everything else working on his DS1054z? Did the problem turn out to be high humidity? Did the cure simply involve opening it up and gently drying with warm air?

I think you are correct!  At least that is how I read it    ...and the scope has worked fine for the last 5 months.
 
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Offline alsetalokin4017

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Re: New Rigol DS1054Z oscilloscope
« Reply #4336 on: September 23, 2018, 12:11:23 am »
I can't seem to find the bug thread at the moment.

Here's a pretty severe bug I just noticed. The "Period Area" measurement is supposed to ... duh... give the area under the waveform. If positive, more area above baseline, if negative, more area below baseline. Very useful, right?

But if I turn on another channel, the "measurement" varies wildly, even changing sign.

 |O    :palm:     :--


ETA: I didn't change anything except to push the CH4 button to turn it on. But it does look like the whole CH1 trace is very slightly moved down in the second shot.


« Last Edit: September 23, 2018, 12:14:23 am by alsetalokin4017 »
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Offline Fungus

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Re: New Rigol DS1054Z oscilloscope
« Reply #4337 on: September 23, 2018, 12:33:57 am »
If I turn on another channel, the "measurement" varies wildly, even changing sign.

I notice the frequency has changed a lot as well (looks to me like the "30kHz" was correct, "25kHz" isn't".

I wonder if it's related to the fact the CH4 is "FGin". Does it happen with other channels or if you change that?
« Last Edit: September 23, 2018, 12:45:15 am by Fungus »
 

Offline ttelectronic

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Re: New Rigol DS1054Z oscilloscope
« Reply #4338 on: September 23, 2018, 01:40:45 am »
How come probe is set to 10 x in the first 1x in the second?
 

Offline alsetalokin4017

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Re: New Rigol DS1054Z oscilloscope
« Reply #4339 on: September 23, 2018, 01:57:31 am »
If I turn on another channel, the "measurement" varies wildly, even changing sign.

I notice the frequency has changed a lot as well (looks to me like the "30kHz" was correct, "25kHz" isn't".

I wonder if it's related to the fact the CH4 is "FGin". Does it happen with other channels or if you change that?

Uh... it's just a label, there is nothing even plugged into CH4 at all. Yes, it happens with other channels too.

How come probe is set to 10 x in the first 1x in the second?

CH4 was set to 1x. The 10x setting of CH1 has not changed. On the Rigol, the channel probe attenuation setting does nothing more than scale the vertical, anyway.

As I said, the only difference between the two scopeshots above is that I pressed the CH4 button to turn CH4 on. No other settings were changed at all between the two scopeshots and there is only about 30 seconds difference in real time between the two.

And I warmed the scope up for about 4 hours, then ran a self-calibration before making the test.

And I'm running the very latest firmware that I know about.     00.04.04.03.05
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Offline alsetalokin4017

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Re: New Rigol DS1054Z oscilloscope
« Reply #4340 on: September 23, 2018, 02:02:17 am »
Do you think I can trust this integral, that doesn't quite return to zero over the full waveform? It doesn't change when I turn on other channels.

« Last Edit: September 23, 2018, 02:05:39 am by alsetalokin4017 »
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Offline Fungus

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Re: New Rigol DS1054Z oscilloscope
« Reply #4341 on: September 23, 2018, 09:21:16 am »
I wonder if it's related to the fact the CH4 is "FGin". Does it happen with other channels or if you change that?

Uh... it's just a label, there is nothing even plugged into CH4 at all. Yes, it happens with other channels too.

OK, I didn't know if you had the signal generator option or not.

And I warmed the scope up for about 4 hours, then ran a self-calibration before making the test.

That shouldn't matter.

Do you think I can trust this integral, that doesn't quite return to zero over the full waveform? It doesn't change when I turn on other channels.

You're working with 8-bit resolution, etc. I wouldn't expect it to return to exactly zero over s wafeform.

I think "integral" is more for measuring the area under a single pulse (eg. calculate its energy).
« Last Edit: September 23, 2018, 09:28:15 am by Fungus »
 

Offline MrW0lf

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Re: New Rigol DS1054Z oscilloscope
« Reply #4342 on: September 23, 2018, 09:28:23 am »
I'd suggest to run functional test of equipment on simple signal (square, sine) you can verify by hand, WolframAlpha etc. Also pay attention to units. Due to noise etc there will be always some small deviation from zero for single integrated wfm. If you could analyze large amount of wfms, DC average etc trend would show if it actually zeroes out or not. In Rigol case you could do it only in external software. Maybe could try averaging instead.
 

Offline Fungus

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Re: New Rigol DS1054Z oscilloscope
« Reply #4343 on: September 23, 2018, 09:31:16 am »
I'm more worried that the frequency changes by 17%. That needs investigation.

You'd think somebody would have noticed by now if the frequency changed when you turned channels on.

Does the area function still change if you zoom in so that a single pulse fills the whole screen width?
« Last Edit: September 23, 2018, 09:32:57 am by Fungus »
 

Offline MrW0lf

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Re: New Rigol DS1054Z oscilloscope
« Reply #4344 on: September 23, 2018, 09:52:29 am »
You'd think somebody would have noticed by now if the frequency changed when you turned channels on.

Of course it changes because counter sensitivity varies with sampling rate. Lines represent reliable reading threshold (sine input).

« Last Edit: September 23, 2018, 09:55:05 am by MrW0lf »
 

Offline Fungus

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Re: New Rigol DS1054Z oscilloscope
« Reply #4345 on: September 23, 2018, 10:05:13 am »
You'd think somebody would have noticed by now if the frequency changed when you turned channels on.
Of course it changes because counter sensitivity varies with sampling rate.

At 30kHz?
 

Offline MrW0lf

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Re: New Rigol DS1054Z oscilloscope
« Reply #4346 on: September 23, 2018, 10:22:50 am »
At 30kHz?

I just did not test low freq, who knows. You might notice that anomaly does not scale with frequency linearly. Also this is complex wfm maybe something else also at play. In any case counter clearly starts counting properly later than seemingly proper signal is visible and there is variation with sampling rate and it has been noticed before :popcorn:
« Last Edit: September 23, 2018, 10:29:22 am by MrW0lf »
 

Offline JohnPen

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Re: New Rigol DS1054Z oscilloscope
« Reply #4347 on: September 23, 2018, 10:44:39 am »
A quick trial using a 30Khz triangle waveform on my scope duplicated the extra CH/CH4 effect on Per Area.   The Area statistic remains relatively stable.  The enabling of an extra Channel does have a small impact on the trigger level but this is quite marginal.   However in my case enabling a third channel, no signal on it, changes the Per Area statistic back to the the original reading for the CH1 alone.  Adding the fourth channel has no effect so it seems enabling any single channel to the displaying channel changes the value of Per Area displayed but adding any third or more channels returns the reading to the single channel value.  Please note this is not a thorough check as my PerArea readings do float around a bit, like by 10%, the enabling of the second channel however changes the reading by approx X5.
 

Offline StillTrying

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Re: New Rigol DS1054Z oscilloscope
« Reply #4348 on: September 23, 2018, 11:05:45 am »
But it does look like the whole CH1 trace is very slightly moved down in the second shot.

With the trigger level near the top edge of the trace, that's probably why the trigger counter is dropping from 30kHz to 25kHz, one of the edge trigger's hysteresis levels slipping off the top of the waveform.
CML+  That took much longer than I thought it would.
 

Offline alsetalokin4017

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Re: New Rigol DS1054Z oscilloscope
« Reply #4349 on: September 23, 2018, 11:42:36 am »
A quick trial using a 30Khz triangle waveform on my scope duplicated the extra CH/CH4 effect on Per Area.   The Area statistic remains relatively stable.  The enabling of an extra Channel does have a small impact on the trigger level but this is quite marginal.   However in my case enabling a third channel, no signal on it, changes the Per Area statistic back to the the original reading for the CH1 alone.  Adding the fourth channel has no effect so it seems enabling any single channel to the displaying channel changes the value of Per Area displayed but adding any third or more channels returns the reading to the single channel value.  Please note this is not a thorough check as my PerArea readings do float around a bit, like by 10%, the enabling of the second channel however changes the reading by approx X5.

Hmm, that's interesting, and for some reason I didn't turn on more than one extra channel when I was doing it. I'm shut down for the day but I'll have to play around later to see if I can get a stable and reliable reading by turning on more channels.    :-//


But it does look like the whole CH1 trace is very slightly moved down in the second shot.

With the trigger level near the top edge of the trace, that's probably why the trigger counter is dropping from 30kHz to 25kHz, one of the edge trigger's hysteresis levels slipping off the top of the waveform.

Yep, this doesn't normally worry me as I usually know the frequency I'm working with, so in practice I wind up tweaking the trigger level so that the hw counter reads correctly. In this case the FG driving the DUT was set to 30.303 kHz. If I actually need to measure a frequency precisely I don't rely on the Rigol, I fire up the Philips 6676 w/ocxo. 
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