So after installing latest firmware this POS (1202X-E) still locks up!!!
So far as I understood it, the triggering in a digital 'scope was just based on processing the data stream coming from the ADCs. This would mean that there is no trigger path available from before the channel coupling.
Checking this: my understanding wasn't correct. The triggering can still be performed in analogue terms, by taking the signal after the initial input gain (analogue). So the triggering selected may involve the sampled data, or it may not.
Presumably this is required if you want DC triggering on an AC coupled waveform.
If this wasn't done, then you would have to base the triggering on the sample data and so would not be able to implement a DC trigger level on AC coupled data (as you wouldn't know what the DC offset of the signal was). Unless there is some other process here that I am unaware of.
(More stuff to figure out for a particular 'scope, I think. Certainly the way that trigger levels are reported back to the user varies, with Siglent not following the same convention that Tektronix does -- misleading me into assuming that this difference was a 'bug'.)
So after installing latest firmware this POS (1202X-E) still locks up!!!
Siglent SDS1000X-E series RTO full digitall side trigger. Sidenote: Because there is one ADC chip internally interleaved for 1GSa/s for one channel mode it can not use for trig from unused main channel without reducing samplerate so there is not this function implemented.
Ext Trig do not have digital trigger system, it use conventional analog pathway with ltrigger comparator circuit. ExtTrig trigger have limited trigger functions and trigger timing quality overall is not at all in same level as trigger from main channel.
Trigger coupling AC (DC Block) 5.8Hz *
Trigger coupling LF reject (Also DC bloc and reduce < 2.08MHz * )
Trigger coupling HF reject (block or reduce > 1.27MHz * ) (also narrow trig hysteresis)
Trigger Noise reject off: normal trig hysteresis, on: wide trig hysteresis.
* limits from user manual version UM0101X-E02B
So definitely different specifications for the different trigger paths, but I'm not certain how the trigger works correctly if it has to use the post-ADC data. Assuming that the AC coupling on the vertical channels takes out the DC component before the trigger system can work with the data (as is implied by the block diagram), there would be no way to set a DC trigger level correctly.
For example, if you had a 6 Vpp sine signal riding on a +3 Vdc offset:
- setting DC coupling on the vertical channel passes this to the ADC, then you can set a DC coupled trigger level at +6 V to trigger in the centre of the trace
- setting AC coupling on the vertical channel strips the +3 Vdc offset out before the ADC, so where does the DC coupled trigger 'zero' position start -- presumably ground in an Earth grounded 'scope
It will be interesting to check this behaviour. If the block diagrams are correct, ....
I have an SDS2000X. Is there a quick way to zoom into a DC offset signal with the channel DC coupled?
I have a 3.3V power rail that looks a little noisy that I need to inspect. When I change the V/Div, the DC offset changes. And once you are in 10mV/Div, even the course adjust is much to fine and takes forever to adjust. The "Auto Setup" button gets close, but it takes a long time to operate and always changes my V/Div.
I'd rather the offset stay fixed as I change V/Div. Instead I've resorted to writing SCPI "Zoom In" and "Zoom Out" commands that does this for me and binding them to hotkeys. This really seems like something the scope should do for me.
Is there a reason the V/Offset has to scale with V/Div in a DSO? Why does pushing the "Position" button change to 0V instead of Vmean?
If just use example.
6Vpp pure sine 1kHz + 3VDC and input coupling AC. DC is blocked and AC part of signal (note freq response) is symmetric between +3V and -3V peak to peak. Trigger setting: Coupling DC and Trig level: 0V. Rising edge.
Trigger point is exactly where signal goes upside crossing vertical zero line. Just as expected and also what is exactly right. It is right because user select that scope hard block DC bias (3Vdc --||-- 0V). Trig is now DC coupled to this signal what it is there after DC block and digitized. Trigger do not need know there is DC blocked. Just as it also do not know if DC is blocked externally.
If just use example.
6Vpp pure sine 1kHz + 3VDC and input coupling AC. DC is blocked and AC part of signal (note freq response) is symmetric between +3V and -3V peak to peak. Trigger setting: Coupling DC and Trig level: 0V. Rising edge.
Trigger point is exactly where signal goes upside crossing vertical zero line. Just as expected and also what is exactly right. It is right because user select that scope hard block DC bias (3Vdc --||-- 0V). Trig is now DC coupled to this signal what it is there after DC block and digitized. Trigger do not need know there is DC blocked. Just as it also do not know if DC is blocked externally.Then there is no difference between AC coupled and DC coupled triggering if the channel is AC coupled. (Which explains the choice about presentation of the trigger level to the user.)
I have read through the user manual and this behaviour isn't explained. Trigger coupling is on page 53 of the user manual (page 71 of the PDF).
It is useful to know exactly what the interactions between the different coupling options produce, so this could be addressed in some examples. (The manual does have significant space devoted to explanation of the serial decoding functions, including trigger interaction, so this isn't an issue of lack of documentation generally.)
I have an SDS2000X. Is there a quick way to zoom into a DC offset signal with the channel DC coupled?
I have a 3.3V power rail that looks a little noisy that I need to inspect. When I change the V/Div, the DC offset changes. And once you are in 10mV/Div, even the course adjust is much to fine and takes forever to adjust. The "Auto Setup" button gets close, but it takes a long time to operate and always changes my V/Div.
I'd rather the offset stay fixed as I change V/Div. Instead I've resorted to writing SCPI "Zoom In" and "Zoom Out" commands that does this for me and binding them to hotkeys. This really seems like something the scope should do for me.
Is there a reason the V/Offset has to scale with V/Div in a DSO? Why does pushing the "Position" button change to 0V instead of Vmean?
There's a new version for the SDS1202X-E that was released a few days ago:
http://www.siglentamerica.com/USA_website_2014/Documents/UserManual/SDS1000X-E_UserManul_UM0101E-E02B.pdf
Off to read it..............
There's a new version for the SDS1202X-E that was released a few days ago:
http://www.siglentamerica.com/USA_website_2014/Documents/UserManual/SDS1000X-E_UserManul_UM0101E-E02B.pdf
Off to read it..............Yes, my reference above is for the new version.
(I have found a few errors already, too. Mostly references to four-channels.)
For some reason the table of contents ("Table of Content" ) and figures ("Content of Figure" ) is poorly formatted again. Why they couldn't spend two minutes to get these aligned with page breaks is a mystery. I don't know if this is typical for Siglent manuals, or if the person working on these is unusually indifferent.
Also, the specifications in the user manual and data sheet concerning trigger coupling don't agree -- refer to the post #830 above.
Hopefully Siglent will get around to producing a service manual with definitive specifications.
DC: allow DC and AC components into the trigger path.
QuoteDC: allow DC and AC components into the trigger path.If the DC input selection removes the capacitor from the input then DC and AC components will enter the scope. e.g. if you had a DC trigger set up of +1 V and then input a 3 V pk-pk signal, the positive-going half of the waveform would trigger when it hit the +1V level, what's wrong with that?
But one thing I can predict and "promise". In future we never get manuals like 1960 - 1980 from Hewlett-Packard or original old Tektronix. Never again. This is impossible. One manual costs more than whole lot of example SDS1000X-E scopes.
We can not say RTFM because manuals are - poor or wrong or junk.
Also, good and technically experienced seller can give some short "course" for model detail or basic things what are good to know (if buy from local place where sellers are engineer level and know also more than just price and carton weight and color.
But one thing I can predict and "promise". In future we never get manuals like 1960 - 1980 from Hewlett-Packard or original old Tektronix. Never again. This is impossible. One manual costs more than whole lot of example SDS1000X-E scopes.Or about one round of drinks at the executives' country club. (Priorities.)
Yes, documentation does take time and effort -- and money -- to produce. That is not an excuse to omit it or do a poor job.Aggree and poor job can not accept. There is also some level in poor job that making better do not cost nearly anything but give job to other person who can do it.QuoteQuoteWe can not say RTFM because manuals are - poor or wrong or junk.Rigol seem to be able to produce better manuals. I see no reason why Siglent can't at least match Rigol.Yes I really hope Siglent do better manuals but Rigol must not be any kind of example that should be imitated. Example what try reach must be Siglent own standards what need develop and then reach.QuoteQuoteAlso, good and technically experienced seller can give some short "course" for model detail or basic things what are good to know (if buy from local place where sellers are engineer level and know also more than just price and carton weight and color.Are you really saying that the reseller / agent should be responsible for effectively documenting what they sell? If so, perhaps you should consider the profit margins on these low-end 'scopes compared to the Tektronix and Keysight price level.
Quote from: rf-loopAlso, good and technically experienced seller can give some short "course" for model detail or basic things what are good to know (if buy from local place where sellers are engineer level and know also more than just price and carton weight and color.Quote from: boggis the catAre you really saying that the reseller / agent should be responsible for effectively documenting what they sell? If so, perhaps you should consider the profit margins on these low-end 'scopes compared to the Tektronix and Keysight price level.False. At least a really weird interpretation of what I said. Talking is pretty difficult if every message is twisted.
Dear SSA3021X staff,
could someone verify the mentioned behavior of the device listed below:
My FW Version is 1.2.8.3
When setting Ref level to 0dBm, scale grid to 1dB and
measuring trace#1 (alias A) switching then via front button
to trace#2 (alias B) and selecting clear trace to start the scan
of the second trace then trace A will be deleted while trace B
plotted.
I observed this behavior only in the 1dB scale factor setting.
When using 10dB scale all looks fine.
Thanks in advance for your explanation.
Markus