Siglent Technical Support join in EEVblog

[rf-loop]

ther things just 

 

Lets take this case: Missing trigger level indicator when trigger coupling is AC. 
Also it looks like you do not know how trigger coupling AC works and what it means. Please study first and after then claim bugs.
(it works perfect and also there is NOT level indicator, and there must NOT be)

You can demonstrate this your self how it works and after  you have done your home works come on again and explain what you see and after then please arguments (and please think carefully before show your arguments) for trigger level indicator mark.

I will set this home work example like this: If you do not have equipments for this please take pen and paper and demonstrate this example.
There is 2Vpp example 28MHz sinewave what is riding on very low frequency signal, nearly like drifting dc, say example 0.2Hz 3Vpp sine or example triangle wave (with these settings it is nice to see on display and immedatelly can understand why there is not trigger level pointer or trig line over screen..

Now connect this signal to scope, set 50ns/div and 1V/div and DC coupling. (because in this example case we want also know this level)
Now set Trigger for rising edge and coupling AC and set trig level zero (remember it is now relative level).

What you see on the scope screen. Specially look how is signal relative to trigger position.

Now change trigger coupling for DC and try trig normal and auto.

What you see now.  Again specially look how is signal relative to trigger position. And tell how it trig, is it fun.

After then you are ready, come on and tell how bad it is that trigger vertical level marker disappear when we go to trigger AC coupling.

Think, think again.

But at this tim I feel this is waste of time. Previous message you just deny nearly all and keep tightly your all opinions what are based only to nothing or  based on beliefs. Just as for noise trig and now with trigger hystreresis... perhaps next is just this trigger AC coupling.

Please keep free your opinions but with this level of knowledge do not so much claim bugs in these  things what works perfect and just right. Yes, there is also bugs but they are not at all these things.

[rf-loop]

Tiny add to previous msg.

There is Dave's old youtube what explain trigger coupling AC/DC because this very basic function confuse some peoples who have equipments but who do not know how to use these and how they work.

There is some flaws or negligence in this video but these are not important in this case and this video is good for explain this function (partially).

<iframe width="640" height="360" src="https://www.youtube.com/embed/y5aAjd9YPok" frameborder="0" allowfullscreen></iframe>



In this video he show Rigol and in nearly end also Keysight and then also how Keyshit have  trigger level 50% function and how it works (but Z box do not have).

Siglent have same 50% function as in Keysight (but without this enormous noisy front end).

Also you can see how also Rigol trigger level mark disappear (right,  it need disappear) just as also in Siglent but some peoples think this func is bug because it is in Siglent. 

[boggis the cat]

Lets take this case: Missing trigger level indicator when trigger coupling is AC. 

This isn't what I stated.  The level indication (the line) disappears sometimes with DC coupling set.

Other people have noted this issue.

Also it looks like you do not know how trigger coupling AC works and what it means. Please study first and after then claim bugs.
(it works perfect and also there is NOT level indicator, and there must NOT be)

No, you aren't following what I wrote correctly.

"Also, it seems odd that if you change from DC to AC coupling the trigger level is still settable, but only the numeric indication is present (and persistent, it doesn't snap back to zero)."

The numeric indication for trigger level is present, with AC coupling.  There should be neither indication, as you can't meaningfully set a trigger level.

Do you have this model 'scope?  It seems that you don't.  There seem to be some weird interactions with settings and incorrect behaviours.

[Gandalf_Sr]

Boggis, I appreciate that you're trying to find bugs and you probably have found several.

However, in the case of not displaying a line when you go to AC-coupled triggering, I am with rf-loop that this is not a bug - it should show a numeric level but no line on the screen.  Watch Dave's video above which is absolutely on point, particularly after 17:17 if you want to save time.

I'm waiting for the new firmware but meanwhile, I'm using the SDS1202X-E and it is doing just fine; I have yet to experience a bug that's stopped me doing anything I have wanted to so far.

I have one other thought/theory about the phantom blip you see in the center of the screen when nothing is connected to the input; digital cell phones pulse RF energy out (try holding one near your speakers) and, even with nothing connected, even with maybe a scope probe connected where the tip is shorted to the ground croc-clip (which forms a small loop antenna), a real signal pulse is being detected which is causing the triggering. Putting a shorted BNC connector on the input might not even make this go away as the PCB trace inside the scope between the BNC connector and the ADC front end might be enough to pick up a signal.  However, I see this as an exercise in futility if you're looking for bugs with no input connected!  My Agilent and Fluke multimeters show fluctuating voltage readings when I have nothing connected to their probes 

[rf-loop]

Do you have this model 'scope?  It seems that you don't.  There seem to be some weird interactions with settings and incorrect behaviours.

Yes I have and not only one and test unit have been just after this model was ready for markets. How you think I can other way publish several tests and result images and define how it works and data and knowledge about it in things what are not told in specs.
Just one example, this. Not possible without scope:




Also I have SDS1000X+ model, SDS2k, Several other brand scopes, including also old boat anchors. Previously lot of more but this kind of retired people do not anymore need so much.


And then this

"Also, it seems odd that if you change from DC to AC coupling the trigger level is still settable, but only the numeric indication is present ...

This is just ok how it should  work.

Then

....... (and persistent, it doesn't snap back to zero)."

this is like design compromise. One like red and other like blue...but some like hot chili.   When people push coupling at this point system do not know if he step over AC and to example HF rej. If he wANT hf Rej then it is wise to keep untouched (as DC).
Some users may need often just HF rej and some other just LF rej or AC.  So, compromise is that do not change user defined trigger level. If user want he can just push one button and there it is. It need note  that 0 is not at all mostly optimum for AC coupled trigger level setting.

Use trig coupling DC and look narrow pulses. Example 3V positive peaks and 1kHz but pulse width say example 1us. Press 50% or set 1.5V trig level. Ok nice trig and all ok but reason or other you want trig AC coupling. Nice, it stay trigged. If it change itself to zero then you need adjust it for trig again.

These kind of things need compromises. Allweays some combination  is not so nice. 

I do not want change it. Overall ok compromise. But user need study his tools. Know your equipment helps in many places and. Learning curve is ....  if you want learn instead of ranting what nearly inhibit learning.

More useful is learn how to use it and how it works. Then when meet real error/bug  then need do real documents with all nessessary and enough accurate data so that peoples in factory can repeat it. Findings what nobody can repeat / reconstruct are waste of time.

[k1ttt]

I am trying to help a friend who has a new SHS-800 series scope, he brought it to me and we went through some of the basics in about 2 hours while I was pulling answers out of the dvd manual and knowledge of other scopes.  we both saw one thing that I could not explain and after he left I kept the pdf manual to try to explain it and still couldn't.  we had 2 probes attached to the scope, press auto and both traces would show up.  blue for channel 1 on top, red for ch2 on bottom, and overlaid on the bottom trace was in blue ch1 signal parameters like Vpp, Prd, Mean, and Freq.  These show up in the user manual Figure 2-1 on page 6 under Automatic Settings.  Our questions are:
1. besides pressing Auto can you turn on these values manually?
2. When displaying 2 channels can you get both of their parameters displayed?
3. my friend pushed some buttons while I wasn't watching and got it to display ch2, but then it went back to ch1 and we couldn't figure out what he did to get ch2 back.  how do you select which channel to display?

[pantelei4]

1. besides pressing Auto can you turn on these values manually?

No, only the menu, the measurement, which occupies a useful part of the screen.
Strange discreteness of automatic measurements of an oscilloscope. 220-224-228V 

In one claim to SHS806, I was mistaken, the delay between channels is regulated by it, and it was not set to zero.

There is also a hardware bug at the 800 series.
With DC offset, especially in the 2V/div range, the error of the position of the scan line relative to the marker is large, on all the devices that I saw, it does not fit within 3% tolerance.

Despite all the bugs, the device is very useful for me. It's a pity that Siglent will never fix them. 

[exe]

Lets take this case: Missing trigger level indicator when trigger coupling is AC. 
Also it looks like you do not know how trigger coupling AC works and what it means. Please study first and after then claim bugs.
(it works perfect and also there is NOT level indicator, and there must NOT be)

I do know what's the difference between AC/DC means. And I still prefer trigger level to be displayed at all times (it's like you can measure min/max values of waveform regardless of channel coupling) with coupling indicator on the marker itself. Just because you don't like this approach does not mean people who don't share the same views are idiots who don't know how the scope works.

[colorado.rob]

I do know what's the difference between AC/DC means. And I still prefer trigger level to be displayed at all times (it's like you can measure min/max values of waveform regardless of channel coupling) with coupling indicator on the marker itself. Just because you don't like this approach does not mean people who don't share the same views are idiots who don't know how the scope works.

Thank you.  And -- when both the channel and the trigger are AC coupled, that trigger marker *is* meaningful.

[DazA1]

Despite all the bugs, the device is very useful for me. It's a pity that Siglent will never fix them. 

I couldn't agree more, sadly there seems to be little interest in fixing these bugs.

Its a shame really as it's a really useful bit of kit.

[N8AUM]

Can someone explain for dummies like myself why only the voltage level is displayed while in AC trigger mode unlike having both the voltage and the horizontal line showing up while in DC trigger coupling mode?

73  N8AUM  Vidas
 

[sng61]

after a week of using the oscilloscope 1202X-E has become very slow even immediately after starting. Delay greater than 1 second on simplest operations. May be something to configure or to do a memory reset and some settings...?
And why is this happening??

[rs20]

Can someone explain for dummies like myself why only the voltage level is displayed while in AC trigger mode unlike having both the voltage and the horizontal line showing up while in DC trigger coupling mode?

73  N8AUM  Vidas

Because if you have a 1Vpp AC signal superimposed on a 5V DC level, and the oscilloscope set to AC trigger mode with the trigger level at 0.5V; the trigger circuitry will only see the 1Vpp AC signal, and will thus trigger successfully. However, drawing a line at 0.5V on the oscilloscope screen will not touch the curve anywhere. Conversely, if the trigger were set at 5.5V, it would appear to pass through the curve on the screen, but the trigger cicuitry wouldn't activate, given that it is only seeing a 1Vpp signal.

In summary, the line becomes completely meaningless; it doesn't represent anything relevant or useful anymore.

If you're still confused, recall that "AC coupling" (in the vertical/channel menu) and "AC trigger mode" (in the trigger menu) are totally different things. You'll have a hard time understanding what's going on here if you think they are the same thing.

[rf-loop]

Can someone explain for dummies like myself why only the voltage level is displayed while in AC trigger mode unlike having both the voltage and the horizontal line showing up while in DC trigger coupling mode?

73  N8AUM  Vidas

When trigger coupling is AC it do not care vertical DC level. Trigger level setting is relative only with higher frequency signal level. So if signal is example riding on moving DC (very low freq) signal position on the screen is movin g up and down on the screen but we want trig to this higher frequency signal what we are interest and so that it keep this relative trigger level.  Now if we show trigger position marker on the screen right side as when it is if T coupling is DC it do not mean anything exept if we then move it up and down when signal is moving up and down. With different signals this may be very confusing mess.

Here two very poor image quality GIF buth still they show idea. You look them and you can see this principle.

In both cases Signal what we want trig is 3MHz 300mVpp sine. This sine is combined with bit over 300mVpp triangle what frequency is 0.1Hz (100mHz) THis moves 3MHz sinewave signal up and down on the screen.

First GIF you can see two things. When signal fall enough down it loose trigger and after it rise to triggel level it trig.   When level change trigger position in 3MHz signal change and you can see signal shift horizontally when level continue changing.   Trig is fixed to vertical100mV level (DC) because I have set trig level 100mV just for this demonstration.

Next GIF. Only change is trigger coupling. Now it is AC and you can imagine where is trigger position when signal moves up and down. Signal keeps also horizontal position (as long as signal vertical moving is quite slow) because trigger is only relative to this 3MHz signal and it do not care this near DC component. As you can imagine if there is now trigger level marker it also need move up and down. Think if this up and down moving happen with some other frequency...

Trigger level adjusting knob. In trigger coupling DC it set trigger to 50% signal p-p.

In AC mode it set trigger level to signal average (0). If signal duty is 50% average is middle and it is triggel level 0. If signal Duty is near zero also trig position zero is too near signal bottom. My personal opinion is that it is more useful if this 50% button also works also in trigger AC coupling so that it check signal p-p and set this for trigger level so also with very low dyty signals with this button can get reliable trig what user can then change if he want.

Do not care image tresolution. Only look signal  shape and how it moves in different trigger coupling.

[rf-loop]

after a week of using the oscilloscope 1202X-E has become very slow even immediately after starting. Delay greater than 1 second on simplest operations. May be something to configure or to do a memory reset and some settings...?
And why is this happening??

I have used this scope after beginning of May. I have  never meet this kind of "feature".
And I have tested it lot. Drop tests on every corner exept front panel, hard break power with random freq, give other person who do not know anything about scopes to do random settings and "monkey" adjustments even these what I do not never do because tens of years knowledge and experience...may reject me to do most stupid things.  Nothing to report but just normally working scope.


But still if there is something... perhaps possible normal front panel button "default" do not default all. Least I do not have checked every single detail.

There is default and security erase function also selectable in menu.

Go to Save/Recall
select Recall
in menu, select type: Security Erase  (it erase all your saved things including what you have defined for front panel default button!! )
then press Recall

then
in menu, select type: Factory Default
press Recall

After it is finished.

Shut off scope

Then turn on.

(there is now chinese language)

Press Utility.
Press language (this read there also with englihs) and select language for you.

[tautech]

after a week of using the oscilloscope 1202X-E has become very slow even immediately after starting. Delay greater than 1 second on simplest operations. May be something to configure or to do a memory reset and some settings...?
And why is this happening??

Following on from rf-loop.

I don't know why this might happen but I suggest using the default button and start again from the factory settings.

In the future if you don't want to loose your setting by using factory default, you can set your own user defined default settings (Ch's on, 10:1 inputs, Trigger levels, display settings etc) from within the Utility menu.

General description of it here:
https://www.eevblog.com/forum/testgear/new-siglent-sds1000x-e-oscilloscope-based-on-xilinx-zynq-7000-soc-architecture/msg1196101/#msg1196101

[PA4TIM]

On the SHS1062, I think most of the strange things are not firmware bugs, could it be a wrong or not connected pin from an IC ? That also gives random faults. This week I planned to change the glass soldered fuse for a sand-filled in decent clips. If I have time I will look for floating pins.

 I decided to buy the scopemeter after I found the problem in a very difficult repair thanks to the logging function of the scope. 
The last days I'm diving in to all possibilities and functions of the scope, I always do that with new instruments. Things that happened:
- I saved two waveforms. Recalled 1 of them  and used it to play with cursors ans measurement values. The scope became very slow in response, the saved waveforms disappeared from memory and then the scope stalled.  The stalling happened when I pressed the scope button while one of the sub-menus was still visible. After rebooting it worked but waveforms are still  gone. Tried to stall it again by doing the same thing several times but no result. Restored to factory settings and everything was fine again.

- A very strange one, I was in playing around a bit in scope mode and by accident pressed a wrong key (I think the scope key) . A menu popped up I have not seen before and I can not find it again. It is only graphics, no text. F1 and F2 are pulseshapes for dutycycle measurements, F3 and F4 are the symbols for rise and fall time measurements.  No values in the menu. Measurement values appeared on the screen not in the F-menu blocks.Then it disappeared, I think I pressed F5 but I'm not sure.

- sometimes screens "merge", it looks like the old screen is not complete erased when the new one appears. Have seen it 3 times now.

- A few seconds after run/stop the trace disappeared. I can not repeat it so again I 1 time event

I'm doing this from memory, I made notes but can not find them. But I do not think it are real bugs. But it is not a good thing. Like it is running under Windows XP 
Strange enough I still like the scope. 

[Gandalf_Sr]

how do you select which channel to display?

This is how most multi-channel scopes work.  Press [Ch1] button and it lights up and channel 1 data/adjustments are shown/possible.  Now press [Ch2] button, channel 1 trace is still visible but Channel 2 data/adjustments are shown/possible.  To go back to channel 1 for adjustments, just press [Ch1] once.  To remove a channel from viewing, make sure that channel has control and then press the [Chx] button - each time you press it the display of that channel will appear/disappear.

Hope this helps.

[ebastler]

how do you select which channel to display?

This is how most multi-channel scopes work.  [...]

Based on the full post from k1ttt, I wonder whether he meant to ask about switching the displayed measurement values between channel 1 and 2, not the trace display itself?

If that's the question -- I do not have the scope, but the section titled "Parameter Measure" in the user manual seems to describe this. After pressing the [cursor/measure] button twice, measurement values and channels are selected using the function buttons below the screen. It's described on page 20 and onwards in the manual version I found online, https://mediacdn.eu/m/media/wysiwyg/siglent/Downloads/Manuals/SHS800_UserManual.pdf.

[k1ttt]

https://mediacdn.eu/m/media/wysiwyg/siglent/Downloads/Manuals/SHS800_UserManual.pdf.

in that manual figure 2-1 on page 6 it shows 4 values that show after you press the auto button.  if you have 2 channels displayed it still seems to show only CH-1 values, except once somehow it switched to CH-2 but we couldn't repeat that.  showing those 4 seems to be related just to the Auto function and they are not displayed like the parameter measurements which are on top of the traces.

[tautech]

I am trying to help a friend who has a new SHS-800 series scope, he brought it to me and we went through some of the basics in about 2 hours while I was pulling answers out of the dvd manual and knowledge of other scopes.  we both saw one thing that I could not explain and after he left I kept the pdf manual to try to explain it and still couldn't.  we had 2 probes attached to the scope, press auto and both traces would show up.  blue for channel 1 on top, red for ch2 on bottom, and overlaid on the bottom trace was in blue ch1 signal parameters like Vpp, Prd, Mean, and Freq.  These show up in the user manual Figure 2-1 on page 6 under Automatic Settings.  Our questions are:

SHS810 here. 

1. besides pressing Auto can you turn on these values manually?

Not apparently. 

2. When displaying 2 channels can you get both of their parameters displayed?

No, only one or the other.

3. my friend pushed some buttons while I wasn't watching and got it to display ch2, but then it went back to ch1 and we couldn't figure out what he did to get ch2 back.  how do you select which channel to display?

Use the Cursor/Measure button and toggle through the options available.
Mode = Manual (Use F1), then Ch selection is visible and you select the type and channel and/or Math functions.
When all of the five boxes above the Function buttons are showing measurements (toggle the Cursor/Measure button) pushing any of the function buttons will give options of Voltage, Time, Delay, All Measure and Return (Exit)
Each of Voltage, Time and Delay are user definable for the source (ch) and the measurement sub type (p-p, mean, Vrms etc)

Spend some time bashing around in Measurements to really get a handle on it.

[Arjan]

Got my 1202X-E last Friday and so far quite happy with it. It did freeze once when I enabled FFT but I've been unable to reproduce that.

Anyway, my rather silly question is if there is any way to make scope music (YouScope etc) display nicely on this? In regular mode the waveforms are updating plenty fast but as soon as I switch to XY mode it seems to update only twice a second.

Now obviously displaying scope music nicely is not a requirement but I do have a use for an XY display that updates properly at audio frequencies (yes I do have software for that as well but...), so are there any settings that will make this work better? Or would improving this require a firmware update?

[boggis the cat]

Boggis, I appreciate that you're trying to find bugs and you probably have found several.

Confirmed several, found the video line bug.  (Difficult to check without a calibration source.)

However, in the case of not displaying a line when you go to AC-coupled triggering, I am with rf-loop that this is not a bug - it should show a numeric level but no line on the screen.  Watch Dave's video above which is absolutely on point, particularly after 17:17 if you want to save time.

The way I have seen other 'scopes handle this is to show the level position as you adjust it.  (I don't see why you'd want to set it, with AC coupling, really.)  We had a Tektronix in today (DPO 2024B) so I had a quick look at this and it does allow trigger adjustment when AC coupled, and also indicates the level on the display.

I think that Siglent should stick to displaying a trigger level position on the main display if you are able to adjust it.  If you know of other 'scopes that don't indicate the level, but still allow you to set it (using the numeric indication only), then perhaps this is a convention -- but it just seems broken to me.

I'm waiting for the new firmware but meanwhile, I'm using the SDS1202X-E and it is doing just fine; I have yet to experience a bug that's stopped me doing anything I have wanted to so far.

Some people have obviously been experiencing more problems than others.  I haven't had to use the 'scope on anything yet and have simply been familiarising with it.  Nothing I have planned should present a problem for it.

This isn't a high-priced instrument, so you can't expect it to be as polished as similar models costing multiples of what this one does.

I have one other thought/theory about the phantom blip you see in the center of the screen when nothing is connected to the input; digital cell phones pulse RF energy out (try holding one near your speakers) and, even with nothing connected, even with maybe a scope probe connected where the tip is shorted to the ground croc-clip (which forms a small loop antenna), a real signal pulse is being detected which is causing the triggering. Putting a shorted BNC connector on the input might not even make this go away as the PCB trace inside the scope between the BNC connector and the ADC front end might be enough to pick up a signal.  However, I see this as an exercise in futility if you're looking for bugs with no input connected!  My Agilent and Fluke multimeters show fluctuating voltage readings when I have nothing connected to their probes 

No, that isn't the case, and isn't what I am concerned about (a noise source isn't a repetitive signal, so I think I see why you're thinking about interference from a signal source).

It seems that I am not getting across my main points about this behaviour.  There is the change in behaviour, suggesting some parameters change from default, and there is the rather odd signal positioning.  Only Siglent know why the behaviour shifts (some sort of retriggering with new parameters would be my guess) -- and it is probably not going to be an issue for real use, particularly if you do set the trigger.  (Poor coding is still something worth fixing.)

The signal issue seems to be an artefact of how the 'scope samples.  If you look at the 'dot' display then you can see that the samples are not uniformly distributed, and you end up with a division at the centre (trigger location) where the triggered samples are stacked together.  My present assumption is that this is just an aliasing effect, but I do wonder if this would present problems for real signals.  (The Tektronix DPO 2024B didn't behave like this.  There is no 'dot' mode available, though, and the behaviour is generally different.  Apples and oranges, perhaps.)

I have a lot of experience working on 'scopes for verification of specs, but that is quite different from poking about in odd corners and uncovering behaviour that may not be documented.  For many things, unless something is documented you can't really tell if it is a bug, or intentional behaviour.

[boggis the cat]

In regular mode the waveforms are updating plenty fast but as soon as I switch to XY mode it seems to update only twice a second.

XY mode is deathly slow, for some reason.

I have no idea why, as this 'scope has plenty of processing power. 

Hopefully they will sort it out.

[Arjan]

XY mode is deathly slow, for some reason.

I have no idea why, as this 'scope has plenty of processing power. 

Hopefully they will sort it out.

Thanks for confirming. Left feedback at siglent.com to ask for a firmware update to fix this. The XY mode is really quite useless to me this way.