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| Siglent SDS800 Zoom out question (problem?) |
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| tautech:
--- Quote from: electr_peter on October 05, 2024, 07:57:49 am ---@tautech, I respectfully would like to ask to read my posts carefully. I do not claim at all that there is some best process of how to zoom in/out to view both long and short timebase events, it is up to the user entirely. All I say is that scopes with zoom out (or more precisely, memory beyond display) are more flexible in some circumstances than scopes without this feature. Especially Keysight implementation. Yet you keep ignoring my clear statements to push for your "zoom in is better process anyway, so why care about zoom out benefits" agenda. You simply shift goal post from case of "user looks at fast timebase as a MAIN focus and decides to look at slower timebase as a secondary check" to "user needs to capture slower timebase all the time and look for full details". In former case, zoom out capability allows not to recapture again - this fact is conveniently ignored, I wonder why? Of course, user then can go to latter case (with MAIN focus on slower timebase) where zoom in can be used straight away. --- End quote --- Zoom out is just one, repeat just one analysis process ! I much prefer thoughtful use of a DSO with emphasis on storage where at slow timebase settings provide the best advantage. However, let's also not forget intelligent use of the trigger suite available, let alone the Search capability that can also be engaged in order to make the term look redundant ! Why engage the brain when the processing power in the modern DSO is far more powerful ? :-// |
| electr_peter:
--- Quote from: tautech on October 05, 2024, 08:06:45 am ---Why engage the brain when the processing power in the modern DSO is far more powerful ? :-// --- End quote --- Why put blinders on and mentally limit available options from scope suite? :-// Anyway, user chooses process that is most suitable for application at hand, I not arguing what one "should use". |
| tautech:
--- Quote from: electr_peter on October 05, 2024, 08:39:05 am --- --- Quote from: tautech on October 05, 2024, 08:06:45 am ---Why engage the brain when the processing power in the modern DSO is far more powerful ? :-// --- End quote --- Why put blinders on and mentally limit available options from scope suite? :-// Anyway, user chooses process that is most suitable for application at hand, I not arguing what one "should use". --- End quote --- Nor am I. A strong feature set is there to use not to ignore. Okay, so you like the Keyshite way, I get that, so show us a $440 model with that capability ? |
| 2N3055:
--- Quote from: electr_peter on October 05, 2024, 08:39:05 am --- --- Quote from: tautech on October 05, 2024, 08:06:45 am ---Why engage the brain when the processing power in the modern DSO is far more powerful ? :-// --- End quote --- Why put blinders on and mentally limit available options from scope suite? :-// Anyway, user chooses process that is most suitable for application at hand, I not arguing what one "should use". --- End quote --- I agree. Let's not put blinders on. So why are you ignoring that Keysight does not "capture outside the screen". What you see on the screen is separate, later capture from separate trigger than the one that made you press Stop. If you have repetitive signal, like clock or even some AWG waveform that may be complex but 100% repetitive and with stable well defined trigger, you won't know the difference. Example 1. - Signal is single sine period burst repeating every 1 µs - Normal trigger mode. - Capture at 20ns/div. (Image 1) - Stop - Change timebase (not zooming out, not using Zoom feature of 3000T) to 50µs/div. - (Image2) We see scope actually captured cca. 40µs before and cca. 360µs after trigger. It is 400µs total, balance before/after trigger is connected with where trigger point is. Great. This i what you say you use and it is very useful to you. Example 2. - Signal is single sine period burst repeating every 500 ms - Normal trigger mode. - Capture at 20ns/div. (Image 1 as previously, nothing changed here) - Stop - Change timebase (not zooming out, not using Zoom feature of 3000T) to 100ns/div. - (see Image 3) Wait, there are no samples outside the area defined by the screen at 20ns/div! There is only 200ns worth of data. Not 400µs. How come? Because scope DOES NOT capture outside the screen. Ever. When you press stop it waits for next trigger event and captures some other, random part of waveform, uncorrelated to what was on the screen when you press Stop. It performs following action, automatically and without warning to the user (pretending that it captures more data than it does): - Once you press Stop, scope waits for another trigger. It can wait for as long as 200-250ms for it so that can be distance between two events. - If there is a trigger within that timeout period, it will take one 400µs long (short?) single capture and then go to STOP state. - If there is NO trigger within timeout period, it will simply show last captured trigger, but just screen bound 200ns So you get something only on timebases faster than 20µs/div, you never get anything more than 400µs worth, and it some random capture up to 250ms away from where original screen was when you pressed stop. That is not 1µs or 100µs, but a whooping quarter of a second... So basically, to observe the neighborhood of some event of the screen, it as useful as simply changing timebase to whatever you want to look at while scope is still in the RUN mode and then STOP. That is exactly what Keysight does, but automatically. I guess it is good if you cannot be bothered to change timebase then stop instead of just single lazy STOP. But result is the same, you get some random uncorrelated time in signal when trigger activates. If that is OK for you because signal is monotonic and auto repetitive to such degree that it does not matter where you look, then what is the point of "looking around". It is all going to be the same. Perfect replica. Once you put whole period on screen, all others are the same. If signal is highly agile, than Keysight is useless. Dangerous I may say. It will show you false data somewhere else than what you were looking at... It is trick, and the scope lies to you. literally. Also, by changing timebase, I can get ANY time period, not just puny 400µs. Capturing long, using long memory to keep sample rate at maximum, is equivalent of 0 blind time for period captured. In the captured period nothing can hide. Note, I have MSOX3104T for years now. I like it and think at the time it was really good scope. I know in detail how it works. And for doing deep signal inspection of the type you are talking about I don't use it. I use Siglent or Picoscope. That are deep memory scope. You get long capture and STOP. Nothing can hide in there. |
| nctnico:
--- Quote from: electr_peter on October 05, 2024, 08:39:05 am --- --- Quote from: tautech on October 05, 2024, 08:06:45 am ---Why engage the brain when the processing power in the modern DSO is far more powerful ? :-// --- End quote --- Why put blinders on and mentally limit available options from scope suite? :-// Anyway, user chooses process that is most suitable for application at hand, I not arguing what one "should use". --- End quote --- Indeed. :horse: The whole discussion reminds me of when I worked at the local chocolate factory for one day when I was a teenager. I had to pull bars of chocolate onto trays from a conveyer belt using an piece of aluminium. I had to reach out quite far so I used one hand to support myself and the other to rake in the chocolate so my back wouldn't hurt at the end of the day. Boss lady comes around and tells me to use two hands because god gave me two hands. FFS! :palm: :palm: I guess she either never had to do this task herself or just wanted to check my ass when I bent over. |
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