Siglent SDS800X HD 12 bit DSO's

[miro123]

Hello,
I'm considering buying an oscilloscope based on the following parameters: price, analog front-end (AFE) noise level, and SFDR (spurious-free dynamic range). My current shortlist includes:
    Siglent SDS 2104X HD
    Siglent SDS 1104X HD
    Siglent SDS 814 HD
    Rigol HDO1104/1074

I have a couple of questions:

    1. Has anyone compared the noise levels and SFDR of the current generation of 12-bit Chinese scopes (Siglent/Rigol/Micsig)?

    2. Are there any hardware differences in the analog front end between the SDS2000X HD SDS1000X HD and  SDS 800? Has anyone done a teardown of these models?

I have read the datasheets but it was difficult to me to make cross-cromparision.  I cannto find the test condition of noise tests - e.g. Sample rate time base acquisition windows, oversampling ratio/hi-res. 50ohm or short  etc.etc.  I have no idea what those datasheet numbers means without explaining the test conditions.
Magnova scopes describes clear the test conditions and their numbers means something to me.

Thanks in advance for your insights
Miro

Quickly:

1. Yes.There are several topics on this specifically.

Can you give me some links or hints how to find them?

But what are you going to do with the scope? What kind of measurements?

Mainly for power electronics and more specifically on firmware side - requirement are
 - High resolution - the streaming data comes from 14bits DACs
 - A lot of memory - if you give me a 1Gbytes/channel i will use it all :-)
 - 70MHz BW is mostly enough.

[miro123]

If you decide on the 800 series I'd go with the SDS804X HD.  In 5 minutes you can make it a SDS824X HD and save about $300.

Thanks,
Maybe buying two SDS804X HD is an option too - sometimes I trace 8 channel DAC data. At the end I will have as much memory as SDS1000x HD but also flexibility of going 8 channels

[Martin72]

Can you give me some links or hints how to find them?

A hint:

Search function with "noise" "Siglent HD" "Rigol DHO" keywords.

Whereby all 12-bit models I know are very close together, i.e. noise can be omitted as a criterion.
At siglent, I would either take the SDS800X HD or the SDS2000X HD. The 1000X HD is basically an 800 with a larger display and 50 ohm inputs.
As for Rigol, I wouldn't consider anything above the DHO1000; basically, you've already reached the limit in terms of the technology behind it, it's only getting “better” in terms of bandwidth/sample rate.

sometimes I trace 8 channel DAC data

Wouldn't digital channels be better suited for this?
If you measure with two scopes that are not synchronized, there will be corresponding deviations in time.

[egonotto]

....
Maybe buying two SDS804X HD is an option too - sometimes I trace 8 channel DAC data. At the end I will have as much memory as SDS1000x HD but also flexibility of going 8 channels

Hello,

8 channel rather not. You need one channel each and a suitable external signal for synchronization (time base accuracy ±25ppm).
But a 6-channel system is feasible with a certain amount of effort.
However, with three SDS804X HD you could build a 9 channel system. Perhaps there is then already a quantity discount.

Best regards
egonotto

PS: Of the devices listed, I have a Siglent SDS2104X HD and a Rigol HDO1074. So that I could possibly answer specific questions.

[bte]

- High resolution - the streaming data comes from 14bits DACs
 - A lot of memory - if you give me a 1Gbytes/channel i will use it all :-)
 - 70MHz BW is mostly enough.

There's this thread about streaming data by using an oscilloscope. Might be useful in making your decision.

https://www.eevblog.com/forum/testgear/using-an-oscilloscope-for-data-acquisition/

[BillyO]

Wouldn't digital channels be better suited for this?
If you measure with two scopes that are not synchronized, there will be corresponding deviations in time.

This brings up a thought I have had for a long time.  It used to be that all decent scopes had sync in and sync out (or trigger in and trigger out).  It would be worth a little extra money to bring that back to the hobby level market.

[egonotto]

Wouldn't digital channels be better suited for this?
If you measure with two scopes that are not synchronized, there will be corresponding deviations in time.

This brings up a thought I have had for a long time.  It used to be that all decent scopes had sync in and sync out (or trigger in and trigger out).  It would be worth a little extra money to bring that back to the hobby level market.

Hello,

in my experience, the problem with trigger out is the non-negligible and non-constant delay.

Best regards
egonotto

[bateau020]

But a 6-channel system is feasible with a certain amount of effort.

It has trigger out at the back. But indeed, to be tested if it allows precise control. It would allow you to go to 7 channels.
With LAN VXI trigger you might be able to go 8 channels, but it would admittedly be even less precise.
Or what about triggering via the front digital inputs for the logic analyzer? That might be best.

Trigger sources for the SDS800X HD series are  {C<n>|D<d>|EX|EX5|LINE}. Not validated, but EX probably means external clock source (which the SDS800xHD doesn't have), EX5 probably means EXT/5, meaning EXT divided by 5?

[BillyO]

Hello,

in my experience, the problem with trigger out is the non-negligible and non-constant delay.

Best regards
egonotto

I'm not sure about non-constant.  I think once you have your set-up the delay between instruments will be constant.  Mostly for slower/lower BW applications that is not a real issue, but nonetheless, most decent hobbyist level scopes these days have a de-skew function, which should deal with the problem.

[egonotto]

Hello,

It's been a while since I tried this. I remember the delay being not constant. But you can work with it for a certain setting.
But with e.g. 25 MSample at +-25 ppm, the samples that belong together can be far apart. ( < 50*25 = 1250 samples)
As an example a delay from the Micsig MHO3.

Best regards
egonotto

[Martin72]

Mostly for slower/lower BW applications that is not a real issue, but nonetheless, most decent hobbyist level scopes these days have a de-skew function, which should deal with the problem.

The de-skewing works on the same time basis.
Otherwise, it drifts apart again, albeit very slowly.

[BillyO]

The de-skewing works on the same time basis.
Otherwise, it drifts apart again, albeit very slowly.

One more reason to have external time base input. 

[crysti]

Could someone please clarify whether power measurements using the Power Analysis Software can be performed with other equipment, such as the Micsig CP2100A and DP10013, without using the DF2001A deskew fixture?
Is it possible to manually align (or synchronize) the voltage and current signals instead?

[Martin72]

Hi,
With the PA option, you are not tied to specific measuring equipment; you can of course also use non-Siglent probes.
You don't necessarily need to have the deskew fixture; it just makes the adjustment easier.
Each channel has a deskew function, which is used to align the signals on the channels in use.
This means that you need a signal on which you measure the voltage with one channel and the current with the other channel.
With higher time resolution, these signals will be slightly out of sync.
The deskew function is then used to align them.
The Siglent Deskew fixture provides such a signal, allowing you to measure current and voltage simultaneously.
You can also use a generator with a resistor as a load to measure the current and voltage.
However, there are clones of the deskew fixture available for DIY, which are much cheaper than the original.
There is at least one thread on this topic here in the forum.

[KungFuJosh]

However, there are clones of the deskew fixture available for DIY, which are much cheaper than the original.
There is at least one thread on this topic here in the forum.

Got a link? 😉

[Martin72]

Yepp...

https://www.eevblog.com/forum/testgear/scope-probe-deskew-fixture-pcb-project/msg3168766/#msg3168766

I also created a schematic from the "original" fixture. I'll see which hard drive it's on.

[Martin72]

Found it, the plan should be correct (created in 2020), but I can't guarantee it.

[tycz]

I recently bought a Siglent SDS824X HD to replace my Rigol DS1052E. I have a question regarding the oscilloscope's waveform buffer and trigger. On the the Rigol, the waveform captured is much larger than the visible screen area, as can be seen by the little map at the top of the screen which shows the visible waveform in relation to the captured waveform and trigger. In the attached screenshot, it shows a trigger event 32ms outside the screen area to the right (about three screens worth).

Is it possible to make the Siglent behave this way? At the moment I cannot figure out how to make it trigger outside of the visible screen area, which limits its usefulness to me.

[tautech]

I recently bought a Siglent SDS824X HD to replace my Rigol DS1052E. I have a question regarding the oscilloscope's waveform buffer and trigger. On the the Rigol, the waveform captured is much larger than the visible screen area, as can be seen by the little map at the top of the screen which shows the visible waveform in relation to the captured waveform and trigger. In the attached screenshot, it shows a trigger event 32ms outside the screen area to the right (about three screens worth).

Is it possible to make the Siglent behave this way? At the moment I cannot figure out how to make it trigger outside of the visible screen area, which limits its usefulness to me.

No, WYSIWYG

Instead engage Zoom by pressing the timebase encoder to access the dual timebase then swap between the 2 displays with touch or a mouse to make s/div adjustments.
In the primary timebase you can set HPos anywhere on the visible display and from within the 2nd timebase the HPos encoder allows for panning anywhere within the primary timebase.

Have a play, you'll soon get the hang of it and learn its usefulness.

[crysti]

Could anyone please let me know how to enable the display of the front-panel buttons in the web interface of the SDS800X HD, similar to the functionality available on the SDS1000X?

[tautech]

Could anyone please let me know how to enable the display of the front-panel buttons in the web interface of the SDS800X HD, similar to the functionality available on the SDS1000X?

You can't.
Instead, in the webserver just click on any of the tabs to make adjustments, just as you would if only using the touch interface.
Of course the attached screenshots don't display the mouse pointer.

[tautech]

Reported elsewhere....but not here....
New firmware for SDS800X HD models.

Version： V1.1.6.5
69MB
https://int.siglent.com/upload_file/zip/firmware/Oscilloscope/SDS800X_HD_V1.1.6.5_EN.zip

Release notes
1. Fixed several bugs
a) Scope won't boot if set for DHCP and connected to LAN without DHCP server
b) An "Acquiring" progress bar is showing up on 1 ms/div instead of 100ms/div as before
c) Remove BW Limit warning
d) When FFT is set to certain frequency bands, such as 1kHz to 6kHz, meaningless axis labels are displayed (sweep mode is set to logarithmic)

[newbrain]

I checked a) and b), and they work as expected.
Moreover, DHCP does not give up:
I disabled my DHCP server and the scope came up with just a slight delay and no other problems.
When I re-enabled DHCP, the scope autonomously got its IP adress and NTP time. 

I don't know what c) is about, but I have a setup tucked somewhere that exhibited something very similar to d), I'll try to load it again and see what happens.

Reported elsewhere....but not here....

Yup, last time I reported it here, and was told to report it on the other thread 

Maybe it would have been more appropriate to post the announcement here:

https://www.eevblog.com/forum/testgear/sds800x-hd-bug-reports-firmware

Damned if you do, damned if you don't.

[mikes]

When I re-enabled DHCP, the scope autonomously got its IP adress and NTP time. 

Sounds like Siglent still hasn't gotten DHCP right.  Testing it, it looks like they're doing a DHCPDISCOVER roughly once a second, forever, if they don't get a response. RFC 2131: "The client MUST adopt a retransmission strategy that incorporates a randomized exponential backoff algorithm to determine the delay between retransmissions."

They also continue to ignore lease times, and do DHCP renewals every minute or so.

[2N3055]

When I re-enabled DHCP, the scope autonomously got its IP adress and NTP time. 

Sounds like Siglent still hasn't gotten DHCP right.  Testing it, it looks like they're doing a DHCPDISCOVER roughly once a second, forever, if they don't get a response. RFC 2131: "The client MUST adopt a retransmission strategy that incorporates a randomized exponential backoff algorithm to determine the delay between retransmissions."

They also continue to ignore lease times, and do DHCP renewals every minute or so.

Ignoring lease time is reported and acknowledged but was not addressed at this moment. To be honest priority for that is low.

As for using backoff, one post up here is a very happy customer that is very happy that scope acquired address immediately after DHCP was available without delay.
Some standards are written while having in mind thousands devices in single LAN, and how to deal with chaos ensuing.
Single device asking for DHCP server like this is not really a heavy load. If you are not using DHCP then it doesn't matter. If you are using DHCP and server is not available, you need to fix DHCP server to be able to use network.
At that moment problem is fact that all your devices can't see DHCP server, not single device asking relentlessly.
I don't see scenario where this will create real problems.
I agree that formally this is not as it should be. In practice, this is not problem.
Make sure I will report this, but critical it is not.
Thanks for the checking.