Siglent SDS3000X HD and upgraded SDS1000X HD

[skander36]

Something like this ?
(sinewave, squarewave, ramp, 1Mhz, 0dBm, 50Ohm)

Yes! Thank you!

[ebastler]

Something like this ?
(sinewave, squarewave, ramp, 1Mhz, 0dBm, 50Ohm)

Proper single-pixel vertical resolution, as expected of course. That will probably be the most pronounced difference compared to the SDS1000X HD and its smaller 800 sibling (for these test signals).

[Martin72]

Do you see something that I don't?
I still have the 800, I'll take the same pictures again.

[ebastler]

Do you see something that I don't?
I still have the 800, I'll take the same pictures again.

Yes, I see doubled-up vertical pixels with the 800, most noticeable in stop mode and with flat slopes. I think these were confirmed by performa01; there is limited block RAM in the FPGAs which are used in the small scopes.

[Martin72]

OK, now I have understood it and have two sections (each 300% enlarged), left 800, right 3000.

[Martin72]

Oh well...
You don't have to enlarge anything and/or put it in stop mode.
It is enough to change the vertical resolution from 100mV/div to 500mV/div.
Note also the frequency counter.

[ebastler]

Oh well...
You don't have to enlarge anything and/or put it in stop mode.
It is enough to change the vertical resolution from 100mV/div to 500mV/div.

Yes, that's what I meant when I mentioned "flat slopes". A couple of menths ago, a few people have pushed back when I grumbled a bit about the vertical resolution compromise in the small HD scopes, and have claimed that they can never see it in practice. But when looking at slowly rising signals, or e.g. at the settling of a square wave after its edge, the stairsteps caused by the limited resolution can become quite obvious.

Nevertheless the 800X HD is a great scope with amazing bang for the buck. I am less convinced about the 1000X HD, with its bigger screen but still compromised vertical resolution. 

[Martin72]

The SML01 is allowed to sweep around a bit...
The first run doesn't look too bad, but I'll let it go for another spin.

[Martin72]

As expected, the bandwidth is not really 350Mhz, so if I upgrade my scope, it could be a bit difficult with the 1.1Ghz generator.
But then I don't care...
After all the sweeping, the scope has warmed up long enough and now I'm going to do a self-calibration, as I've done a firmware update before.
If anything else changes as a result of the calibration, I will report accordingly.

 

[KungFuJosh]

465MHz is pretty impressive for a device pretending to be limited to 350MHz. 😉

[Martin72]

I have not yet seen a scope that "goes down" strictly at the specified bandwidth.
It's the same with the 800 and also with your 2000.

[KungFuJosh]

Of course, but usually it's like 40 to 70MHz above the stated BW...though I've never tried on the fake lower limits. 😉

[Martin72]

That's right, I just looked at my measurements on the 800 again.
I'll just accept it.
After the self-calibration, which took about 45 minutes, nothing has changed.
The fact that you can change the colors is just as good as the fact that you can now position the axis label left/right/center.

[ebastler]

That's right, I just looked at my measurements on the 800 again.
I'll just accept it.

804X HD gives you the best deal: 37% free extra bandwidth! 

[electr_peter]

What is minimum rising/falling edge trigger sensitivity level on SDS1000X HD and SDS3000X HD?
On some other scopes trigger level needs to be at least 0.25-0.3 div from min/max signal level.

[Performa01]

The trigger sensitivity of a fully digital trgger system is determined by its noise immunity.

The Siglent SDS3000X HD spcifies 0.26 divisions (0.33 div with noise reject on) for vertical gains >10 mV/div.

Specification on SDS800/1000X HD is less detailed and just says 0.6 divisions.

I've checked the SDS824X HD (which is representative for the 1000X HD) and its trigger sensitivity is actually 0.27 divisions. Indication for this is a correct and stable trigger frequency readout.

See attached screenshot: SDS824X HD_Trig_edge_1MHz_0.27div

[electr_peter]

Thanks for clarification and test.

As I understand from manuals, SDSx000X HD range have analog trigger system (not digital with selectable threshold) and thus trigger sensitivity comparable with other analog trigger scopes (8 or 12-bit). I was just expecting slightly more sensitivity on 12-bit lower noise scope.

Not an issue, just a specification to be aware of.

[2N3055]

Thanks for clarification and test.

As I understand from manuals, SDSx000X HD range have analog trigger system (not digital with selectable threshold)

Very wrong.
Triggering system is fully digital. Where on earth did you find that wrong information?

[Performa01]

Thanks for clarification and test.

As I understand from manuals, SDSx000X HD range have analog trigger system (not digital with selectable threshold) and thus trigger sensitivity comparable with other analog trigger scopes (8 or 12-bit). I was just expecting slightly more sensitivity on 12-bit lower noise scope.

I don't think there is any remotely modern digital oscilloscope around which still has an analog trigger system - except for the external trigger input, quite obviously. So I wonder what "other analog trigger scopes (8 or 12-bit)" you want to to compare. Apart from that, analog triggers usually were even less sensitive.

The number of bits in the ADC has nothing to do with trigger sensitivity. As I've already explained, trigger sensitivity is defined by noise immunity. Also known as hysteresis. Analog trigger systems needed that as well of course, otherwise a clean trigger cannot be obtained. The noise reduction in the trigger engine is nothing else but an increased hysteresis.

[electr_peter]

Sorry if I mistaken anyone w.r.t. digital/analog triggering. Digital/analog triggering is not mentioned explicitly in most descriptions, I made wrong assumption on this.

Siglent HD scopes have digital triggering with many trigger types, but am I missing something here w.r.t. name "digital triggering"? From SDS3000X HD manual, pages 34-35:

Trigger coupling: Coupling mode of the current trigger source. It is only valid when the trigger source is C1~C4, EXT, or EXT/5
...
LFR: The signal is coupled through a capacitive high-pass filter network, DC is rejected and low frequencies are attenuated

Does this applies to external trigger only? Is there physical filter for CH1-CH4 trigger?

I consider (full) digital triggering as implemented in scopes like R&S RTO, MXO4/5 where it is possible to set very low (<0.1 div) hysteresis threshold, ADC data stream is crunched to extract trigger events even in high resolution mode, HF reject filter is user tunable, etc.
Do Siglent scopes have some digital triggering specific features as in R&S scopes (i.e. trigger in high resolution mode or change hysteresis to low value)?

[tautech]

Sorry if I mistaken anyone w.r.t. digital/analog triggering. Digital/analog triggering is not mentioned explicitly in most descriptions, I made wrong assumption on this.

Siglent HD scopes have digital triggering with many trigger types, but am I missing something here w.r.t. name "digital triggering"? From SDS3000X HD manual, pages 34-35:

Trigger coupling: Coupling mode of the current trigger source. It is only valid when the trigger source is C1~C4, EXT, or EXT/5
...
LFR: The signal is coupled through a capacitive high-pass filter network, DC is rejected and low frequencies are attenuated

Does this applies to external trigger only? Is there physical filter for CH1-CH4 trigger?

I consider (full) digital triggering as implemented in scopes like R&S RTO, MXO4/5 where it is possible to set very low (<0.1 div) hysteresis threshold, ADC data stream is crunched to extract trigger events even in high resolution mode, HF reject filter is user tunable, etc.
Do Siglent scopes have some digital triggering specific features as in R&S scopes (i.e. trigger in high resolution mode or change hysteresis to low value)?

Increasing sensitivity reduces trigger hysteresis, pure and simple.

Of the many types of trigger types available some permit setting a qualifying trigger to within a range.
We can also use Vertical zoom to finely adjust triggering when that might matter.

If that's insufficient, Zone trigger, available in some models allows us to set tight constraints where the scope must trigger, or use the 2 Zone triggers to further tighten triggering.

[2N3055]

Sorry if I mistaken anyone w.r.t. digital/analog triggering. Digital/analog triggering is not mentioned explicitly in most descriptions, I made wrong assumption on this.

Siglent HD scopes have digital triggering with many trigger types, but am I missing something here w.r.t. name "digital triggering"? From SDS3000X HD manual, pages 34-35:

Trigger coupling: Coupling mode of the current trigger source. It is only valid when the trigger source is C1~C4, EXT, or EXT/5
...
LFR: The signal is coupled through a capacitive high-pass filter network, DC is rejected and low frequencies are attenuated

Does this applies to external trigger only? Is there physical filter for CH1-CH4 trigger?

I consider (full) digital triggering as implemented in scopes like R&S RTO, MXO4/5 where it is possible to set very low (<0.1 div) hysteresis threshold, ADC data stream is crunched to extract trigger events even in high resolution mode, HF reject filter is user tunable, etc.
Do Siglent scopes have some digital triggering specific features as in R&S scopes (i.e. trigger in high resolution mode or change hysteresis to low value)?

You are confusing details of how one manufacturer implemented some functions with a concept of how digital triggering work.

Siglent (and many others) use fully digital triggering.
It is digital because it works in digital domain, on sampled data from ADC.

Analog triggering has physical analog comparator in schematic, that is detecting where edge is.

Some other scopes, like Keysight MSOX3000T/G has hybrid system, where they have analog comparator for Edge trigger but use digital trigger for other types.

Other things R&S implements are just something they implemented in their implementation of full digital triggering.

So your sentence "I consider (full) digital triggering as implemented in scopes..." is not really a thing.

It is like saying "I consider electric car to be fully electric car only if it has 17" multimedia screen like Tesla".
No, fully electric car is any car that has 4 wheels and only electric motor and battery as sole source of motion. Any other equipment is just equipment on fully electric car. It defines features, class, price but not the fact it is fully electric car.

[electr_peter]

Of the many types of trigger types available some permit setting a qualifying trigger to within a range.
We can also use Vertical zoom to finely adjust triggering when that might matter.

Is there a video of how vertical zoom can allow trigger level adjustment?
I am interested triggering signal where small amplitude square wave pulse train is riding on top of much higher DC level. Lets say <10MHz BW max, DC coupling only, 6-10 div DC signal and <0.1-0.2 div square wave. How sensitive rising edge trigger can be in such case?

[Performa01]

Of the many types of trigger types available some permit setting a qualifying trigger to within a range.
We can also use Vertical zoom to finely adjust triggering when that might matter.

Is there a video of how vertical zoom can allow trigger level adjustment?

While vertical zoom can help to adjust the trigger level more precisely, it certainly doesn’t change the hysteresis, hence the trigger sensitivity. Naturally the trigger works only on physical channels, not zoom or math channels.

I am interested triggering signal where small amplitude square wave pulse train is riding on top of much higher DC level. Lets say <10MHz BW max, DC coupling only, 6-10 div DC signal and <0.1-0.2 div square wave. How sensitive rising edge trigger can be in such case?

Okay, that’s finally a practical use case – even though in this case we would just make use of the DC-offset compensation by the vertical position control and use a higher input gain to get a sufficient signal amplitude to trigger on. This is a 10 mV pulse riding on a 1 V DC signal:


SDS2504X HD_Trig_DC1V

But there could be another scenario, where a tiny pulse rides on a square wave with much higher amplitude.

The following example combines a 600 mV (6 div) square wave at 100 Hz with a 1 ms wide 10 mV (0.1 div) pulse at a repetition rate of 1 Hz.

The example uses window trigger to reliably catch the rising edge of the small pulse:


SDS2504X HD_Trig_0.1 div

This experiment has been run on an SDS2504X HD.

EDIT: Here’s a better example, with the tiny pulse sitting in the middle of the square top and using plain edge triggering:


SDS2504X HD_Trig_0.1 div_Edge

[kripton2035]

what device did you use to generate these signals ?