Siglent SDG1032 as bad as rigol DG812? - Page 1
Forum section: electronics / testgear

author: eTobey
author_rank: Super Contributor
timestamp: May 16, 2024, 07:11:21 am
content: Found some issues that dissapointed me quite a bit. Never thought i would be that dissapointed, since the step from the Rigol DHO814 to the Siglent SDS814X HD was a good one.Some issues on my list have not been fixed in 7 years (as they can be found in an old youtube video).- Turning the knob faster, has the opposite effect of slowing down the change in the number, to almost non at all.- Turning it in the right speed takes still 13 seconds to get from 0 to 100.- Low level of -560mV for 5.3ms when changing waveform from sine to square- Changing values of 100´s down to zero and back up again changes the cursor to 1´s...- Changing the frequency of one channel, disrupts signal of other channel.- Polarity invert changes waveform to negative values, even when lowlevel is set to 0V.

author: 2N3055
author_rank: Super Contributor
timestamp: May 16, 2024, 07:35:10 am
content: Quote from: eTobey on May 16, 2024, 07:11:21 am

author: tautech
author_rank: Super Contributor
timestamp: May 16, 2024, 07:47:21 am
content: Quote from: eTobey on May 16, 2024, 07:11:21 amBoot to Default is the default setting.Boot to Lastsaves all settings.^^^ something we set before dispatch.

author: eTobey
author_rank: Super Contributor
timestamp: May 16, 2024, 07:57:52 am
content: Quote from: tautech on May 16, 2024, 07:47:21 amI set that too, but the firmwareupdate reset it. Should have checked...

author: eTobey
author_rank: Super Contributor
timestamp: May 16, 2024, 07:59:44 am
content: Lucky me, i havent hooked up my circuit yet:Set up a square wave from 0V to 3.3V. Set up FM mod -> boom! -1.6V

author: EvgenyG
author_rank: Regular Contributor
timestamp: May 16, 2024, 08:16:23 am
content: Wow. One of the reasons I sold my no-name signal gen to buy an SDG1000X was that no-name gen would output -10.5v during OS boot. Found that "feature" the hard wayPlease don't tell me that SDG1000X still has teething issues.

author: tautech
author_rank: Super Contributor
timestamp: May 16, 2024, 08:22:34 am
content: Quote from: EvgenyG on May 16, 2024, 08:16:23 amOutputs are open at boot unless you configure them otherwise.

author: ArdWar
author_rank: Frequent Contributor
timestamp: May 16, 2024, 08:40:16 am
content: Who connect their sig gen to DUT first before powering it on anyway?Sure I often do that with DMM or PSU or scope, but I definitely draw the line with SG and SA...

author: tautech
author_rank: Super Contributor
timestamp: May 16, 2024, 09:42:11 am
content: Quote from: ArdWar on May 16, 2024, 08:40:16 amSimply, those that need to.Not all instruments are used in a lab environment.

author: EvgenyG
author_rank: Regular Contributor
timestamp: May 16, 2024, 09:57:15 am
content: Quote from: ArdWar on May 16, 2024, 08:40:16 amI know right? The DUT was under test when power briefly went out. That was followed by special effects(magic smoke) as soon as arb gen turned back on with -10.5v.

author: EvgenyG
author_rank: Regular Contributor
timestamp: May 16, 2024, 09:59:12 am
content: Quote from: tautech on May 16, 2024, 08:22:34 amWell, if they output same signal as at time of shutdown that is fine. If I shut it down with 200mVppk and then turn on and it has 2Vppk that would be unacceptable.

author: tautech
author_rank: Super Contributor
timestamp: May 16, 2024, 10:10:14 am
content: Quote from: EvgenyG on May 16, 2024, 09:59:12 amWell when you get yours you can test its behavior to your hearts content.Output ON at boot is not a setting anyone would use much unless you need it as I did a few months back on a film set we equipped with instruments.They all had to boot to their preset states at power ON which was done by wireless control at the Directors command.As is normal with takes on a film set, not all go as planned as the humans involved are unfortunately unprogrammable.Whereas the instruments performed admirably.Documented in this post:https://www.eevblog.com/forum/chat/movie-scopes-(and-other-tm-props)/msg5201928/#msg5201928

author: EvgenyG
author_rank: Regular Contributor
timestamp: May 16, 2024, 10:29:54 am
content: This is a really cool video! Just change the last slide to Siglent logo and you have an ad for them ready

author: tautech
author_rank: Super Contributor
timestamp: May 16, 2024, 10:45:22 am
content: Quote from: EvgenyG on May 16, 2024, 10:29:54 amYeah it was a lot of fun and being behind the scenes a real privilege.Only 5km down the road was a real bonus too as trudging into town takes the gloss off things.However we were under NDA until the film went public before I could share it here.Not our first film rodeo even for TE and the block of land we have here has hosted several film sets over the years.Another done some years back:https://www.eevblog.com/forum/testgear/true-analog-scopes/msg4583536/#msg4583536

author: BillyO
author_rank: Super Contributor
timestamp: May 16, 2024, 02:59:05 pm
content: Quote from: EvgenyG on May 16, 2024, 09:57:15 amThat's why I built these for all my benches:

author: Aldo22
author_rank: Super Contributor
timestamp: May 16, 2024, 03:54:25 pm
content: The FY3224S even blows out +7-8V when switching it off. Even if the channel is not active.If I have something sensitive, I always put a 20dB attenuator in.Attachment shows FY3224S saying goodbye (with attenuator).

author: EvgenyG
author_rank: Regular Contributor
timestamp: May 17, 2024, 03:27:05 am
content: Could you please do the same measurement at power up? One of the things that must be tested on all signal gens during reviews: what happens at power up/shut down. A bad design could kill your DUT.To SDG1000X owners, could someone please do same measurements on your unit?The signal gen may change waveform/frequency on power down but not go higher than set amplitude/offset. Ideally it should just cut out.On power up, I expect exactly 0 volts until I press CH1/2 on buttons.

author: Aldo22
author_rank: Super Contributor
timestamp: May 17, 2024, 08:30:36 am
content: Quote from: EvgenyG on May 17, 2024, 03:27:05 amThe FY3234S is even worse at power up (Attached image).But that was to be expected. However, you might not expect another voltage increase when switching off, which is why I only showed that at first.The internal AWG of the Hantek DSO2000 is somewhat better.It remains at 0 when switched off.At power up, however, it's approx. -3.8V max.

author: eTobey
author_rank: Super Contributor
timestamp: May 17, 2024, 03:31:33 pm
content: Quote from: EvgenyG on May 17, 2024, 03:27:05 amToo much expectation for a >300 bucks device...I might not even use this on my circuit and send it straight back...Picture of SDG 1032X on turning off:

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 17, 2024, 04:15:40 pm
content: What is your setup on your scope and AWG that you're able to see that?I tried with the SDG2122X connected to my SDS2504X+, and I couldn't get anything like that. I tried with the channel power button, and power cycling the AWG, and didn't get anything like that at all. Cycling the channel gave a clean waveform that simply ended/disappeared when disabled. No effect at all while power cycling the AWG. Even searching in History didn't give me anything like that.I dunno if the 2000 series is that different than the 1000 series in this regard. 🤷

author: eTobey
author_rank: Super Contributor
timestamp: May 17, 2024, 06:53:00 pm
content: Quote from: KungFuJosh on May 17, 2024, 04:15:40 pmI got squarewave set up with 0V to 3.3V or there abouts. I used 5s period, since it only seems to happen from high level on. t also only seems to happen on channel 1.Follow this topic here:https://www.eevblog.com/forum/chat/will-this-signal-destroy-my-uc-pin/

author: eTobey
author_rank: Super Contributor
timestamp: May 17, 2024, 06:54:33 pm
content: I just tried to see, when the sinewave amplitude would decrese with rising frequency: It did increase to 4.17V amplitude, with a set up amplitude of 3.3V.Am i missing something?

author: Njk
author_rank: Frequent Contributor
timestamp: May 17, 2024, 06:58:02 pm
content: Just blew up the dust from my DG812 to check it once again. But found nothing new.Quote from: EvgenyG on May 17, 2024, 03:27:05 amHow else it can be since there is a mechanical relay that keeps the output physically disconnected unless user pressed the key to turn the channel on. Power disappears, the relay disconnects. Actually, there are a lot of relays as the entire voltage range is not continuous. According to the doc, it's broken into 10 scales, which are switched by the mechanical relays. No doubt a curious user can capture a nice trace for relay bounce event and show the screenshot. But I doubt it's something unexpected.

author: thm_w
author_rank: Super Contributor
timestamp: May 17, 2024, 09:49:48 pm
content: Quote from: eTobey on May 17, 2024, 06:54:33 pmAre you sampling a 30MHz sine wave at 100ks/s?

author: EvgenyG
author_rank: Regular Contributor
timestamp: May 18, 2024, 02:32:15 am
content: Quote from: Njk on May 17, 2024, 06:58:02 pmUnfortunately this is not the case with SDG1000X and the FY gens, see screenshots above.

author: csuhi17
author_rank: Frequent Contributor
timestamp: May 18, 2024, 04:53:15 am
content: DG912ProIn its settings, I could not find one that would start with an active output, and I could not detect an abnormal wave when it was switched on.no problem with normal shutdown.when cutoff the main, it produces similar waves on the active output.Pictures 3 and 5 with 50 ohm terminationPictures 2 and 4 are without 50 ohms.

author: eTobey
author_rank: Super Contributor
timestamp: May 18, 2024, 05:38:39 am
content: Quote from: thm_w on May 17, 2024, 09:49:48 pmNo, i sampled a frequency sweep of a sine wave with 100ks/s. I did it again with 10Ms/s, and it makes no difference.Quote from: csuhi17 on May 18, 2024, 04:53:15 amIf you call an exceeeding of a level of about 3-4V not a problem, then i wonder, on what circuits you work, that dont have a problem with this.How does this look with a 3.3V level? How do both channels look then?

author: csuhi17
author_rank: Frequent Contributor
timestamp: May 18, 2024, 06:33:01 am
content: Quote from: eTobey on May 18, 2024, 05:38:39 amMaybe I misunderstood your question.When the channel is active and I press the power button and press restart or shutdown, the output waveform is the image of R1.There is only a problem with it in the event of a power failure.Which could be solved with an uninterruptible power supply.This is the Pro version, not the older one. DG912 ProAnd R0 is the 3.3V square wave.CH2 with 50 ohm termination.Without CH3 50 ohms.

author: rf-loop
author_rank: Super Contributor
timestamp: May 18, 2024, 08:22:34 am
content: Quote from: eTobey on May 17, 2024, 03:31:33 pmSDG1062X Power button shut OFF whenCh1 1kHz square 0-5VCh1 50ohm (SDG), Ch1 in oscilloscope 50ohmand Ch2 5Vdc out.Ch2 HiZ (SDG) and Ch4 in oscilloscope 1Mohm(of course SDG hardware output impedance is always 50ohm)Both channels direct connect with ~1m Suhner RG223/UScope Trig: Ch1, Edge, Rising, NormalWhere is the problem?SDS3104X HD

author: eTobey
author_rank: Super Contributor
timestamp: May 18, 2024, 10:40:32 am
content: Quote from: rf-loop on May 18, 2024, 08:22:34 amThe Problem is, that limits were exceeded.You obviously havent tried much with it. It seems to only happen on high level. Turn it off on high level.

author: 2N3055
author_rank: Super Contributor
timestamp: May 18, 2024, 11:24:02 am
content: Quote from: eTobey on May 18, 2024, 10:40:32 amWhat high level?You used 4V he used 5V...If you use 10V (max) then there cannot be higher pulse...I suspect there is something in your setup that shoots in inductive spike when you forcefully shut off device...Maybe ground loop of sorts..

author: rf-loop
author_rank: Super Contributor
timestamp: May 18, 2024, 01:56:05 pm
content: Quote from: eTobey on May 18, 2024, 10:40:32 amDo you really want to embarrass yourself at this point too?At least if you're starting from scratch to judge what I've done for testing this device for as long as this model has been around and the same goes for some previous models as well. In that case, you're guaranteed to bump your head into an old pine tree.I think it is now better I'll stop feeding the Troll.

author: Martin72
author_rank: Super Contributor
timestamp: May 18, 2024, 02:25:50 pm
content: Profile-->Modify Profile-->Buddy/Ignorelist-->Edit...

author: eTobey
author_rank: Super Contributor
timestamp: May 18, 2024, 02:37:07 pm
content: Quote from: rf-loop on May 18, 2024, 01:56:05 pmI was not referring to the device itself, or the topic. I was referring to this issue. Mind the language barrier, and that i sometimes choose the wrong words.This issues seemingly only happens, when there is a high level.

author: eTobey
author_rank: Super Contributor
timestamp: May 18, 2024, 02:41:36 pm
content: Quote from: 2N3055 on May 18, 2024, 11:24:02 amThere is not much setup:Gen -> allig. clips -> probe -> scope

author: Mortymore
author_rank: Frequent Contributor
timestamp: May 18, 2024, 02:57:04 pm
content: Are you referring to some overshoot when the generator is turned OFF with the outputs still on, right?It seems that it could happen depending were the square wave is caught at power off. Sometimes it doesn't happen, sometimes overshoots up, other down.Anyway, I suppose that the ON/OFF output buttons serves a purpose, and that doesn't happen when they're usedEDIT: It would be so much easier for everybody if at least you had the trouble to proper stand your case with adequate description and images. After all you have the devices.

author: temperance
author_rank: Super Contributor
timestamp: May 18, 2024, 03:16:12 pm
content: That what you are seeing is probably a common mode transient caused by you switching of the function gen with the power switch. You will probably see the same signal even with the output disabled.Infact, let me try that. Yes, it is a common mode transient caused by the almost infinity fast opening and closing times of mechanical switches.@ eTobeyyour problem has nothing to do with a language barrier. It's the non stop bashing. For example the tittle of this topic:Siglent SDG1032 as bad as rigol DG812?-You could state: Weird signal on SDG1032 output when switched on and off.-In your post you explain in a proper technical way the problem. Instead you scream high and low, insult people and don't provide a proper context.In the end after the dust has settled and it turns out to be your fault your next step is bashing the manual.Go and think for a while where this common mode noise is coming from and why your scope is displaying this signal (You might learn something very valuable and something you might find useful one day). What are the rise and fall times of a mechanical switches?EDit: something to make you think a little harder and to mess with your mind in a positive way:connect a shorted probe to the signal gen BNC GND. Set the scope to something like 5 µs and 1 V div. normal trigger 0.5 V. Switch the function gen on/off a few times and observe what happens.

author: nctnico
author_rank: Super Contributor
timestamp: May 18, 2024, 04:05:26 pm
content: Quote from: temperance on May 18, 2024, 03:16:12 pmIt is too slow to be a common mode transient. Those are typically in sub-microsecond time spans. What you see in the screenshots is typical for less than optimal power-supply sequencing at power down.

author: 2N3055
author_rank: Super Contributor
timestamp: May 18, 2024, 04:31:46 pm
content: Quote from: nctnico on May 18, 2024, 04:05:26 pmExcept that nobody can reproduce it in such form.And you that don't own that AWG (or even similar one) are making conclusions based on some scope images that are made God know how. Scope was sampling at 2Ms/s using Peak detect mode. Any high frequency would be sampled as outside envelope, not as base frequency..I don't have SDG1000X either. But believe RF-Loops results, who made VERY comprehensive tests at the time. He knows it inside out.If some specific test could be defined he could run it.But the way I see it, whatever is on the scope screen has more to do with what and how was tested.You and I might disagree from time to time but one thing I agree with you 100% is your signature.OP should connect scope to an AWG directly, use full memory, maximum sample rate, and try then.To exclude DUT, it's power supply, connection to computer ground via ICP connector etc etc..When something is wrong, you reduce variables. Eliminate sources of confusion. Reduce problem complexity.

author: eTobey
author_rank: Super Contributor
timestamp: May 18, 2024, 04:51:39 pm
content: Quote from: temperance on May 18, 2024, 03:16:12 pmI will do this, but only if you tell me, what you expect to see/happen.And dont anybody else dare to answer this request!

author: eTobey
author_rank: Super Contributor
timestamp: May 18, 2024, 05:04:49 pm
content: Quote from: 2N3055 on May 18, 2024, 04:31:46 pmWell even the best specialist can miss a detail... and that detail was the "high level" which i could not explain to you.Quote from: 2N3055 on May 18, 2024, 04:31:46 pmI am happy, that you realized, that you can see yourself on what ever side you want. That is the beauty of this signature. ;-)Quote from: 2N3055 on May 18, 2024, 04:31:46 pmThe OP never had the DUT never connected to that AWG, as he is not that stupid to hook it up to an unknown device.But tell me, how should full memory and sample rate change anything on that signal???

author: eTobey
author_rank: Super Contributor
timestamp: May 18, 2024, 05:06:28 pm
content: Quote from: Mortymore on May 18, 2024, 02:57:04 pmPortugal 1:0 Finland

author: temperance
author_rank: Super Contributor
timestamp: May 18, 2024, 05:10:58 pm
content: I just tried to reproduce the problem captured by eTobey but the sig gen. is a SDG2042. It does a clean shut down every time. The only artifacts one can see are caused by common mode currents. But they look different. (There is nothing connected except an oscilloscope short to GND).So maybe I'm wrong.QuoteSomething like this

author: rf-loop
author_rank: Super Contributor
timestamp: May 18, 2024, 05:45:42 pm
content: Quote from: Mortymore on May 18, 2024, 02:57:04 pmI want look this bit more when I have time for it.If it is very "random" after shut off with power line, I want still catch it (these upper level "peaks" in end.)The signal outputs should be cut off before the collapse of the operating voltages progresses to a level where the device starts to run out of control.How was signals connected. (in your image looks it looks like well connceted with external 50 ohm and coaxial but still I like facts and not my quess.)What is your SDGHardwareversion.

author: temperance
author_rank: Super Contributor
timestamp: May 18, 2024, 05:57:52 pm
content: I'm able to catch this when the sig gen is starting. That's when some relays are switching just after boot.As soon as you attach even the smallest load onto the output, nothing of this can be seen at the output. Nothing abnormal.Edit: this is an SGD2042

author: nctnico
author_rank: Super Contributor
timestamp: May 18, 2024, 06:13:12 pm
content: Quote from: temperance on May 18, 2024, 05:10:58 pmYour screendump looks like what I'd expect where it comes to connecting / disconnecting mains. Also keep in mind that your SDG2042 is a totally different instrument and there might be different hardware versions as well.

author: eTobey
author_rank: Super Contributor
timestamp: May 18, 2024, 06:33:12 pm
content: Quote from: temperance on May 18, 2024, 05:10:58 pmDo you expect this to happen when turning it off and turning it on?

author: eTobey
author_rank: Super Contributor
timestamp: May 18, 2024, 06:38:12 pm
content: Quote from: rf-loop on May 18, 2024, 05:45:42 pmIts not really random. Just set up a 99% duty square and you should get it quite easy. I had it the first time just now.I got the probe now directly inserterted into the BNC, and it looks pretty much the same. See picture.

author: eTobey
author_rank: Super Contributor
timestamp: May 18, 2024, 06:39:37 pm
content: Quote from: temperance on May 18, 2024, 05:57:52 pmI would not care about a one time noise burst of about 80mV ;-)

author: Mortymore
author_rank: Frequent Contributor
timestamp: May 18, 2024, 07:29:08 pm
content: Quote from: rf-loop on May 18, 2024, 05:45:42 pmHi rf-loopThe AWG is an SDG1032X (upgraded to SDG1062X), SW version: 1.01.01.33R8 ; HW version: 02-01-00-24-00The cables used are a very old pair of RG-58/CU with 1m aprox.Only one feedthrough 50Ohm terminator was used at CH1 of the scope, were the square wave was applied.The over and undershoot captured in previous images, doesn't always happen. I could have posted a similar picture as yours, but it would have been redundant.I assume that the "spikes" seems to be controlled somehow, because there are flattops, when a differential voltage goes over roughly 1.5V.If any further info or diligence from me is needed, please inform.

author: eTobey
author_rank: Super Contributor
timestamp: May 18, 2024, 08:29:56 pm
content: Quote from: Mortymore on May 18, 2024, 07:29:08 pmWhich one exactly?

author: Mortymore
author_rank: Frequent Contributor
timestamp: May 18, 2024, 08:36:57 pm
content: Quote from: eTobey on May 18, 2024, 08:29:56 pmThe terminator? No brand. Does it matter for a low frequency signal?

author: eTobey
author_rank: Super Contributor
timestamp: May 18, 2024, 09:14:39 pm
content: Quote from: Mortymore on May 18, 2024, 08:36:57 pmProbably not, but i might want to buy one ;-)

author: Aldo22
author_rank: Super Contributor
timestamp: May 18, 2024, 10:30:34 pm
content: Quote from: eTobey on May 18, 2024, 09:14:39 pmYou can make one yourself to start with.I made one from 2x100Ω SMD.Certainly not perfect, but much better than without (attached images).Or something like this:https://de.aliexpress.com/item/1005005986180797.html

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 18, 2024, 11:00:52 pm
content: I have a couple Rigol ADP0150BNC. Which will probably be the only Rigol gear I ever own. 🤣

author: Sensorcat
author_rank: Regular Contributor
timestamp: May 19, 2024, 01:31:11 am
content: Quote from: KungFuJosh on May 18, 2024, 11:00:52 pmUsually not needed. Many people think a 50ohm termination is necessary to avoid errors due to reflections at oscilloscope inputs. But this is only true if you use regular coax cables to the scope inputs. Up to several hundred MHz, the best thing you can connect to these inputs is a good 10x probe instead. Its cable is not a regular coax, but a special lossy transmission line, which effectively solves the problem at no additional cost, since you need these anyway. If you have some sort of coax wiring on your desk, with BNC connectors, all you need is a BNC probe tip adaptor. A cheap and easy solution, which does not require external terminators (which are accesories offered quite often in low quality), and no internal termination (which restricts the choice of scopes to expensive models).Best source I know to explain the details:https://cleverscope.com/downloads/articles/THE_SECRET_WORLD_OF_PROBES_OCt09.pdf

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 19, 2024, 01:37:41 am
content: Quote from: Sensorcat on May 19, 2024, 01:31:11 amIndeed, especially considering my SDS2504X+ has 50Ω inputs when I need it. However, they have come in handy a few times over the years. The quality of them seems fine for what they are.

author: Sensorcat
author_rank: Regular Contributor
timestamp: May 19, 2024, 01:48:40 am
content: Quote from: KungFuJosh on May 19, 2024, 01:37:41 amAnother advantage of the 10x passive probe everybody has is the DC load: You can avoid reflection issues and have input resistance of 10MΩ at the same time.Good for you if you have 50Ω inputs. My intent was to write something useful for those who don't.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 19, 2024, 02:12:09 am
content: Quote from: Sensorcat on May 19, 2024, 01:48:40 amThank you. 😉 Anyway, sometimes simple coax is the correct choice, and those individuals without the 50Ω inputs will need the terminators.

author: Njk
author_rank: Frequent Contributor
timestamp: May 19, 2024, 10:21:13 am
content: Quote from: nctnico on May 18, 2024, 04:05:26 pmDefinitely. Looks like the power good signal from PSU is missing or the sw pays little attention to it. It's impossible to specify everything by formal requirements. But customers typically assume that the designer is from the same planet.

author: rf-loop
author_rank: Super Contributor
timestamp: May 19, 2024, 11:03:26 am
content: Quote from: rf-loop on May 18, 2024, 05:45:42 pmQuote from: Mortymore on May 18, 2024, 07:29:08 pmI have now been testing this phenomenon for several hours repeatedly, last evening and continuing today. I haven't counted the repetition times, but I estimate at least more than 200. I also did experiments with different frequencies, amplitudes and offsets. I have never seen anything similar that appears in your picture right when channel 1 ends. Those nearly 2V spikes.Each time I have seen a quite nice landing.My HW version is the same as yours.I run FW version .33R1 because I have modulation and ramp etc. modifications that should be done again if I update. There are more important things to do, so I'll update sometime later if necessary. I also can't really believe that this would affect exactly this behavior when the operating voltages start to drop when the power goes OFF.It is actually impossible to completely prove that something does not exist.Besides, even though the HW version is the same, there are still differences, in fact in every component. (for example, if one were to examine very carefully at which point the relays related to the output stage of the signal change state after PowerOFF when all power supplies voltages start fall, time differences will certainly be found.)

author: eTobey
author_rank: Super Contributor
timestamp: May 19, 2024, 11:25:31 am
content: I got:FW: 1.01.01.33R8HW: 03-00-00-24-00High level 3.3V, Low level 0VAnd almost 3V of "limit overshoot".And a mean of 4.5V for 240us

author: rf-loop
author_rank: Super Contributor
timestamp: May 19, 2024, 12:36:28 pm
content: @MortymoreHere just one random result during this PowOFF test.Yes there are some small differences with different frequencies, different levels and offsets etc...In this image full max voltages with HiZ loads. Ch1 1kHz, 20Vpp and Ch2 (scope Ch4) 10Vdc(signals connected directly using 50ohm coaxials)Least with my unit there can not find problem in output signals when hard PowOFF.But naturally my predictable rest of lifetime is not enough for test every possible setup combinations even once per setup.

author: eTobey
author_rank: Super Contributor
timestamp: May 19, 2024, 01:28:27 pm
content: Quote from: rf-loop on May 19, 2024, 12:36:28 pmIf you would choose a 100mHz square, and a 99% duty, you are more likely to hit that high level right at the beginning of the rest of your life.On that picture it looks like you hit that low level...

author: rf-loop
author_rank: Super Contributor
timestamp: May 19, 2024, 02:04:22 pm
content: Quote from: eTobey on May 19, 2024, 01:28:27 pmThat one magpie's nest type of signal connection that you recently brought up when you criticized the generator's frequency response. I will say one more and one last time. Most of the problems you'll encounter with oscilloscopes or generators are between them and the chair you sit. Next time I might say it less nicely.Here is 100mHz and 99% Duty. And again hard PowOFF.And yes, signal is 20Vpp and other is generator 10V DC out (also for trig)

author: eTobey
author_rank: Super Contributor
timestamp: May 19, 2024, 03:00:43 pm
content: Quote from: rf-loop on May 19, 2024, 02:04:22 pmIf you set up values, that are far away from those that showed the issue, and want to compare, you also have a problem between the chair and the screen.

author: TurboTom
author_rank: Super Contributor
timestamp: May 19, 2024, 03:38:33 pm
content: If you want to be sure that you won't overload your digital circuitry's input (Microprocessor?), why don't you set up a special test lead with a unidirectional protection diode installed in the connector closest to the DUT? If the threshold voltage in the conduction direction is still too high, you may want to use a protection (zener) diode with a small signal schottky diode in parallel.If you need something more versatile, set up two half-way powerful opamp followers, wired to two pots at their inputs and two clamping diodes at their outputs, connected to the signal - this, done properly and capacitively decoupled, will enable you to properly clamp any input signal asymmetrically in any desired way. It should also protect the DUT input from ESD to some degree.P.S. I never felt the need to use such a contraption with any of my AWGs (DG811++, DG4000+, SDG6000+, HDG2000, MSO2000S). But I made it a habit to use a scope to look at the AWG output signal before I connect it to a sensitive input.

author: mawyatt
author_rank: Super Contributor
timestamp: May 19, 2024, 03:49:06 pm
content: Quote from: TurboTom on May 19, 2024, 03:38:33 pmThe wisdom of experienceIf one is concerned about a power mains glitch/outage, then a UPS is in proper order!!Edit: BTW the same goes for the Power Supply for sensitive circuits!!Best,

author: rf-loop
author_rank: Super Contributor
timestamp: May 19, 2024, 04:52:32 pm
content: Quote from: eTobey on May 19, 2024, 03:00:43 pmYOU ask'd this (if you remember)! And you get it.And it still didn't show the problem you so desperately hoped for.

author: eTobey
author_rank: Super Contributor
timestamp: May 19, 2024, 05:22:10 pm
content: Quote from: rf-loop on May 19, 2024, 04:52:32 pmOf course it did not mean those values that i told you.I talked about spikes that went up to ~5V but you already set a level of 10V!Are you trying to hide the issue, or are you trying to make me look bad?

author: eTobey
author_rank: Super Contributor
timestamp: May 19, 2024, 05:30:59 pm
content: Quote from: TurboTom on May 19, 2024, 03:38:33 pmYes i do want to make sure. Seems like i have to make such contraption, or spend a few figures more for a gen.While trying and changing settings a lot, i do not really consider to get into a habit of checking the signal everytime. A contraption, that guards it well, no matter what, would be my choice.Since the storing of the settings also does not work in all cases, i will not trust this device anyway.

author: 2N3055
author_rank: Super Contributor
timestamp: May 19, 2024, 05:34:21 pm
content: Quote from: eTobey on May 19, 2024, 05:22:10 pmHe already did..https://www.eevblog.com/forum/testgear/siglent-sdg1032-as-bad-as-rigol-dg812/msg5505127/#msg5505127

author: eTobey
author_rank: Super Contributor
timestamp: May 19, 2024, 05:42:16 pm
content: Quote from: 2N3055 on May 19, 2024, 05:34:21 pmDude, thats the wrong level, and the wrong time on the signal, i tried to tell you, but it didnt work...

author: nctnico
author_rank: Super Contributor
timestamp: May 19, 2024, 07:54:44 pm
content: Quote from: eTobey on May 19, 2024, 05:22:10 pmYou make a good point here. When the generator is set to maximum output level, the output value is very unlikely to overshoot in the same way you and mortymore have shown. However, with a lower output level, the generator could overshoot when a mains interruption occurs. IOW: rf-loop should test with the same levels you and Mortymore have used. His screendump in the other thread does already show some negative undershoot.

author: Njk
author_rank: Frequent Contributor
timestamp: May 19, 2024, 08:35:50 pm
content: Gentlemen, you're right, of course. It may not be strictly related to any real use case. End of discussion?But I would like to say that the screenshots make me slightly concerned about the instrument's reliability because the voltages are dropping too soon. Perhaps I'm missing something, but with DG811, the process takes an order of magnitude time longer (see the image below). Similar signals, the yellow trace shows the DC waveform which is used to trigger the scope and the other trace is for the same 500 Hz square wave signal. There are almost 11 ms between the first sign of power problem in the left and the last falling edge in the right part of the screen. Both the channels are loaded with 50 Ohm pass-throug terminators. Nevertheless, the yellow line is horizontal, the voltage is not dropping. While on the screenshots above, despite the DC channel is not loaded, the voltage starts gradually decaying in less than 1 ms after the power off event. If enough energy remains inside?It seems in DG811 the power failure signal is generated well in advance, likely using the information from the primary side of the PS (as it should be done). What if Rigol is more used to design an instrument-grade PSUs in-house (whatever it costs), while it's natural for Siglent to outsource that work to contractors? That also explains why the problem can be seen not with every instrument, as it depends on exact model of the general-purpose PSU, which may vary from batch to batch.The timing may be directly related to the reliability because the device is controlled by application processor. Typically, a chip like that uses several power voltages and the power on and off sequences are not up to the user. The sequences are stipulated by the chip vendor and must be obeyed. To make it easier to use the chip, the vendor typically provides an auxiliary chip (PMIC) that performs the sequencing automatically. Anyway, for that processor, the sequence takes tens of milliseconds, IIRC.So on power failure notification, the processor have to gracefully finish with all the business logic and with all the housekeeping tasks like bad block re-allocation, etc., then, optionally, to disable as much peripherals as possible, and finally to instruct the PMIC to start with the power off sequence. That requires reservation of enough energy for PMIC. Otherwise, all the power voltages will be abruptly interrupted, violating the prescribed sequence. The vendor does not qualify the processor for such abnormal cases. Nobody knows what will happen. Perhaps nothing, but it's actually a Russian roulette.

author: rf-loop
author_rank: Super Contributor
timestamp: May 20, 2024, 08:14:57 am
content: Quote from: nctnico on May 19, 2024, 07:54:44 pmLooks like you did not read what I have told previously. Several tests with also using several different setups, example voltages and so on.With few exceptions, this forum is starting to look more and more like some kind of clown club.Take a look example at when @eTobey is wondering about the frequency response (in other thread) and then there is a kind of kindergarten-level connection of the investigated signal...where actually everything is wrong and of course there is a bug or issue in the devices...of course. Here, even vocational school kids don't make magpie nests like that.HeeHere below some few samples about tests. And these are one shots. Not selected shots like "try until wanted result". Maybe some others can do that on purpose.SDG1000XFW:1.01.01.33R1HW: 02-02-00-24-00Max Out V: 0-10 Vpk, 20Vpk-pk (HiZ Load and up to 10MHz. Over 10MHz half level)Source impedance 50 ohm.2pcs Suhner RG223/U between SDG and oscilloscope.SDS2504X HD. Inputs 1 Mohm10 kHz,1 Voffset, 300 mVpp1 kHz,0 V - +5 Vpk10 kHz,0 V - +5 Vpka. 1 MHz,17.5 Vppb. 1 MHz,17.5 Vpp1 kHz,17.5 Vpp10 kHz,17.5 Vpp1 kHz,10 Vpp10 kHz,10 Vpp1 kHz,5 Vpp10 kHz,5 Vpp1 kHz,2.5 Vpp10 kHz,2.5 Vpp1 kHz,1 Vpp10 kHz,1 Vpp1 kHz,500 mVpp10 kHz,500 mVppOf course, the some dog's chin can now wonder why I didn't test the 6 V level, or 3.33V level, is there something I'm hiding. If it continues to happen, I say: Grow up.I won't publish 300 more pictures because nothing else essential is shown in them.EOC

author: nctnico
author_rank: Super Contributor
timestamp: May 20, 2024, 09:14:03 am
content: Thanks for elaborating further on your testing. The conclusion has to be that there have to be differences between units then. Maybe Siglent decided to remove some capacitors or a capacitor with a different behaviour has been placed (*). 2 forum members have showed an effect your unit doesn't have.* Do not assume that ordering the same part number gets you an identical capacitor every time! This sounds silly but I have experienced this myself.

author: eTobey
author_rank: Super Contributor
timestamp: May 20, 2024, 09:23:26 am
content: Quote from: rf-loop on May 20, 2024, 08:14:57 amYet those "experts with a lot of experience" failed to figure this out and help this noob. Instead they trashed him again (hope that is the right translation). Yes, indeed it looks like a clown club!300 more pictures? You could have just choosen one (the right one) of them to satisfy me, or proven the fact, but you failed.

author: eTobey
author_rank: Super Contributor
timestamp: May 20, 2024, 09:35:03 am
content: Quote from: nctnico on May 20, 2024, 09:14:03 amI just noticed, that the "fun" happens in around 10ms, where as rf-loop has some action going on for 400ms!It seems that his device has some much bigger caps somewhere. Or some relais are different.

author: csuhi17
author_rank: Frequent Contributor
timestamp: May 20, 2024, 09:54:04 am
content: I was a little confused, the lack of language skills is a disadvantage for me.What is the end result, what causes this?From previous conversations, I came to the conclusion that if my signal generator and oscilloscope do not have the same earth.My micsig is operating on its own battery.andNot the method used by most of the other.Siggen -> aligatorclip -> scopeProbe10x -> scope.Then will not be an over -shot?I tried itRigol dg912proChinese BNC-BNC wire that was added to the FY6800, the entire connectors do not reach 50cm.The internal wire has a DC resistance of 50mohm and the exterior is 28mohm.Micsig to1104 1MOHM input impedanceIf I understand it, the over -shot occurs when the AC230V disappears, breaks. when the outout is active.I simply pulled the Rigol USB-C cable during operation.If this is a real event and can occur with any brand -independent signal generator, why is it a problem to discuss?I think it is worthwhile to test their own, lest you accidentally catch a bad series and ruin their own project.I am lucky enough to have a USB-C, so I don't have to buy a uninterrupted PSU.I think.

author: tautech
author_rank: Super Contributor
timestamp: May 20, 2024, 10:06:42 am
content: Quote from: eTobey on May 20, 2024, 09:23:26 amYou would do well to Default your scope and set up just as rf-loop has shown and test again....or be the unchallenged captain of your own clown club.rf-loop has extensively tested these units since release in 2016 based on scope experience of 50+yrs.Show some correct and detailed screenshots or zip it.

author: eTobey
author_rank: Super Contributor
timestamp: May 20, 2024, 10:49:19 am
content: Quote from: tautech on May 20, 2024, 10:06:42 amIf you can explain, how a 2-3V rise for about 100-150us can come from a tiny bit of "magpie nest", i will do this, otherwise i will just set sail...

author: 2N3055
author_rank: Super Contributor
timestamp: May 20, 2024, 12:01:07 pm
content: Quote from: csuhi17 on May 20, 2024, 09:54:04 amThat is exactly my point. If you connect instruments in in any number of (pathological)way, you can get any kind of weird artefacts when doing weird stuff.You should not simply yank cables, or power to any piece of equipment during active testing.Even if your electricity supply is cut (power out) there is no saying in which order will any of your pieces of equipment power down. There can be reverse currents flowing too..

author: nctnico
author_rank: Super Contributor
timestamp: May 20, 2024, 12:29:34 pm
content: Quote from: eTobey on May 20, 2024, 09:35:03 amTrue. That is something I observed as well in your and Mortymore's screendumps.

author: nctnico
author_rank: Super Contributor
timestamp: May 20, 2024, 12:32:44 pm
content: Quote from: csuhi17 on May 20, 2024, 09:54:04 amThey have the same earth. Or better put, the same reference as the grounds are connected by the 0V of the outputs (typically the outer shell of the BNC connector).Again, good test equipment shouldn't have an overshoot on outputs when the mains power is cut. Power outages do happen.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 20, 2024, 01:22:35 pm
content: Quote from: nctnico on May 20, 2024, 09:14:03 amIt wouldn't surprise me.Quote from: eTobey on May 16, 2024, 07:11:21 amThe one I looked at would also decrement when it should increment and vice versa. This unit was purchased a couple of years ago. If yours is brand new, it could be different hardware. If you like, I can attempt to replicate what you are seeing. I could then provide a build date or something. If there was a hardware change that caused the unstable output, maybe we could narrow it down. Then again, Siglent should be able to answer this.

author: rf-loop
author_rank: Super Contributor
timestamp: May 20, 2024, 01:34:28 pm
content: Quote from: eTobey on May 20, 2024, 09:35:03 amLets do some fact check. Add some clarification to this fairy tale. For example, let's start with you telling where and what.When you refer to me, please state what I have said or shown. Don't make up your own fairy tales or interpretations of them!

author: rf-loop
author_rank: Super Contributor
timestamp: May 20, 2024, 01:52:27 pm
content: Quote from: nctnico on May 20, 2024, 12:29:34 pmThis is completely self-evident everyday life for anyone who has worked, for example, in the manufacturing industry and also designed various devices there. In very many cases, the so-called worst case combinations must be taken, more or less, into account and planned in such a way that even in those situations the devices work within the specifications.Of course, this problem is also limited, for example, by inspecting the components before they are used, especially if something a little more critical (and valuable) is being done. On the other hand, it is also normal that during production testing some of the finished products just go to scrap or recycling or, if it is an expensive device, to a repair / rework round.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 20, 2024, 02:01:15 pm
content: Quote from: rf-loop on May 20, 2024, 01:52:27 pmReminds me of when Robert Pease took on Taguchi.https://www.electronicdesign.com/archive/article/21754886/whats-all-this-taguchi-stuff-anyhow

author: eTobey
author_rank: Super Contributor
timestamp: May 20, 2024, 03:38:26 pm
content: Quote from: rf-loop on May 20, 2024, 01:34:28 pmFact is, you havent delivered a comparable test...

author: eTobey
author_rank: Super Contributor
timestamp: May 21, 2024, 10:47:21 am
content: Just found out, that the squarewave has a glitch (seemingly) when starting with the enable button.The first low pulse is not as the duty is set up. The length of the low pulse is longer with different deviations.200mHz0-3.3V99% duty50 OhmChannel 1

author: tautech
author_rank: Super Contributor
timestamp: May 21, 2024, 11:11:32 am
content: Quote from: eTobey on May 21, 2024, 10:47:21 amProperly captured screenshots or nothing.Hint, the trigger is your best friend if you take the time to learn its power.

author: eTobey
author_rank: Super Contributor
timestamp: May 21, 2024, 11:19:38 am
content: Quote from: tautech on May 21, 2024, 11:11:32 amI was in roll mode, but there is an issue, i would like to call the b** word for. Couldnt zoom out.But yes the trigger is actually a good idea, to overlay then with the other captures in persistant mode, combined with a measurement, that shows the exact deviations. I couldnt care less, but i cant refuse what is excpect from others ;-).I hope no other issues are coming at me then... Issues when investigating issues...

author: rf-loop
author_rank: Super Contributor
timestamp: May 21, 2024, 11:32:57 am
content: Quote from: joeqsmith on May 20, 2024, 02:01:15 pmThis was a great find. Absolutely stunning and so true...

author: eTobey
author_rank: Super Contributor
timestamp: May 21, 2024, 11:36:51 am
content: Quote from: rf-loop on May 21, 2024, 11:32:57 amDont you want to post a screen shot of a comparable test?Quote from: tautech on May 21, 2024, 11:11:32 amIs this properly enough?

author: rf-loop
author_rank: Super Contributor
timestamp: May 21, 2024, 01:17:51 pm
content: Quote from: eTobey on May 21, 2024, 11:36:51 amIf I have extra time, I'd rather play with my own grandchildrens than yours. If you think it's discriminatory, file a discrimination complaint. :/

author: TurboTom
author_rank: Super Contributor
timestamp: May 21, 2024, 01:37:42 pm
content: Quote from: eTobey on May 21, 2024, 10:47:21 amRelay bounce? That would be something to expect, present on all AWGs that I'm aware of that provide complete galvanic isolation of the outputs in disabled condition.

author: eTobey
author_rank: Super Contributor
timestamp: May 21, 2024, 02:07:41 pm
content: Quote from: TurboTom on May 21, 2024, 01:37:42 pmShow me a relay, that has a bounce after 5 seconds ;-)

author: Fgrir
author_rank: Regular Contributor
timestamp: May 21, 2024, 02:32:52 pm
content: Quote from: eTobey on May 21, 2024, 10:47:21 amI see a similar effect on an SDG2042X - seems like the first cycle is running with a random falling edge.

author: Fgrir
author_rank: Regular Contributor
timestamp: May 21, 2024, 02:44:41 pm
content: On the SDG2042X using Pulse waveform instead of Square seems to behave better for this case. Ran it multiple times and they always come out looking good.

author: eTobey
author_rank: Super Contributor
timestamp: May 21, 2024, 02:52:23 pm
content: Quote from: Fgrir on May 21, 2024, 02:44:41 pmSo you have the same issue (wrong pulses) on the SDG2042X ?I am currently trying to test something. I want to have channel 2 as a trigger, and the other channel to test. I found only "track" to work in this case, but you cant have different loads on those.( Yes it does not matter in my case, but there are likely some cases...)

author: eTobey
author_rank: Super Contributor
timestamp: May 21, 2024, 02:55:53 pm
content: Quote from: Fgrir on May 21, 2024, 02:44:41 pmCould you try something?- Set up square wave.- set high 3.3V- set low 0V- Invert the signalDoes it then go below 0V?

author: Fgrir
author_rank: Regular Contributor
timestamp: May 21, 2024, 03:24:56 pm
content: Quote from: eTobey on May 21, 2024, 02:55:53 pmYes, on the SDG2042X inverting the output seems to be always relative to 0V, not relative to the Offset voltage setting as specified in the user manual. So the 3.3V/0V setting gives -3.3V/0V levels when inverted. It doesn't seem to matter if you use High/Low levels or Amplitude/Offset settings.

author: 2N3055
author_rank: Super Contributor
timestamp: May 21, 2024, 04:03:30 pm
content: Quote from: Fgrir on May 21, 2024, 03:24:56 pmInverting signal means exactly that: inverting it. Meaning multiplying amplitude values with -1 in analog domain.It is equivalent to scope invert function.It does not perform digital logic NOT function.AWG is not logic gate. It can go negative and positive values, by design.It is a good thing.

author: Fgrir
author_rank: Regular Contributor
timestamp: May 21, 2024, 04:39:40 pm
content: Yeah, I'm not saying it's good or bad to invert about 0V or the Offset voltage, but the instrument behavior does not agree with what the user manual says it should do.

author: 2N3055
author_rank: Super Contributor
timestamp: May 21, 2024, 05:51:03 pm
content: Quote from: Fgrir on May 21, 2024, 04:39:40 pmUser manual is wrong. I will report it.Polarity flip is symmetrical around the 0V. It is multiplying voltage with -1.So signal that goes from 1V to 2V and back becomes signal that goes from -1 to -2.Good catch.

author: nctnico
author_rank: Super Contributor
timestamp: May 21, 2024, 05:55:53 pm
content: Quote from: 2N3055 on May 21, 2024, 05:51:03 pmThe device is definitely wrong. There are lots of differential signalling protocols (LVDS, CAN and RS485 for example) which have a DC offset. With the way the SDG1000 is working right now, you can never generate such signals. IOW: the DC offset should be applied to both outputs in the same way, only the AC part of the signal should be inverted.

author: 2N3055
author_rank: Super Contributor
timestamp: May 21, 2024, 06:04:07 pm
content: Quote from: nctnico on May 21, 2024, 05:55:53 pmDon't arbitrarily invent things.AWG is analog device, not digital pulse generator.Inverting analog signal is just that: inverting it, as in put it through unity gain inverting amplifier.We could argue that a request could be made to Siglent to enhance AWGs with adding a choice to cater for digital signals.Adding option Logic NOT, for instance. So you would have "Normal", "Inverted" (both would be same as now) and "Logic NOT" that would invert signal in a logic NOT manner (inverting it but inside current voltage envelope as set).I don't think that is a bad idea. But certainly not a default behavior of an AWG.

author: Fgrir
author_rank: Regular Contributor
timestamp: May 21, 2024, 06:22:20 pm
content: I really shouldn't get in the middle of which mode is right or wrong, but I think my preference is to invert about the offset voltage. In a perfect world I think there would be a control to let you do either. A quick check with the function generator on my RTB2004 shows that its invert control works relative to the offset voltage, so there is at least one other example of a function generator that would invert +3.3/0V to 0V/+3.3V.If you think the behavior of the SDG generators are correct, then they would also need to change their GUI representation of the signals when they are inverted. I have to say that this GUI is often times not accurately representing the active settings, but for the invert control the GUI clearly agrees with the user manual.EDIT: Fixed the invert attachment

author: 2N3055
author_rank: Super Contributor
timestamp: May 21, 2024, 06:37:00 pm
content: Quote from: Fgrir on May 21, 2024, 06:22:20 pmI'm not arguing that sometimes to someone because of work they do some options seems more logical.Full name of that function is "Invert polarity".Which explains it.Like I said, if you are doing analog work, inverting polarity will accomplish same thing as adding inverting unity gain buffer in signal chain. You set one channel to track another and then invert one and you have fully differential signals.RTB does what it does because it's dynamic range is already very low so they did that...I reported documentation error to Siglent.I also asked to consider enhancing this with more user control.More user control is good.GUI representation is more symbolic. It shows the shape but not offset.We will see what they think.In meantime, documentation needs to follow the reality.

author: nctnico
author_rank: Super Contributor
timestamp: May 21, 2024, 06:42:33 pm
content: Quote from: 2N3055 on May 21, 2024, 06:04:07 pmHint: digital signals do not exist in the real world! If you want to generate any of the signalling protocols I listed before (especially for introducing analog domain errors), an AWG isthetool for that purpose.

author: Fgrir
author_rank: Regular Contributor
timestamp: May 21, 2024, 06:48:43 pm
content: Quote from: 2N3055 on May 21, 2024, 06:37:00 pmExcept the GUI does show the offset, and it disagrees with what is coming out of the output.But I agree that the main important thing is that documentation, GUI and output all agree.

author: 2N3055
author_rank: Super Contributor
timestamp: May 21, 2024, 06:58:56 pm
content: Quote from: nctnico on May 21, 2024, 06:42:33 pmYou are changing a subject by introducing truisms.Of course that digital signals are analog signals. We are calling signals digital when we are referring to signals as used in various digital circuits, where that implies some sort of logic signals that have two defined voltages for LO/HIGH states and transitions between the two are made fast.Some kind of square wave ish signals that have defined low and high voltages.General purpose AWG is not specialized generator for generating LVDS, CAN and RS485 or that sort of data. Especially inexpensive one that costs same as cheap analog function generators few years ago. With little care you can create them but AWG are not specialized for that. Digital pattern and pulse generators are made for that.Some AWG are made to do that too. SDG7000A has differential outputs and does the stuff you are saying. But it is expensive.

author: 2N3055
author_rank: Super Contributor
timestamp: May 21, 2024, 07:02:20 pm
content: Quote from: Fgrir on May 21, 2024, 06:48:43 pmYou are correct it show something, but it was not how I expected it so I didn't even realize. Thank you for that. Yes, it should show and document what it does.

author: eTobey
author_rank: Super Contributor
timestamp: May 21, 2024, 07:53:22 pm
content: Either way: The low level that is set up, is exceeded. So its not just an error in the manual.

author: 2N3055
author_rank: Super Contributor
timestamp: May 21, 2024, 08:20:05 pm
content: Quote from: eTobey on May 21, 2024, 07:53:22 pmYou are wrong. Read again.

author: TurboTom
author_rank: Super Contributor
timestamp: May 21, 2024, 08:23:15 pm
content: Interesting: DG800/900/2000 keep the offset / limits and invert only the signal amplitude.

author: Njk
author_rank: Frequent Contributor
timestamp: May 21, 2024, 09:45:20 pm
content: That really make sense. With the inverted output setting, it's simple to generate a diff. signal manually (by tapping the Copy menu item) or automatically (with the track mode feature)

author: thm_w
author_rank: Super Contributor
timestamp: May 21, 2024, 09:48:32 pm
content: Quote from: TurboTom on May 21, 2024, 08:23:15 pmFrom the manual (Dg800 pro, which is the same behavior BUT it doesn't show on the UI like the siglent which would be nice):

author: Njk
author_rank: Frequent Contributor
timestamp: May 21, 2024, 11:00:18 pm
content: I presume the intention was to show something like this

author: eTobey
author_rank: Super Contributor
timestamp: May 22, 2024, 04:53:47 am
content: Quote from: 2N3055 on May 21, 2024, 08:20:05 pmI am talking about the SDG1032X that i got. It does not work like in the manual and i would have expected. And it does not correspond with the settings that there are.Do they actually test these models at all?

author: nctnico
author_rank: Super Contributor
timestamp: May 22, 2024, 08:52:14 am
content: Quote from: eTobey on May 22, 2024, 04:53:47 amNo they don't. While testing is very easy to automate using scripting. Just hook up an oscilloscope to the AWG and have a PC run through a bunch of tests which verify functional behaviour using SCPI commands send over the network. This setup does take effort to make but once that is done, the benefits are huge as testing firmware hardly takes any manual labour. It would greatly improve the quality of Siglent firmware where it comes to introducing new bugs in existing software and verifying functionality of new features.

author: eTobey
author_rank: Super Contributor
timestamp: May 22, 2024, 09:41:02 am
content: Quote from: nctnico on May 22, 2024, 08:52:14 amBut then they could just give some people some scopes to test for free?I mean i would not mind doing some work for them in exchange ;-)

author: tautech
author_rank: Super Contributor
timestamp: May 22, 2024, 09:48:16 am
content: Quote from: eTobey on May 22, 2024, 09:41:02 amOnly properly competent people need apply.

author: eTobey
author_rank: Super Contributor
timestamp: May 22, 2024, 10:04:51 am
content: Quote from: tautech on May 22, 2024, 09:48:16 amReally? How do they determine the proper competence?

author: eTobey
author_rank: Super Contributor
timestamp: May 22, 2024, 10:11:21 am
content: I have something that could really be interesting for siglent:I am thinking about the possibility, of relays switching off after device power off, so that the voltage of a higher voltage rail is put onto a lower voltage rail. Obviously it does not do damage immediately, but i could over time.

author: nctnico
author_rank: Super Contributor
timestamp: May 22, 2024, 01:00:29 pm
content: Quote from: eTobey on May 22, 2024, 09:41:02 amSiglent is doing that but it doesn't work at all as the test coverage is too limited. I did some in-depth oscilloscope reviews in the past and going through the functions 'quickly' takes nearly a work-week worth of test time already. Doing a full functional test by going through a test plan with a decent coverage manually likely takes 3 to 4 weeks full-time for a modern DSO. And each firmware release needs a full re-test. Where it comes to complex pieces of equipment, you really need to do automated testing in order to verify existing and new functionality before releasing firmware with confidence that it works to a satisfactory level. Testing also reveals issues which can be listed under 'known issues' which can be fixed later or never.

author: eTobey
author_rank: Super Contributor
timestamp: May 22, 2024, 06:00:32 pm
content: Quote from: nctnico on May 22, 2024, 01:00:29 pmYeah, indeed i know how tedious it can be to test firm/software. But if someone who hasnt got a glue, and this scope for only a few weeks, can find dozends of bugs and issues, then, there is room for improvement.

author: eTobey
author_rank: Super Contributor
timestamp: May 25, 2024, 07:45:58 am
content: I have made some more investigation:I have put a piece of piezo on the BNC connector, to have a exact time (more or less) on the scope, when the relais are switching.On the picture "Turn off spike 2" you can see how it looks when turning it off. The green trace is the piezo, that captures the "shockwaves".The picture "2.3V to 3.3V 50Ohm" shows just a change of the outputvoltage (when relais do switch).I used the change of the voltages, to see exactly, how the green trace looks when relais switch. It has a characteristic of 2 bumps ("2-3V bumbs.png"). I believe, that these 2 bumbs are actually the contact hitting each other (the opposite not connected ones).This together with the capture of the turn off spikes ("first bump on turnff.png"), lets me conclude, that this is not a case of a relais "failing" to early, but a chip that would control the voltages of the output.Furthermore, i made another discovery, that one may find good to know: in track mode, the channels do not switch simultaneously. Funny thing is, that you otherwise even cant have different load outputs. ("channel 2 leads.png")Ps. Yes, it looks a bit weird to do all that investigation, but i just choosed to investigate its flaws, instead destroying something because of these flaws.

author: nctnico
author_rank: Super Contributor
timestamp: May 25, 2024, 04:54:25 pm
content: Quote from: 2N3055 on May 21, 2024, 06:58:56 pmI'm not introducing truisms. You are just so horribly wrong by being blinded by what you perceive as digital signals. You really need to seperate your thinking towards considering the output signal of an AWG as multiple components. For starters: A) a waveform and B) a DC offset. These are two very different things. When inverting the waveform, the phase is shifted by 180 degrees. The DC offset stays the same. On a decent AWG like the Tektronix AFG31000, you'll see that the waveform gets inverted but not the offset. As Tektronix has decades of experience with designing AWGs, you can rest assured they got this basic feature implemented correctly. What the SDG1032 is doing is inverting both the waveform and the offset which is the wrong thing to do.

author: 2N3055
author_rank: Super Contributor
timestamp: May 25, 2024, 07:22:42 pm
content: Quote from: nctnico on May 25, 2024, 04:54:25 pmNo it is not.It behaves differently.I will repeat for 3rd time: Function is called INVERT POLARITY.It inserts inverting unity buffer in signal chain. If you don't know what that is, you need to go read..Phase shifting signal by 180° makes no sense for single signal. It is still the same. Only frame of reference changes and that makes sense only compared to second channel, and for that you have 180° phase delay command.What you have on Tek does not create fully differential signal in analog sense. In analog sense differential pair is fully inverted including DC component of input signal. If you subtract both, you get same signal as positive one but twice the amplitude. Otherwise you get DC component subtracted out. Which is not the original signal.What you are talking about is what digital differential drivers do: they have differential signal riding on the common mode DC offset. And that common DC offset is unwanted and gets suppressed. And I agree the way your Tek works makes it simple to do that.And since this is something useful to you you that makes it the only way that is right...How typical of you.What Signal did wrong is that when you invert signal it won't show voltages as negative in GUI.That is a mistake.And to make sure I don't disagree that the way your Tek work is useful for some type of work. You can achieve same thing on Siglent now by Inverting and entering negative offset.But being able to choose which way it should work would be nice.And I did report this to Siglent, documentation errata, GUI not showing negative voltages when inverted, and also a request to add the way your Tek works as additional operational mode.Which if they manage to add that mode, it will be able to do both what Tek can and what Tek cannot do...

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 25, 2024, 07:45:08 pm
content: Quote from: nctnico on May 25, 2024, 04:54:25 pm100% correct! But missing qualifications. Tek didn't set any standards that other brands are beholden to. What Tek did is what is expected by Tek users. They don't dictate the behavior of Siglent or any other brand. It's not right or wrong, it's brand specific design choices.

author: nctnico
author_rank: Super Contributor
timestamp: May 25, 2024, 09:05:23 pm
content: Quote from: KungFuJosh on May 25, 2024, 07:45:08 pmThere are things like industry standards as set by the manufacturers who pioneered the type of instrument. Stick to those standard and people will have no problem using your equipment.Have you ever noticed that most (if not all) range selectors on auto-ranging handheld multi-meters operate clock-wise from the off position into the measurement mode and start with measuring voltage? Why would that be? Which standard dictates that?

author: 2N3055
author_rank: Super Contributor
timestamp: May 25, 2024, 09:12:59 pm
content: Quote from: nctnico on May 25, 2024, 09:05:23 pmCultural biases. Didn't you notice all knobs have same layout of zero being left and clockwise to max. And voltage is first because that was traditionally most used function.There are many de facto standards, but they are not mandatory. And also not universally applicable always.

author: mawyatt
author_rank: Super Contributor
timestamp: May 25, 2024, 09:44:08 pm
content: Quote from: 2N3055 on May 25, 2024, 09:12:59 pmQuoteAlso, wouldn't want a handheld that rotated first to ohms, then diode, then current, then voltageBest,

author: Mortymore
author_rank: Frequent Contributor
timestamp: May 25, 2024, 10:29:08 pm
content: The "Invert" in my old analog generator works as nctnico described, as does some Tektronix, Tenma, Kenwood, and others that I know of.My old Fordham generator can be seen here.https://www.eevblog.com/forum/testgear/siglent-sdg1000x-waveform-generators/msg5504575/#msg5504575However, Siglent is in its right to do whatever they please. What's not right is that that the generator does not behave as advertised in the manual and as represented on screen, posing a potential risk of destruction of a DUT by inverting the DC offset. It doesn't matter if one is used to Tektronix way of invert or not. The displayed image is wrong and it's up to Siglent to decide what they really meant by invert polarity, but it's an urgent fix, be it at the image and manual or the outputted signal. They must match.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 25, 2024, 10:52:13 pm
content: Quote from: nctnico on May 25, 2024, 09:05:23 pmIIRC HPAK pioneered signal generator type TE before their competitor Tek started making any. Both brands do things differently, it's not new information.Like you said, most, not all. There are many touch screen meters now that don't use a dial at all. Or just use button arrays like the DE-5000. Use what you like, and what you're comfortable with, but don't expect everybody to do the same thing. If everything was the same, only the least expensive devices would sell.If I get new TE, I RTFM and learn what's different about it. Just going from the 3045X/3055 to the SDM3065X required some learning for me. It's fine...as long as the manual makes sense. 😉

author: eTobey
author_rank: Super Contributor
timestamp: May 27, 2024, 12:31:18 pm
content: Another issue:Low level set to 1mV is about right, but setting it to 0 mV comes out at about -40mV. One step further on the knob, and *boom* the magic smoke of the DUT is gonna escape.Behaves like a 50$ chinese thing at some points.

author: Njk
author_rank: Frequent Contributor
timestamp: May 27, 2024, 05:29:54 pm
content: Thank you for not using red font to announce your findings