Products > Test Equipment
Oscilloscope Zoom Out Quirk
tautech:
--- Quote from: Gandalf_Sr on May 08, 2020, 09:37:58 pm ---I was actually making a reference to the Monty Python argument sketch; the conversation is quite illuminating.
--- End quote ---
Immediately, a good slapping with a wet fish for using a DSO in some obscure manner seems quite appropriate. :P
2N3055:
Off I go first thing in a morning, I'm gonna silly walk to fish market....
Someone:
The confusion has kicked off once again.
nctnico talks about their way of working that has several things happening at the same time:
slow trigger rate
interesting detail at short time window
possibly interesting detail in the larger capture (but can't rely on another trigger arriving)
[<------- acquisition ------- [ < screen > ] -------------------- acquisition -----> ]
trigger rate is inherently limited, so on most scopes you have to specifically request this sort of mode rather than leaving a scope on auto memory depth.
Now, this makes no sense to 99% of other oscilloscope users, but nctnico insists on making lots of noise about it every chance they can (for some bizarre reason).
Everyone else does one of the following:
has plenty of triggers and captures another capture at the wider window
uses zoom to view the small time window and full acquisition at the same time
... has some entirely different application that has nothing to do with this extreme corner case use (yep, that'd be just about everyone)
So when nctnico says a scope can't do this very specific (and not fully explained) thing, just ignore it. Because with only a tiny change to any part of the application or acceptable solution, just about any scope will do the job.
EEVblog:
--- Quote from: Someone on May 08, 2020, 11:59:42 pm ---So when nctnico says a scope can't do this very specific (and not fully explained) thing, just ignore it. Because with only a tiny change to any part of the application or acceptable solution, just about any scope will do the job.
--- End quote ---
Yeah, but he's not wrong.
It's an interesting and demonstrably potentially useful benefit.
EEVblog:
--- Quote from: 2N3055 on May 08, 2020, 04:32:26 pm ---What does it mean? Well, when you're on 1ns/div, you get 40000x length worth of data than what is on your screen (10ns to 400us) if you stop it. If you are at 20us/div you get only 2x (200us to 400us).
And from that point on sample rate goes down, and game repeats, changing ratio "screen/stopped capture length" all the time. I guess table could be compiled. It's just I couldn't care less.
I'm not going to base my work based on side-effects of sample engine architecture..
--- End quote ---
So if you captured something and then thought "gee I wonder what's either side of that, and you knew your scope worked like this, you'd actually rather re-capture instead of just changing the timebase?
That's kinda, well, silly.
If your answer is yes I would, then what happens if your capture was infrequent and wasn't easy to reproduce?
Sorry but I can't see a way to successfully argue this isn't a potentially useful feature.
It's so interesting it's probably worthy of a video.
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