Rigol DS1054Z vs Siglent SDS1202X-E

[tautech]

tautech, may I ask you to watch my video and check if your scope is affected?

I'm asking because Siglent support is not helpful. I was given an e-mail of their engineer, he answered me once, but then silence (although, it passed less than 24h since last reply). Their point was that trigger has accuracy +-0.2div typical, but I don't buy this. It's not accuracy problem (=offset issue?), it fails to trigger.

Also would like to know what they call "digital" trigger. So far it looks like the trigger itself is "analog", but it is assisted by the code that tries to compensate for, e.g., jitter or may be even offset. But I would like to know more.

Will do ....soon. Other demands are pressing.

I have been told FW is due out this week so until we have it we don't know all the issues that have been fixed. I do understand there is a # of things but we must wait and then check for the fixes.

[boggis the cat]

Their point was that trigger has accuracy +-0.2div typical, but I don't buy this. It's not accuracy problem (=offset issue?), it fails to trigger.

The triggering system has some bugs, I think.

Once the first firmware update is out we can review them and see if they have been addressed.

Also would like to know what they call "digital" trigger. So far it looks like the trigger itself is "analog", but it is assisted by the code that tries to compensate for, e.g., jitter or may be even offset. But I would like to know more.

Analogue triggering would use hardware, and it does not appear to have this.  What it seems to do (common to a lot of 'scopes now) is simply capture data and process it as fast as possible.  Part of that continuous processing is the triggering system -- this is a 'digital' (software) trigger.

There are some obvious potential problems with this approach, notably that if the processor gets too busy it may miss trigger events.  For this to work well it requires a very low latency process and fast memory buffers.  It seems to have the latter (with the 14 million point capture), however many things may have a bad effect on the latency.

[Fungus]

Analogue triggering would use hardware, and it does not appear to have this.  What it seems to do (common to a lot of 'scopes now) is simply capture data and process it as fast as possible.  Part of that continuous processing is the triggering system -- this is a 'digital' (software) trigger.

Yep.

There are some obvious potential problems with this approach, notably that if the processor gets too busy it may miss trigger events.  For this to work well it requires a very low latency process and fast memory buffers.  It seems to have the latter (with the 14 million point capture), however many things may have a bad effect on the latency.

There's no way the "processor" could do this (data is coming in at 1GHz). It will be done in hardware inside the ASIC/FPGA.

[exe]

The guy from Siglent wrote me the trigger is fully digital and it's a software bug. I hope this is true and they fix it soon. It's not critical to me, but extremely annoying. I would expect bugs anywhere, but not in very basic triggering. Also makes mask pass/fail useless when it starts "twitching". Anyway, "what you expected from a $400 Chinese scope".

I don't understand why trigger is specified to have +-0.2div accuracy. It should be dead-on. Are they accounting for software bugs?

[boggis the cat]

I don't understand why trigger is specified to have +-0.2div accuracy. It should be dead-on. Are they accounting for software bugs?

To account for the quantisation error, probably.  Digital 'scopes have a finite sample rate to consider (analogous to rise time with an analogue signal), and you can't be sure that a signal won't sneak past the ideal trigger point before it gets caught.  This is also why glitches (very fast voltage spikes or drop-outs) have to be at least a minimal duration to be sure they will be caught.

Set your trace to 'dot' mode to see what the 'scope is actually working with.

[TurboTom]

...
Analogue triggering would use hardware, and it does not appear to have this.  What it seems to do (common to a lot of 'scopes now) is simply capture data and process it as fast as possible.  Part of that continuous processing is the triggering system -- this is a 'digital' (software) trigger.

There are some obvious potential problems with this approach, notably that if the processor gets too busy it may miss trigger events.  For this to work well it requires a very low latency process and fast memory buffers.  It seems to have the latter (with the 14 million point capture), however many things may have a bad effect on the latency.

There has been some discussion about how the trigger works on entry level digital oscilloscopes and I did some comparative tests with three Rigol models which differ substantially regarding the trigger system. You'll find the corresponding contributions starting here: https://www.eevblog.com/forum/testgear/new-rigol-ds1054z-oscilloscope/msg1066593/#msg1066593
Related posts continue for a page or two if it's interesting for you. If you like, you could possibly take similar readings on the Siglent scope, I'ld be curious to see how it compares.

Cheers,
Thomas

[exe]

Damn, guys, this thing drives me nuts. Today it stopped capturing when I set vertical to 100mV/div and below: https://goo.gl/photos/MDa8mEdBG7anj6J59 . Reboot didn't help, nor default button. The waveform was displaying only if I enabled both channels. I was not able not make it working, but eventually the problem... gone. I don't know what I changed in settings, but it's operational again.

Please tell me I'm doing something wrong. I don't believe they released such a buggy firmware.

[boggis the cat]

Please tell me I'm doing something wrong. I don't believe they released such a buggy firmware.

Did you alter the trigger settings?  I suspect that that it has a tendency to lose the plot sometimes, requiring triggering to be reset.

There are definitely bugs...  And this is 'normal' for new equipment.  Cost of being an early adopter, unfortunately.   

[exe]

Did you alter the trigger settings?

May be, but I rebooted the scope and pressed "default" button... And I did this many times before recording the video. It's a shame there is no reliable way to completely reset unit's state. What made it working again is changing trigger or acquisition settings (as you guys suggested a few messages back). Looks like default button does not do its job well.

The unit is on sales for a few month from now, so I wouldn't call myself "early adopter".

One thing that bothers me is that I don't see much reports on problems, while I spend like 50% of the time troubleshooting the scope. Either my unit is faulty or I don't know. I want to send the unit back, but I don't know what to buy as a replacement.

[nctnico]

The unit is on sales for a few month from now, so I wouldn't call myself "early adopter".

With Siglent you have the honour to be an early adopter during the first 3 years (or longer) after a product has been released. You should have done more research before buying your scope. Return it and buy a DS1054Z (at least the firmware is mature), MicSig TO1000 series, GW Instek 1000B or GW Instek 2000E series. All have more mature firmware than the Siglent scope you have now.

[stj]

Cost of being an early adopter, unfortunately.   

the actor Sid James once said:

it's like the washing up pal, somebody has to do it!

[exe]

You should have done more research before buying your scope.

But I did . So far reviews are only positive. How is this possible?

The reason I'm going to return my unit (if possible) is that I don't trust Siglent to fix bugs promptly. So, it's either usable (for me) out of the box, or it goes back.

Thank you, guys, for helping me.

[Fungus]

The unit is on sales for a few month from now, so I wouldn't call myself "early adopter".

With Siglent you have the honour to be an early adopter during the first 3 years (or longer) after a product has been released. You should have done more research before buying your scope.

Have the DS1054Z haters got a new whipping boy?

Return it and buy a DS1054Z

Looks like it!

I guess some people just gotta hate.

(at least the firmware is mature), MicSig TO1000 series, GW Instek 1000B or GW Instek 2000E series. All have more mature firmware than the Siglent scope you have now.

Or at least wait for the first update, which is supposed to be this week.

I agree it's not wise to buy anything until a few  'tell-it-like-it-is' reviewers have had their hands on it, even if you have to wait a couple of weeks. Still, I'm sure they're been working around the clock on their firmware since the PHBs and marketers decided Launch Day couldn't wait.

[Fungus]

You should have done more research before buying your scope.

But I did . So far reviews are only positive. How is this possible?

It's all about the clicks. Finding bugs needs real use, not just an unboxing video.

Also: Lots of reviewers just want to be the first on Youtube, they don't care about really using it.

[boggis the cat]

Did you alter the trigger settings?

May be, but I rebooted the scope and pressed "default" button... And I did this many times before recording the video. It's a shame there is no reliable way to completely reset unit's state. What made it working again is changing trigger or acquisition settings (as you guys suggested a few messages back). Looks like default button does not do its job well.

So the short answer is "no".  Why do you expect it to work by repeating an operation that you know is not going to work?

If you select triggering, then open up the [Type] menu, it may correct itself and stay corrected.  (You don't need to select anything, just open the menu.)  The default settings actually seem to create the problem, so avoid them.

Perhaps this will be fixed in the next firmware.  If not, the work-around isn't too difficult.  Subtle bugs are more of an issue than what appears to be a default settings blunder.

[boggis the cat]

The reason I'm going to return my unit (if possible) is that I don't trust Siglent to fix bugs promptly. So, it's either usable (for me) out of the box, or it goes back.

GW Instek 'scopes are less buggy, and have a fast UI.  Cost in the US is low, but in Europe and elsewhere tends to be a bit higher than Rigol or Siglent.  Give them a look.

If you really want to avoid all bugs then you should be buying an older 'scope in any case.  A cheap 'scope based on a new architecture for the manufacturer is unlikely to be completely solid for several firmware iterations.

[StillTrying]

Damn, guys, this thing drives me nuts. Today it stopped capturing when I set vertical to 100mV/div and below: https://goo.gl/photos/MDa8mEdBG7anj6J59 . Reboot didn't help, nor default button.

In trying to set the trigger level on a possibly unknown and possibly small amplitude signal, I'd carefully and slowly adjust the trig level 0.5 div. above and below the flat trace that you can see.
In the video you seem to just give the trig level a quick twiddle around -100mV and -230mV. So there wasn't enough there to convince me it was a bug.

Anytime you change the Y sensitivity it's safest to assume any carefully set trig level is lost and will need a tweak - depends on the waveform.
I think trig is better DC coupled most of the time, even if the CH is AC coupled.

The unit is on sales for a few month from now, so I wouldn't call myself "early adopter".

The CML+ has been available for over a year now. (That's all I need to say!)

One thing that bothers me is that I don't see much reports on problems, while I spend like 50% of the time troubleshooting the scope.

All Slignet scopes should come with a contract of employment. 

[exe]

If you select triggering, then open up the [Type] menu, it may correct itself and stay corrected.  (You don't need to select anything, just open the menu.) 

This never helped me. Changing settings did the job.

In trying to set the trigger level on a possibly unknown and possibly small amplitude signal, I'd carefully and slowly adjust the trig level 0.5 div. above and below the flat trace that you can see.

I tried this, no luck (also tried AC/DC coupling). It only worked if both channels were enabled (but trigger was set to the first channel). Anyway, the trigger was in auto mode, so I don't think trigger position is any relevant. Again, eventually it started to work again after I changed settings either in triggering or in acquisition menu. But I believe I didn't do anything stupid to make this bug happen. I only changed display option to dots.

GW Instek 'scopes are less buggy, and have a fast UI.  Cost in the US is low, but in Europe and elsewhere tends to be a bit higher than Rigol or Siglent.  Give them a look.

I did I spent like two hours playing with their 2000e series. The only thing that stopped me is it does not have intensity grade. And twice more expensive, damn

[nctnico]

I did I spent like two hours playing with their 2000e series. The only thing that stopped me is it does not have intensity grade. And twice more expensive, damn

The GW Instek 2000E series sure has intensity grading but it depends on the brightness and persistence settings.

[Mechatrommer]

You should have done more research before buying your scope.

But I did . So far reviews are only positive. How is this possible?

because you only look for positive. and the individuals who did that are rare chunks that come and go, and remember, any reviews from the manufacturer should be discounted. if you look for problems, you can search for "siglent problem" in google or here... not easy though as they are scattered around forums and threads or very few users who made a review. not a specific consentrated "siglent list of bug" thread.... but if you stay around, you should get a slight grasp on what level of "famousity" the siglent scope around here... "very few users" should also tells you something about it... if you want to be white rat experiment, or as they said "early adopters" then be our guest, we always appreciate reviews and teardowns...

https://www.eevblog.com/forum/testgear/siglent-sds1072cml-problem-buggy-or-broken/msg299933/#msg299933
https://www.eevblog.com/forum/testgear/siglent-sds-1202x-e-cursor-measurement/msg1221469/#msg1221469
https://www.eevblog.com/forum/testgear/siglent-software-issue/msg843730/#msg843730
https://www.eevblog.com/forum/testgear/siglent-sds2000-new-v2-firmware/150/

as the ds1054z still is the eevblog's landlord approved scope, that should prove some practicality to it, we better stick to it imho. there are bugs, but that doesnt prohibit us from doing what we should do.. we have community of rigol users here since version 1 (ds1052e) that can help with problems, developed softwares to add value to the product, reverse engineer and hardware teardown review and evaluation on it etc etc...

[exe]

https://www.eevblog.com/forum/testgear/siglent-sds1072cml-problem-buggy-or-broken/msg299933/#msg299933
https://www.eevblog.com/forum/testgear/siglent-sds-1202x-e-cursor-measurement/msg1221469/#msg1221469
https://www.eevblog.com/forum/testgear/siglent-software-issue/msg843730/#msg843730
https://www.eevblog.com/forum/testgear/siglent-sds2000-new-v2-firmware/150/

But these links are not specific for sds1202x-e (except for cursor problem). I decided not to extrapolate experience from products of the past (no company is ideal). I wanted to give Siglent another chance (taking into account positive reviews!). But yes, I sort of fooled myself.

[exe]

The GW Instek 2000E series sure has intensity grading but it depends on the brightness and persistence settings.

Can you please check on this? I didn't find this function. I also asked the consultant, he said it's only for more expensive scopes. I do see "VPO" logo on the front panel, but I'm not sure what it does.

[nctnico]

The GW Instek 2000E series sure has intensity grading but it depends on the brightness and persistence settings.

Can you please check on this? I didn't find this function. I also asked the consultant, he said it's only for more expensive scopes. I do see "VPO" logo on the front panel, but I'm not sure what it does.

Intensity grading isn't a special function. It depends on the display settings. I've made a screendump with an AM modulated wave just to show the GDS2000E has intensity grading.

Don't get too hung up on intensity grading though. Just like high waveforms per second it is more hype than actual usefulness beyond some point. GW Instek understood that by having the intensity grading not going down all the way to zero so the signal stays visible.

[StillTrying]

Anyway, the trigger was in auto mode, so I don't think trigger position is any relevant.

As long as you don't think AUTO trigger finds or sets a suitable trigger level for you.
AUTO trigger only starts when the scope has been doing nothing for a short while, in the video I think some of your changes to the Y sensitivity were shorter than a short while, - so no AUTO trace(ing) on occasions.

[exe]

AUTO trigger only starts when the scope has been doing nothing for a short while, in the video I think some of your changes to the Y sensitivity were shorter than a short while, - so no AUTO trace(ing) on occasions.

C'mon, a "short while" is much less than a second in case of auto-triggering. Anyway 1) now it works as I expect 2) enabling second channel made it working as expected 3) I waited for some tens of minutes for it to trigger (while reading and writing on this forum).