EEVblog #1146 - New Low Cost Rigol MSO5000 Oscilloscope

[mroek]

But still, as long as the input signal is below Nyquist and has sufficient amplitude, you are able to detect the presence of the signal, and also approximate the frequency.

The signal does not even need to be below the Nyquist frequency but it does need to have sufficient amplitude to make up for the loss from frequency response.

True, as long as you don't care about detecting/measuring the frequency of the signal. If you also want to be able to at least estimate the frequency, you need to stay below Nyquist (as I also stated).

[David Hess]

But still, as long as the input signal is below Nyquist and has sufficient amplitude, you are able to detect the presence of the signal, and also approximate the frequency.

The signal does not even need to be below the Nyquist frequency but it does need to have sufficient amplitude to make up for the loss from frequency response.

True, as long as you don't care about detecting/measuring the frequency of the signal. If you also want to be able to at least estimate the frequency, you need to stay below Nyquist (as I also stated).

Even then, if you know which aliased image it is you can convert the time/div to the aliased time/div and make time measurements which are just as accurate.  Usually it is the first aliased image simply because any of the higher ones will be too far down the frequency response curve.

The above does not work very well with analog triggering because the trigger becomes essentially random if it works at all but with digital triggering, it should work fine because the digital trigger sees the aliased waveform and not the original one.

[Martin72]

Hi,

Can anyone try the same setup and verify?
EDIT: changed 1KHz to 10KHz in my post.  Thanks Martin72

The 10KHz was used by the keysight, by the rigol it was 1khz.(saw it today)

I did measures with both frequencies, but they look the same so I post only the 1K pics.

Normal Mode :



Average Mode (2times) :



"Hires" (  ) Mode:




Setup was 1:10 probe on rigol awg, sinewave 1(10)Khz, amplitude 600mV p-p

Can anyone comment if their screen is shimmering/flickering at all?

Will do it tomorrow.

Together with testing my new toy:

[el_man]

Photo attached of the plugs they put on 2ch model.

Interesting - are they somehow permanently attached or a just a caps ? 

[TK]

Photo attached of the plugs they put on 2ch model.

Interesting - are they somehow permanently attached or a just a caps ?

They must be caps because the scope can be software upgraded to 4 channels

[NED88]

Hi all.

I posted a question to the other Rigol MSO5000-related thread (see https://www.eevblog.com/forum/testgear/hacking-the-rigol-mso5000-series-oscilloscopes/msg2264904/#msg2264904) but wasn't sure if it was the right thread, so I'm re-posting it here if ok with you...

So, I decided to use the Measure menu to add Frequency, Period, Undershoot and Overshoot measurements in order to calibrate the four passive probes supplied with my MSO5104. 

I managed to get both the Under/Overshoot down to ~0.6060% for channels 1, 2 and 4 using the 1KHz square wave (from the probe compensation terminal) and those three channels now show a good flat square wave.  However, channel 3 is showing a bit of overshoot (0.6711%) that I can't get rid of - is this normal and/or is it possible to rectify it??  Also, I am not sure if it's a software or hardware problem either.

I have attached, below, a screenshot of the measurements and I did run the SelfCal function beforehand.

I'd appreciate any advice that you can give. 

Thanks.

[mabl]

HiRes renders far better for me in dot render mode, than in vector mode. Give it a try. 

[Martin72]

Can anyone comment if their screen is shimmering/flickering at all?

Will do it tomorrow.

Done:



(sinewave)



(squarewave)

No issues at all....

HiRes renders far better for me in dot render mode, then in vector mode. Give it a try.

Ok, maybe I can get the same measure object as used a few weeks ago:

Hi-Res Mode rigol:





Normal Mode siglent:




Hi-Res Mode (+3bits) :



I don´t think it will look like this in dot mode, but I´ll try it out.

[thm_w]

Interesting - are they somehow permanently attached or a just a caps ?

Just BNC caps with nothing inside. Would have been too nice if they were 50 ohm terminators.

I managed to get both the Under/Overshoot down to ~0.6060% for channels 1, 2 and 4 using the 1KHz square wave (from the probe compensation terminal) and those three channels now show a good flat square wave.  However, channel 3 is showing a bit of overshoot (0.6711%) that I can't get rid of - is this normal and/or is it possible to rectify it??  Also, I am not sure if it's a software or hardware problem either.

In the other thread they said Rigol is working on a software fix.
With a generic cheap probe I'm getting the same 0.6% overshoot, and with rigols own probe its a bit worse at 1.2% (maybe due to 350MHz vs 100MHz probe).

Done:

Thank you, looks like this screen is bad or some connection inside. Will see how electrometers deals with returns.

[TK]

Is anyone testing serial decoding on the MSO5074?  So far, it is a piece of crap, it is soooo slow and it cannot trigger in normal mode, when in Auto mode I can see the signals being decoded on the Event table... I plug in my EDUX1002G and I can be decoding in less than 1 minute, with the Rigol, It takes forever to get the right parameters, and when you start seeing some data, it is so slow that it is kind of useless... and you need to navigate infinite levels of menus and you see repeated parameters all over the menus  and in SPI they name the signals SCL and SDA 

UI is also very slow and unresponsive, display is very dim unless you are in a basement with no exterior light and most of the lights off...

It is my third attempt with Rigol (MSO2K, DSO1054Z and MSO5074) but I think it is going back and I will take my chances with the new 4-channel Keysight...

I should have listened to Dave when He said this is another Rigol piece of crap

[Martin72]

Oh, did he said it ?

SPI decoding here was no problem, it´s definitely hardware-based and seems not too slow for me.

[thm_w]

and in SPI they name the signals SCL and SDA 

For me its showing MOSI and MISO, as expected. Are you on the latest software version?

UI is also very slow and unresponsive, display is very dim unless you are in a basement with no exterior light and most of the lights off...

Brightness is OK for me and I'm in a well lit room with windows. But I am used to black screens, and I agree some sort of brightness control option would be highly appreciated.

I'm surprised you didn't care for 2k or DSO1054Z, they were by far the best value/$ at the time. Of course I would never use them for serial decoding, prefer a dedicated USB analyzer.
Anyway, I would encourage you to return the scope and give them the reasons provided here.

[Shodge]

Latest firmware... (04.04)

Tested RS-232.  Easy to find baud, polarity, bits, stop...  Manual trigger (edge) - worked great.  Copied decoder into trigger, set up for hex = 0x41.  Worked great.  It would be useful to have a ASCII method...

Table view - same results.

It was definitely not slow.  You do have to navigate several menus - but I don't see a better way, unless you go the keyboard mouse method - which I do not want for a scope...

-Stan

[TK]

Sorry for the previous rant... it was giving me a terrible headache trying to get anything meaningful from this scope...

SPI triggering menu showing SCL / SDA

[TK]

Oh, did he said it ?

Here: https://youtu.be/UDGsZcAWgL8

[TK]

Now my MSO5074 got offended because of my post... it hung on me!!! it is completely frozen... time to reboot.

EDIT: After reboot, still scope is almost 99% unresponsive... it reacts to buttons after 30-60 seconds.  It is set to trigger on SPI timeout 34uS, single trigger, with Event Table open.  It was working fine until today (for 1 week).

[thm_w]

Sorry for the previous rant... it was giving me a terrible headache trying to get anything meaningful from this scope...

SPI triggering menu showing SCL / SDA

You are right, submitted menu typo to Rigol.
edit: Same typo is also seen in the Search -> SPI -> Threshold menu
edit: Rigol noted bug is recorded

[TK]

Another big issue is that the BACK key does not go back on the menu hierarchy navigation, it goes back on the menu navigation steps you took.  I cannot reproduce it, but in one case I ended up in a menu option where the settings were changed and I was shown a previous setting

And it also bothers me a lot that the menu options on the display are not aligned to the right navigation buttons.  Maybe it is time to create a new thread of all the problems with this scope...



One last rant... you need to press the multi-purpose knob all the time, and it is prone to moving and selecting an adjacent option instead of the one you need... you can scroll and it should set the last option where you stopped when scrolling, without needing to press the knob.

One last last rant... when you press the option key, you are presented to the touch keypad... if you want to use the multi-purpose knob, you need to press the option key again to make the touch keypad go away... then you need to scroll and there is no accelerated function, it just scrolls slowly through all the values... you are not presented by default with the typical values, like the UART baud options, etc

And so on and on and on...

The firmware needs to be completely rewritten...

[Martin72]

Hi,

Another big issue is that the BACK key does not go back on the menu hierarchy navigation, it goes back on the menu navigation steps you took.

Hm ? One step fore then back to the last with the "back" key….seems normal to me.

you can scroll and it should set the last option where you stopped when scrolling, without needing to press the knob.

For me, I find this art of confirmation better - I think it´s a personal taste and not a real problem which is needing to be fixed.

And it also bothers me a lot that the menu options on the display are not aligned to the right navigation buttons.

Personal taste, the second - I´m working with it since more than 4 months and it didn´t disturb me - To be honest, NOW that you show it in the pic, I realize it for the first time.

The firmware needs to be completely rewritten…

For one or a few more persons who aren´t satisfied with the operation at the scope…I don´t think so - Or it´s completely the opposite and I´m one of the few, who hadn´t a problem with it.
We´ll see.

Maybe it is time to create a new thread of all the problems with this scope...

There was a thread started for general problems/real bugs :

https://www.eevblog.com/forum/testgear/rigol-5000-bugs/msg2085496/#msg2085496

[Martin72]

One thing more…..

What we´re talking about..
About a scope for appx 1000 bucks, €, $ .
As I was bothered with some issues about the lecroy WS 3024, lecroy told me, well it is our low-cost model.
Low cost…..over 4K bucks and they told me it´s low cost.
But they´re right.
A really useful current probe even from rigol cost about/over 5000 bucks.
5000.
For an current probe only.

So what can we expect from a scope which costs a fifth of an current probe...

[TK]

This is not a $999 scope... yes, it is $999 for 70MHz and no software options.  If you add all the options, it is a very expensive scope!!!

I have the Keysight EDUX1002G 2.5 channels, and the Micsig 4 channel scope.  Both are very nice and the battery operated Micsig has its own purpose... I was looking for a 4 channel scope that can be a mix of both the EDUX1002G and the Micsig, but the UI responsiveness and the quality of the software is not worth paying $999 for this Rigol... Now that I have experienced it, I wouldn't buy it even for $500, probably the Siglent is better at $500

[David Hess]

One last rant... you need to press the multi-purpose knob all the time, and it is prone to moving and selecting an adjacent option instead of the one you need... you can scroll and it should set the last option where you stopped when scrolling, without needing to press the knob.

I hate that in modern products.  The designers think they are so clever to include using the encoder as a push-button but completely miss the human factors engineering.  There are several ways to fix it including aligned strong detents, debounce hysteresis (Tektronix did this at least 29 years ago when faced with the same problem), and just using a separate button but they implement none of them.

Rigol of course will never consider it a problem so they are in good company with Apple.  You are pushing the encoder wrong.

[mroek]

I hate that in modern products.  The designers think they are so clever to include using the encoder as a push-button but completely miss the human factors engineering.  There are several ways to fix it including aligned strong detents, debounce hysteresis (Tektronix did this at least 29 years ago when faced with the same problem), and just using a separate button but they implement none of them.

This appears to be a rather common issue these days, and it is a bit of a mystery why they don't fix this with software debouncing (like you said). Strong detents are OK on some of the encoders (like the ones for vertical gain and horizontal sweep speed), but for a universal selector, detents isn't always desirable. Now, debouncing in software is a bit more complicated than for a simple switch, but still shouldn't be very difficult. Since it can't know that the button has been pressed until it actually is, it needs to check if there was any changes to the rotational posision immediately prior to registering the press, and if so, revert to the menu choice that was active some time (say 100 milliseconds) ago. Not very complicated, but it obviously requires some form of timestamping positional changes of the encoder.

[TK]

As the encoder is also used not only to select an option but also to increase / decrease values, a hard stopping detent or dent can make turning the knob for long time make it hard to use... and also Rigol did not implement a good acceleration algorithm (I don't think there is one), you need to rotate it many times or use the touch keypad but sometime you don't know which value to set unless you navigate through many values.  On the Keysight it is very easy to go from MHz to KHz using the knob, i.e. to select the output frequency of the AWG.  I could not find a fine/coarse option on the Rigol knob.

[Fungus]

Photo attached of the plugs they put on 2ch model.

Nice!

I'm guessing they had a lot of idiots sending 'scopes back because "Two of the channels don't work!", but those are cool.

A full set of them might of them might fetch $10 on eBay.